Cocoa: Correct enter/leave event handling.

Make top-level windows generate enter/leave events
for sub-windows. Keep track of the current "under mouse"
window in mouseMoved and send EnterLeave events when
it changes.

mouseEntered/mouseExited handles enters and leaves
from the top-level window.

Add tests/manual/cocoa/nativewidgets.

Task-number: QTBUG-27550
Task-number: QTBUG-29751

Change-Id: If4b9f9e0f39d9fb05fdab45a100ffdcf107965ad
Reviewed-by: Gabriel de Dietrich <gabriel.dedietrich@digia.com>

src/plugins/platforms/cocoa/qcocoawindow.h

@@ -150,6 +150,7 @@ public:
     qreal devicePixelRatio() const;
     void exposeWindow();
     void obscureWindow();
+    QWindow *childWindowAt(QPoint windowPoint);
 protected:
     // NSWindow handling. The QCocoaWindow/QNSView can either be displayed
     // in an existing NSWindow or in one created by Qt.
@@ -177,6 +178,7 @@ public: // for QNSView
     Qt::WindowState m_synchedWindowState;
     Qt::WindowModality m_windowModality;
     QPointer<QWindow> m_activePopupWindow;
+    QPointer<QWindow> m_underMouseWindow;
 
     bool m_inConstructor;
     QCocoaGLContext *m_glContext;

src/plugins/platforms/cocoa/qcocoawindow.mm

@@ -927,6 +927,21 @@ void QCocoaWindow::obscureWindow()
     }
 }
 
+QWindow *QCocoaWindow::childWindowAt(QPoint windowPoint)
+{
+    QWindow *targetWindow = window();
+    foreach (QObject *child, targetWindow->children()) {
+        if (QWindow *childWindow = qobject_cast<QWindow *>(child)) {
+            if (childWindow->geometry().contains(windowPoint)) {
+                QCocoaWindow* platformWindow = static_cast<QCocoaWindow*>(childWindow->handle());
+                targetWindow = platformWindow->childWindowAt(windowPoint - childWindow->position());
+            }
+        }
+    }
+
+    return targetWindow;
+}
+
 QMargins QCocoaWindow::frameMargins() const
 {
     NSRect frameW = [m_nsWindow frame];

src/plugins/platforms/cocoa/qnsview.mm

@@ -599,6 +599,7 @@ static QTouchDevice *touchDevice = 0;
     if (NSIsEmptyRect([self visibleRect]))
         return;
 
+    // Remove current trakcing areas:
     QCocoaAutoReleasePool pool;
     if (NSArray *trackingArray = [self trackingAreas]) {
         NSUInteger size = [trackingArray count];
@@ -611,7 +612,7 @@ static QTouchDevice *touchDevice = 0;
     // Ideally, we shouldn't have NSTrackingMouseMoved events included below, it should
     // only be turned on if mouseTracking, hover is on or a tool tip is set.
     // Unfortunately, Qt will send "tooltip" events on mouse moves, so we need to
-    // turn it on in ALL case. That means EVERY QCocoaView gets to pay the cost of
+    // turn it on in ALL case. That means EVERY QWindow gets to pay the cost of
     // mouse moves delivered to it (Apple recommends keeping it OFF because there
     // is a performance hit). So it goes.
     NSUInteger trackingOptions = NSTrackingMouseEnteredAndExited | NSTrackingActiveInActiveApp
@@ -628,23 +629,58 @@ static QTouchDevice *touchDevice = 0;
 {
     if (m_window->flags() & Qt::WindowTransparentForInput)
         return [super mouseMoved:theEvent];
-    [self handleMouseEvent:theEvent];
+
+    QPoint windowPoint, screenPoint;
+    [self convertFromEvent:theEvent toWindowPoint:&windowPoint andScreenPoint:&screenPoint];
+    QWindow *childWindow = m_platformWindow->childWindowAt(windowPoint);
+
+    // Top-level windows generate enter-leave events for sub-windows.
+    // Qt wants to know which window (if any) will be entered at the
+    // the time of the leave. This is dificult to accomplish by
+    // handling mouseEnter and mouseLeave envents, since they are sent
+    // individually to different views.
+    if (m_platformWindow->m_nsWindow && childWindow) {
+        if (childWindow != m_platformWindow->m_underMouseWindow) {
+            QWindowSystemInterface::handleEnterLeaveEvent(childWindow, m_platformWindow->m_underMouseWindow, windowPoint, screenPoint);
+            m_platformWindow->m_underMouseWindow = childWindow;
+        }
+    }
+
+    // Cocoa keeps firing mouse move events for obscured parent views. Qt should not
+    // send those events so filter them out here.
+    if (childWindow != m_window)
+        return;
+
+    [self handleMouseEvent: theEvent];
 }
 
 - (void)mouseEntered:(NSEvent *)theEvent
 {
     if (m_window->flags() & Qt::WindowTransparentForInput)
         return [super mouseEntered:theEvent];
+
+    // Top-level windows generate enter events for sub-windows.
+    if (!m_platformWindow->m_nsWindow)
+        return;
+
     QPoint windowPoint, screenPoint;
     [self convertFromEvent:theEvent toWindowPoint:&windowPoint andScreenPoint:&screenPoint];
-    QWindowSystemInterface::handleEnterEvent(m_window, windowPoint, screenPoint);
+    m_platformWindow->m_underMouseWindow = m_platformWindow->childWindowAt(windowPoint);
+    QWindowSystemInterface::handleEnterEvent(m_platformWindow->m_underMouseWindow, windowPoint, screenPoint);
 }
 
 - (void)mouseExited:(NSEvent *)theEvent
 {
     if (m_window->flags() & Qt::WindowTransparentForInput)
         return [super mouseExited:theEvent];
-    QWindowSystemInterface::handleLeaveEvent(m_window);
+    Q_UNUSED(theEvent);
+
+    // Top-level windows generate leave events for sub-windows.
+    if (!m_platformWindow->m_nsWindow)
+        return;
+
+    QWindowSystemInterface::handleLeaveEvent(m_platformWindow->m_underMouseWindow);
+    m_platformWindow->m_underMouseWindow = 0;
 }
 
 - (void)rightMouseDown:(NSEvent *)theEvent

tests/manual/cocoa/nativewidgets/main.cpp

@@ -0,0 +1,147 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the test suite of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QtCore>
+#include <QtWidgets>
+
+class ColorWidget : public QWidget
+{
+    QColor color;
+    int s;
+    int v;
+
+    void changeColor()
+    {
+        color.setHsv((qreal(qrand()) / RAND_MAX) * 50 + 200, s, s);
+    }
+
+public:
+    ColorWidget()
+    {
+        s = 150;
+        v = 150;
+        changeColor();
+        setMouseTracking(true);
+    }
+
+    void mousePressEvent(QMouseEvent *)
+    {
+        changeColor();
+        update();
+    }
+
+    void mouseMoveEvent(QMouseEvent *)
+    {
+        changeColor();
+        update();
+    }
+
+    void enterEvent(QEvent *)
+    {
+        s = 200;
+        v = 200;
+        changeColor();
+        update();
+    }
+
+    void leaveEvent(QEvent *)
+    {
+        s = 75;
+        v = 75;
+        changeColor();
+        update();
+    }
+
+    void paintEvent(QPaintEvent *){
+        QPainter p(this);
+        p.fillRect(QRect(QPoint(0, 0), size()), QBrush(color));
+    }
+};
+
+
+int main(int argc, char *argv[])
+{
+    QApplication app(argc, argv);
+
+    ColorWidget window;
+
+    QWidget *w1 = new ColorWidget;
+    QWidget *w2 = new ColorWidget;
+    QWidget *w3 = new ColorWidget;
+
+    QHBoxLayout *layout = new QHBoxLayout;
+    layout->addWidget(w1);
+    layout->addWidget(w2);
+    layout->addWidget(w3);
+
+    QWidget *w3_1 = new ColorWidget;
+    QWidget *w3_2 = new ColorWidget;
+    QWidget *w3_3 = new ColorWidget;
+
+    QVBoxLayout *layout3 = new QVBoxLayout;
+    layout3->setMargin(0);
+    layout3->addWidget(w3_1);
+    layout3->addWidget(w3_2);
+    layout3->addWidget(w3_3);
+    w3->setLayout(layout3);
+
+    window.setLayout(layout);
+
+    bool native = 1;
+
+    if (native) {
+        w1->winId();
+        w2->winId();
+        w3->winId();
+
+        w3_1->winId();
+        w3_2->winId();
+        w3_3->winId();
+    }
+
+    window.resize(640, 480);
+    window.show();
+
+    return app.exec();
+}
+
+
+

tests/manual/cocoa/nativewidgets/nativewigets.pro

@@ -0,0 +1,7 @@
+TEMPLATE = app
+
+HEADERS +=
+SOURCES += main.cpp
+
+QT += core widgets
+DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0