add Windows taskbar control buttons (TODO: icons)

backend/windows/taskbar_buttons.go

@@ -0,0 +1,29 @@
+//go:build windows
+
+package windows
+
+/*
+#cgo LDFLAGS: -lole32
+#include "taskbar_buttons.h"
+
+extern void goButtonClicked(int);
+*/
+import "C"
+import (
+	"unsafe"
+)
+
+var gTaskbarButtonCallback func(TaskbarButton)
+
+func InitializeTaskbarButtons(hwnd uintptr, callback func(TaskbarButton)) error {
+	gTaskbarButtonCallback = callback
+	C.initialize_taskbar_buttons(unsafe.Pointer(hwnd), C.ThumbnailCallback(C.goButtonClicked))
+	return nil
+}
+
+//export goButtonClicked
+func goButtonClicked(buttonID C.int) {
+	if gTaskbarButtonCallback != nil {
+		gTaskbarButtonCallback(TaskbarButton(buttonID))
+	}
+}