src/Components/ElementsSidebar/ElementsSidebar.tsx

@@ -3,6 +3,8 @@ import { motion } from 'framer-motion';
 import { Properties } from '../Properties/Properties';
 import { IContainerModel } from '../../Interfaces/ContainerModel';
 import { getDepth, MakeIterator } from '../../utils/itertools';
+import { Menu } from '../Menu/Menu';
+import { MenuItem } from '../Menu/MenuItem';
 
 interface IElementsSidebarProps {
   MainContainer: IContainerModel | null
@@ -11,9 +13,77 @@ interface IElementsSidebarProps {
   SelectedContainer: IContainerModel | null
   onPropertyChange: (key: string, value: string) => void
   selectContainer: (container: IContainerModel) => void
+  deleteContainer: (containerid: string) => void
+}
+
+interface Point {
+  x: number
+  y: number
+}
+
+interface IElementsSidebarState {
+  isContextMenuOpen: boolean
+  contextMenuPosition: Point
+  onClickContainerId: string
 }
 
 export class ElementsSidebar extends React.PureComponent<IElementsSidebarProps> {
+  public state: IElementsSidebarState;
+  public elementRef: React.RefObject<HTMLDivElement>;
+
+  constructor(props: IElementsSidebarProps) {
+    super(props);
+    this.state = {
+      isContextMenuOpen: false,
+      contextMenuPosition: {
+        x: 0,
+        y: 0
+      },
+      onClickContainerId: ''
+    };
+    this.elementRef = React.createRef();
+  }
+
+  componentDidMount(): void {
+    this.elementRef.current?.addEventListener('contextmenu', (event) => this.handleRightClick(event));
+    window.addEventListener('click', (event) => this.handleLeftClick(event));
+  }
+
+  componentWillUnmount(): void {
+    this.elementRef.current?.removeEventListener('contextmenu', (event) => this.handleRightClick(event));
+    window.removeEventListener('click', (event) => this.handleLeftClick(event));
+  }
+
+  public handleRightClick(event: MouseEvent): void {
+    event.preventDefault();
+
+    if (!(event.target instanceof HTMLButtonElement)) {
+      this.setState({
+        isContextMenuOpen: false,
+        onClickContainerId: ''
+      });
+      return;
+    }
+
+    const contextMenuPosition: Point = { x: event.pageX, y: event.pageY };
+    this.setState({
+      isContextMenuOpen: true,
+      contextMenuPosition,
+      onClickContainerId: event.target.id
+    });
+  }
+
+  public handleLeftClick(event: MouseEvent): void {
+    if (!this.state.isContextMenuOpen) {
+      return;
+    }
+
+    this.setState({
+      isContextMenuOpen: false,
+      onClickContainerId: ''
+    });
+  }
+
   public iterateChilds(handleContainer: (container: IContainerModel) => void): React.ReactNode {
     if (this.props.MainContainer == null) {
       return null;
@@ -56,6 +126,7 @@ export class ElementsSidebar extends React.PureComponent<IElementsSidebarProps>
             `w-full elements-sidebar-row whitespace-pre
           text-left text-sm font-medium transition-all ${selectedClass}`
           }
+          id={key}
           key={key}
           onClick={() => this.props.selectContainer(container)}>
           { text }
@@ -68,9 +139,17 @@ export class ElementsSidebar extends React.PureComponent<IElementsSidebarProps>
         <div className='bg-slate-100 font-bold sidebar-title'>
           Elements
         </div>
-        <div className='overflow-y-auto overflow-x-hidden text-gray-800 flex-grow'>
+        <div ref={this.elementRef} className='overflow-y-auto overflow-x-hidden text-gray-800 flex-grow'>
           { containerRows }
         </div>
+        <Menu
+          className='transition-opacity rounded bg-slate-200 py-1 drop-shadow-xl'
+          x={this.state.contextMenuPosition.x}
+          y={this.state.contextMenuPosition.y}
+          isOpen={this.state.isContextMenuOpen}
+        >
+          <MenuItem className='contextmenu-item' text='Delete' onClick={() => this.props.deleteContainer(this.state.onClickContainerId)} />
+        </Menu>
         <Properties properties={this.props.SelectedContainer?.properties} onChange={this.props.onPropertyChange}></Properties>
       </div>
     );

src/Components/Menu/Menu.tsx

@@ -0,0 +1,23 @@
+import * as React from 'react';
+
+interface IMenuProps {
+  className?: string
+  x: number
+  y: number
+  isOpen: boolean
+  children: React.ReactNode[] | React.ReactNode
+}
+
+export const Menu: React.FC<IMenuProps> = (props) => {
+  const visible = props.isOpen ? 'visible opacity-1' : 'invisible opacity-0';
+  return (
+    <div
+      className={`fixed ${props.className ?? ''} ${visible}`}
+      style={{
+        left: props.x,
+        top: props.y
+      }}>
+      { props.children }
+    </div>
+  );
+};

src/Components/Menu/MenuItem.tsx

@@ -0,0 +1,16 @@
+import * as React from 'react';
+
+interface IMenuItemProps {
+  className?: string
+  text: string
+  onClick: () => void
+}
+
+export const MenuItem: React.FC<IMenuItemProps> = (props) => {
+  return (
+    <button
+      className={props.className}
+      onClick={() => props.onClick()}>{props.text}
+    </button>
+  );
+};

src/Components/UI/UI.tsx

@@ -15,6 +15,7 @@ interface IUIProps {
   historyCurrentStep: number
   AvailableContainers: AvailableContainer[]
   SelectContainer: (container: ContainerModel) => void
+  DeleteContainer: (containerId: string) => void
   OnPropertyChange: (key: string, value: string) => void
   AddContainer: (type: string) => void
   SaveEditorAsJSON: () => void
@@ -97,6 +98,7 @@ export class UI extends React.PureComponent<IUIProps, IUIState> {
           isHistoryOpen={this.state.isHistoryOpen}
           onPropertyChange={this.props.OnPropertyChange}
           selectContainer={this.props.SelectContainer}
+          deleteContainer={this.props.DeleteContainer}
         />
         <History
           history={this.props.history}

src/Editor.tsx

@@ -91,6 +91,49 @@ class Editor extends React.Component<IEditorProps> {
     });
   }
 
+  public DeleteContainer(containerId: string): void {
+    const history = this.getCurrentHistory();
+    const current = history[this.state.historyCurrentStep];
+
+    if (current.MainContainer === null) {
+      throw new Error('[DeleteContainer] Error: Tried to delete a container without a main container');
+    }
+
+    const mainContainerClone: IContainerModel = structuredClone(current.MainContainer);
+    const container = findContainerById(mainContainerClone, containerId);
+
+    if (container === undefined) {
+      throw new Error(`[DeleteContainer] Tried to delete a container that is not present in the main container: ${containerId}`);
+    }
+
+    if (container === mainContainerClone) {
+      // TODO: Implement alert
+      throw new Error('[DeleteContainer] Tried to delete the main container! Deleting the main container is not allowed !');
+    }
+
+    if (container === null || container === undefined) {
+      throw new Error('[OnPropertyChange] Container model was not found among children of the main container!');
+    }
+
+    if (container.parent != null) {
+      const index = container.parent.children.indexOf(container);
+      if (index > -1) {
+        container.parent.children.splice(index, 1);
+      }
+    }
+
+    this.setState(
+      {
+        history: history.concat([{
+          SelectedContainer: null,
+          SelectedContainerId: '',
+          MainContainer: mainContainerClone,
+          TypeCounters: Object.assign({}, current.TypeCounters)
+        }]),
+        historyCurrentStep: history.length
+      });
+  }
+
   /**
    * Handled the property change event in the properties form
    * @param key Property name
@@ -286,6 +329,7 @@ class Editor extends React.Component<IEditorProps> {
           historyCurrentStep={this.state.historyCurrentStep}
           AvailableContainers={this.state.configuration.AvailableContainers}
           SelectContainer={(container) => this.SelectContainer(container)}
+          DeleteContainer={(containerId: string) => this.DeleteContainer(containerId)}
           OnPropertyChange={(key, value) => this.OnPropertyChange(key, value)}
           AddContainer={(type) => this.AddContainer(type)}
           SaveEditorAsJSON={() => this.SaveEditorAsJSON()}

src/index.scss

@@ -44,4 +44,8 @@
     text-xs font-bold
     transition-all duration-100 scale-0 origin-left;
   }
+
+  .contextmenu-item {
+    @apply px-2 py-1 hover:bg-slate-300 text-left
+  }
 }

src/utils/itertools.ts

@@ -11,14 +11,14 @@ export function * MakeIterator(root: IContainerModel): Generator<IContainerModel
 
     yield container;
 
-    // if this reverse() gets costly, replace it by a simple for
+    for (let i = container.children.length - 1; i >= 0; i--) {
-    container.children.forEach((child) => {
+      const child = container.children[i];
       if (visited.has(child)) {
         return;
       }
       visited.add(child);
       queue.push(child);
-    });
+    }
   }
 }