rewrite

gui/xfyne/window.go

@@ -0,0 +1,23 @@
+package xfyne
+
+import (
+	"fyne.io/fyne/v2"
+	"github.com/go-gl/glfw/v3.3/glfw"
+	"reflect"
+	"unsafe"
+)
+
+// getGlfwWindow returns the glfw.Window pointer from a fyne.Window.
+// very unsafe and ugly hacks. but it works.
+func getGlfwWindow(window fyne.Window) *glfw.Window {
+	rv := reflect.ValueOf(window)
+	if rv.Type().String() != "*glfw.window" {
+		return nil
+	}
+	rv = rv.Elem()
+	var glfwWindowPtr uintptr = rv.FieldByName("viewport").Pointer()
+	for glfwWindowPtr == 0 {
+		glfwWindowPtr = rv.FieldByName("viewport").Pointer()
+	}
+	return (*glfw.Window)(unsafe.Pointer(glfwWindowPtr))
+}

gui/xfyne/window_darwin.go

@@ -0,0 +1,12 @@
+//go:build darwin
+// +build darwin
+
+package xfyne
+
+func GetWindowHandle(window fyne.Window) uintptr {
+	glfwWindow := getGlfwWindow(window)
+	if glfwWindow == nil {
+		return 0
+	}
+	return uintptr(glfwWindow.GetCocoaWindow())
+}

gui/xfyne/window_linux.go

@@ -0,0 +1,16 @@
+//go:build linux
+// +build linux
+
+package xfyne
+
+import (
+	"fyne.io/fyne/v2"
+)
+
+func GetWindowHandle(window fyne.Window) uintptr {
+	glfwWindow := getGlfwWindow(window)
+	if glfwWindow == nil {
+		return 0
+	}
+	return uintptr(glfwWindow.GetX11Window())
+}

gui/xfyne/window_other.go

@@ -0,0 +1,10 @@
+//go:build !darwin && !windows && !linux
+// +build !darwin,!windows,!linux
+
+package xfyne
+
+import "fyne.io/fyne/v2"
+
+func GetWindowHandle(window fyne.Window) uintptr {
+	return 0
+}

gui/xfyne/window_windows.go

@@ -0,0 +1,14 @@
+//go:build windows
+// +build windows
+
+package xfyne
+
+import "fyne.io/fyne/v2"
+
+func GetWindowHandle(window fyne.Window) uintptr {
+	glfwWindow := getGlfwWindow(window)
+	if glfwWindow == nil {
+		return 0
+	}
+	return uintptr(glfwWindow.GetWin32Window())
+}