Save pre-batched-redraw snapshot

Button.cpp

@@ -276,9 +276,11 @@ bool Button::handleEvent(const ExMessage& msg)
 {
 	if (!show)
 		return false;
+	resetEventVisualChanged();
 
 	bool oldHover = hover;// 注意：只在状态变化时记录，避免 WM_MOUSEMOVE 刷屏
 	bool oldClick = click;
+	const bool oldTipVisible = tipVisible;
 	
 	bool consume = false;//是否消耗事件
 	const bool isMouseMessage =
@@ -312,12 +314,6 @@ bool Button::handleEvent(const ExMessage& msg)
 			break;
 		}
 	}
-	if (hover != oldHover)
-	{
-		SX_LOG_TRACE("Button") << SX_T("悬停变化: ","hover change: ") << "id=" << id
-			<< " text= " << text
-			<< " " << (oldHover ? 1 : 0) << "->" << (hover ? 1 : 0);
-	}
 	// 处理鼠标点击事件
 	if (msg.message == WM_LBUTTONDOWN && hover && mode != StellarX::ButtonMode::DISABLED)
 	{
@@ -396,8 +392,6 @@ bool Button::handleEvent(const ExMessage& msg)
 			// 到点就显示
 			if (GetTickCount64() - tipHoverTick >= (ULONGLONG)tipDelayMs)
 			{
-				SX_LOG_TRACE("Button") << SX_T("提示信息显示: ","tooltip show:")<<" id = " << id <<SX_T("延时时间: ", " delayMs = ") << tipDelayMs;
-
 				tipVisible = true;
 
 				// 定位（跟随鼠标 or 相对按钮）
@@ -424,8 +418,16 @@ bool Button::handleEvent(const ExMessage& msg)
 	}
 
 	// 如果状态发生变化，标记需要重绘
-	if (hover != oldHover || click != oldClick)
+	const bool stateChanged = (hover != oldHover || click != oldClick);
+	if (stateChanged)
 		dirty = true;
+	const bool tipVisibilityChanged = (tipVisible != oldTipVisible);
+
+	// 鼠标命中按钮区域，或按钮自身状态因此发生变化时，吞掉该事件。
+	// 这样可以避免被遮挡/重叠的下层控件继续收到同一事件并把自己重绘到上层。
+	if (isMouseMessage && (hover || oldHover || click != oldClick))
+		consume = true;
+	markEventVisualChanged(stateChanged || tipVisibilityChanged);
 
 	// 如果需要重绘，立即执行
 	if (dirty)