Add framestrut mouse events.

- Add infrastructure to QWindowSystemInterface.
- Add a setter for enabling framestrut events
  to QPlatformWindow.
- Add Windows implementation, pass keyboard modifiers.

QDockWidget relies on it for docking.

Task-number: QTBUG-26296
Change-Id: I9d84b356e9a5eb341f57b6f51f34b6b494ff7f87
Reviewed-by: Jørgen Lind <jorgen.lind@nokia.com>

5 files changed, 50 insertions, 8 deletions

diff --git a/src/plugins/platforms/windows/qwindowscontext.cpp b/src/plugins/platforms/windows/qwindowscontext.cpp
index 891753215d..ba32369c03 100644
--- a/src/plugins/platforms/windows/qwindowscontext.cpp
+++ b/src/plugins/platforms/windows/qwindowscontext.cpp
@@ -817,9 +817,12 @@ bool QWindowsContext::windowsProc(HWND hwnd, UINT message,
 #endif
     case QtWindows::ExposeEvent:
         return platformWindow->handleWmPaint(hwnd, message, wParam, lParam);
+    case QtWindows::NonClientMouseEvent:
+        if (platformWindow->frameStrutEventsEnabled())
+            return d->m_mouseHandler.translateMouseEvent(platformWindow->window(), hwnd, et, msg, result);
+        break;
     case QtWindows::MouseWheelEvent:
     case QtWindows::MouseEvent:
-    case QtWindows::NonClientMouseEvent:
     case QtWindows::LeaveEvent:
         return d->m_mouseHandler.translateMouseEvent(platformWindow->window(), hwnd, et, msg, result);
     case QtWindows::TouchEvent:
diff --git a/src/plugins/platforms/windows/qwindowsmousehandler.cpp b/src/plugins/platforms/windows/qwindowsmousehandler.cpp
index eb7d2912bb..e9a2b5c19d 100644
--- a/src/plugins/platforms/windows/qwindowsmousehandler.cpp
+++ b/src/plugins/platforms/windows/qwindowsmousehandler.cpp
@@ -40,6 +40,7 @@
 ****************************************************************************/
 
 #include "qwindowsmousehandler.h"
+#include "qwindowskeymapper.h"
 #include "qwindowscontext.h"
 #include "qwindowswindow.h"
 #include "qwindowsintegration.h"
@@ -130,14 +131,37 @@ QWindowsMouseHandler::QWindowsMouseHandler() :
 {
 }
 
+Qt::MouseButtons QWindowsMouseHandler::queryMouseButtons()
+{
+    Qt::MouseButtons result = 0;
+    const bool mouseSwapped = GetSystemMetrics(SM_SWAPBUTTON);
+    if (GetAsyncKeyState(VK_LBUTTON) < 0)
+        result |= mouseSwapped ? Qt::RightButton: Qt::LeftButton;
+    if (GetAsyncKeyState(VK_RBUTTON) < 0)
+        result |= mouseSwapped ? Qt::LeftButton : Qt::RightButton;
+    if (GetAsyncKeyState(VK_MBUTTON) < 0)
+        result |= Qt::MidButton;
+    return result;
+}
+
 bool QWindowsMouseHandler::translateMouseEvent(QWindow *window, HWND hwnd,
                                                QtWindows::WindowsEventType et,
                                                MSG msg, LRESULT *result)
 {
-    if (et & QtWindows::NonClientEventFlag)
-        return false;
     if (et == QtWindows::MouseWheelEvent)
         return translateMouseWheelEvent(window, hwnd, msg, result);
+
+    const QPoint winEventPosition(GET_X_LPARAM(msg.lParam), GET_Y_LPARAM(msg.lParam));
+    if (et & QtWindows::NonClientEventFlag) {
+        const QPoint globalPosition = winEventPosition;
+        const QPoint clientPosition = QWindowsGeometryHint::mapFromGlobal(hwnd, globalPosition);
+        const Qt::MouseButtons buttons = QWindowsMouseHandler::queryMouseButtons();
+        QWindowSystemInterface::handleFrameStrutMouseEvent(window, clientPosition,
+                                                           globalPosition, buttons,
+                                                           QWindowsKeyMapper::queryKeyboardModifiers());
+        return false; // Allow further event processing (dragging of windows).
+    }
+
     *result = 0;
     if (msg.message == WM_MOUSELEAVE) {
         // When moving out of a child, MouseMove within parent is received first
@@ -161,7 +185,6 @@ bool QWindowsMouseHandler::translateMouseEvent(QWindow *window, HWND hwnd,
             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) {
         // The tracking on m_windowUnderMouse might still be active and
@@ -186,9 +209,11 @@ bool QWindowsMouseHandler::translateMouseEvent(QWindow *window, HWND hwnd,
             qWarning("TrackMouseEvent failed.");
 #endif // !Q_OS_WINCE
     }
-    QWindowSystemInterface::handleMouseEvent(window, client,
-                                             QWindowsGeometryHint::mapToGlobal(hwnd, client),
-                                             keyStateToMouseButtons((int)msg.wParam));
+    const QPoint clientPosition = winEventPosition;
+    QWindowSystemInterface::handleMouseEvent(window, clientPosition,
+                                             QWindowsGeometryHint::mapToGlobal(hwnd, clientPosition),
+                                             keyStateToMouseButtons((int)msg.wParam),
+                                             QWindowsKeyMapper::queryKeyboardModifiers());
     return true;
 }
 
diff --git a/src/plugins/platforms/windows/qwindowsmousehandler.h b/src/plugins/platforms/windows/qwindowsmousehandler.h
index a978840d67..e3d329e872 100644
--- a/src/plugins/platforms/windows/qwindowsmousehandler.h
+++ b/src/plugins/platforms/windows/qwindowsmousehandler.h
@@ -70,6 +70,7 @@ public:
     static inline Qt::KeyboardModifiers keyStateToModifiers(int);
     static inline int mouseButtonsToKeyState(Qt::MouseButtons);
 
+    static Qt::MouseButtons queryMouseButtons();
     QWindow *windowUnderMouse() const { return m_windowUnderMouse.data(); }
 
 private:
diff --git a/src/plugins/platforms/windows/qwindowswindow.cpp b/src/plugins/platforms/windows/qwindowswindow.cpp
index 7fa43e03e6..b553c15864 100644
--- a/src/plugins/platforms/windows/qwindowswindow.cpp
+++ b/src/plugins/platforms/windows/qwindowswindow.cpp
@@ -1489,6 +1489,15 @@ bool QWindowsWindow::startSystemResize(const QPoint &, Qt::Corner corner)
     return true;
 }
 
+void QWindowsWindow::setFrameStrutEventsEnabled(bool enabled)
+{
+    if (enabled) {
+        setFlag(FrameStrutEventsEnabled);
+    } else {
+        clearFlag(FrameStrutEventsEnabled);
+    }
+}
+
 #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 182bef78e4..475982aba4 100644
--- a/src/plugins/platforms/windows/qwindowswindow.h
+++ b/src/plugins/platforms/windows/qwindowswindow.h
@@ -123,7 +123,8 @@ public:
         OpenGLDoubleBuffered = 0x20,
         OpenGlPixelFormatInitialized = 0x40,
         BlockedByModal = 0x80,
-        SizeGripOperation = 0x100
+        SizeGripOperation = 0x100,
+        FrameStrutEventsEnabled = 0x200
     };
 
     struct WindowData
@@ -178,6 +179,9 @@ public:
 
     virtual bool startSystemResize(const QPoint &pos, Qt::Corner corner);
 
+    void setFrameStrutEventsEnabled(bool enabled);
+    bool frameStrutEventsEnabled() const { return testFlag(FrameStrutEventsEnabled); }
+
     Qt::WindowState windowState_sys() const;
     Qt::WindowStates windowStates_sys() const;