[V3] MacOS + Linux Screen Management Fixes

v3/internal/runtime/desktop/@wailsio/runtime/src/screens.ts

@@ -59,6 +59,8 @@ const call = newRuntimeCaller(objectNames.Screens);
 const getAll = 0;
 const getPrimary = 1;
 const getCurrent = 2;
+const getByID = 3;
+const getByIndex = 4;
 
 /**
  * Gets all screens.
@@ -86,3 +88,23 @@ export function GetPrimary(): Promise<Screen> {
 export function GetCurrent(): Promise<Screen> {
     return call(getCurrent);
 }
+
+/**
+ * Gets a screen by its unique display ID.
+ *
+ * @param id - The unique identifier of the screen.
+ * @returns A promise that resolves to the matching Screen.
+ */
+export function GetByID(id: string): Promise<Screen> {
+    return call(getByID, { id });
+}
+
+/**
+ * Gets a screen by its index in the screen list.
+ *
+ * @param index - The zero-based index of the screen.
+ * @returns A promise that resolves to the matching Screen.
+ */
+export function GetByIndex(index: number): Promise<Screen> {
+    return call(getByIndex, { index });
+}

v3/internal/runtime/desktop/@wailsio/runtime/src/window.ts

@@ -68,6 +68,7 @@ const ZoomResetMethod                   = 48;
 const SnapAssistMethod                  = 49;
 const FilesDropped                      = 50;
 const PrintMethod                       = 51;
+const SetScreenMethod                   = 52;
 
 /**
  * Finds the nearest drop target element by walking up the DOM tree.
@@ -671,6 +672,15 @@ class Window {
         cleanupNativeDrag();
     }
 
+    /**
+     * Moves the window to the center of the specified screen's work area.
+     *
+     * @param screenID - The ID of the target screen.
+     */
+    SetScreen(screenID: string): Promise<void> {
+        return this[callerSym](SetScreenMethod, { screenID });
+    }
+
     /* Triggers Windows 11 Snap Assist feature (Windows only).
      * This is equivalent to pressing Win+Z and shows snap layout options.
      */

v3/pkg/application/application_darwin.go

@@ -300,6 +300,18 @@ func (m *macosApp) run() error {
 			)
 			C.setActivationPolicy(C.int(m.parent.options.Mac.ActivationPolicy))
 			C.activateIgnoringOtherApps()
+			if err := m.processAndCacheScreens(); err != nil {
+				m.parent.handleError(err)
+			}
+		},
+	)
+	// Refresh screen cache when display configuration changes
+	m.parent.Event.OnApplicationEvent(
+		events.Mac.ApplicationDidChangeScreenParameters,
+		func(*ApplicationEvent) {
+			if err := m.processAndCacheScreens(); err != nil {
+				m.parent.handleError(err)
+			}
 		},
 	)
 	m.setupCommonEvents()

v3/pkg/application/application_linux.go

@@ -174,7 +174,9 @@ func (a *linuxApp) run() error {
 	}
 
 	a.parent.Event.OnApplicationEvent(events.Linux.ApplicationStartup, func(evt *ApplicationEvent) {
-		// TODO: What should happen here?
+		if err := a.processAndCacheScreens(); err != nil {
+			a.parent.handleError(err)
+		}
 	})
 	a.setupCommonEvents()
 	a.monitorThemeChanges()

v3/pkg/application/application_linux_gtk4.go

@@ -90,6 +90,11 @@ func (a *linuxApp) name() string {
 }
 
 func (a *linuxApp) run() error {
+	a.parent.Event.OnApplicationEvent(events.Linux.ApplicationStartup, func(evt *ApplicationEvent) {
+		if err := a.processAndCacheScreens(); err != nil {
+			a.parent.handleError(err)
+		}
+	})
 	return appRun(a.application)
 }
 

v3/pkg/application/application_server.go

@@ -529,6 +529,7 @@ func (w *serverWebviewWindow) bounds() Rect                               { retu
 func (w *serverWebviewWindow) setBounds(bounds Rect)                      {}
 func (w *serverWebviewWindow) position() (int, int)                       { return 0, 0 }
 func (w *serverWebviewWindow) setPosition(x int, y int)                   {}
+func (w *serverWebviewWindow) centerOnScreen(_ *Screen)                   {}
 func (w *serverWebviewWindow) relativePosition() (int, int)               { return 0, 0 }
 func (w *serverWebviewWindow) setRelativePosition(x int, y int)           {}
 func (w *serverWebviewWindow) flash(enabled bool)                         {}

v3/pkg/application/linux_cgo.go

@@ -970,50 +970,71 @@ func menuRadioItemNew(group *GSList, label string) pointer {
 
 func getScreenByIndex(display *C.struct__GdkDisplay, index int) *Screen {
 	monitor := C.gdk_display_get_monitor(display, C.int(index))
-	// TODO: Do we need to update Screen to contain current info?
-	//	currentMonitor := C.gdk_display_get_monitor_at_window(display, window)
 
 	var geometry C.GdkRectangle
 	C.gdk_monitor_get_geometry(monitor, &geometry)
-	primary := false
-	if C.gdk_monitor_is_primary(monitor) == 1 {
-		primary = true
-	}
+
+	var workarea C.GdkRectangle
+	C.gdk_monitor_get_workarea(monitor, &workarea)
+
+	scaleFactor := float32(C.gdk_monitor_get_scale_factor(monitor))
+	primary := C.gdk_monitor_is_primary(monitor) == 1
 	name := C.gdk_monitor_get_model(monitor)
+
+	x := int(geometry.x)
+	y := int(geometry.y)
+	width := int(geometry.width)
+	height := int(geometry.height)
+
+	pX := int(float32(x) * scaleFactor)
+	pY := int(float32(y) * scaleFactor)
+	pWidth := int(float32(width) * scaleFactor)
+	pHeight := int(float32(height) * scaleFactor)
+
+	waX := int(workarea.x)
+	waY := int(workarea.y)
+	waWidth := int(workarea.width)
+	waHeight := int(workarea.height)
+
+	pwaX := int(float32(waX) * scaleFactor)
+	pwaY := int(float32(waY) * scaleFactor)
+	pwaWidth := int(float32(waWidth) * scaleFactor)
+	pwaHeight := int(float32(waHeight) * scaleFactor)
+
 	return &Screen{
 		ID:          fmt.Sprintf("%d", index),
 		Name:        C.GoString(name),
 		IsPrimary:   primary,
-		ScaleFactor: float32(C.gdk_monitor_get_scale_factor(monitor)),
-		X:           int(geometry.x),
-		Y:           int(geometry.y),
+		ScaleFactor: scaleFactor,
+		X:           x,
+		Y:           y,
 		Size: Size{
-			Height: int(geometry.height),
-			Width:  int(geometry.width),
+			Height: height,
+			Width:  width,
 		},
 		Bounds: Rect{
-			X:      int(geometry.x),
-			Y:      int(geometry.y),
-			Height: int(geometry.height),
-			Width:  int(geometry.width),
+			X:      x,
+			Y:      y,
+			Height: height,
+			Width:  width,
 		},
 		PhysicalBounds: Rect{
-			X:      int(geometry.x),
-			Y:      int(geometry.y),
-			Height: int(geometry.height),
-			Width:  int(geometry.width),
+			X:      pX,
+			Y:      pY,
+			Height: pHeight,
+			Width:  pWidth,
 		},
 		WorkArea: Rect{
-			X:      int(geometry.x),
-			Y:      int(geometry.y),
-			Height: int(geometry.height),
-			Width:  int(geometry.width),
+			X:      waX,
+			Y:      waY,
+			Height: waHeight,
+			Width:  waWidth,
 		},
 		PhysicalWorkArea: Rect{
-			X:      int(geometry.x),
-			Y:      int(geometry.y),
-			Height: int(geometry.height),
-			Width:  int(geometry.width),
+			X:      pwaX,
+			Y:      pwaY,
+			Height: pwaHeight,
+			Width:  pwaWidth,
 		},
 		Rotation: 0.0,
 	}
@@ -1489,29 +1510,67 @@ func (w *linuxWebviewWindow) setBackgroundColour(colour RGBA) {
 
 func getPrimaryScreen() (*Screen, error) {
 	display := C.gdk_display_get_default()
-	monitor := C.gdk_display_get_primary_monitor(display)
-	geometry := C.GdkRectangle{}
-	C.gdk_monitor_get_geometry(monitor, &geometry)
-	scaleFactor := int(C.gdk_monitor_get_scale_factor(monitor))
-	// get the name for the screen
-	name := C.gdk_monitor_get_model(monitor)
+	primaryMonitor := C.gdk_display_get_primary_monitor(display)
+
+	// Find the index of the primary monitor so the ID matches getScreenByIndex's contract.
+	primaryIndex := 0
+	count := int(C.gdk_display_get_n_monitors(display))
+	for i := 0; i < count; i++ {
+		if C.gdk_display_get_monitor(display, C.int(i)) == primaryMonitor {
+			primaryIndex = i
+			break
+		}
+	}
+
+	var geometry C.GdkRectangle
+	C.gdk_monitor_get_geometry(primaryMonitor, &geometry)
+
+	var workarea C.GdkRectangle
+	C.gdk_monitor_get_workarea(primaryMonitor, &workarea)
+
+	scaleFactor := float32(C.gdk_monitor_get_scale_factor(primaryMonitor))
+	name := C.gdk_monitor_get_model(primaryMonitor)
+
+	x := int(geometry.x)
+	y := int(geometry.y)
+	width := int(geometry.width)
+	height := int(geometry.height)
+
 	return &Screen{
-		ID:        "0",
-		Name:      C.GoString(name),
-		IsPrimary: true,
-		X:         int(geometry.x),
-		Y:         int(geometry.y),
+		ID:          fmt.Sprintf("%d", primaryIndex),
+		Name:        C.GoString(name),
+		IsPrimary:   true,
+		ScaleFactor: scaleFactor,
+		X:           x,
+		Y:           y,
 		Size: Size{
-			Height: int(geometry.height),
-			Width:  int(geometry.width),
+			Height: height,
+			Width:  width,
 		},
 		Bounds: Rect{
-			X:      int(geometry.x),
-			Y:      int(geometry.y),
-			Height: int(geometry.height),
-			Width:  int(geometry.width),
+			X:      x,
+			Y:      y,
+			Height: height,
+			Width:  width,
+		},
+		PhysicalBounds: Rect{
+			X:      int(float32(x) * scaleFactor),
+			Y:      int(float32(y) * scaleFactor),
+			Height: int(float32(height) * scaleFactor),
+			Width:  int(float32(width) * scaleFactor),
+		},
+		WorkArea: Rect{
+			X:      int(workarea.x),
+			Y:      int(workarea.y),
+			Height: int(workarea.height),
+			Width:  int(workarea.width),
+		},
+		PhysicalWorkArea: Rect{
+			X:      int(float32(workarea.x) * scaleFactor),
+			Y:      int(float32(workarea.y) * scaleFactor),
+			Height: int(float32(workarea.height) * scaleFactor),
+			Width:  int(float32(workarea.width) * scaleFactor),
 		},
-		ScaleFactor: float32(scaleFactor),
 	}, nil
 }