A: on message paint

cef/browser-window-lcl.go

@@ -58,6 +58,7 @@ type LCLBrowserWindow struct {
 	hWnd                      types.HWND           //
 	cwcap                     *customWindowCaption //自定义窗口标题栏
 	drag                      *drag                //自定义拖拽
+	wmPaintMessage            wmPaint              //
 	wmMoveMessage             wmMove               //
 	wmSizeMessage             wmSize               //
 	wmWindowPosChangedMessage wmWindowPosChanged   //
@@ -1043,13 +1044,23 @@ const (
 	mtMove messageType = iota + 1
 	mtSize
 	mtWindowPosChanged
+	mtPaint
 )
 
+type wmPaint func(message *t.TPaint)
 type wmMove func(message *t.TMove)
 type wmSize func(message *t.TSize)
 type wmWindowPosChanged func(message *t.TWindowPosChanged)
 
 func (m *LCLBrowserWindow) onFormMessages() {
+	m.setOnWMPaint(func(message *t.TPaint) {
+		if m.Chromium() != nil {
+			m.Chromium().NotifyMoveOrResizeStarted()
+		}
+		if m.wmPaintMessage != nil {
+			m.wmPaintMessage(message)
+		}
+	})
 	m.setOnWMMove(func(message *t.TMove) {
 		if m.Chromium() != nil {
 			m.Chromium().NotifyMoveOrResizeStarted()
@@ -1076,6 +1087,10 @@ func (m *LCLBrowserWindow) onFormMessages() {
 	})
 }
 
+func (m *LCLBrowserWindow) setOnWMPaint(fn wmPaint) {
+	imports.Proc(def.Form_SetOnMessagesEvent).Call(m.Instance(), uintptr(mtPaint), api.MakeEventDataPtr(fn))
+}
+
 func (m *LCLBrowserWindow) setOnWMMove(fn wmMove) {
 	imports.Proc(def.Form_SetOnMessagesEvent).Call(m.Instance(), uintptr(mtMove), api.MakeEventDataPtr(fn))
 }
@@ -1088,6 +1103,10 @@ func (m *LCLBrowserWindow) setOnWMWindowPosChanged(fn wmWindowPosChanged) {
 	imports.Proc(def.Form_SetOnMessagesEvent).Call(m.Instance(), uintptr(mtWindowPosChanged), api.MakeEventDataPtr(fn))
 }
 
+func (m *LCLBrowserWindow) SetOnWMPaint(fn wmPaint) {
+	m.wmPaintMessage = fn
+}
+
 func (m *LCLBrowserWindow) SetOnWMMove(fn wmMove) {
 	m.wmMoveMessage = fn
 }

types/message.go

@@ -10,6 +10,13 @@
 
 package types
 
+type TRect struct {
+	Left   int32
+	Top    int32
+	Right  int32
+	Bottom int32
+}
+
 type WindowPos struct {
 	Hwnd            THandle
 	HwndInsertAfter THandle
@@ -19,3 +26,12 @@ type WindowPos struct {
 	Cy              Integer
 	Flags           Cardinal
 }
+
+type Paint struct {
+	Hdc         HDC
+	FErase      BOOL
+	RcPaint     TRect
+	FRestore    BOOL
+	FIncUpdate  BOOL
+	RgbReserved [32]uint8
+}

types/message_386.go

@@ -12,6 +12,13 @@
 
 package types
 
+type TPaint struct {
+	Msg         Cardinal
+	DC          HDC
+	PaintStruct Paint
+	Result      LResult
+}
+
 type TMove struct {
 	Msg      Cardinal
 	MoveType PtrInt // 0 = update, 1 = force RequestAlign, 128 = Source is Interface (Widget has moved)

types/message_amd64arm64.go

@@ -16,6 +16,14 @@ type TDWordFiller struct {
 	Filler [4]uint8
 }
 
+type TPaint struct {
+	Msg         Cardinal
+	_UnusedMsg  Cardinal
+	DC          HDC
+	PaintStruct Paint
+	Result      LResult
+}
+
 type TMove struct {
 	Msg        Cardinal
 	_UnusedMsg Cardinal