Merged PR 167: Add Flex and fix bugs (read desc)

Note: The branch name does not fit the new features. - Implement Flex with simplex - Enable rigid body by default (removed IsRigidBody property) <=== possibly a bad idea - Sort children in add and update properties - Implement MaxWidth - Add more docs Fixes : - .env.production url - Symbols: not blocking the linked container when the parent is moving
2022-08-25 13:28:32 +00:00 · 2022-08-25 13:28:32 +00:00 · 7f3f6a489a
commit 7f3f6a489a
parent ec3fddec9d
43 changed files with 1127 additions and 453 deletions
--- a/.env.production
+++ b/.env.production
@ -1,2 +1,2 @@

-VITE_API_URL=https://localhost/SmartMenuiserieTemplate
+VITE_API_URL=https://localhost/SmartMenuiserieTemplate/Service.svc/GetSVGLayoutConfiguration
--- a/.gitattributes
+++ b/.gitattributes
@ -1 +1,4 @@
 *.drawio filter=lfs diff=lfs merge=lfs -text
+*.pdf filter=lfs diff=lfs merge=lfs -text
+*.dwg filter=lfs diff=lfs merge=lfs -text
+*.jpg filter=lfs diff=lfs merge=lfs -text
--- a/README.md
+++ b/README.md
@ -14,6 +14,7 @@ Requierements :
 - NodeJS
 - npm
 - pnpm (optional but recommanded unless you prefer having a huge `node_modules` directory)
+- Chrome > 98

 # Developping

--- a/BF/01_141017-WG-11328-SYME-VERNUCCI-DET
+++ b/BF/01_141017-WG-11328-SYME-VERNUCCI-DET
--- a/BF/02_141017-WG-11328-SYME-VERNUCCI-DET
+++ b/BF/02_141017-WG-11328-SYME-VERNUCCI-DET
--- a/BF/03_SYME
+++ b/BF/03_SYME
--- a/KL_K1485985-ARC-K1485985.pdf
+++ b/KL_K1485985-ARC-K1485985.pdf
--- a/BF/05_DT_K1485985.pdf
+++ b/BF/05_DT_K1485985.pdf
--- a/IMG_1406.jpg
+++ b/IMG_1406.jpg
--- a/BF/131421
+++ b/BF/131421
--- a/BF/131421
+++ b/BF/131421
--- a/BF/image0000001.jpg
+++ b/BF/image0000001.jpg
--- a/docs/assets/yule-log-cake.jpg
+++ b/docs/assets/yule-log-cake.jpg
--- a/public/Interfaces.d.ts
+++ b/public/Interfaces.d.ts
@ -38,7 +38,7 @@ declare interface IProperties extends React.CSSProperties {
  parentId: string | null
  x: number
  y: number
-  isRigidBody: boolean
+
  XPositionReference?: XPositionReference
 }

--- a/src/Components/ContainerProperties/ContainerForm.tsx
+++ b/src/Components/ContainerProperties/ContainerForm.tsx
@ -1,9 +1,10 @@
 import { MenuAlt2Icon, MenuAlt3Icon, MenuIcon } from '@heroicons/react/outline';
 import * as React from 'react';
+import { PropertyType } from '../../Enums/PropertyType';
 import { XPositionReference } from '../../Enums/XPositionReference';
 import IContainerProperties from '../../Interfaces/IContainerProperties';
 import { ISymbolModel } from '../../Interfaces/ISymbolModel';
-import { restoreX, transformX } from '../../utils/svg';
+import { ApplyWidthMargin, ApplyXMargin, RemoveWidthMargin, RemoveXMargin, restoreX, transformX } from '../../utils/svg';
 import { InputGroup } from '../InputGroup/InputGroup';
 import { RadioGroupButtons } from '../RadioGroupButtons/RadioGroupButtons';
 import { Select } from '../Select/Select';
@ -11,12 +12,12 @@ import { Select } from '../Select/Select';
 interface IContainerFormProps {
  properties: IContainerProperties
  symbols: Map<string, ISymbolModel>
-  onChange: (key: string, value: string | number | boolean, isStyle?: boolean) => void
+  onChange: (key: string, value: string | number | boolean, type?: PropertyType) => void
 }

 const getCSSInputs = (
  properties: IContainerProperties,
-  onChange: (key: string, value: string | number | boolean, isStyle?: boolean) => void
+  onChange: (key: string, value: string | number | boolean, type: PropertyType) => void
 ): JSX.Element[] => {
  const groupInput: JSX.Element[] = [];
  for (const key in properties.style) {
@ -28,7 +29,7 @@ const getCSSInputs = (
      inputClassName=''
      type='string'
      value={(properties.style as any)[key]}
-      onChange={(event) => onChange(key, event.target.value, true)}
+      onChange={(event) => onChange(key, event.target.value, PropertyType.STYLE)}
    />);
  }
  return groupInput;
@ -52,7 +53,16 @@ const ContainerForm: React.FunctionComponent<IContainerFormProps> = (props) => {
        labelClassName=''
        inputClassName=''
        type='string'
-        value={props.properties.parentId?.toString()}
+        value={props.properties.parentId}
+        isDisabled={true}
+      />
+      <InputGroup
+        labelText='Type'
+        inputKey='type'
+        labelClassName=''
+        inputClassName=''
+        type='string'
+        value={props.properties.type}
        isDisabled={true}
      />
      <InputGroup
@ -71,8 +81,18 @@ const ContainerForm: React.FunctionComponent<IContainerFormProps> = (props) => {
        inputClassName=''
        type='number'
        isDisabled={props.properties.linkedSymbolId !== ''}
-        value={transformX(props.properties.x, props.properties.width, props.properties.XPositionReference).toString()}
-        onChange={(event) => props.onChange('x', restoreX(Number(event.target.value), props.properties.width, props.properties.XPositionReference))}
+        value={transformX(RemoveXMargin(props.properties.x, props.properties.margin.left), props.properties.width, props.properties.XPositionReference).toString()}
+        onChange={(event) => props.onChange(
+          'x',
+          ApplyXMargin(
+            restoreX(
+              Number(event.target.value),
+              props.properties.width,
+              props.properties.XPositionReference
+            ),
+            props.properties.margin.left
+          )
+        )}
      />
      <InputGroup
        labelText='y'
@ -80,8 +100,8 @@ const ContainerForm: React.FunctionComponent<IContainerFormProps> = (props) => {
        labelClassName=''
        inputClassName=''
        type='number'
-        value={props.properties.y.toString()}
-        onChange={(event) => props.onChange('y', Number(event.target.value))}
+        value={(props.properties.y - (props.properties.margin?.top ?? 0)).toString()}
+        onChange={(event) => props.onChange('y', Number(event.target.value) + (props.properties.margin?.top ?? 0))}
      />
      <InputGroup
        labelText='Minimum width'
@ -93,6 +113,16 @@ const ContainerForm: React.FunctionComponent<IContainerFormProps> = (props) => {
        value={props.properties.minWidth.toString()}
        onChange={(event) => props.onChange('minWidth', Number(event.target.value))}
      />
+      <InputGroup
+        labelText='Maximum width'
+        inputKey='maxWidth'
+        labelClassName=''
+        inputClassName=''
+        type='number'
+        min={1}
+        value={props.properties.maxWidth.toString()}
+        onChange={(event) => props.onChange('maxWidth', Number(event.target.value))}
+      />
      <InputGroup
        labelText='Width'
        inputKey='width'
@ -100,8 +130,9 @@ const ContainerForm: React.FunctionComponent<IContainerFormProps> = (props) => {
        inputClassName=''
        type='number'
        min={props.properties.minWidth}
-        value={props.properties.width.toString()}
-        onChange={(event) => props.onChange('width', Number(event.target.value))}
+        value={(RemoveWidthMargin(props.properties.width, props.properties.margin.left, props.properties.margin.right)).toString()}
+        onChange={(event) => props.onChange('width', ApplyWidthMargin(Number(event.target.value), props.properties.margin.left, props.properties.margin.right))}
+        isDisabled={props.properties.isFlex}
      />
      <InputGroup
        labelText='Height'
@ -110,17 +141,57 @@ const ContainerForm: React.FunctionComponent<IContainerFormProps> = (props) => {
        inputClassName=''
        type='number'
        min={0}
-        value={props.properties.height.toString()}
-        onChange={(event) => props.onChange('height', Number(event.target.value))}
+        value={(props.properties.height + (props.properties.margin?.top ?? 0) + (props.properties.margin?.bottom ?? 0)).toString()}
+        onChange={(event) => props.onChange('height', Number(event.target.value) - (props.properties.margin?.top ?? 0) - (props.properties.margin?.bottom ?? 0))}
      />
      <InputGroup
-        labelText='Rigid'
-        inputKey='isRigidBody'
+        labelText='Margin left'
+        inputKey='left'
+        labelClassName=''
+        inputClassName=''
+        type='number'
+        min={0}
+        value={(props.properties.margin.left ?? 0).toString()}
+        onChange={(event) => props.onChange('left', Number(event.target.value), PropertyType.MARGIN)}
+      />
+      <InputGroup
+        labelText='Margin bottom'
+        inputKey='bottom'
+        labelClassName=''
+        inputClassName=''
+        type='number'
+        min={0}
+        value={(props.properties.margin.bottom ?? 0).toString()}
+        onChange={(event) => props.onChange('bottom', Number(event.target.value), PropertyType.MARGIN)}
+      />
+      <InputGroup
+        labelText='Margin top'
+        inputKey='top'
+        labelClassName=''
+        inputClassName=''
+        type='number'
+        min={0}
+        value={(props.properties.margin.top ?? 0).toString()}
+        onChange={(event) => props.onChange('top', Number(event.target.value), PropertyType.MARGIN)}
+      />
+      <InputGroup
+        labelText='Margin right'
+        inputKey='right'
+        labelClassName=''
+        inputClassName=''
+        type='number'
+        min={0}
+        value={(props.properties.margin.right ?? 0).toString()}
+        onChange={(event) => props.onChange('right', Number(event.target.value), PropertyType.MARGIN)}
+      />
+      <InputGroup
+        labelText='Flex'
+        inputKey='isFlex'
        labelClassName=''
        inputClassName=''
        type='checkbox'
-        checked={props.properties.isRigidBody}
-        onChange={(event) => props.onChange('isRigidBody', event.target.checked)}
+        checked={props.properties.isFlex}
+        onChange={(event) => props.onChange('isFlex', event.target.checked)}
      />
      <InputGroup
        labelText='Anchor'
--- a/src/Components/ContainerProperties/ContainerProperties.test.tsx
+++ b/src/Components/ContainerProperties/ContainerProperties.test.tsx
@ -22,6 +22,7 @@ describe.concurrent('Properties', () => {
  it('Some properties, change values with dynamic input', () => {
    const prop: IContainerProperties = {
      id: 'stuff',
+      type: 'type',
      parentId: 'parentId',
      linkedSymbolId: '',
      displayedText: 'stuff',
@ -30,8 +31,10 @@ describe.concurrent('Properties', () => {
      width: 1,
      height: 1,
      minWidth: 1,
+      maxWidth: Infinity,
+      margin: {},
      XPositionReference: XPositionReference.Left,
-      isRigidBody: false,
+      isFlex: false,
      isAnchor: false
    };

--- a/src/Components/ContainerProperties/ContainerProperties.tsx
+++ b/src/Components/ContainerProperties/ContainerProperties.tsx
@ -1,4 +1,5 @@
 import React from 'react';
+import { PropertyType } from '../../Enums/PropertyType';
 import IContainerProperties from '../../Interfaces/IContainerProperties';
 import { ISymbolModel } from '../../Interfaces/ISymbolModel';
 import ContainerForm from './ContainerForm';
@ -6,7 +7,7 @@ import ContainerForm from './ContainerForm';
 interface IPropertiesProps {
  properties?: IContainerProperties
  symbols: Map<string, ISymbolModel>
-  onChange: (key: string, value: string | number | boolean, isStyle?: boolean) => void
+  onChange: (key: string, value: string | number | boolean, type?: PropertyType) => void
 }

 export const Properties: React.FC<IPropertiesProps> = (props: IPropertiesProps) => {
--- a/src/Components/Editor/Actions/ContainerOperations.ts
+++ b/src/Components/Editor/Actions/ContainerOperations.ts
@ -10,6 +10,9 @@ import { GetDefaultContainerProps, DEFAULTCHILDTYPE_ALLOW_CYCLIC, DEFAULTCHILDTY
 import { ApplyBehaviors } from '../Behaviors/Behaviors';
 import { ISymbolModel } from '../../../Interfaces/ISymbolModel';
 import Swal from 'sweetalert2';
+import { ApplyMargin, transformX } from '../../../utils/svg';
+import { Flex } from '../Behaviors/FlexBehaviors';
+import { PropertyType } from '../../../Enums/PropertyType';

 /**
 * Select a container
@ -87,6 +90,8 @@ export function DeleteContainer(
    throw new Error('[DeleteContainer] Could not find container among parent\'s children');
  }

+  Flex(container);
+
  // Select the previous container
  // or select the one above
  const SelectedContainerId = GetSelectedContainerOnDelete(
@ -147,7 +152,7 @@ export function AddContainerToSelectedContainer(
  setHistoryCurrentStep: Dispatch<SetStateAction<number>>
 ): void {
  if (selected === null ||
-      selected === undefined) {
+    selected === undefined) {
    return;
  }

@ -213,9 +218,17 @@ export function AddContainer(
  if (parentClone === null || parentClone === undefined) {
    throw new Error('[AddContainer] Container model was not found among children of the main container!');
  }
+  const left: number = containerConfig.Margin?.left ?? 0;
+  const bottom: number = containerConfig.Margin?.bottom ?? 0;
+  const top: number = containerConfig.Margin?.top ?? 0;
+  const right: number = containerConfig.Margin?.right ?? 0;

  let x = containerConfig.DefaultX ?? 0;
-  const y = containerConfig.DefaultY ?? 0;
+  let y = containerConfig.DefaultY ?? 0;
+  let width = containerConfig.Width ?? containerConfig.MaxWidth ?? containerConfig.MinWidth ?? parentClone.properties.width;
+  let height = containerConfig.Height ?? parentClone.properties.height;
+
+  ({ x, y, width, height } = ApplyMargin(x, y, width, height, left, bottom, top, right));

  x = ApplyAddMethod(index, containerConfig, parentClone, x);

@ -225,6 +238,8 @@ export function AddContainer(
    parentClone,
    x,
    y,
+    width,
+    height,
    containerConfig
  );

@ -238,17 +253,15 @@ export function AddContainer(
    }
  );

-  ApplyBehaviors(newContainer, current.Symbols);
-
-  // And push it the the parent children
-  if (index === parentClone.children.length) {
-    parentClone.children.push(newContainer);
-  } else {
-    parentClone.children.splice(index, 0, newContainer);
-  }
+  parentClone.children.push(newContainer);
+  UpdateParentChildrenList(parentClone);

  InitializeDefaultChild(configuration, containerConfig, newContainer, newCounters);

+  ApplyBehaviors(newContainer, current.Symbols);
+
+  ApplyBehaviorsOnSiblings(newContainer, current.Symbols);
+
  // Update the state
  history.push({
    LastAction: `Add ${newContainer.properties.id} in ${parentClone.properties.id}`,
@ -262,6 +275,16 @@ export function AddContainer(
  setHistoryCurrentStep(history.length - 1);
 }

+function UpdateParentChildrenList(parentClone: IContainerModel | null): void {
+  if (parentClone === null) {
+    return;
+  }
+  parentClone.children.sort(
+    (a, b) => transformX(a.properties.x, a.properties.width, a.properties.XPositionReference) -
+      transformX(b.properties.x, b.properties.width, b.properties.XPositionReference)
+  );
+}
+
 function InitializeDefaultChild(
  configuration: IConfiguration,
  containerConfig: IAvailableContainer,
@ -286,8 +309,17 @@ function InitializeDefaultChild(
    }

    seen.add(currentConfig.Type);
-    const x = currentConfig.DefaultX ?? 0;
-    const y = currentConfig.DefaultY ?? 0;
+
+    const left: number = currentConfig.Margin?.left ?? 0;
+    const bottom: number = currentConfig.Margin?.bottom ?? 0;
+    const top: number = currentConfig.Margin?.top ?? 0;
+    const right: number = currentConfig.Margin?.right ?? 0;
+    let x = currentConfig.DefaultX ?? 0;
+    let y = currentConfig.DefaultY ?? 0;
+    let width = currentConfig.Width ?? currentConfig.MaxWidth ?? currentConfig.MinWidth ?? parent.properties.width;
+    let height = currentConfig.Height ?? parent.properties.height;
+
+    ({ x, y, width, height } = ApplyMargin(x, y, width, height, left, bottom, top, right));

    UpdateCounters(newCounters, currentConfig.Type);
    const count = newCounters[currentConfig.Type];
@ -297,6 +329,8 @@ function InitializeDefaultChild(
      parent,
      x,
      y,
+      width,
+      height,
      currentConfig
    );

@ -353,7 +387,7 @@ function ApplyAddMethod(index: number, containerConfig: IAvailableContainer, par
 export function OnPropertyChange(
  key: string,
  value: string | number | boolean,
-  isStyle: boolean = false,
+  type: PropertyType = PropertyType.SIMPLE,
  selected: IContainerModel | undefined,
  fullHistory: IHistoryState[],
  historyCurrentStep: number,
@ -364,7 +398,7 @@ export function OnPropertyChange(
  const current = history[history.length - 1];

  if (selected === null ||
-      selected === undefined) {
+    selected === undefined) {
    throw new Error('[OnPropertyChange] Property was changed before selecting a Container');
  }

@ -375,22 +409,7 @@ export function OnPropertyChange(
    throw new Error('[OnPropertyChange] Container model was not found among children of the main container!');
  }

-  const oldSymbolId = container.properties.linkedSymbolId;
-
-  if (isStyle) {
-    (container.properties.style as any)[key] = value;
-  } else {
-    (container.properties as any)[key] = value;
-  }
-
-  LinkSymbol(
-    container.properties.id,
-    oldSymbolId,
-    container.properties.linkedSymbolId,
-    current.Symbols
-  );
-
-  ApplyBehaviors(container, current.Symbols);
+  SetContainer(container, key, value, type, current.Symbols);

  history.push({
    LastAction: `Change ${key} of ${container.properties.id}`,
@ -404,6 +423,79 @@ export function OnPropertyChange(
  setHistoryCurrentStep(history.length - 1);
 }

+/**
+ * Set the container with properties and behaviors (mutate)
+ * @param container Container to update
+ * @param key Key of the property to update
+ * @param value Value of the property to update
+ * @param type Type of the property to update
+ * @param symbols Current list of symbols
+ */
+function SetContainer(
+  container: ContainerModel,
+  key: string, value: string | number | boolean,
+  type: PropertyType,
+  symbols: Map<string, ISymbolModel>
+): void {
+  // get the old symbol to detect unlink
+  const oldSymbolId = container.properties.linkedSymbolId;
+
+  // update the property
+  AssignProperty(container, key, value, type);
+
+  // link the symbol if it exists
+  LinkSymbol(
+    container.properties.id,
+    oldSymbolId,
+    container.properties.linkedSymbolId,
+    symbols
+  );
+
+  // Apply special behaviors: rigid, flex, symbol, anchor
+  ApplyBehaviors(container, symbols);
+
+  // Apply special behaviors on siblings
+  ApplyBehaviorsOnSiblings(container, symbols);
+
+  // sort the children list by their position
+  UpdateParentChildrenList(container.parent);
+}
+
+function AssignProperty(container: ContainerModel, key: string, value: string | number | boolean, type: PropertyType): void {
+  switch (type) {
+    case PropertyType.STYLE:
+      (container.properties.style as any)[key] = value;
+      break;
+    case PropertyType.MARGIN:
+      SetMargin();
+      break;
+    default:
+      (container.properties as any)[key] = value;
+  }
+
+  function SetMargin(): void {
+    const oldMarginValue: number = (container.properties.margin as any)[key];
+    const diff = Number(value) - oldMarginValue;
+    switch (key) {
+      case 'left':
+        container.properties.x += diff;
+        container.properties.width -= diff;
+        break;
+      case 'right':
+        container.properties.width -= diff;
+        break;
+      case 'bottom':
+        container.properties.height -= diff;
+        break;
+      case 'top':
+        container.properties.y += diff;
+        container.properties.height -= diff;
+        break;
+    }
+    (container.properties.margin as any)[key] = value;
+  }
+}
+
 function LinkSymbol(
  containerId: string,
  oldSymbolId: string,
@ -422,3 +514,10 @@ function LinkSymbol(

  newSymbol.linkedContainers.add(containerId);
 }
+function ApplyBehaviorsOnSiblings(newContainer: ContainerModel, Symbols: Map<string, ISymbolModel>): void {
+  if (newContainer.parent === null || newContainer.parent === undefined) {
+    return;
+  }
+
+  newContainer.parent.children.filter(container => newContainer !== container).forEach(container => ApplyBehaviors(container, Symbols));
+}
--- a/src/Components/Editor/Behaviors/AnchorBehaviors.ts
+++ b/src/Components/Editor/Behaviors/AnchorBehaviors.ts
@ -28,7 +28,7 @@ export function ApplyAnchor(container: IContainerModel): IContainerModel {
  }

  const rigidBodies = container.parent.children.filter(
-    child => child.properties.isRigidBody && !child.properties.isAnchor
+    child => !child.properties.isAnchor
  );

  const overlappingContainers = getOverlappingContainers(container, rigidBodies);
--- a/src/Components/Editor/Behaviors/Behaviors.ts
+++ b/src/Components/Editor/Behaviors/Behaviors.ts
@ -2,6 +2,7 @@ import { IContainerModel } from '../../../Interfaces/IContainerModel';
 import { ISymbolModel } from '../../../Interfaces/ISymbolModel';
 import { APPLY_BEHAVIORS_ON_CHILDREN } from '../../../utils/default';
 import { ApplyAnchor } from './AnchorBehaviors';
+import { Flex } from './FlexBehaviors';
 import { ApplyRigidBody } from './RigidBodyBehaviors';
 import { ApplySymbol } from './SymbolBehaviors';

@ -16,10 +17,12 @@ export function ApplyBehaviors(container: IContainerModel, symbols: Map<string,
    ApplyAnchor(container);
  }

-  if (container.properties.isRigidBody) {
-    ApplyRigidBody(container);
+  if (container.properties.isFlex) {
+    Flex(container);
  }

+  ApplyRigidBody(container);
+
  const symbol = symbols.get(container.properties.linkedSymbolId);
  if (container.properties.linkedSymbolId !== '' && symbol !== undefined) {
    ApplySymbol(container, symbol);
--- a/src/Components/Editor/Behaviors/FlexBehaviors.ts
+++ b/src/Components/Editor/Behaviors/FlexBehaviors.ts
@ -0,0 +1,144 @@
+import Swal from 'sweetalert2';
+import { IContainerModel } from '../../../Interfaces/IContainerModel';
+import { reversePairwise } from '../../../utils/itertools';
+import { Simplex } from '../../../utils/simplex';
+import { ApplyWidthMargin, ApplyXMargin } from '../../../utils/svg';
+
+/**
+ * Try to push the siblings
+ * @param container
+ * @returns
+ */
+export function PushContainers(container: IContainerModel): IContainerModel {
+  if (container.parent === null) {
+    return container;
+  }
+
+  if (container.parent.children.length <= 1) {
+    return container;
+  }
+
+  const prevIndex = container.parent.children.length - 2;
+  const prev: IContainerModel = container.parent.children[prevIndex];
+  const isOverlapping = prev.properties.x + prev.properties.width > container.properties.x;
+  if (!isOverlapping) {
+    return container;
+  }
+
+  // find hole
+  let lastContainer: IContainerModel | null = null;
+  let space: number = 0;
+
+  while (space.toFixed(2) < container.properties.width.toFixed(2)) {
+    // FIXME: possible infinite loop due to floating point
+    // FIXME: A fix was applied using toFixed(2).
+    // FIXME: A coverture check must be done to ensure that all scenarios are covered
+
+    const it = reversePairwise<IContainerModel>(container.parent.children.filter(child => child !== container));
+
+    for (const { cur, next } of it) {
+      const hasSpaceBetween = next.properties.x + next.properties.width < cur.properties.x;
+      if (hasSpaceBetween) {
+        lastContainer = cur;
+        space = cur.properties.x - (next.properties.x + next.properties.width);
+        break;
+      }
+    }
+
+    if (lastContainer === null) {
+      // no space between
+      break;
+    }
+
+    const indexLastContainer = container.parent.children.indexOf(lastContainer);
+    for (let i = indexLastContainer; i <= container.parent.children.length - 2; i++) {
+      const sibling = container.parent.children[i];
+      sibling.properties.x -= space;
+    }
+  }
+
+  const hasNoSpaceBetween = lastContainer === null;
+  if (hasNoSpaceBetween) {
+    // test gap between the left of the parent and the first container
+    space = container.parent.children[0].properties.x;
+    if (space > 0) {
+      for (let i = 0; i <= container.parent.children.length - 2; i++) {
+        const sibling = container.parent.children[i];
+        sibling.properties.x -= space;
+      }
+      return container;
+    }
+  }
+
+  Flex(container);
+  return container;
+}
+
+/**
+ * Flex the container and its siblings (mutate)
+ * @param container Container to flex
+ * @returns Flexed container
+ */
+export function Flex(container: IContainerModel): void {
+  if (container.parent === null || container.parent === undefined) {
+    return;
+  }
+  const flexibleContainers = container.parent.children
+    .filter(sibling => sibling.properties.isFlex);
+
+  const minWidths = flexibleContainers
+    .map(sibling => sibling.properties.minWidth);
+
+  const fixedWidth = container.parent.children
+    .filter(sibling => !sibling.properties.isFlex)
+    .map(sibling => sibling.properties.width)
+    .reduce((partialSum, a) => partialSum + a, 0);
+
+  const requiredMaxWidth = container.parent.properties.width - fixedWidth;
+
+  const minimumPossibleWidth = minWidths.reduce((partialSum, a) => partialSum + a, 0);
+  if (minimumPossibleWidth > requiredMaxWidth) {
+    Swal.fire({
+      icon: 'error',
+      title: 'Cannot fit!',
+      text: 'Cannot fit at all even when squeezing all flex containers to the minimum.'
+    });
+    return;
+  }
+
+  const maxMinWidths = Math.max(...minWidths);
+  if (maxMinWidths * minWidths.length < requiredMaxWidth) {
+    const wantedWidth = requiredMaxWidth / minWidths.length;
+    // it fits, flex with maxMinWidths and fixed width
+    let right = 0;
+    for (const sibling of container.parent.children) {
+      if (!sibling.properties.isFlex) {
+        sibling.properties.x = right;
+        right += sibling.properties.width;
+        continue;
+      }
+      sibling.properties.x = ApplyXMargin(right, sibling.properties.margin.left);
+      sibling.properties.width = ApplyWidthMargin(wantedWidth, sibling.properties.margin.left, sibling.properties.margin.right);
+      right += wantedWidth;
+    }
+
+    return;
+  }
+
+  // does not fit
+
+  /// SIMPLEX ///
+  const solutions: number[] = Simplex(minWidths, requiredMaxWidth);
+
+  // apply the solutions
+  for (let i = 0; i < flexibleContainers.length; i++) {
+    flexibleContainers[i].properties.width = ApplyWidthMargin(solutions[i], flexibleContainers[i].properties.margin.left, flexibleContainers[i].properties.margin.right)
+  }
+
+  // move the containers
+  let right = 0;
+  for (const sibling of container.parent.children) {
+    sibling.properties.x = ApplyXMargin(right, sibling.properties.margin.left);
+    right += sibling.properties.width;
+  }
+}
--- a/src/Components/Editor/Behaviors/RigidBodyBehaviors.ts
+++ b/src/Components/Editor/Behaviors/RigidBodyBehaviors.ts
@ -9,6 +9,7 @@
 import Swal from 'sweetalert2';
 import { IContainerModel } from '../../../Interfaces/IContainerModel';
 import { ISizePointer } from '../../../Interfaces/ISizePointer';
+import { PushContainers } from './FlexBehaviors';

 /**
 * "Transform the container into a rigid body"
@ -23,6 +24,7 @@ export function ApplyRigidBody(
  container: IContainerModel
 ): IContainerModel {
  container = constraintBodyInsideParent(container);
+  container = PushContainers(container);
  container = constraintBodyInsideUnallocatedWidth(container);
  return container;
 }
@ -183,7 +185,6 @@ export function constraintBodyInsideUnallocatedWidth(
        showConfirmButton: false,
        timer: 5000
      });
-      container.properties.isRigidBody = false;
      return container;
    }

@ -238,8 +239,7 @@ function getAvailableWidths(

    // Ignore the exception
    // And we will also only uses containers that also are rigid or are anchors
-    if (child === exception ||
-      (!child.properties.isRigidBody && !child.properties.isAnchor)) {
+    if (child === exception) {
      continue;
    }
    const childX = child.properties.x;
--- a/src/Components/Editor/Behaviors/SymbolBehaviors.ts
+++ b/src/Components/Editor/Behaviors/SymbolBehaviors.ts
@ -1,9 +1,12 @@
 import { IContainerModel } from '../../../Interfaces/IContainerModel';
 import { ISymbolModel } from '../../../Interfaces/ISymbolModel';
+import { applyParentTransform } from '../../../utils/itertools';
 import { restoreX, transformX } from '../../../utils/svg';

 export function ApplySymbol(container: IContainerModel, symbol: ISymbolModel): IContainerModel {
  container.properties.x = transformX(symbol.x, symbol.width, symbol.config.XPositionReference);
  container.properties.x = restoreX(container.properties.x, container.properties.width, container.properties.XPositionReference);
+  const [x] = applyParentTransform(container.parent, container.properties.x, 0);
+  container.properties.x = x;
  return container;
 }
--- a/src/Components/Editor/Editor.tsx
+++ b/src/Components/Editor/Editor.tsx
@ -4,7 +4,7 @@ import { IConfiguration } from '../../Interfaces/IConfiguration';
 import { SVG } from '../SVG/SVG';
 import { IHistoryState } from '../../Interfaces/IHistoryState';
 import { UI } from '../UI/UI';
-import { SelectContainer, DeleteContainer, AddContainerToSelectedContainer, AddContainer, OnPropertyChange } from './Actions/ContainerOperations';
+import { SelectContainer, DeleteContainer, AddContainerToSelectedContainer, OnPropertyChange } from './Actions/ContainerOperations';
 import { SaveEditorAsJSON, SaveEditorAsSVG } from './Actions/Save';
 import { onKeyDown } from './Actions/Shortcuts';
 import EditorEvents from '../../Events/EditorEvents';
@ -60,7 +60,9 @@ function useWindowEvents(
  history: IHistoryState[],
  historyCurrentStep: number,
  configuration: IConfiguration,
-  editorRef: React.RefObject<HTMLDivElement>
+  editorRef: React.RefObject<HTMLDivElement>,
+  setHistory: Dispatch<SetStateAction<IHistoryState[]>>,
+  setHistoryCurrentStep: Dispatch<SetStateAction<number>>
 ): void {
  useEffect(() => {
    const events = EditorEvents;
@ -72,7 +74,12 @@ function useWindowEvents(

    const funcs = new Map<string, () => void>();
    for (const event of events) {
-      const func = (): void => event.func(editorState);
+      const func = (eventInitDict?: CustomEventInit): void => event.func(
+        editorState,
+        setHistory,
+        setHistoryCurrentStep,
+        eventInitDict
+      );
      editorRef.current?.addEventListener(event.name, func);
      funcs.set(event.name, func);
    }
@ -94,7 +101,14 @@ const Editor: React.FunctionComponent<IEditorProps> = (props) => {
  const editorRef = useRef<HTMLDivElement>(null);

  useShortcuts(history, historyCurrentStep, setHistoryCurrentStep);
-  useWindowEvents(history, historyCurrentStep, props.configuration, editorRef);
+  useWindowEvents(
+    history,
+    historyCurrentStep,
+    props.configuration,
+    editorRef,
+    setHistory,
+    setHistoryCurrentStep
+  );

  const configuration = props.configuration;
  const current = getCurrentHistoryState(history, historyCurrentStep);
@ -122,15 +136,15 @@ const Editor: React.FunctionComponent<IEditorProps> = (props) => {
          setHistory,
          setHistoryCurrentStep
        )}
-        OnPropertyChange={(key, value, isStyle) => OnPropertyChange(
-          key, value, isStyle,
+        OnPropertyChange={(key, value, type) => OnPropertyChange(
+          key, value, type,
          selected,
          history,
          historyCurrentStep,
          setHistory,
          setHistoryCurrentStep
        )}
-        AddContainerToSelectedContainer={(type) => AddContainerToSelectedContainer(
+        AddContainer={(type) => AddContainerToSelectedContainer(
          type,
          selected,
          configuration,
@ -139,16 +153,6 @@ const Editor: React.FunctionComponent<IEditorProps> = (props) => {
          setHistory,
          setHistoryCurrentStep
        )}
-        AddContainer={(index, type, parentId) => AddContainer(
-          index,
-          type,
-          parentId,
-          configuration,
-          history,
-          historyCurrentStep,
-          setHistory,
-          setHistoryCurrentStep
-        )}
        AddSymbol={(type) => AddSymbol(
          type,
          configuration,
--- a/src/Components/ElementsSidebar/ElementsSidebar.test.tsx
+++ b/src/Components/ElementsSidebar/ElementsSidebar.test.tsx
@ -22,9 +22,12 @@ describe.concurrent('Elements sidebar', () => {
          y: 0,
          width: 2000,
          height: 100,
+          margin: {},
          minWidth: 1,
+          type: 'type',
+          maxWidth: Infinity,
+          isFlex: false,
          XPositionReference: XPositionReference.Left,
-          isRigidBody: false,
          isAnchor: false
        },
        userData: {}
@ -35,7 +38,6 @@ describe.concurrent('Elements sidebar', () => {
      OnPropertyChange={() => {}}
      SelectContainer={() => {}}
      DeleteContainer={() => {}}
-      AddContainer={() => {}}
    />);

    expect(screen.getByText(/Elements/i));
@ -56,8 +58,11 @@ describe.concurrent('Elements sidebar', () => {
        y: 0,
        width: 2000,
        height: 100,
+        margin: {},
        minWidth: 1,
-        isRigidBody: false,
+        isFlex: false,
+        maxWidth: Infinity,
+        type: 'type',
        isAnchor: false,
        XPositionReference: XPositionReference.Left
      },
@ -73,7 +78,6 @@ describe.concurrent('Elements sidebar', () => {
      OnPropertyChange={() => {}}
      SelectContainer={() => {}}
      DeleteContainer={() => {}}
-      AddContainer={() => {}}
    />);

    expect(screen.getByText(/Elements/i));
@ -119,7 +123,10 @@ describe.concurrent('Elements sidebar', () => {
        width: 2000,
        height: 100,
        XPositionReference: XPositionReference.Left,
-        isRigidBody: false,
+        margin: {},
+        isFlex: false,
+        maxWidth: Infinity,
+        type: 'type',
        isAnchor: false
      },
      userData: {}
@ -139,7 +146,10 @@ describe.concurrent('Elements sidebar', () => {
          minWidth: 1,
          width: 0,
          height: 0,
-          isRigidBody: false,
+          margin: {},
+          isFlex: false,
+          maxWidth: Infinity,
+          type: 'type',
          isAnchor: false,
          XPositionReference: XPositionReference.Left
        },
@ -158,11 +168,14 @@ describe.concurrent('Elements sidebar', () => {
          displayedText: 'child-2',
          x: 0,
          y: 0,
+          margin: {},
          minWidth: 1,
          width: 0,
          height: 0,
          XPositionReference: XPositionReference.Left,
-          isRigidBody: false,
+          isFlex: false,
+          maxWidth: Infinity,
+          type: 'type',
          isAnchor: false
        },
        userData: {}
@ -178,7 +191,6 @@ describe.concurrent('Elements sidebar', () => {
      OnPropertyChange={() => {}}
      SelectContainer={() => {}}
      DeleteContainer={() => {}}
-      AddContainer={() => {}}
    />);

    expect(screen.getByText(/Elements/i));
@ -204,7 +216,10 @@ describe.concurrent('Elements sidebar', () => {
        width: 2000,
        height: 100,
        XPositionReference: XPositionReference.Left,
-        isRigidBody: false,
+        margin: {},
+        isFlex: false,
+        maxWidth: Infinity,
+        type: 'type',
        isAnchor: false
      },
      userData: {}
@ -224,7 +239,10 @@ describe.concurrent('Elements sidebar', () => {
        width: 0,
        height: 0,
        XPositionReference: XPositionReference.Left,
-        isRigidBody: false,
+        margin: {},
+        isFlex: false,
+        maxWidth: Infinity,
+        type: 'type',
        isAnchor: false
      },
      userData: {}
@ -245,7 +263,6 @@ describe.concurrent('Elements sidebar', () => {
      OnPropertyChange={() => {}}
      SelectContainer={selectContainer}
      DeleteContainer={() => {}}
-      AddContainer={() => {}}
    />);

    expect(screen.getByText(/Elements/i));
@ -269,7 +286,6 @@ describe.concurrent('Elements sidebar', () => {
      OnPropertyChange={() => {}}
      SelectContainer={selectContainer}
      DeleteContainer={() => {}}
-      AddContainer={() => {}}
    />);

    expect((propertyId as HTMLInputElement).value === 'main').toBeFalsy();
--- a/src/Components/ElementsSidebar/ElementsSidebar.tsx
+++ b/src/Components/ElementsSidebar/ElementsSidebar.tsx
@ -5,10 +5,10 @@ import { IContainerModel } from '../../Interfaces/IContainerModel';
 import { getDepth, MakeIterator } from '../../utils/itertools';
 import { Menu } from '../Menu/Menu';
 import { MenuItem } from '../Menu/MenuItem';
-import { handleDragLeave, handleDragOver, handleLeftClick, handleOnDrop, handleRightClick, useMouseEvents } from './MouseEventHandlers';
+import { useMouseEvents } from './MouseEventHandlers';
 import { IPoint } from '../../Interfaces/IPoint';
 import { ISymbolModel } from '../../Interfaces/ISymbolModel';
-import { Dispatch, RefObject, SetStateAction } from 'react';
+import { PropertyType } from '../../Enums/PropertyType';

 interface IElementsSidebarProps {
  MainContainer: IContainerModel
@ -16,16 +16,23 @@ interface IElementsSidebarProps {
  isOpen: boolean
  isHistoryOpen: boolean
  SelectedContainer: IContainerModel | undefined
-  OnPropertyChange: (key: string, value: string | number | boolean, isStyle?: boolean) => void
+  OnPropertyChange: (
+    key: string,
+    value: string | number | boolean,
+    type?: PropertyType
+  ) => void
  SelectContainer: (containerId: string) => void
  DeleteContainer: (containerid: string) => void
-  AddContainer: (index: number, type: string, parent: string) => void
 }

-export const ElementsSidebar: React.FC<IElementsSidebarProps> = (props: IElementsSidebarProps): JSX.Element => {
+export const ElementsSidebar: React.FC<IElementsSidebarProps> = (
+  props: IElementsSidebarProps
+): JSX.Element => {
  // States
-  const [isContextMenuOpen, setIsContextMenuOpen] = React.useState<boolean>(false);
-  const [onClickContainerId, setOnClickContainerId] = React.useState<string>('');
+  const [isContextMenuOpen, setIsContextMenuOpen] =
+    React.useState<boolean>(false);
+  const [onClickContainerId, setOnClickContainerId] =
+    React.useState<string>('');
  const [contextMenuPosition, setContextMenuPosition] = React.useState<IPoint>({
    x: 0,
    y: 0
@ -45,71 +52,78 @@ export const ElementsSidebar: React.FC<IElementsSidebarProps> = (props: IElement
  // Render
  let isOpenClasses = '-right-64';
  if (props.isOpen) {
-    isOpenClasses = props.isHistoryOpen
-      ? 'right-64'
-      : 'right-0';
+    isOpenClasses = props.isHistoryOpen ? 'right-64' : 'right-0';
  }

  const it = MakeIterator(props.MainContainer);
  const containers = [...it];
-  const Row = ({ index, style }: {index: number, style: React.CSSProperties}): JSX.Element => {
+  const Row = ({
+    index,
+    style
+  }: {
+    index: number
+    style: React.CSSProperties
+  }): JSX.Element => {
    const container = containers[index];
    const depth: number = getDepth(container);
    const key = container.properties.id.toString();
-    const text = container.properties.displayedText === key
-      ? `${'|\t'.repeat(depth)} ${key}`
-      : `${'|\t'.repeat(depth)} ${container.properties.displayedText} (${key})`;
-    const selectedClass: string = props.SelectedContainer !== undefined &&
-        props.SelectedContainer !== null &&
-        props.SelectedContainer.properties.id === container.properties.id
-      ? 'border-l-4 bg-slate-400/60 hover:bg-slate-400'
-      : 'bg-slate-300/60 hover:bg-slate-300';
+    const text =
+      container.properties.displayedText === key
+        ? `${'|\t'.repeat(depth)} ${key}`
+        : `${'|\t'.repeat(depth)} ${
+          container.properties.displayedText
+        } (${key})`;
+    const selectedClass: string =
+      props.SelectedContainer !== undefined &&
+      props.SelectedContainer !== null &&
+      props.SelectedContainer.properties.id === container.properties.id
+        ? 'border-l-4 bg-slate-400/60 hover:bg-slate-400'
+        : 'bg-slate-300/60 hover:bg-slate-300';

    return (
      <button
-        className={
-          `w-full border-blue-500 elements-sidebar-row whitespace-pre
-          text-left text-sm font-medium transition-all ${selectedClass}`
-        }
+        className={`w-full border-blue-500 elements-sidebar-row whitespace-pre
+          text-left text-sm font-medium transition-all ${selectedClass}`}
        id={key}
        key={key}
        style={style}
-        onDrop={(event) => handleOnDrop(event, props.MainContainer, props.AddContainer)}
-        onDragOver={(event) => handleDragOver(event, props.MainContainer)}
-        onDragLeave={(event) => handleDragLeave(event)}
        onClick={() => props.SelectContainer(container.properties.id)}
      >
-        { text }
+        {text}
      </button>
    );
  };

  return (
-    <div className={`fixed flex flex-col bg-slate-100 text-gray-800 transition-all h-full w-64 overflow-y-auto z-20 ${isOpenClasses}`}>
-      <div className='bg-slate-100 font-bold sidebar-title'>
-          Elements
-      </div>
-      <div ref={elementRef} className='h-96 text-gray-800'>
+    <div
+      className={`fixed flex flex-col bg-slate-100 text-gray-800 transition-all h-full w-64 overflow-y-auto z-20 ${isOpenClasses}`}
+    >
+      <div className="bg-slate-100 font-bold sidebar-title">Elements</div>
+      <div ref={elementRef} className="h-96 text-gray-800">
        <List
-          className='List divide-y divide-black'
+          className="List divide-y divide-black"
          itemCount={containers.length}
          itemSize={35}
          height={384}
          width={256}
        >
-          { Row }
+          {Row}
        </List>
      </div>
      <Menu
-        className='transition-opacity rounded bg-slate-200 py-1 drop-shadow-xl'
+        className="transition-opacity rounded bg-slate-200 py-1 drop-shadow-xl"
        x={contextMenuPosition.x}
        y={contextMenuPosition.y}
        isOpen={isContextMenuOpen}
      >
-        <MenuItem className='contextmenu-item' text='Delete' onClick={() => {
-          setIsContextMenuOpen(false);
-          props.DeleteContainer(onClickContainerId);
-        }} />
+        <MenuItem
+          className="contextmenu-item"
+          text="Delete"
+          onClick={() => {
+            setIsContextMenuOpen(false);
+            props.DeleteContainer(onClickContainerId);
+          }}
+        />
      </Menu>
      <Properties
        properties={props.SelectedContainer?.properties}
--- a/src/Components/ElementsSidebar/MouseEventHandlers.ts
+++ b/src/Components/ElementsSidebar/MouseEventHandlers.ts
@ -1,7 +1,5 @@
 import React, { RefObject, Dispatch, SetStateAction, useEffect } from 'react';
-import { IContainerModel } from '../../Interfaces/IContainerModel';
 import { IPoint } from '../../Interfaces/IPoint';
-import { findContainerById } from '../../utils/itertools';

 export function useMouseEvents(
  isContextMenuOpen: boolean,
@ -81,95 +79,3 @@ export function handleLeftClick(
  setOnClickContainerId('');
 }

-export function removeBorderClasses(target: HTMLButtonElement): void {
-  const bordersClasses = ['border-t-8', 'border-8', 'border-b-8'];
-  target.classList.remove(...bordersClasses);
-}
-
-export function handleDragLeave(event: React.DragEvent): void {
-  const target: HTMLButtonElement = event.target as HTMLButtonElement;
-  removeBorderClasses(target);
-}
-
-export function handleDragOver(
-  event: React.DragEvent,
-  mainContainer: IContainerModel
-): void {
-  event.preventDefault();
-  const target: HTMLButtonElement = event.target as HTMLButtonElement;
-  const rect = target.getBoundingClientRect();
-  const y = event.clientY - rect.top; // y position within the element.
-  removeBorderClasses(target);
-
-  if (target.id === mainContainer.properties.id) {
-    target.classList.add('border-8');
-    return;
-  }
-
-  if (y < 12) {
-    target.classList.add('border-t-8');
-  } else if (y < 24) {
-    target.classList.add('border-8');
-  } else {
-    target.classList.add('border-b-8');
-  }
-}
-
-export function handleOnDrop(
-  event: React.DragEvent,
-  mainContainer: IContainerModel,
-  addContainer: (index: number, type: string, parent: string) => void
-): void {
-  event.preventDefault();
-  const type = event.dataTransfer.getData('type');
-  const target: HTMLButtonElement = event.target as HTMLButtonElement;
-  removeBorderClasses(target);
-
-  const targetContainer: IContainerModel | undefined = findContainerById(
-    mainContainer,
-    target.id
-  );
-
-  if (targetContainer === undefined) {
-    throw new Error('[handleOnDrop] Tried to drop onto a unknown container!');
-  }
-
-  if (targetContainer === mainContainer) {
-    // if the container is the root, only add type as child
-    addContainer(
-      targetContainer.children.length,
-      type,
-      targetContainer.properties.id);
-    return;
-  }
-
-  if (targetContainer.parent === null ||
-      targetContainer.parent === undefined) {
-    throw new Error('[handleDrop] Tried to drop into a child container without a parent!');
-  }
-
-  const rect = target.getBoundingClientRect();
-  const y = event.clientY - rect.top; // y position within the element.
-
-  // locate the hitboxes
-  if (y < 12) {
-    const index = targetContainer.parent.children.indexOf(targetContainer);
-    addContainer(
-      index,
-      type,
-      targetContainer.parent.properties.id
-    );
-  } else if (y < 24) {
-    addContainer(
-      targetContainer.children.length,
-      type,
-      targetContainer.properties.id);
-  } else {
-    const index = targetContainer.parent.children.indexOf(targetContainer);
-    addContainer(
-      index + 1,
-      type,
-      targetContainer.parent.properties.id
-    );
-  }
-}
--- a/src/Components/SVG/Elements/Container.tsx
+++ b/src/Components/SVG/Elements/Container.tsx
@ -18,10 +18,17 @@ interface IContainerProps {
 */
 export const Container: React.FC<IContainerProps> = (props: IContainerProps) => {
  const containersElements = props.model.children.map(child => <Container key={`container-${child.properties.id}`} model={child} />);
-  const xText = props.model.properties.width / 2;
-  const yText = props.model.properties.height / 2;

-  const transform = `translate(${props.model.properties.x}, ${props.model.properties.y})`;
+  const width: number = props.model.properties.width;
+  const height: number = props.model.properties.height;
+
+  const x = props.model.properties.x;
+  const y = props.model.properties.y;
+
+  const xText = width / 2;
+  const yText = height / 2;
+
+  const transform = `translate(${x}, ${y})`;

  // g style
  const defaultStyle: React.CSSProperties = {
@ -39,8 +46,8 @@ export const Container: React.FC<IContainerProps> = (props: IContainerProps) =>
  const svg = (props.model.properties.customSVG != null)
    ? CreateReactCustomSVG(props.model.properties.customSVG, props.model.properties)
    : (<rect
-      width={props.model.properties.width}
-      height={props.model.properties.height}
+      width={width}
+      height={height}
      style={style}
    >
    </rect>);
@ -49,10 +56,10 @@ export const Container: React.FC<IContainerProps> = (props: IContainerProps) =>
  const dimensionMargin = DIMENSION_MARGIN * depth;
  const id = `dim-${props.model.properties.id}`;
  const xStart: number = 0;
-  const xEnd = props.model.properties.width;
-  const y = -dimensionMargin;
+  const xEnd = width;
+  const yDim = -dimensionMargin;
  const strokeWidth = 1;
-  const text = (props.model.properties.width ?? 0).toString();
+  const text = (width ?? 0).toString();

  let dimensionChildren: JSX.Element | null = null;
  if (props.model.children.length > 1 && SHOW_CHILDREN_DIMENSIONS) {
@ -80,35 +87,34 @@ export const Container: React.FC<IContainerProps> = (props: IContainerProps) =>
      transform={transform}
      key={`container-${props.model.properties.id}`}
    >
-      { SHOW_PARENT_DIMENSION
+      {SHOW_PARENT_DIMENSION
        ? <Dimension
          id={id}
          xStart={xStart}
          xEnd={xEnd}
-          yStart={y}
-          yEnd={y}
+          yStart={yDim}
+          yEnd={yDim}
          strokeWidth={strokeWidth}
          text={text}
        />
        : null
      }
-      { dimensionChildren }
-      { svg }
-      { SHOW_TEXT
+      {dimensionChildren}
+      {svg}
+      {SHOW_TEXT
        ? <text
          x={xText}
          y={yText}
        >
          {props.model.properties.displayedText}
        </text>
-        : null }
-      { containersElements }
+        : null}
+      {containersElements}
    </g>
  );
 };

-function GetChildrenDimensionProps(props: IContainerProps, dimensionMargin: number):
-{ childrenId: string, xChildrenStart: number, xChildrenEnd: number, yChildren: number, textChildren: string } {
+function GetChildrenDimensionProps(props: IContainerProps, dimensionMargin: number): { childrenId: string, xChildrenStart: number, xChildrenEnd: number, yChildren: number, textChildren: string } {
  const childrenId = `dim-children-${props.model.properties.id}`;

  const lastChild = props.model.children[props.model.children.length - 1];
@ -146,7 +152,7 @@ function CreateReactCustomSVG(customSVG: string, props: IContainerProperties): R
 function transform(node: HTMLElement, children: Node[], props: IContainerProperties): React.ReactNode {
  const supportedTags = ['line', 'path', 'rect'];
  if (supportedTags.includes(node.tagName.toLowerCase())) {
-    const attributes: {[att: string]: string | object | null} = {};
+    const attributes: { [att: string]: string | object | null } = {};
    node.getAttributeNames().forEach(attName => {
      const attributeValue = node.getAttribute(attName);
      if (attributeValue === null) {
--- a/src/Components/SVG/Elements/Selector.tsx
+++ b/src/Components/SVG/Elements/Selector.tsx
@ -1,6 +1,7 @@
 import * as React from 'react';
 import { IContainerModel } from '../../../Interfaces/IContainerModel';
 import { getAbsolutePosition } from '../../../utils/itertools';
+import { RemoveMargin } from '../../../utils/svg';

 interface ISelectorProps {
  selected?: IContainerModel
@ -14,11 +15,19 @@ export const Selector: React.FC<ISelectorProps> = (props) => {
    );
  }

-  const [x, y] = getAbsolutePosition(props.selected);
-  const [width, height] = [
+  let [x, y] = getAbsolutePosition(props.selected);
+  let [width, height] = [
    props.selected.properties.width,
    props.selected.properties.height
  ];
+
+  ({ x, y, width, height } = RemoveMargin(x, y, width, height,
+    props.selected.properties.margin.left,
+    props.selected.properties.margin.bottom,
+    props.selected.properties.margin.top,
+    props.selected.properties.margin.right
+  ));
+
  const style: React.CSSProperties = {
    stroke: '#3B82F6', // tw blue-500
    strokeWidth: 4,
--- a/src/Components/UI/UI.tsx
+++ b/src/Components/UI/UI.tsx
@ -11,6 +11,7 @@ import { Bar } from '../Bar/Bar';
 import { IAvailableSymbol } from '../../Interfaces/IAvailableSymbol';
 import { Symbols } from '../Symbols/Symbols';
 import { SymbolsSidebar } from '../SymbolsSidebar/SymbolsSidebar';
+import { PropertyType } from '../../Enums/PropertyType';

 interface IUIProps {
  SelectedContainer: IContainerModel | undefined
@ -21,9 +22,8 @@ interface IUIProps {
  AvailableSymbols: IAvailableSymbol[]
  SelectContainer: (containerId: string) => void
  DeleteContainer: (containerId: string) => void
-  OnPropertyChange: (key: string, value: string | number | boolean, isStyle?: boolean) => void
-  AddContainerToSelectedContainer: (type: string) => void
-  AddContainer: (index: number, type: string, parentId: string) => void
+  OnPropertyChange: (key: string, value: string | number | boolean, type?: PropertyType) => void
+  AddContainer: (type: string) => void
  AddSymbol: (type: string) => void
  OnSymbolPropertyChange: (key: string, value: string | number | boolean) => void
  SelectSymbol: (symbolId: string) => void
@ -75,7 +75,7 @@ export const UI: React.FunctionComponent<IUIProps> = (props: IUIProps) => {
      <Sidebar
        componentOptions={props.AvailableContainers}
        isOpen={isSidebarOpen}
-        buttonOnClick={props.AddContainerToSelectedContainer}
+        buttonOnClick={props.AddContainer}
      />
      <Symbols
        componentOptions={props.AvailableSymbols}
@ -91,7 +91,6 @@ export const UI: React.FunctionComponent<IUIProps> = (props: IUIProps) => {
        OnPropertyChange={props.OnPropertyChange}
        SelectContainer={props.SelectContainer}
        DeleteContainer={props.DeleteContainer}
-        AddContainer={props.AddContainer}
      />
      <SymbolsSidebar
        SelectedSymbolId={props.current.SelectedSymbolId}
--- a/src/Enums/AddMethod.ts
+++ b/src/Enums/AddMethod.ts
@ -2,9 +2,11 @@
 * Add method when creating a container
 * - Append will append to the last children in list
 * - Insert will always place it at the begining
+ * - Replace will remove the selected container and insert a new one
 * (default: Append)
 */
 export enum AddMethod {
  Append,
-  Insert
+  Insert,
+  Replace // TODO: Implement this
 }
--- a/src/Enums/PropertyType.ts
+++ b/src/Enums/PropertyType.ts
@ -0,0 +1,22 @@
+
+/**
+ * Describe the type of the property.
+ * Used for the assignation in the OnPropertyChange function
+ * See ContainerOperations.ts's OnPropertyChange
+ */
+export enum PropertyType {
+  /**
+   * Simple property: is not inside any object: id, x, width... (default)
+   */
+  SIMPLE,
+
+  /**
+   * Style property: is inside the style object: stroke, fillOpacity...
+   */
+  STYLE,
+
+  /**
+   * Margin property: is inside the margin property: left, bottom, top, right...
+   */
+  MARGIN,
+}
--- a/src/Events/EditorEvents.ts
+++ b/src/Events/EditorEvents.ts
@ -1,5 +1,15 @@
+import { Dispatch, SetStateAction } from 'react';
+import { getCurrentHistory } from '../Components/Editor/Editor';
+import { IConfiguration } from '../Interfaces/IConfiguration';
 import { IEditorState } from '../Interfaces/IEditorState';
 import { IHistoryState } from '../Interfaces/IHistoryState';
+import { ReviveState } from '../utils/saveload';
+
+
+const initEditor = (configuration: IConfiguration): void => {
+  // faire comme la callback de fetch
+  
+}

 const getEditorState = (editorState: IEditorState): void => {
  const customEvent = new CustomEvent<IEditorState>('getEditorState', { detail: editorState });
@ -13,14 +23,35 @@ const getCurrentHistoryState = (editorState: IEditorState): void => {
  document.dispatchEvent(customEvent);
 };

+const appendNewState = (
+  editorState: IEditorState,
+  setHistory: Dispatch<SetStateAction<IHistoryState[]>>,
+  setHistoryCurrentStep: Dispatch<SetStateAction<number>>,
+  eventInitDict?: CustomEventInit
+): void => {
+  const state: IHistoryState = JSON.parse(eventInitDict?.detail.state);
+  ReviveState(state);
+  const history = getCurrentHistory(editorState.history, editorState.historyCurrentStep);
+
+  history.push(state);
+  setHistory(history);
+  setHistoryCurrentStep(history.length - 1);
+};
+
 export interface IEditorEvent {
  name: string
-  func: (editorState: IEditorState) => void
+  func: (
+    editorState: IEditorState,
+    setHistory: Dispatch<SetStateAction<IHistoryState[]>>,
+    setHistoryCurrentStep: Dispatch<SetStateAction<number>>,
+    eventInitDict?: CustomEventInit
+  ) => void
 }

 const events: IEditorEvent[] = [
  { name: 'getEditorState', func: getEditorState },
-  { name: 'getCurrentHistoryState', func: getCurrentHistoryState }
+  { name: 'getCurrentHistoryState', func: getCurrentHistoryState },
+  { name: 'appendNewState', func: appendNewState }
 ];

 export default events;
--- a/src/Interfaces/IAvailableContainer.ts
+++ b/src/Interfaces/IAvailableContainer.ts
@ -1,6 +1,7 @@
 import React from 'react';
 import { AddMethod } from '../Enums/AddMethod';
 import { XPositionReference } from '../Enums/XPositionReference';
+import { IMargin } from './IMargin';

 /** Model of available container used in application configuration */
 export interface IAvailableContainer {
@ -10,6 +11,9 @@ export interface IAvailableContainer {
  Width?: number
  Height?: number
  MinWidth?: number
+  MaxWidth?: number
+  Margin?: IMargin
+  IsFlex?: boolean
  AddMethod?: AddMethod
  XPositionReference?: XPositionReference
  CustomSVG?: string
--- a/src/Interfaces/IContainerProperties.ts
+++ b/src/Interfaces/IContainerProperties.ts
@ -1,5 +1,6 @@
 import * as React from 'react';
 import { XPositionReference } from '../Enums/XPositionReference';
+import { IMargin } from './IMargin';

 /**
 * Properties of a container
@ -8,6 +9,9 @@ export default interface IContainerProperties {
  /** id of the container */
  id: string

+  /** type matching the configuration on construction */
+  type: string
+
  /** id of the parent container (null when there is no parent) */
  parentId: string

@ -23,6 +27,9 @@ export default interface IContainerProperties {
  /** vertical offset */
  y: number

+  /** margin */
+  margin: IMargin
+
  /**
   * Minimum width (min=1)
   * Allows the container to set isRigidBody to false when it gets squeezed
@ -30,18 +37,23 @@ export default interface IContainerProperties {
   */
  minWidth: number

+  /**
+   * Maximum width
+   */
+  maxWidth: number
+
  /** width */
  width: number

  /** height */
  height: number

-  /** true if rigid, false otherwise */
-  isRigidBody: boolean
-
  /** true if anchor, false otherwise */
  isAnchor: boolean

+  /** true if flex, false otherwise */
+  isFlex: boolean
+
  /** Horizontal alignment, also determines the visual location of x {Left = 0, Center, Right } */
  XPositionReference: XPositionReference

--- a/src/Interfaces/IMargin.ts
+++ b/src/Interfaces/IMargin.ts
@ -0,0 +1,6 @@
+export interface IMargin {
+  left?: number
+  bottom?: number
+  top?: number
+  right?: number
+}
--- a/src/utils/default.ts
+++ b/src/utils/default.ts
@ -68,7 +68,7 @@ export const DEFAULT_CONFIG: IConfiguration = {
  AvailableContainers: [
    {
      Type: 'Container',
-      Width: 75,
+      MaxWidth: 200,
      Height: 100,
      Style: {
        fillOpacity: 0,
@ -79,7 +79,7 @@ export const DEFAULT_CONFIG: IConfiguration = {
  AvailableSymbols: [],
  MainContainer: {
    Type: 'Container',
-    Width: 2000,
+    Width: 800,
    Height: 100,
    Style: {
      fillOpacity: 0,
@ -93,16 +93,19 @@ export const DEFAULT_CONFIG: IConfiguration = {
 */
 export const DEFAULT_MAINCONTAINER_PROPS: IContainerProperties = {
  id: 'main',
+  type: 'container',
  parentId: '',
  linkedSymbolId: '',
  displayedText: 'main',
  x: 0,
  y: 0,
+  margin: {},
  minWidth: 1,
+  maxWidth: Number.MAX_SAFE_INTEGER,
  width: Number(DEFAULT_CONFIG.MainContainer.Width),
  height: Number(DEFAULT_CONFIG.MainContainer.Height),
-  isRigidBody: false,
  isAnchor: false,
+  isFlex: false,
  XPositionReference: XPositionReference.Left,
  style: {
    stroke: 'black',
@ -126,20 +129,25 @@ export const GetDefaultContainerProps = (
  parent: IContainerModel,
  x: number,
  y: number,
+  width: number,
+  height: number,
  containerConfig: IAvailableContainer
 ): IContainerProperties => ({
  id: `${type}-${typeCount}`,
+  type,
  parentId: parent.properties.id,
  linkedSymbolId: '',
  displayedText: `${type}-${typeCount}`,
  x,
  y,
-  width: containerConfig.Width ?? containerConfig.MinWidth ?? parent.properties.width,
-  height: containerConfig.Height ?? parent.properties.height,
-  isRigidBody: false, // set this to true to replicate Florian's project
+  margin: containerConfig.Margin ?? {},
+  width,
+  height,
  isAnchor: false,
+  isFlex: containerConfig.IsFlex ?? containerConfig.Width === undefined,
  XPositionReference: containerConfig.XPositionReference ?? XPositionReference.Left,
  minWidth: containerConfig.MinWidth ?? 1,
+  maxWidth: containerConfig.MaxWidth ?? Number.MAX_SAFE_INTEGER,
  customSVG: containerConfig.CustomSVG,
  style: structuredClone(containerConfig.Style),
  userData: structuredClone(containerConfig.UserData)
--- a/src/utils/itertools.ts
+++ b/src/utils/itertools.ts
@ -14,7 +14,7 @@ export function * MakeIterator(root: IContainerModel): Generator<IContainerModel
    for (let i = container.children.length - 1; i >= 0; i--) {
      const child = container.children[i];
      if (visited.has(child)) {
-        return;
+        continue;
      }
      visited.add(child);
      queue.push(child);
@ -71,9 +71,20 @@ export function getDepth(parent: IContainerModel): number {
 * @returns The absolute position of the container
 */
 export function getAbsolutePosition(container: IContainerModel): [number, number] {
-  let x = container.properties.x;
-  let y = container.properties.y;
-  let current = container.parent;
+  const x = container.properties.x;
+  const y = container.properties.y;
+  return cancelParentTransform(container.parent, x, y);
+}
+
+/**
+ * Cancel the hierarchic transformations to the given x, y
+ * @param parent Parent of the container to remove its transform
+ * @param x value to be restored
+ * @param y value to be restored
+ * @returns x and y such that the transformations of the parent are cancelled
+ */
+export function cancelParentTransform(parent: IContainerModel | null, x: number, y: number): [number, number] {
+  let current = parent;
  while (current != null) {
    x += current.properties.x;
    y += current.properties.y;
@ -82,6 +93,23 @@ export function getAbsolutePosition(container: IContainerModel): [number, number
  return [x, y];
 }

+/**
+ * Cancel the hierarchic transformations to the given x, y
+ * @param parent Parent of the container to remove its transform
+ * @param x value to be restored
+ * @param y value to be restored
+ * @returns x and y such that the transformations of the parent are cancelled
+ */
+export function applyParentTransform(parent: IContainerModel | null, x: number, y: number): [number, number] {
+  let current = parent;
+  while (current != null) {
+    x -= current.properties.x;
+    y -= current.properties.y;
+    current = current.parent;
+  }
+  return [x, y];
+}
+
 export function findContainerById(root: IContainerModel, id: string): IContainerModel | undefined {
  const it = MakeIterator(root);
  for (const container of it) {
@ -91,3 +119,20 @@ export function findContainerById(root: IContainerModel, id: string): IContainer
  }
  return undefined;
 }
+
+export interface IPair<T> {
+  cur: T
+  next: T
+}
+
+export function * pairwise<T>(arr: T[]): Generator<IPair<T>, void, unknown> {
+  for (let i = 0; i < arr.length - 1; i++) {
+    yield { cur: arr[i], next: arr[i + 1] };
+  }
+}
+
+export function * reversePairwise<T>(arr: T[]): Generator<IPair<T>, void, unknown> {
+  for (let i = arr.length - 1; i > 0; i--) {
+    yield { cur: arr[i], next: arr[i - 1] };
+  }
+}
--- a/src/utils/saveload.ts
+++ b/src/utils/saveload.ts
@ -1,5 +1,6 @@
 import { findContainerById, MakeIterator } from './itertools';
 import { IEditorState } from '../Interfaces/IEditorState';
+import { IHistoryState } from '../Interfaces/IHistoryState';

 /**
 * Revive the Editor state
@ -14,31 +15,37 @@ export function Revive(editorState: IEditorState): void {

  // restore the parents and the selected container
  for (const state of history) {
-    if (state.MainContainer === null || state.MainContainer === undefined) {
-      continue;
-    }
-
-    state.Symbols = new Map(state.Symbols);
-    for (const symbol of state.Symbols.values()) {
-      symbol.linkedContainers = new Set(symbol.linkedContainers);
-    }
-
-    const it = MakeIterator(state.MainContainer);
-    for (const container of it) {
-      const parentId = container.properties.parentId;
-      if (parentId === null) {
-        container.parent = null;
-        continue;
-      }
-      const parent = findContainerById(state.MainContainer, parentId);
-      if (parent === undefined) {
-        continue;
-      }
-      container.parent = parent;
-    }
+    ReviveState(state);
  }
 }

+export const ReviveState = (
+  state: IHistoryState
+): void => {
+  if (state.MainContainer === null || state.MainContainer === undefined) {
+    return;
+  }
+
+  state.Symbols = new Map(state.Symbols);
+  for (const symbol of state.Symbols.values()) {
+    symbol.linkedContainers = new Set(symbol.linkedContainers);
+  }
+
+  const it = MakeIterator(state.MainContainer);
+  for (const container of it) {
+    const parentId = container.properties.parentId;
+    if (parentId === null) {
+      container.parent = null;
+      continue;
+    }
+    const parent = findContainerById(state.MainContainer, parentId);
+    if (parent === undefined) {
+      continue;
+    }
+    container.parent = parent;
+  }
+};
+
 export const getCircularReplacer = (): (key: any, value: object | Map<string, any> | null) => object | null | undefined => {
  return (key: any, value: object | null) => {
    if (key === 'parent') {
--- a/src/utils/simplex.ts
+++ b/src/utils/simplex.ts
@ -0,0 +1,246 @@
+/**
+ * @module {Simplex} Apply the simplex algorithm
+ * https://www.imse.iastate.edu/files/2015/08/Explanation-of-Simplex-Method.docx
+ */
+
+/**
+ * Apply the simplex algorithms to the minimum widths
+ *
+ * Note: Some optimizations were made to improve performance in order to solve
+ *  with max(minWidths). In point of fact most coefficient are equal to 1 or -1.
+ *
+ * Let the following format be the linear problem :
+ * x >= b are the minimum widths constraint
+ * sum(x) <= b is the maximum width constraint
+ * s are slack variables
+ * @param minWidths
+ * @param requiredMaxWidth
+ * @returns
+ */
+export function Simplex(minWidths: number[], requiredMaxWidth: number): number[] {
+  /// 1) standardized the equations
+  // add the min widths constraints
+  const maximumConstraints = minWidths.map(minWidth => minWidth * -1);
+
+  // add the max width constraint
+  maximumConstraints.push(requiredMaxWidth);
+
+  /// 2) Create the initial matrix
+  // get row length (nVariables + nConstraints + 1 (z) + 1 (b))
+  const nVariables = minWidths.length;
+  const nConstraints = maximumConstraints.length;
+  const rowlength = nVariables + nConstraints + 2;
+  const matrix = GetInitialMatrix(maximumConstraints, rowlength, nVariables);
+
+  /// Apply the algorithm
+  const finalMatrix = ApplyMainLoop(matrix, rowlength);
+
+  // 5) read the solutions
+  const solutions: number[] = GetSolutions(nVariables + nConstraints + 1, finalMatrix);
+  return solutions;
+}
+
+const MAX_TRIES = 10;
+
+/**
+ * Specific to min widths algorithm
+ * Get the initial matrix from the maximum constraints
+ * and the number of variables
+ * @param maximumConstraints
+ * @param rowlength
+ * @param nVariables
+ * @returns
+ */
+function GetInitialMatrix(
+  maximumConstraints: number[],
+  rowlength: number,
+  nVariables: number
+): number[][] {
+  const nConstraints = maximumConstraints.length;
+  const matrix = maximumConstraints.map((maximumConstraint, index) => {
+    const row: number[] = Array(rowlength).fill(0);
+
+    // insert the variable coefficient a of a*x
+    if (index <= nConstraints - 2) {
+      // insert the the variable coefficient of the minimum widths constraints (negative identity matrix)
+      row[index] = -1;
+    } else {
+      // insert the the variable coefficient of the maximum width constraint
+      row.fill(1, 0, nVariables);
+    }
+
+    // insert the slack variable coefficient b of b*s (identity matrix)
+    row[index + nVariables] = 1;
+
+    // insert the constraint coefficient (b)
+    row[rowlength - 1] = maximumConstraint;
+    return row;
+  });
+
+  // add objective function in the last row
+  const row: number[] = Array(rowlength).fill(0);
+
+  // insert z coefficient
+  row[rowlength - 2] = 1;
+
+  // insert variable coefficients
+  row.fill(-1, 0, nVariables);
+  matrix.push(row);
+  return matrix;
+}
+
+function getAllIndexes(arr: number[], val: number): number[] {
+  const indexes = []; let i = -1;
+  while ((i = arr.indexOf(val, i + 1)) !== -1) {
+    indexes.push(i);
+  }
+  return indexes;
+}
+
+/**
+ * Apply the main loop of the simplex algorithm and return the final matrix:
+ * - While the last row of the matrix has negative values :
+ *  - 1) find the column with the smallest negative coefficient in the last row
+ *  - 2) in that column, find the pivot by selecting the row with the smallest ratio
+ *      such as ratio = constraint of last column / coefficient of the selected row of the selected column
+ *  - 3) create the new matrix such as:
+ *  - 4) the selected column must have 1 in the pivot and zeroes in the other rows
+ *  - 5) in the selected rows other columns (other than the selected column)
+ *      must be divided by that pivot: coef / pivot
+ *  - 6) for the others cells, apply the pivot: new value = (-coefficient in the old col) * (coefficient in the new row) + old value
+ *  - 7) if in the new matrix there are still negative values in the last row,
+ *      redo the algorithm with the new matrix as the base matrix
+ *  - 8) otherwise returns the basic variable such as
+ *      a basic variable is defined by a single 1 and only zeroes in its column
+ *      other variables are equal to zeroes
+ * @param oldMatrix
+ * @param rowlength
+ * @returns
+ */
+function ApplyMainLoop(oldMatrix: number[][], rowlength: number): number[][] {
+  let matrix = oldMatrix;
+  let tries = MAX_TRIES;
+  const indexesTried: Record<number, number> = {};
+  while (matrix[matrix.length - 1].some((v: number) => v < 0) && tries > 0) {
+    // 1) find the index with smallest coefficient (O(n)+)
+    const lastRow = matrix[matrix.length - 1];
+    const min = Math.min(...lastRow);
+    const indexes = getAllIndexes(lastRow, min);
+    // to avoid infinite loop try to select the least used selected index
+    const pivotColIndex = getLeastUsedIndex(indexes, indexesTried);
+    // record the usage of index by incrementing
+    indexesTried[pivotColIndex] = indexesTried[pivotColIndex] !== undefined ? indexesTried[pivotColIndex] + 1 : 1;
+
+    // 2) find the smallest non negative non null ratio bi/xij (O(m))
+    const ratios = [];
+    for (let i = 0; i <= matrix.length - 2; i++) {
+      const coefficient = matrix[i][pivotColIndex];
+      const constraint = matrix[i][rowlength - 1];
+      if (coefficient === 0) {
+        ratios.push(Infinity);
+        continue;
+      }
+      const ratio = constraint / coefficient;
+      if (ratio < 0) {
+        ratios.push(Infinity);
+        continue;
+      }
+      ratios.push(ratio);
+    }
+    const minRatio = Math.min(...ratios);
+    const pivotRowIndex = ratios.indexOf(minRatio); // i
+
+    /// Init the new matrix
+    const newMatrix = structuredClone(matrix);
+    const pivot = matrix[pivotRowIndex][pivotColIndex];
+
+    // 3) apply on the pivot row the inverse of the pivot
+    const newPivotRow = newMatrix[pivotRowIndex];
+    newPivotRow.forEach((coef, colIndex) => {
+      newPivotRow[colIndex] = coef / pivot;
+    });
+
+    // 4) update all values
+    newMatrix.forEach((row, rowIndex) => {
+      if (rowIndex === pivotRowIndex) {
+        return;
+      }
+
+      row.forEach((coef, colIndex) => {
+        if (colIndex === pivotColIndex) {
+          // set zeroes on pivot col
+          row[colIndex] = 0;
+          return;
+        }
+
+        // update value = old value + ((-old coef of pivot column) * (new coef of pivot row))
+        row[colIndex] = coef + (-matrix[rowIndex][pivotColIndex] * newMatrix[pivotRowIndex][colIndex]);
+      });
+    });
+
+    matrix = newMatrix;
+    tries--;
+  }
+
+  if (tries === 0) {
+    throw new Error('[Flex]Simplexe: Could not find a solution');
+  }
+
+  return matrix;
+}
+
+/**
+ * Get the solutions from the final matrix
+ *
+ * @param {number} nCols Number of solutions that you want to obtain
+ * @param {number[][]} finalMatrix Final matrix after the algorithm is applied
+ * @return {*}  {number[]} A list of solutions of the final matrix
+ */
+function GetSolutions(nCols: number, finalMatrix: number[][]): number[] {
+  const solutions: number[] = Array(nCols).fill(0);
+  for (let i = 0; i < nCols; i++) {
+    const counts: Record<number, number> = {};
+    const col: number[] = [];
+    for (let j = 0; j < finalMatrix.length; j++) {
+      const row = finalMatrix[j];
+      counts[row[i]] = counts[row[i]] !== undefined ? counts[row[i]] + 1 : 1;
+      col.push(row[i]);
+    }
+
+    // a basic variable has a single 1 and only zeroes in the column
+    const nRows = finalMatrix.length;
+    const isBasic = counts[1] === 1 && counts[0] === (nRows - 1);
+    if (isBasic) {
+      const oneIndex = col.indexOf(1);
+      const row = finalMatrix[oneIndex];
+      solutions[i] = row[row.length - 1];
+    } else {
+      solutions[i] = 0;
+    }
+  }
+  return solutions;
+}
+
+/**
+ * Returns the least used index from the indexesTried
+ * @param indexes Indexes of all occurences
+ * @param indexesTried Record of indexes. Count the number of times the index was used.
+ * @returns The least used index
+ */
+function getLeastUsedIndex(indexes: number[], indexesTried: Record<number, number>): number {
+  let minUsed = Infinity;
+  let minIndex = -1;
+  for (const index of indexes) {
+    const occ = indexesTried[index];
+    if (occ === undefined) {
+      minIndex = index;
+      break;
+    }
+
+    if (occ < minUsed) {
+      minIndex = index;
+      minUsed = occ;
+    }
+  }
+  return minIndex;
+}
--- a/src/utils/svg.ts
+++ b/src/utils/svg.ts
@ -1,5 +1,15 @@
 import { XPositionReference } from '../Enums/XPositionReference';

+// TODO: Big refactoring
+/**
+ * TODO:
+ * All of these methods should have been
+ * inside ContainerModel class
+ * But because of serialization, the methods are lost.
+ * Rather than adding more functions to this class,
+ * it is better to fix serialization with the reviver.
+ */
+
 export function transformX(x: number, width: number, xPositionReference = XPositionReference.Left): number {
  let transformedX = x;
  if (xPositionReference === XPositionReference.Center) {
@ -19,3 +29,69 @@ export function restoreX(x: number, width: number, xPositionReference = XPositio
  }
  return transformedX;
 }
+
+export function ApplyMargin(
+  x: number,
+  y: number,
+  width: number,
+  height: number,
+  left?: number,
+  bottom?: number,
+  top?: number,
+  right?: number
+): { x: number, y: number, width: number, height: number } {
+  left = left ?? 0;
+  right = right ?? 0;
+  bottom = bottom ?? 0;
+  top = top ?? 0;
+  x = ApplyXMargin(x, left);
+  y += top;
+  width = ApplyWidthMargin(width, left, right);
+  height -= (bottom + top);
+  return { x, y, width, height };
+}
+
+export function RemoveMargin(
+  x: number,
+  y: number,
+  width: number,
+  height: number,
+  left?: number,
+  bottom?: number,
+  top?: number,
+  right?: number
+): { x: number, y: number, width: number, height: number } {
+  bottom = bottom ?? 0;
+  top = top ?? 0;
+  x = RemoveXMargin(x, left);
+  y -= top;
+  width = RemoveWidthMargin(width, left, right);
+  height += (bottom + top);
+  return { x, y, width, height };
+}
+
+export function ApplyXMargin(x: number, left?: number): number {
+  left = left ?? 0;
+  x += left;
+  return x;
+}
+
+export function RemoveXMargin(x: number, left?: number): number {
+  left = left ?? 0;
+  x -= left;
+  return x;
+}
+
+export function ApplyWidthMargin(width: number, left?: number, right?: number): number {
+  left = left ?? 0;
+  right = right ?? 0;
+  width -= (left + right);
+  return width;
+}
+
+export function RemoveWidthMargin(width: number, left?: number, right?: number): number {
+  left = left ?? 0;
+  right = right ?? 0;
+  width += (left + right);
+  return width;
+}
--- a/test-server/http.js
+++ b/test-server/http.js
@ -53,7 +53,7 @@ const GetSVGLayoutConfiguration = () => {
    AvailableContainers: [
      {
        Type: 'Chassis',
-        Width: 500,
+        MaxWidth: 500,
        MinWidth: 200,
        DefaultChildType: 'Trou',
        Style: {
@ -65,10 +65,14 @@ const GetSVGLayoutConfiguration = () => {
      },
      {
        Type: 'Trou',
-        DefaultX: 10,
-        DefaultY: 10,
-        Width: 480,
-        Height: 180,
+        DefaultX: 0,
+        DefaultY: 0,
+        Margin: {
+          left: 10,
+          bottom: 10,
+          top: 10,
+          right: 10,
+        },
        DefaultChildType: 'Remplissage',
        Style: {
          fillOpacity: 1,
@ -108,6 +112,28 @@ const GetSVGLayoutConfiguration = () => {
          stroke: '#713f12',
          fill: '#713f12',
        }
+      },
+      {
+        Type: '200',
+        MaxWidth: 500,
+        MinWidth: 200,
+        Style: {
+          fillOpacity: 1,
+          strokeWidth: 2,
+          stroke: 'blue',
+          fill: 'blue',
+        }
+      },
+      {
+        Type: '400',
+        MaxWidth: 500,
+        MinWidth: 400,
+        Style: {
+          fillOpacity: 1,
+          strokeWidth: 2,
+          stroke: 'red',
+          fill: 'red',
+        }
      }
    ],
    AvailableSymbols: [
@ -138,7 +164,7 @@ const GetSVGLayoutConfiguration = () => {
    ],
    MainContainer: {
      Height: 200,
-      Width: 1000
+      Width: 800
    }
  };
 };
--- a/test-server/node-http.js
+++ b/test-server/node-http.js
@ -53,182 +53,62 @@ const GetSVGLayoutConfiguration = () => {
  return {
    AvailableContainers: [
      {
-        BodyColor: null,
-        BorderColor: '#ff0000',
-        BorderWidth: 48,
-        ContainerActions: null,
-        ContainerDimensionning: null,
-        DefaultChildrenContainers: null,
-        Height: 0,
-        IsPositionFixed: false,
-        IsWidthFixed: false,
-        MaxHeight: 0,
-        MaxWidth: 3000,
-        MinHeight: 0,
-        MinWidth: 500,
        Type: 'Chassis',
-        TypeChildContainerDefault: 'Trou',
        Width: 500,
-        XPositionReference: 0,
+        MinWidth: 200,
+        DefaultChildType: 'Trou',
        Style: {
-          fillOpacity: 0,
-          borderWidth: 2,
-          stroke: 'red'
+          fillOpacity: 1,
+          strokeWidth: 2,
+          stroke: 'red',
+          fill: '#d3c9b7',
        }
      },
      {
-        BodyColor: null,
-        BorderColor: '#FFFFFF',
-        BorderWidth: 0,
-        ContainerActions: null,
-        ContainerDimensionning: null,
-        DefaultChildrenContainers: null,
-        Height: 0,
-        IsPositionFixed: false,
-        IsWidthFixed: false,
-        MaxHeight: 0,
-        MaxWidth: 0,
-        MinHeight: 0,
-        MinWidth: 0,
        Type: 'Trou',
-        TypeChildContainerDefault: 'Remplissage',
-        Width: 0,
-        XPositionReference: 0
+        DefaultX: 10,
+        DefaultY: 10,
+        Width: 480,
+        Height: 180,
+        DefaultChildType: 'Remplissage',
+        Style: {
+          fillOpacity: 1,
+          strokeWidth: 2,
+          stroke: 'green',
+          fill: 'white'
+        }
      },
      {
-        BodyColor: '#99C8FF',
-        BorderColor: '#00FF00',
-        BorderWidth: 0,
-        ContainerActions: [
-          {
-            Action: 'SplitRemplissage',
-            AddingBehavior: 0,
-            CustomLogo: {
-              Base64Image: null,
-              Name: null,
-              Svg: null,
-              Url: ''
-            },
-            Description: 'Diviser le remplissage en insérant un montant',
-            Id: null,
-            Label: 'Diviser le remplissage'
-          }
-        ],
-        ContainerDimensionning: {
-          DimensionningStyle: 1,
-          ShowDimensionning: false,
-          ShowLabel: false
-        },
-        DefaultChildrenContainers: null,
-        Height: 0,
-        IsPositionFixed: false,
-        IsWidthFixed: false,
-        MaxHeight: 0,
-        MaxWidth: 0,
-        MinHeight: 0,
-        MinWidth: 0,
        Type: 'Remplissage',
-        TypeChildContainerDefault: null,
-        Width: 0,
-        XPositionReference: 0
-      },
-      {
-        BodyColor: '#FFA947',
-        BorderColor: '#FFA947',
-        BorderWidth: 0,
-        ContainerActions: null,
-        ContainerDimensionning: null,
-        DefaultChildrenContainers: null,
-        Height: 0,
-        IsPositionFixed: false,
-        IsWidthFixed: false,
-        MaxHeight: 0,
-        MaxWidth: 0,
-        MinHeight: 0,
-        MinWidth: 0,
-        Type: 'Montant',
-        TypeChildContainerDefault: null,
-        Width: 50,
-        XPositionReference: 1
-      },
-      {
-        BodyColor: '#FFA3D1',
-        BorderColor: '#FF6DE6',
-        BorderWidth: 0,
-        ContainerActions: null,
-        ContainerDimensionning: {
-          DimensionningStyle: 0,
-          ShowDimensionning: false,
-          ShowLabel: false
+        CustomSVG: `
+          <rect width="{width}" height="{height}" style="{style}"></rect>
+          <rect  width="{width}" height="{height}" stroke="black" fill-opacity="0"></rect>
+          <line x1="0" y1="0" x2="{width}" y2="{height}" stroke="black" style='{{ "transform":"scaleY(0.5)"}}'></line>
+          <line x1="{width}" y1="0" x2="0" y2="{height}" stroke="black" style='{userData.styleLine}'></line>
+        `
+        ,
+        Style: {
+          fillOpacity: 1,
+          strokeWidth: 1,
+          fill: '#bfdbfe'
        },
-        DefaultChildrenContainers: null,
-        Height: 0,
-        IsPositionFixed: false,
-        IsWidthFixed: false,
-        MaxHeight: 0,
-        MaxWidth: 0,
-        MinHeight: 0,
-        MinWidth: 0,
-        Type: 'Ouverture',
-        TypeChildContainerDefault: null,
-        Width: 0,
-        XPositionReference: 0
-      },
-      {
-        BodyColor: '#000000',
-        BorderColor: null,
-        BorderWidth: 0,
-        ContainerActions: null,
-        ContainerDimensionning: {
-          DimensionningStyle: 0,
-          ShowDimensionning: false,
-          ShowLabel: false
-        },
-        DefaultChildrenContainers: null,
-        Height: 0,
-        IsPositionFixed: false,
-        IsWidthFixed: false,
-        MaxHeight: 0,
-        MaxWidth: 0,
-        MinHeight: 0,
-        MinWidth: 0,
-        Type: 'Dilatation',
-        TypeChildContainerDefault: null,
-        Width: 8,
-        XPositionReference: 0
-      },
-      {
-        BodyColor: '#dee2e4',
-        BorderColor: '#54616c',
-        BorderWidth: 0,
-        ContainerActions: [
-          {
-            Action: 'FillHoleWithChassis',
-            AddingBehavior: 1,
-            CustomLogo: {
-              Base64Image: null,
-              Name: null,
-              Svg: null,
-              Url: ''
-            },
-            Description: 'Remplir le trou avec des châssis',
-            Id: null,
-            Label: 'Calepiner'
+        UserData: {
+          styleLine: {
+            transform: "scaleY(0.5) translateY(100%)",
+            transformBox: "fill-box"
          }
-        ],
-        ContainerDimensionning: null,
-        DefaultChildrenContainers: null,
-        Height: 0,
-        IsPositionFixed: false,
-        IsWidthFixed: false,
-        MaxHeight: 0,
-        MaxWidth: 0,
-        MinHeight: 0,
-        MinWidth: 0,
-        Type: '',
-        TypeChildContainerDefault: null,
-        Width: 0,
-        XPositionReference: 0
+        }
+      },
+      {
+        Type: 'Montant',
+        Width: 10,
+        XPositionReference: 1,
+        Style: {
+          fillOpacity: 0,
+          strokeWidth: 2,
+          stroke: '#713f12',
+          fill: '#713f12',
+        }
      }
    ],
    AvailableSymbols: [