Implement full-screen property for slint Window item

Make it possible to programatically to switch to full-screen mode
via a new property in the Windows item.
The SLINT_FULLSCREEN environment variable will default set this
property to true. However settings this property in the slint code
will override the SLINT_FULLSCREEN.

Fixes slint-ui#6665

examples/gallery/gallery.pot

@@ -116,6 +116,11 @@ msgctxt "Page"
 msgid "Dark Mode"
 msgstr ""
 
+#: ui/pages/page.slint:41
+msgctxt "Page"
+msgid "Full Screen"
+msgstr ""
+
 #: ui/pages/about_page.slint:9
 msgctxt "AboutPage"
 msgid "About"

examples/gallery/gallery.slint

@@ -13,6 +13,7 @@ export component App inherits Window {
     preferred-height: 500px;
     title: @tr("Slint Widgets Gallery");
     icon: @image-url("../../logo/slint-logo-small-light.png");
+    full-screen <=> GallerySettings.full-screen;
 
     HorizontalLayout {
         side-bar := SideBar {

examples/gallery/lang/de/LC_MESSAGES/gallery.po

@@ -124,6 +124,11 @@ msgctxt "Page"
 msgid "Dark Mode"
 msgstr ""
 
+#: ui/pages/page.slint:41
+msgctxt "Page"
+msgid "Full Screen"
+msgstr ""
+
 #: ui/pages/about_page.slint:9
 msgctxt "AboutPage"
 msgid "About"

examples/gallery/lang/fr/LC_MESSAGES/gallery.po

@@ -125,6 +125,11 @@ msgctxt "Page"
 msgid "Dark Mode"
 msgstr ""
 
+#: ui/pages/page.slint:41
+msgctxt "Page"
+msgid "Full Screen"
+msgstr ""
+
 #: ui/pages/about_page.slint:9
 #, fuzzy
 msgctxt "AboutPage"

examples/gallery/ui/gallery_settings.slint

@@ -3,4 +3,5 @@
 
 export global GallerySettings  {
     in property <bool> widgets-enabled: true;
+    in-out property <bool> full-screen: false;
 }

examples/gallery/ui/pages/page.slint

@@ -30,10 +30,17 @@ export component Page inherits VerticalBox {
             horizontal-stretch: 0;
             text: @tr("Dark Mode");
             checked: Palette.color-scheme == ColorScheme.dark;
-            toggled => {                
+            toggled => {
                 Palette.color-scheme = self.checked ? ColorScheme.dark : ColorScheme.light;
             }
         }
+
+
+        Switch {
+            horizontal-stretch: 0;
+            text: @tr("Full Screen");
+            checked <=> GallerySettings.full-screen;
+        }
     }
 
     @children

internal/backends/winit/winitwindowadapter.rs

@@ -818,6 +818,7 @@ impl WindowAdapter for WinitWindowAdapter {
             } else {
                 winit_window_or_none.set_fullscreen(None);
             }
+            self.fullscreen.set(m);
         }
 
         let m = properties.is_maximized();

internal/compiler/builtins.slint

@@ -192,6 +192,7 @@ component WindowItem {
     in property <bool> no-frame;
     in property <length> resize-border-width;
     in property <bool> always-on-top;
+    in-out property <bool> full-screen;
     in property <string> default-font-family;
     in-out property <length> default-font-size; // <=> StyleMetrics.default-font-size  set in apply_default_properties_from_style
     in property <int> default-font-weight;
@@ -418,7 +419,7 @@ export component PopupWindow {
     in property <length> anchor_y;
     in property <length> anchor_height;
     in property <length> anchor_width;*/
-    in property <bool> close-on-click;      
+    in property <bool> close-on-click;
     in property <PopupClosePolicy> close-policy; // constexpr hardcoded in typeregister.rs
     //show() is hardcoded in typeregister.rs
 }

internal/core/items.rs

@@ -953,6 +953,7 @@ pub struct WindowItem {
     pub no_frame: Property<bool>,
     pub resize_border_width: Property<LogicalLength>,
     pub always_on_top: Property<bool>,
+    pub full_screen: Property<bool>,
     pub icon: Property<crate::graphics::Image>,
     pub default_font_family: Property<SharedString>,
     pub default_font_size: Property<LogicalLength>,
@@ -961,7 +962,10 @@ pub struct WindowItem {
 }
 
 impl Item for WindowItem {
-    fn init(self: Pin<&Self>, _self_rc: &ItemRc) {}
+    fn init(self: Pin<&Self>, _self_rc: &ItemRc) {
+        #[cfg(feature = "std")]
+        self.full_screen.set(std::env::var("SLINT_FULLSCREEN").is_ok());
+    }
 
     fn layout_info(
         self: Pin<&Self>,

internal/core/window.rs

@@ -331,7 +331,7 @@ impl<'a> WindowProperties<'a> {
 
     /// Returns true if the window should be shown fullscreen; false otherwise.
     pub fn is_fullscreen(&self) -> bool {
-        self.0.fullscreen.get()
+        self.0.is_fullscreen()
     }
 
     /// true if the window is in a maximized state, otherwise false
@@ -427,7 +427,6 @@ pub struct WindowInner {
     cursor_blinker: RefCell<pin_weak::rc::PinWeak<crate::input::TextCursorBlinker>>,
 
     pinned_fields: Pin<Box<WindowPinnedFields>>,
-    fullscreen: Cell<bool>,
     maximized: Cell<bool>,
     minimized: Cell<bool>,
 
@@ -483,10 +482,6 @@ impl WindowInner {
                     "i_slint_core::Window::text_input_focused",
                 ),
             }),
-            #[cfg(feature = "std")]
-            fullscreen: Cell::new(std::env::var("SLINT_FULLSCREEN").is_ok()),
-            #[cfg(not(feature = "std"))]
-            fullscreen: Cell::new(false),
             maximized: Cell::new(false),
             minimized: Cell::new(false),
             focus_item: Default::default(),
@@ -1146,13 +1141,19 @@ impl WindowInner {
 
     /// Returns if the window is currently maximized
     pub fn is_fullscreen(&self) -> bool {
-        self.fullscreen.get()
+        if let Some(window_item) = self.window_item() {
+            window_item.as_pin_ref().full_screen()
+        } else {
+            false
+        }
     }
 
     /// Set or unset the window to display fullscreen.
     pub fn set_fullscreen(&self, enabled: bool) {
-        self.fullscreen.set(enabled);
-        self.update_window_properties()
+        if let Some(window_item) = self.window_item() {
+            window_item.as_pin_ref().full_screen.set(enabled);
+            self.update_window_properties()
+        }
     }
 
     /// Returns if the window is currently maximized