Some improvements to Window visibility

- From C++, always call the Window::show() and hide() function instead
   of going through set_visible directly as it doesn't set the size of
   the WindowItem
 - show() should also call resize on the renderer
 - remove the is_visible in the WindowAdapterInternal as it is no longer
   needed

api/node/native/lib.rs

@@ -492,7 +492,7 @@ declare_types! {
             let this = cx.this();
             let window = cx.borrow(&this, |x| x.0.as_ref().cloned());
             let window_adapter = window.ok_or(()).or_else(|()| cx.throw_error("Invalid type"))?;
-            window_adapter.set_visible(true).unwrap();
+            window_adapter.window().show().unwrap();
             Ok(JsUndefined::new().as_value(&mut cx))
         }
 
@@ -500,7 +500,7 @@ declare_types! {
             let this = cx.this();
             let window = cx.borrow(&this, |x| x.0.as_ref().cloned());
             let window_adapter = window.ok_or(()).or_else(|()| cx.throw_error("Invalid type"))?;
-            window_adapter.set_visible(false).unwrap();
+            window_adapter.window().hide().unwrap();
             Ok(JsUndefined::new().as_value(&mut cx))
         }
 

internal/backends/qt/qt_window.rs

@@ -1802,13 +1802,6 @@ impl WindowAdapterInternal for QtWindow {
         });
         ds.as_ref().get()
     }
-
-    fn is_visible(&self) -> bool {
-        let widget_ptr = self.widget_ptr();
-        cpp! {unsafe [widget_ptr as "QWidget*"] -> bool as "bool" {
-            return widget_ptr->isVisible();
-        }}
-    }
 }
 
 impl i_slint_core::renderer::RendererSealed for QtWindow {

internal/backends/testing/lib.rs

@@ -28,8 +28,7 @@ impl i_slint_core::platform::Platform for TestingBackend {
     ) -> Result<Rc<dyn WindowAdapter>, i_slint_core::platform::PlatformError> {
         Ok(Rc::new_cyclic(|self_weak| TestingWindow {
             window: i_slint_core::api::Window::new(self_weak.clone() as _),
-            shown: false.into(),
-            size: Default::default(),
+            size: PhysicalSize::new(600, 800).into(),
             ime_requests: Default::default(),
         }))
     }
@@ -78,7 +77,6 @@ impl i_slint_core::platform::Platform for TestingBackend {
 
 pub struct TestingWindow {
     window: i_slint_core::api::Window,
-    shown: core::cell::Cell<bool>,
     size: core::cell::Cell<PhysicalSize>,
     pub ime_requests: RefCell<Vec<InputMethodRequest>>,
 }
@@ -88,10 +86,6 @@ impl WindowAdapterInternal for TestingWindow {
         self
     }
 
-    fn is_visible(&self) -> bool {
-        self.shown.get()
-    }
-
     fn input_method_request(&self, request: i_slint_core::window::InputMethodRequest) {
         self.ime_requests.borrow_mut().push(request)
     }
@@ -102,11 +96,6 @@ impl WindowAdapter for TestingWindow {
         &self.window
     }
 
-    fn set_visible(&self, visible: bool) -> Result<(), PlatformError> {
-        self.shown.set(visible);
-        Ok(())
-    }
-
     fn size(&self) -> PhysicalSize {
         self.size.get()
     }

internal/backends/winit/winitwindowadapter.rs

@@ -662,10 +662,6 @@ impl WindowAdapterInternal for WinitWindowAdapter {
             .get()
     }
 
-    fn is_visible(&self) -> bool {
-        self.winit_window().is_visible().unwrap_or(true)
-    }
-
     #[cfg(enable_accesskit)]
     fn handle_focus_change(&self, _old: Option<ItemRc>, _new: Option<ItemRc>) {
         self.accesskit_adapter.handle_focus_item_change();

internal/core/api.rs

@@ -524,11 +524,7 @@ impl Window {
     /// Returns the visibility state of the window. This function can return false even if you previously called show()
     /// on it, for example if the user minimized the window.
     pub fn is_visible(&self) -> bool {
-        self.0
-            .window_adapter()
-            .internal(crate::InternalToken)
-            .map(|w| w.is_visible())
-            .unwrap_or(false)
+        self.0.is_visible()
     }
 }
 

internal/core/window.rs

@@ -200,12 +200,6 @@ pub trait WindowAdapterInternal {
     fn dark_color_scheme(&self) -> bool {
         false
     }
-
-    /// Get the visibility of the window
-    // todo: replace with WindowEvent::VisibilityChanged and require backend to dispatch event
-    fn is_visible(&self) -> bool {
-        false
-    }
 }
 
 /// This is the parameter from [`WindowAdapterInternal::input_method_request()`] which lets the editable text input field
@@ -349,7 +343,8 @@ struct WindowPinnedFields {
 pub struct WindowInner {
     window_adapter_weak: Weak<dyn WindowAdapter>,
     component: RefCell<ComponentWeak>,
-    strong_component_ref: RefCell<Option<ComponentRc>>, // When the window is visible, keep a strong reference
+    /// When the window is visible, keep a strong reference
+    strong_component_ref: RefCell<Option<ComponentRc>>,
     mouse_input_state: Cell<MouseInputState>,
     pub(crate) modifiers: Cell<InternalKeyboardModifierState>,
 
@@ -782,10 +777,9 @@ impl WindowInner {
         self.window_adapter().set_visible(true)?;
         // Make sure that the window's inner size is in sync with the root window item's
         // width/height.
-        self.set_window_item_geometry(
-            self.window_adapter().size().to_logical(self.scale_factor()).to_euclid(),
-        );
-
+        let size = self.window_adapter().size();
+        self.set_window_item_geometry(size.to_logical(self.scale_factor()).to_euclid());
+        self.window_adapter().renderer().resize(size).unwrap();
         Ok(())
     }
 
@@ -919,6 +913,11 @@ impl WindowInner {
         self.pinned_fields.text_input_focused.set(value)
     }
 
+    /// Returns true if the window is visible
+    pub fn is_visible(&self) -> bool {
+        self.strong_component_ref.borrow().is_some()
+    }
+
     /// Returns the window item that is the first item in the component.
     pub fn window_item(&self) -> Option<VRcMapped<ComponentVTable, crate::items::WindowItem>> {
         self.try_component().and_then(|component_rc| {
@@ -1025,14 +1024,14 @@ pub mod ffi {
     pub unsafe extern "C" fn slint_windowrc_show(handle: *const WindowAdapterRcOpaque) {
         let window_adapter = &*(handle as *const Rc<dyn WindowAdapter>);
 
-        window_adapter.set_visible(true).unwrap();
+        window_adapter.window().show().unwrap();
     }
 
     /// Spins an event loop and renders the items of the provided component in this window.
     #[no_mangle]
     pub unsafe extern "C" fn slint_windowrc_hide(handle: *const WindowAdapterRcOpaque) {
         let window_adapter = &*(handle as *const Rc<dyn WindowAdapter>);
-        window_adapter.set_visible(false).unwrap();
+        window_adapter.window().hide().unwrap();
     }
 
     /// Returns the visibility state of the window. This function can return false even if you previously called show()
@@ -1042,7 +1041,7 @@ pub mod ffi {
         handle: *const WindowAdapterRcOpaque,
     ) -> bool {
         let window = &*(handle as *const Rc<dyn WindowAdapter>);
-        window.internal(crate::InternalToken).map_or(false, |w| w.is_visible())
+        window.window().is_visible()
     }
 
     /// Returns the window scale factor.

internal/interpreter/ffi.rs

@@ -561,7 +561,10 @@ pub extern "C" fn slint_interpreter_component_instance_show(
 ) {
     generativity::make_guard!(guard);
     let comp = inst.unerase(guard);
-    comp.borrow_instance().window_adapter().set_visible(is_visible).unwrap();
+    match is_visible {
+        true => comp.borrow_instance().window_adapter().window().show().unwrap(),
+        false => comp.borrow_instance().window_adapter().window().hide().unwrap(),
+    }
 }
 
 /// Return a window for the component

tests/cases/examples/hello.slint

@@ -169,6 +169,7 @@ Hello := Rectangle {
 
     property <string> arrow_down_commands: "M21.8,311.1l84.2-82.1c15.7-15.2,41-15.2,56.7,0l341.1,304.1l333.7-297.5c15.5-15.2,41-15.2,56.6,0l84.3,82.1c15.6,15.2,15.6,40,0,55.2L531.7,771c-15.7,15.3-41,15.3-56.7,0l-6.9-6.7L21.8,366.3C6.1,351,6.1,326.3,21.8,311.1z";
     property <string> funky_shape_commands: "M 100 300 Q 150 50 250 150 C 250 300 300 300 300 450 A 50 50 0 1 0 450 450 L 550 300";
+    property <length> width2 <=> root.width;
 }
 
 /*
@@ -177,8 +178,12 @@ Hello := Rectangle {
 auto handle = Hello::create();
 const Hello &instance = *handle;
 assert(!instance.window().is_visible());
+assert_eq(instance.get_width2(), 0); //Before it is shown, no size is set
 instance.window().show();
 assert(instance.window().is_visible());
+assert(instance.get_width2() > 0); // default size from the backend
+instance.window().set_size(slint::LogicalSize({123., 456.}));
+assert_eq(instance.get_width2(), 123.);
 instance.window().hide();
 assert(!instance.window().is_visible());
 ```
@@ -187,8 +192,12 @@ assert(!instance.window().is_visible());
 ```rust
 let instance = Hello::new().unwrap();
 assert!(!instance.window().is_visible());
+assert_eq!(instance.get_width2(), 0.);
 instance.window().show().unwrap();
 assert!(instance.window().is_visible());
+assert!(instance.get_width2() > 0.); // default size from the backend
+instance.window().set_size(slint::LogicalSize::new(123., 456.));
+assert_eq!(instance.get_width2(), 123.);
 instance.window().hide().unwrap();
 assert!(!instance.window().is_visible());
 ```