QTBUG-26296, dock widget moving

Cocoa lacked implementation of FrameStrut events, and also frameMargins on
QPlatformWindow. Fix both of these issues. Unfortunately QDockWidget also
contains a tangle of #ifdef MAC behaviour which I am unclear about. What's
included here disables some logic on Mac that seems definitely wrong -
while moving a window on Mac we now generate NonClientArea events
(as intended, I believe), but this should not cause dock-widget dragging to end.

Note the window titlebar is the only frame-strut/non-client area on Mac (as far as I can see)

Task-number: QTBUG-26296
Change-Id: Id0c6e954db64b9f9f71d16355cb92922877e5ebe
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@nokia.com>

src/plugins/platforms/cocoa/qcocoawindow.h

@@ -55,12 +55,14 @@ class QT_PREPEND_NAMESPACE(QCocoaWindow);
     @public QCocoaWindow *m_cocoaPlatformWindow;
 }
 
+- (void)clearPlatformWindow;
 - (BOOL)canBecomeKeyWindow;
 @end
 
 @interface QNSPanel : NSPanel {
     @public QT_PREPEND_NAMESPACE(QCocoaWindow) *m_cocoaPlatformWindow;
 }
+- (void)clearPlatformWindow;
 - (BOOL)canBecomeKeyWindow;
 @end
 
@@ -105,6 +107,7 @@ public:
     void setOpacity(qreal level);
     bool setKeyboardGrabEnabled(bool grab);
     bool setMouseGrabEnabled(bool grab);
+    QMargins frameMargins() const;
 
     WId winId() const;
     void setParent(const QPlatformWindow *window);
@@ -122,6 +125,10 @@ public:
 
     bool setWindowModified(bool modified) Q_DECL_OVERRIDE;
 
+    void setFrameStrutEventsEnabled(bool enabled);
+    bool frameStrutEventsEnabled() const
+        { return m_frameStrutEventsEnabled; }
+
     void setMenubar(QCocoaMenuBar *mb);
     QCocoaMenuBar *menubar() const;
 protected:
@@ -152,6 +159,7 @@ public: // for QNSView
     QCocoaMenuBar *m_menubar;
 
     bool m_hasModalSession;
+    bool m_frameStrutEventsEnabled;
 };
 
 QT_END_NAMESPACE

src/plugins/platforms/cocoa/qcocoawindow.mm

@@ -47,7 +47,7 @@
 #include "qnsview.h"
 #include <QtCore/private/qcore_mac_p.h>
 #include <qwindow.h>
-#include <QtGui/qwindowsysteminterface.h>
+#include <QtGui/QWindowSystemInterface>
 #include <qpa/qplatformscreen.h>
 
 #include <Cocoa/Cocoa.h>
@@ -55,6 +55,45 @@
 
 #include <QDebug>
 
+static bool isMouseEvent(NSEvent *ev)
+{
+    switch ([ev type]) {
+    case NSLeftMouseDown:
+    case NSLeftMouseUp:
+    case NSRightMouseDown:
+    case NSRightMouseUp:
+    case NSMouseMoved:
+    case NSLeftMouseDragged:
+    case NSRightMouseDragged:
+        return true;
+    default:
+        return false;
+    }
+}
+
+@interface NSWindow (CocoaWindowCategory)
+- (void) clearPlatformWindow;
+- (NSRect) legacyConvertRectFromScreen:(NSRect) rect;
+@end
+
+@implementation NSWindow (CocoaWindowCategory)
+- (void) clearPlatformWindow
+{
+}
+
+- (NSRect) legacyConvertRectFromScreen:(NSRect) rect
+{
+#if MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_7
+    if (QSysInfo::QSysInfo::MacintoshVersion >= QSysInfo::MV_10_7) {
+        return [self convertRectFromScreen: rect];
+    }
+#endif
+    NSRect r = rect;
+    r.origin = [self convertScreenToBase:rect.origin];
+    return r;
+}
+@end
+
 @implementation QNSWindow
 
 - (BOOL)canBecomeKeyWindow
@@ -77,6 +116,30 @@
     return canBecomeMain;
 }
 
+- (void) sendEvent: (NSEvent*) theEvent
+{
+    [super sendEvent: theEvent];
+
+    if (!m_cocoaPlatformWindow)
+        return;
+
+    if (m_cocoaPlatformWindow->frameStrutEventsEnabled() && isMouseEvent(theEvent)) {
+        NSPoint loc = [theEvent locationInWindow];
+        NSRect windowFrame = [self legacyConvertRectFromScreen:[self frame]];
+        NSRect contentFrame = [[self contentView] frame];
+        if (NSMouseInRect(loc, windowFrame, NO) &&
+            !NSMouseInRect(loc, contentFrame, NO))
+        {
+            QNSView *contentView = (QNSView *) m_cocoaPlatformWindow->contentView();
+            [contentView handleFrameStrutMouseEvent: theEvent];
+        }
+    }
+}
+
+- (void)clearPlatformWindow
+{
+    m_cocoaPlatformWindow = 0;
+}
 
 @end
 
@@ -92,6 +155,31 @@
     return YES;
 }
 
+- (void) sendEvent: (NSEvent*) theEvent
+{
+    [super sendEvent: theEvent];
+
+    if (!m_cocoaPlatformWindow)
+        return;
+
+    if (m_cocoaPlatformWindow->frameStrutEventsEnabled() && isMouseEvent(theEvent)) {
+        NSPoint loc = [theEvent locationInWindow];
+        NSRect windowFrame = [self legacyConvertRectFromScreen:[self frame]];
+        NSRect contentFrame = [[self contentView] frame];
+        if (NSMouseInRect(loc, windowFrame, NO) &&
+            !NSMouseInRect(loc, contentFrame, NO))
+        {
+            QNSView *contentView = (QNSView *) m_cocoaPlatformWindow->contentView();
+            [contentView handleFrameStrutMouseEvent: theEvent];
+        }
+    }
+}
+
+- (void)clearPlatformWindow
+{
+    m_cocoaPlatformWindow = 0;
+}
+
 @end
 
 QCocoaWindow::QCocoaWindow(QWindow *tlw)
@@ -102,6 +190,7 @@ QCocoaWindow::QCocoaWindow(QWindow *tlw)
     , m_glContext(0)
     , m_menubar(0)
     , m_hasModalSession(false)
+    , m_frameStrutEventsEnabled(false)
 {
 #ifdef QT_COCOA_ENABLE_WINDOW_DEBUG
     qDebug() << "QCocoaWindow::QCocoaWindow" << this;
@@ -118,6 +207,10 @@ QCocoaWindow::QCocoaWindow(QWindow *tlw)
 
 QCocoaWindow::~QCocoaWindow()
 {
+#ifdef QT_COCOA_ENABLE_WINDOW_DEBUG
+    qDebug() << "QCocoaWindow::~QCocoaWindow" << this;
+#endif
+
     clearNSWindow(m_nsWindow);
     [m_contentView release];
     [m_nsWindow release];
@@ -542,6 +635,7 @@ void QCocoaWindow::setNSWindow(NSWindow *window)
 void QCocoaWindow::clearNSWindow(NSWindow *window)
 {
     [window setDelegate:nil];
+    [window clearPlatformWindow];
     [[NSNotificationCenter defaultCenter] removeObserver:m_contentView];
 }
 
@@ -616,3 +710,19 @@ QCocoaMenuBar *QCocoaWindow::menubar() const
 {
     return m_menubar;
 }
+
+QMargins QCocoaWindow::frameMargins() const
+{
+    NSRect frameW = [m_nsWindow frame];
+    NSRect frameC = [m_nsWindow contentRectForFrameRect:frameW];
+
+    return QMargins(frameW.origin.x - frameC.origin.x,
+        (frameW.origin.y + frameW.size.height) - (frameC.origin.y + frameC.size.height),
+        (frameW.origin.x + frameW.size.width) - (frameC.origin.x + frameC.size.width),
+        frameC.origin.y - frameW.origin.y);
+}
+
+void QCocoaWindow::setFrameStrutEventsEnabled(bool enabled)
+{
+    m_frameStrutEventsEnabled = enabled;
+}

src/plugins/platforms/cocoa/qnsview.h

@@ -88,6 +88,7 @@ QT_END_NAMESPACE
 - (void)otherMouseDown:(NSEvent *)theEvent;
 - (void)otherMouseDragged:(NSEvent *)theEvent;
 - (void)otherMouseUp:(NSEvent *)theEvent;
+- (void)handleFrameStrutMouseEvent:(NSEvent *)theEvent;
 
 - (int) convertKeyCode : (QChar)keyCode;
 - (Qt::KeyboardModifiers) convertKeyModifiers : (ulong)modifierFlags;

src/plugins/platforms/cocoa/qnsview.mm

@@ -310,6 +310,39 @@ static QTouchDevice *touchDevice = 0;
     QWindowSystemInterface::handleMouseEvent(m_window, timestamp, qtWindowPoint, qtScreenPoint, m_buttons);
 }
 
+- (void)handleFrameStrutMouseEvent:(NSEvent *)theEvent
+{
+    // get m_buttons in sync
+    NSEventType ty = [theEvent type];
+    switch (ty) {
+    case NSLeftMouseDown:
+        m_buttons |= Qt::LeftButton;
+        break;
+    case NSLeftMouseUp:
+         m_buttons &= QFlag(~int(Qt::LeftButton));
+         break;
+    case NSRightMouseDown:
+        m_buttons |= Qt::RightButton;
+        break;
+    case NSRightMouseUp:
+        m_buttons &= QFlag(~int(Qt::RightButton));
+        break;
+    default:
+        break;
+    }
+
+    NSWindow *window = [self window];
+    int windowHeight = [window frame].size.height;
+    NSPoint windowPoint = [theEvent locationInWindow];
+    NSPoint nsViewPoint = [self convertPoint: windowPoint fromView: nil];
+    QPoint qtWindowPoint = QPoint(windowPoint.x, windowHeight - windowPoint.y);
+    NSPoint screenPoint = [window convertBaseToScreen : windowPoint];
+    QPoint qtScreenPoint = QPoint(screenPoint.x, qt_mac_flipYCoordinate(screenPoint.y));
+
+    ulong timestamp = [theEvent timestamp] * 1000;
+    QWindowSystemInterface::handleFrameStrutMouseEvent(m_window, timestamp, qtWindowPoint, qtScreenPoint, m_buttons);
+}
+
 - (void)mouseDown:(NSEvent *)theEvent
 {
     if (m_platformWindow->m_activePopupWindow) {

src/widgets/styles/qmacstyle_mac.mm

@@ -2584,7 +2584,7 @@ int QMacStyle::pixelMetric(PixelMetric metric, const QStyleOption *opt, const QW
         ret = 1;
         break;
     case PM_DockWidgetFrameWidth:
-        ret = 2;
+        ret = 0;
         break;
     case PM_DockWidgetTitleMargin:
         ret = 0;

src/widgets/widgets/qdockwidget.cpp

@@ -943,18 +943,11 @@ void QDockWidgetPrivate::nonClientAreaMouseEvent(QMouseEvent *event)
         case QEvent::NonClientAreaMouseMove:
             if (state == 0 || !state->dragging)
                 break;
+
+#ifndef Q_OS_MAC
             if (state->nca) {
                 endDrag();
             }
-#ifdef Q_OS_MAC
-            else { // workaround for lack of mouse-grab on Mac
-                QMainWindowLayout *layout = qt_mainwindow_layout(qobject_cast<QMainWindow *>(q->parentWidget()));
-                Q_ASSERT(layout != 0);
-
-                q->move(event->globalPos() - state->pressPos);
-                if (!state->ctrlDrag)
-                    layout->hover(state->widgetItem, event->globalPos());
-            }
 #endif
             break;
         case QEvent::NonClientAreaMouseButtonRelease: