Introduce QPA API for size grip handling.

- Introduce API to do size grip handling (mouse press
  and move).
- Move Windows code to Windows plugin.
- Move X11 code to XCB plugin and activate it.

Change-Id: I2f61d6ddc1fa07447e668554d41ecc820efca23f
Reviewed-by: Samuel Rødal <samuel.rodal@nokia.com>

5 files changed, 77 insertions, 1 deletions

diff --git a/src/plugins/platforms/windows/qwindowsmousehandler.cpp b/src/plugins/platforms/windows/qwindowsmousehandler.cpp
index 2a98b7f404..48d43857e9 100644
--- a/src/plugins/platforms/windows/qwindowsmousehandler.cpp
+++ b/src/plugins/platforms/windows/qwindowsmousehandler.cpp
@@ -151,6 +151,16 @@ bool QWindowsMouseHandler::translateMouseEvent(QWindow *window, HWND hwnd,
         return true;
     }
     compressMouseMove(&msg);
+    // Eat mouse move after size grip drag.
+    if (msg.message == WM_MOUSEMOVE) {
+        QWindowsWindow *platformWindow = static_cast<QWindowsWindow *>(window->handle());
+        if (platformWindow->testFlag(QWindowsWindow::SizeGripOperation)) {
+            MSG mouseMsg;
+            while (PeekMessage(&mouseMsg, platformWindow->handle(), WM_MOUSEMOVE, WM_MOUSEMOVE, PM_REMOVE)) ;
+            platformWindow->clearFlag(QWindowsWindow::SizeGripOperation);
+            return true;
+        }
+    }
     const QPoint client(GET_X_LPARAM(msg.lParam), GET_Y_LPARAM(msg.lParam));
     // Enter new window: track to generate leave event.
     if (m_windowUnderMouse != window) {
diff --git a/src/plugins/platforms/windows/qwindowswindow.cpp b/src/plugins/platforms/windows/qwindowswindow.cpp
index b96d61561c..e49b215422 100644
--- a/src/plugins/platforms/windows/qwindowswindow.cpp
+++ b/src/plugins/platforms/windows/qwindowswindow.cpp
@@ -1402,6 +1402,32 @@ void QWindowsWindow::setMouseGrabEnabled_sys(bool grab)
     }
 }
 
+static inline DWORD cornerToWinOrientation(Qt::Corner corner)
+{
+    switch (corner) {
+    case Qt::TopLeftCorner:
+        return 0xf004; // SZ_SIZETOPLEFT;
+    case Qt::TopRightCorner:
+        return 0xf005; // SZ_SIZETOPRIGHT
+    case Qt::BottomLeftCorner:
+        return 0xf007; // SZ_SIZEBOTTOMLEFT
+    case Qt::BottomRightCorner:
+        return 0xf008; // SZ_SIZEBOTTOMRIGHT
+    }
+    return 0;
+}
+
+bool QWindowsWindow::startSystemResize(const QPoint &, Qt::Corner corner)
+{
+    if (!GetSystemMenu(m_data.hwnd, FALSE))
+        return false;
+
+    ReleaseCapture();
+    PostMessage(m_data.hwnd, WM_SYSCOMMAND, cornerToWinOrientation(corner), 0);
+    setFlag(SizeGripOperation);
+    return true;
+}
+
 #ifndef Q_OS_WINCE // maybe available on some SDKs revisit WM_GETMINMAXINFO
 void QWindowsWindow::getSizeHints(MINMAXINFO *mmi) const
 {
diff --git a/src/plugins/platforms/windows/qwindowswindow.h b/src/plugins/platforms/windows/qwindowswindow.h
index ee45be18cd..2fd401029e 100644
--- a/src/plugins/platforms/windows/qwindowswindow.h
+++ b/src/plugins/platforms/windows/qwindowswindow.h
@@ -122,7 +122,8 @@ public:
         OpenGLSurface = 0x10,
         OpenGLDoubleBuffered = 0x20,
         OpenGlPixelFormatInitialized = 0x40,
-        BlockedByModal = 0x80
+        BlockedByModal = 0x80,
+        SizeGripOperation = 0x100
     };
 
     struct WindowData
@@ -173,6 +174,8 @@ public:
     virtual bool setKeyboardGrabEnabled(bool grab);
     virtual bool setMouseGrabEnabled(bool grab);
 
+    virtual bool startSystemResize(const QPoint &pos, Qt::Corner corner);
+
     Qt::WindowState windowState_sys() const;
     Qt::WindowStates windowStates_sys() const;
 
diff --git a/src/plugins/platforms/xcb/qxcbwindow.cpp b/src/plugins/platforms/xcb/qxcbwindow.cpp
index 390628d291..a1ac5c5eb1 100644
--- a/src/plugins/platforms/xcb/qxcbwindow.cpp
+++ b/src/plugins/platforms/xcb/qxcbwindow.cpp
@@ -1670,4 +1670,37 @@ void QXcbWindow::setCursor(xcb_cursor_t cursor)
     xcb_flush(xcb_connection());
 }
 
+#ifdef XCB_USE_XLIB
+
+bool QXcbWindow::startSystemResize(const QPoint &pos, Qt::Corner corner)
+{
+    const xcb_atom_t moveResize = connection()->atom(QXcbAtom::_NET_WM_MOVERESIZE);
+    if (!connection()->wmSupport()->isSupportedByWM(moveResize))
+        return false;
+    XEvent xev;
+    xev.xclient.type = ClientMessage;
+    xev.xclient.message_type = moveResize;
+    Display *display = (Display *)connection()->xlib_display();
+    xev.xclient.display = display;
+    xev.xclient.window = xcb_window();
+    xev.xclient.format = 32;
+    const QPoint globalPos = window()->mapToGlobal(pos);
+    xev.xclient.data.l[0] = globalPos.x();
+    xev.xclient.data.l[1] = globalPos.y();
+    const bool bottom = corner == Qt::BottomRightCorner || corner == Qt::BottomLeftCorner;
+    const bool left = corner == Qt::BottomLeftCorner || corner == Qt::TopLeftCorner;
+    if (bottom)
+        xev.xclient.data.l[2] = left ? 6 : 4; // bottomleft/bottomright
+    else
+        xev.xclient.data.l[2] = left ? 0 : 2; // topleft/topright
+    xev.xclient.data.l[3] = Button1;
+    xev.xclient.data.l[4] = 0;
+    XUngrabPointer(display, CurrentTime);
+    XSendEvent(display, m_screen->root(), False,
+               SubstructureRedirectMask | SubstructureNotifyMask, &xev);
+    return true;
+}
+
+#endif // XCB_USE_XLIB
+
 QT_END_NAMESPACE
diff --git a/src/plugins/platforms/xcb/qxcbwindow.h b/src/plugins/platforms/xcb/qxcbwindow.h
index c3ea4af83c..6cafa0330b 100644
--- a/src/plugins/platforms/xcb/qxcbwindow.h
+++ b/src/plugins/platforms/xcb/qxcbwindow.h
@@ -107,6 +107,10 @@ public:
 
     QSurfaceFormat format() const;
 
+#ifdef XCB_USE_XLIB
+    bool startSystemResize(const QPoint &pos, Qt::Corner corner);
+#endif // XCB_USE_XLIB
+
     xcb_window_t xcb_window() const { return m_window; }
     uint depth() const { return m_depth; }
     QImage::Format imageFormat() const { return m_imageFormat; }