add a11y rules

blueprintcompiler/linter.py

@@ -21,8 +21,9 @@
 from blueprintcompiler.language.gobject_object import Object
 from blueprintcompiler.language.gtkbuilder_child import Child
 from blueprintcompiler.language.gobject_property import Property
-from blueprintcompiler.language.values import Translated, Literal
+from blueprintcompiler.language.values import Translated
 from .errors import CompileError, CompileWarning
+from blueprintcompiler.language.gtk_a11y import ExtAccessibility
 
 def lint(ast, problems = []): 
     for child in ast.children:
@@ -31,6 +32,10 @@ def lint(ast, problems = []):
             properties = child.content.children[Property]
             type = child.class_name.gir_type.full_name
 
+            # problems are for logical errors
+            # suggestions are for alternative/recommended way of doing things
+
+            # rule problem/number-of-children
             if (type in gir_types_no_children and len(children) > 0):
                 range = children[0].range
                 problem = CompileError(f'{type} cannot have children', range)
@@ -40,11 +45,14 @@ def lint(ast, problems = []):
                 problem = CompileError(f'{type} cannot have more than one child', range)
                 problems.append(problem)
             
+            # rule suggestion/prefer-adwbin
+            # FIXME: Only if use Adw is in scope and no Gtk.Box properties are used
             if (type == 'Gtk.Box' and len(children) == 1):
                 range = children[0].range
                 problem = CompileWarning(f'Use Adw.Bin instead of a Gtk.Box for a single child', range)
                 problems.append(problem)
 
+            # rule suggestion/translatable-display-string
             for translatable_property in translatable_properties:
                 if type == translatable_property[0] or translatable_property[0] == None:
                     for property in properties:
@@ -55,6 +63,7 @@ def lint(ast, problems = []):
                                 problem = CompileWarning(f'Mark {type} {property.name} as translatable using _("...")', range)
                                 problems.append(problem)
 
+            # rule suggestion/no-visible-true
             # FIXME GTK4 only
             for property in properties:
                 if (property.name == 'visible'):
@@ -62,17 +71,57 @@ def lint(ast, problems = []):
                     ident = value.value.ident
                     if ident == 'true':
                         range = value.range
-                        problem = CompileWarning(f'Property {property.name} default value is already true', range)
+                        problem = CompileWarning(f'In GTK4 widgets are visible by default', range)
                         problems.append(problem)
 
-
+            # rule problem/no-gtkswitch-state
             if (type == 'Gtk.Switch'):
                 for property in properties:
                     if (property.name == 'state'):
                         range = property.range
-                        problem = CompileError(f'Use the Gtk.Switch active property instead of the state property', range)
+                        problem = CompileError(f'Use the active property instead of the state property', range)
                         problems.append(problem)
 
+            # rule suggestion/require-a11y-label
+            if (type == 'Gtk.Button'):
+                label = None
+                tooltip_text = None
+                accessibility_label = False
+
+                # FIXME: Check what ATs actually do
+
+                for property in properties:
+                    if (property.name == 'label'):
+                        label = property.value
+                    elif (property.name == 'tooltip-text'):
+                        tooltip_text = property.value
+
+                accessibility__child = child.content.children[ExtAccessibility]
+                if len(accessibility__child) > 0:
+                    accessibility_properties = child.content.children[ExtAccessibility][0].properties
+                    for accessibility_property in accessibility_properties:
+                        if (accessibility_property.name == 'label'):
+                            accessibility_label = True
+
+                if (label is None and tooltip_text is None and accessibility_label is False):
+                    problem = CompileWarning(f'{type} is missing an accessibility label', child.range)
+                    problems.append(problem)
+
+            # rule suggestion/require-a11y-label
+            elif (type == 'Gtk.Image' or type == 'Gtk.Picture'):
+                accessibility_label = False
+
+                accessibility__child = child.content.children[ExtAccessibility]
+                if len(accessibility__child) > 0:
+                    accessibility_properties = child.content.children[ExtAccessibility][0].properties
+                    for accessibility_property in accessibility_properties:
+                        if (accessibility_property.name == 'label'):
+                            accessibility_label = True
+
+                if (accessibility_label is False):
+                    problem = CompileWarning(f'{type} is missing an accessibility label', child.range)
+                    problems.append(problem)
+
         lint(child, problems)
 
     return problems
@@ -84,4 +133,5 @@ translatable_properties = [
     (None, 'tooltip-text'),
     ('Gtk.Label', 'label'),
     ('Gtk.Window', 'title'),
+    ('Gtk.Button', 'label')
 ]

linter.blp

@@ -1,35 +1,48 @@
 using Gtk 4.0;
 using Adw 1;
 
+// I don't have an accessibility label
+Gtk.Image {
+  icon-name: "cat-symbolic";
+}
+Button {
+  icon-name: "foobar";
+}
+
+// I don't display children
 Label {
   Box {}
 }
 
+// I only diplay the last child
 Adw.StatusPage {
   Box {}
   Box {}
 }
 
+// Prefer Adw.Bin if you have a single child
 Gtk.Box {
   Label {}
 }
 
+// I'm a user visible string that is not marked as translatable
 Label {
   label: "foo";
 }
-
-Switch {
-  state: false;
-}
-
 Button {
   tooltip-text: "foo";
 }
-
 Window {
   title: "foobar";
 }
 
+// State isn't the right property to use here
+// use active instead
+Switch {
+  state: false;
+}
+
+// In GTK4 widgets are visible by default
 Box {
   visible: true;
 }