sync: from linuxdeepin/qt5platform-plugins

Synchronize source files from linuxdeepin/qt5platform-plugins.

Source-pull-request: linuxdeepin/qt5platform-plugins#252

xcb/dnotitlebarwindowhelper.cpp

@@ -29,6 +29,8 @@ DPP_BEGIN_NAMESPACE
 
 QHash<const QWindow*, DNoTitlebarWindowHelper*> DNoTitlebarWindowHelper::mapped;
 
+static QHash<DNoTitlebarWindowHelper*, QPointF> g_pressPoint;
+
 DNoTitlebarWindowHelper::DNoTitlebarWindowHelper(QWindow *window, quint32 windowID)
     : QObject(window)
     , m_window(window)
@@ -75,6 +77,8 @@ DNoTitlebarWindowHelper::DNoTitlebarWindowHelper(QWindow *window, quint32 window
 
 DNoTitlebarWindowHelper::~DNoTitlebarWindowHelper()
 {
+    g_pressPoint.remove(this);
+
     if (VtableHook::hasVtable(m_window)) {
         VtableHook::resetVtable(m_window);
     }
@@ -505,6 +509,7 @@ bool DNoTitlebarWindowHelper::windowEvent(QEvent *event)
     // keeping the moving state, we can just reset ti back to normal.
     if (event->type() == QEvent::MouseButtonPress) {
         self->m_windowMoving = false;
+        g_pressPoint[this] = dynamic_cast<QMouseEvent*>(event)->globalPos();
     }
 
     if (is_mouse_move && !event->isAccepted()) {
@@ -514,6 +519,11 @@ bool DNoTitlebarWindowHelper::windowEvent(QEvent *event)
             return ret;
         }
 
+        QPointF delta = me->globalPos() - g_pressPoint[this];
+        if (delta.manhattanLength() < QGuiApplication::styleHints()->startDragDistance()) {
+            return ret;
+        }
+
         if (!self->m_windowMoving && self->isEnableSystemMove(winId)) {
             self->m_windowMoving = true;