[Backend] Set window icon.

src/DirectMpvPlayerBackend.cpp

@@ -159,6 +159,7 @@ DirectMpvPlayerBackend::sync()
 {
 
   if (!renderer) {
+    window()->setIcon(QIcon(":/icon.png"));
     renderer = new MpvRenderer(mpv, mpv_gl);
     connect(window(),
             &QQuickWindow::beforeRendering,

src/MpvPlayerBackend.cpp

@@ -601,6 +601,7 @@ MpvPlayerBackend::handle_mpv_event(mpv_event* event)
 QQuickFramebufferObject::Renderer*
 MpvPlayerBackend::createRenderer() const
 {
+  window()->setIcon(QIcon(":/icon.png"));
   window()->setPersistentOpenGLContext(true);
   window()->setPersistentSceneGraph(true);
   return new MpvRenderer(const_cast<MpvPlayerBackend*>(this));

src/main.cpp

@@ -102,7 +102,7 @@ main(int argc, char* argv[])
   app.setOrganizationName("KittehPlayer");
   app.setOrganizationDomain("namedkitten.pw");
   app.setApplicationName("KittehPlayer");
-
+  
   QSettings settings;
   QString backendSetting = settings.value("Backend/backend", "").toString();
   if (backendSetting.length() == 0) {

src/qml/qml.qrc

@@ -1,5 +1,6 @@
 <RCC>
     <qresource prefix="/">
+        <file>icon.png</file>
         <file>main.qml</file>
         <file>CustomMenu.qml</file>
         <file>ControlsBar.qml</file>