Improve accessibility of ComboBox widgets

api/cpp/include/slint-testing.h

@@ -382,6 +382,52 @@ class ElementHandle
         return std::nullopt;
     }
 
+    /// Returns the accessible-expanded of that element, if any.
+    std::optional<bool> accessible_expanded() const
+    {
+        if (auto result = get_accessible_string_property(
+                    cbindgen_private::AccessibleStringProperty::Expanded)) {
+            if (*result == "true")
+                return true;
+            else if (*result == "false")
+                return false;
+        }
+        return std::nullopt;
+    }
+    /// Returns the accessible-expandable of that element, if any.
+    std::optional<bool> accessible_expandable() const
+    {
+        if (auto result = get_accessible_string_property(
+                    cbindgen_private::AccessibleStringProperty::Expandable)) {
+            if (*result == "true")
+                return true;
+            else if (*result == "false")
+                return false;
+        }
+        return std::nullopt;
+    }
+
+    /// Invokes the expand accessibility action of that element
+    /// (`accessible-action-expand`).
+    void invoke_accessible_expand_action() const
+    {
+        if (inner.element_index != 0)
+            return;
+        if (auto item = private_api::upgrade_item_weak(inner.item)) {
+            union ExpandActionHelper {
+                cbindgen_private::AccessibilityAction action;
+                ExpandActionHelper()
+                {
+                    action.tag = cbindgen_private::AccessibilityAction::Tag::Expand;
+                }
+                ~ExpandActionHelper() { }
+
+            } action;
+            item->item_tree.vtable()->accessibility_action(item->item_tree.borrow(), item->index,
+                                                           &action.action);
+        }
+    }
+
     /// Sets the accessible-value of that element.
     ///
     /// Setting the value will invoke the `accessible-action-set-value` callback.

docs/astro/src/content/docs/reference/common.mdx

@@ -207,6 +207,17 @@ The description for the current element.
 Whether the element is enabled or not. This maps to the "enabled" state of most widgets. (default value: `true`)
 </SlintProperty>
 
+### accessible-expandable
+<SlintProperty typeName="bool" propName="accessible-expandable" default="false">
+Whether the element can be expanded or not.
+</SlintProperty>
+
+### accessible-expanded
+<SlintProperty typeName="bool" propName="accessible-expanded" default="false">
+Whether the element is expanded or not. Applies to combo boxes, menu items,
+tree view items and other widgets.
+</SlintProperty>
+
 ### accessible-label
 <SlintProperty typeName="string" propName="accessible-label" default='""'>
 The label for an interactive element. (default value: empty for most elements, or the value of the `text` property for Text elements)
@@ -272,3 +283,6 @@ Invoked when the user requests to increment the value.
 
 ### accessible-action-decrement()
 Invoked when the user requests to decrement the value.
+
+### accessible-action-expand()
+Invoked when the user requests to expand the widget (eg: disclose the list of available choices for a combo box).

internal/backends/qt/qt_accessible.rs

@@ -30,6 +30,8 @@ const VALUE_MINIMUM: u32 = CHECKED + 1;
 const VALUE_MAXIMUM: u32 = VALUE_MINIMUM + 1;
 const VALUE_STEP: u32 = VALUE_MAXIMUM + 1;
 const CHECKABLE: u32 = VALUE_STEP + 1;
+const EXPANDABLE: u32 = CHECKABLE + 1;
+const EXPANDED: u32 = EXPANDABLE + 1;
 
 pub struct AccessibleItemPropertiesTracker {
     obj: *mut c_void,
@@ -208,6 +210,8 @@ impl SlintAccessibleItemData {
             if let Some(item_rc) = item.upgrade() {
                 item_rc.accessible_string_property(AccessibleStringProperty::Checkable);
                 item_rc.accessible_string_property(AccessibleStringProperty::Checked);
+                item_rc.accessible_string_property(AccessibleStringProperty::Expandable);
+                item_rc.accessible_string_property(AccessibleStringProperty::Expanded);
             }
         });
     }
@@ -267,6 +271,8 @@ cpp! {{
     const uint32_t VALUE_MAXIMUM { VALUE_MINIMUM + 1 };
     const uint32_t VALUE_STEP { VALUE_MAXIMUM + 1 };
     const uint32_t CHECKABLE { VALUE_STEP + 1 };
+    const uint32_t EXPANDABLE { CHECKABLE + 1 };
+    const uint32_t EXPANDED { EXPANDABLE + 1 };
 
     // ------------------------------------------------------------------------------
     // Helper:
@@ -362,6 +368,8 @@ cpp! {{
                     VALUE_MAXIMUM => item.accessible_string_property(AccessibleStringProperty::ValueMaximum),
                     VALUE_STEP => item.accessible_string_property(AccessibleStringProperty::ValueStep),
                     CHECKABLE => item.accessible_string_property(AccessibleStringProperty::Checkable),
+                    EXPANDABLE => item.accessible_string_property(AccessibleStringProperty::Expandable),
+                    EXPANDED => item.accessible_string_property(AccessibleStringProperty::Expanded),
                     _ => None,
                 };
                 if let Some(string) = string {
@@ -621,6 +629,14 @@ cpp! {{
             state.focused = has_focus_delegation;
             state.checked = (checked == "true") ? 1 : 0;
             state.checkable = (item_string_property(m_data, CHECKABLE) == "true") ? 1 : 0;
+            if (item_string_property(m_data, EXPANDABLE) == "true") {
+                state.expandable = 1;
+                if (item_string_property(m_data, EXPANDED) == "true") {
+                    state.expanded = 1;
+                } else {
+                    state.collapsed = 1;
+                }
+            }
             return state; /* FIXME */
         }
 
@@ -669,14 +685,21 @@ cpp! {{
                 actions << QAccessibleActionInterface::increaseAction();
             if (supported & rust!(Slint_accessible_item_an3 [] -> SupportedAccessibilityAction as "uint" { SupportedAccessibilityAction::Decrement }))
                 actions << QAccessibleActionInterface::decreaseAction();
+            if (supported & rust!(Slint_accessible_item_an4 [] -> SupportedAccessibilityAction as "uint" { SupportedAccessibilityAction::Expand }))
+                actions << QAccessibleActionInterface::pressAction();
             return actions;
         }
 
         void doAction(const QString &actionName) override {
             if (actionName == QAccessibleActionInterface::pressAction()) {
                 rust!(Slint_accessible_item_do_action1 [m_data: Pin<&SlintAccessibleItemData> as "void*"] {
                     let Some(item) = m_data.item.upgrade() else {return};
-                    item.accessible_action(&AccessibilityAction::Default);
+                    let supported_actions = item.supported_accessibility_actions();
+                    if supported_actions.contains(SupportedAccessibilityAction::Expand) {
+                        item.accessible_action(&AccessibilityAction::Expand);
+                    } else {
+                        item.accessible_action(&AccessibilityAction::Default);
+                    }
                 });
             } else if (actionName == QAccessibleActionInterface::increaseAction()) {
                 rust!(Slint_accessible_item_do_action2 [m_data: Pin<&SlintAccessibleItemData> as "void*"] {

internal/backends/testing/search_api.rs

@@ -647,6 +647,28 @@ impl ElementHandle {
         })
     }
 
+    /// Returns the value of the `accessible-expanded` property, if present
+    pub fn accessible_expanded(&self) -> Option<bool> {
+        if self.element_index != 0 {
+            return None;
+        }
+        self.item
+            .upgrade()
+            .and_then(|item| item.accessible_string_property(AccessibleStringProperty::Expanded))
+            .and_then(|item| item.parse().ok())
+    }
+
+    /// Returns the value of the `accessible-expandable` property, if present
+    pub fn accessible_expandable(&self) -> Option<bool> {
+        if self.element_index != 0 {
+            return None;
+        }
+        self.item
+            .upgrade()
+            .and_then(|item| item.accessible_string_property(AccessibleStringProperty::Expandable))
+            .and_then(|item| item.parse().ok())
+    }
+
     /// Returns the size of the element in logical pixels. This corresponds to the value of the `width` and
     /// `height` properties in Slint code. Returns a zero size if the element is not valid.
     pub fn size(&self) -> i_slint_core::api::LogicalSize {
@@ -715,6 +737,17 @@ impl ElementHandle {
         }
     }
 
+    /// Invokes the element's `accessible-action-expand` callback, if declared. On widgets such as combo boxes, this
+    /// typically discloses the list of available choices.
+    pub fn invoke_accessible_expand_action(&self) {
+        if self.element_index != 0 {
+            return;
+        }
+        if let Some(item) = self.item.upgrade() {
+            item.accessible_action(&AccessibilityAction::Expand)
+        }
+    }
+
     /// Simulates a single click (or touch tap) on the element at its center point with the
     /// specified button.
     pub async fn single_click(&self, button: i_slint_core::platform::PointerEventButton) {

internal/backends/testing/slint_systest.proto

@@ -16,6 +16,7 @@ enum ElementAccessibilityAction {
     Default_ = 0;
     Increment = 1;
     Decrement = 2;
+    Expand = 3;
 }
 
 enum PointerEventButton {

internal/backends/testing/systest.rs

@@ -380,6 +380,7 @@ impl TestingClient {
             proto::ElementAccessibilityAction::Decrement => {
                 element.invoke_accessible_decrement_action()
             }
+            proto::ElementAccessibilityAction::Expand => element.invoke_accessible_expand_action(),
         }
         Ok(())
     }

internal/backends/winit/accesskit.rs

@@ -149,6 +149,7 @@ impl AccessKitAdapter {
                 }
                 _ => return None,
             },
+            Action::Expand => AccessibilityAction::Expand,
             _ => return None,
         };
         self.nodes
@@ -520,6 +521,16 @@ impl NodeCollection {
             node.set_description(description.to_string());
         }
 
+        if item
+            .accessible_string_property(AccessibleStringProperty::Expandable)
+            .is_some_and(|x| x == "true")
+        {
+            node.set_expanded(
+                item.accessible_string_property(AccessibleStringProperty::Expanded)
+                    .is_some_and(|x| x == "true"),
+            );
+        }
+
         if matches!(
             role,
             Role::Button
@@ -614,6 +625,9 @@ impl NodeCollection {
         if supported.contains(SupportedAccessibilityAction::ReplaceSelectedText) {
             node.add_action(accesskit::Action::ReplaceSelectedText);
         }
+        if supported.contains(SupportedAccessibilityAction::Expand) {
+            node.add_action(accesskit::Action::Expand);
+        }
 
         node
     }

internal/compiler/typeregister.rs

@@ -197,6 +197,8 @@ pub fn reserved_accessibility_properties() -> impl Iterator<Item = (&'static str
         ("accessible-delegate-focus", Type::Int32),
         ("accessible-description", Type::String),
         ("accessible-enabled", Type::Bool),
+        ("accessible-expandable", Type::Bool),
+        ("accessible-expanded", Type::Bool),
         ("accessible-label", Type::String),
         ("accessible-value", Type::String),
         ("accessible-value-maximum", Type::Float32),
@@ -207,6 +209,7 @@ pub fn reserved_accessibility_properties() -> impl Iterator<Item = (&'static str
         ("accessible-action-increment", noarg_callback_type()),
         ("accessible-action-decrement", noarg_callback_type()),
         ("accessible-action-set-value", strarg_callback_type()),
+        ("accessible-action-expand", noarg_callback_type()),
         ("accessible-item-selectable", Type::Bool),
         ("accessible-item-selected", Type::Bool),
         ("accessible-item-index", Type::Int32),

internal/compiler/widgets/cosmic/combobox.slint

@@ -26,6 +26,10 @@ export component ComboBox {
     forward-focus: base;
     accessible-role: combobox;
     accessible-enabled: root.enabled;
+    accessible-expandable: true;
+    accessible-expanded: base.popup-has-focus;
+    accessible-value <=> root.current-value;
+    accessible-action-expand => { base.show-popup(); }
 
     states [
         disabled when !root.enabled : {
@@ -63,6 +67,7 @@ export component ComboBox {
                 font-weight: CosmicFontSettings.body.font-weight;
                 color: CosmicPalette.control-foreground;
                 text: root.current-value;
+                accessible-role: none;
             }
 
             Image {

internal/compiler/widgets/cupertino/combobox.slint

@@ -26,6 +26,10 @@ export component ComboBox {
     forward-focus: base;
     accessible-role: combobox;
     accessible-enabled: root.enabled;
+    accessible-expandable: true;
+    accessible-expanded: base.popup-has-focus;
+    accessible-value <=> root.current-value;
+    accessible-action-expand => { base.show-popup(); }
 
     states [
         disabled when !root.enabled : {
@@ -95,6 +99,7 @@ export component ComboBox {
             font-weight: CupertinoFontSettings.body.font-weight;
             color: CupertinoPalette.foreground;
             text: root.current-value;
+            accessible-role: none;
         }
 
         VerticalLayout {

internal/compiler/widgets/fluent/combobox.slint

@@ -26,6 +26,10 @@ export component ComboBox {
 
     accessible-role: combobox;
     accessible-enabled: root.enabled;
+    accessible-expandable: true;
+    accessible-expanded: base.popup-has-focus;
+    accessible-value <=> root.current-value;
+    accessible-action-expand => { base.show-popup(); }
 
     states [
         disabled when !root.enabled : {
@@ -77,6 +81,7 @@ export component ComboBox {
                 font-weight: FluentFontSettings.body.font-weight;
                 color: FluentPalette.control-foreground;
                 text: root.current-value;
+                accessible-role: none;
             }
 
             icon := Image {

internal/compiler/widgets/material/combobox.slint

@@ -25,6 +25,10 @@ export component ComboBox {
     forward-focus: base;
     accessible-role: combobox;
     accessible-enabled: root.enabled;
+    accessible-expandable: true;
+    accessible-expanded: base.popup-has-focus;
+    accessible-value <=> root.current-value;
+    accessible-action-expand => { base.show-popup(); }
 
     states [
         disabled when !root.enabled : {
@@ -74,6 +78,7 @@ export component ComboBox {
             // font-family: MaterialFontSettings.body-large.font;
             font-size: MaterialFontSettings.body-large.font-size;
             font-weight: MaterialFontSettings.body-large.font-weight;
+            accessible-role: none;
         }
 
         icon := Image {

internal/compiler/widgets/qt/combobox.slint

@@ -15,7 +15,12 @@ export component ComboBox {
 
     accessible-role: combobox;
     accessible-enabled: root.enabled;
+    accessible-expandable: true;
+    accessible-expanded: base.popup-has-focus;
     accessible-value <=> root.current-value;
+    accessible-action-expand => {
+        base.show-popup();
+    }
     forward-focus: base;
 
     HorizontalLayout {

internal/core/accessibility.rs

@@ -17,6 +17,8 @@ pub enum AccessibleStringProperty {
     DelegateFocus,
     Description,
     Enabled,
+    Expandable,
+    Expanded,
     ItemCount,
     ItemIndex,
     ItemSelectable,
@@ -36,6 +38,7 @@ pub enum AccessibilityAction {
     Default,
     Decrement,
     Increment,
+    Expand,
     /// This is currently unused
     ReplaceSelectedText(SharedString),
     SetValue(SharedString),
@@ -49,8 +52,9 @@ bitflags! {
         const Default = 1;
         const Decrement = 1 << 1;
         const Increment = 1 << 2;
-        const ReplaceSelectedText = 1 << 3;
-        const SetValue = 1 << 4;
+        const Expand = 1 << 3;
+        const ReplaceSelectedText = 1 << 4;
+        const SetValue = 1 << 5;
     }
 }
 

internal/interpreter/dynamic_item_tree.rs

@@ -2113,6 +2113,7 @@ extern "C" fn accessibility_action(
         AccessibilityAction::Default => perform("accessible-action-default", &[]),
         AccessibilityAction::Decrement => perform("accessible-action-decrement", &[]),
         AccessibilityAction::Increment => perform("accessible-action-increment", &[]),
+        AccessibilityAction::Expand => perform("accessible-action-expand", &[]),
         AccessibilityAction::ReplaceSelectedText(_a) => {
             //perform("accessible-action-replace-selected-text", &[Value::String(a.clone())])
             i_slint_core::debug_log!("AccessibilityAction::ReplaceSelectedText not implemented in interpreter's accessibility_action");