Add view modifier to observe and set focus

Documentation/Reference/extensions/View.md

@@ -159,6 +159,12 @@ Set the view's visibility.
 - Parameter visible: Whether the view is visible.
 - Returns: A view.
 
+### `focused(_:)`
+
+Bind to the view's focus.
+- Parameter focus: Whether the view is focused.
+- Returns: A view.
+
 ### `stopModifiers()`
 
 Remove all of the content modifiers for the wrapped views.

Sources/Adwaita/View/Modifiers/InspectorWrapper.swift

@@ -138,4 +138,21 @@ extension View {
         inspect { gtk_widget_set_visible($0.pointer?.cast(), visible.cBool) }
     }
 
+    /// Bind to the view's focus.
+    /// - Parameter focus: Whether the view is focused.
+    /// - Returns: A view.
+    public func focused(_ focused: Binding<Bool>) -> View {
+        inspect { storage in
+            storage.notify(name: "has-focus", id: "focused") {
+                let newValue = gtk_widget_has_focus(storage.pointer?.cast()) != 0
+                if focused.wrappedValue != newValue {
+                    focused.wrappedValue = newValue
+                }
+            }
+            if focused.wrappedValue != (gtk_widget_has_focus(storage.pointer?.cast()) != 0) {
+                gtk_widget_grab_focus(storage.pointer?.cast())
+            }
+        }
+    }
+
 }

user-manual/Information/Widgets.md

@@ -47,6 +47,7 @@ There are many more widgets available using auto-generation. Learn [how to use t
 | `overlay(_:)`                     | Overlay a view with another view.                                                                                              |
 | `insensitive(_:)`                 | Make a view unable to detect actions. This is especially useful for overlays.                                                  |
 | `onClick(handler:)`               | Run a function when the user clicks on the widget.                                                                             |
+| `focused(_:)`                     | Set and observe whether a view is focused.                                                                                     |
 | `verticalCenter()`                | Wrap a view in a `VStack` and center vertically.                                                                               |
 | `horizontalCenter()`              | Wrap a view in an `HStack` and center horizontally.                                                                            |