Implement support for WA_MacNoClickThrough

This is done by adding a QWindowPrivate::allowsClickThrough() function,
so this could easily be adapted later on if desired for other
platforms.

Fixes: QTBUG-41126
Change-Id: I1157e5e7e7667ff11d1a5d21b3ce8c4b13202272
Reviewed-by: Morten Johan Sørvig <morten.sorvig@qt.io>

src/gui/kernel/qwindow_p.h

@@ -164,6 +164,8 @@ public:
 
     static Qt::WindowState effectiveState(Qt::WindowStates);
 
+    virtual bool allowClickThrough(const QPoint &) const { return true; }
+
     QWindow::SurfaceType surfaceType;
     Qt::WindowFlags windowFlags;
     QWindow *parentWindow;

src/plugins/platforms/cocoa/qnsview_mouse.mm

@@ -197,6 +197,11 @@
         return NO;
     if ([self isTransparentForUserInput])
         return NO;
+    QPointF windowPoint;
+    QPointF screenPoint;
+    [self convertFromScreen:[NSEvent mouseLocation] toWindowPoint: &windowPoint andScreenPoint: &screenPoint];
+    if (!qt_window_private(m_platformWindow->window())->allowClickThrough(screenPoint.toPoint()))
+        return NO;
     return YES;
 }
 

src/widgets/kernel/qwidgetwindow.cpp

@@ -106,6 +106,7 @@ public:
         if (QWidget *widget = q->widget())
             QWidgetPrivate::get(widget)->updateContentsRect();
     }
+    bool allowClickThrough(const QPoint &) const override;
 };
 
 QRectF QWidgetWindowPrivate::closestAcceptableGeometry(const QRectF &rect) const
@@ -221,6 +222,12 @@ static inline bool shouldBePropagatedToWidget(QEvent *event)
     }
 }
 
+bool QWidgetWindowPrivate::allowClickThrough(const QPoint &globalPos) const
+{
+    QWidget *w = QApplication::widgetAt(globalPos);
+    return w && !w->testAttribute(Qt::WA_MacNoClickThrough);
+}
+
 bool QWidgetWindow::event(QEvent *event)
 {
     if (!m_widget)

tests/manual/cocoa/noclickthrough/main.cpp

@@ -0,0 +1,48 @@
+/****************************************************************************
+ **
+ ** Copyright (C) 2019 The Qt Company Ltd.
+ ** Contact: https://www.qt.io/licensing/
+ **
+ ** This file is part of the test suite of the Qt Toolkit.
+ **
+ ** $QT_BEGIN_LICENSE:GPL-EXCEPT$
+ ** 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 The Qt Company. For licensing terms
+ ** and conditions see https://www.qt.io/terms-conditions. For further
+ ** information use the contact form at https://www.qt.io/contact-us.
+ **
+ ** GNU General Public License Usage
+ ** Alternatively, this file may be used under the terms of the GNU
+ ** General Public License version 3 as published by the Free Software
+ ** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+ ** included in the packaging of this file. Please review the following
+ ** information to ensure the GNU General Public License requirements will
+ ** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+ **
+ ** $QT_END_LICENSE$
+ **
+ ****************************************************************************/
+
+#include <QtWidgets>
+
+int main(int argc, char **argv)
+{
+    QApplication a(argc, argv);
+    QWidget w;
+    QVBoxLayout *vbox = new QVBoxLayout;
+    QLabel *label = new QLabel("Make the window inactive, but visible.\n"
+                               "Then click on the Two item.\n"
+                               "The item should not be selected, but the window should be active.");
+    vbox->addWidget(label);
+    QListWidget *list = new QListWidget;
+    list->addItems(QStringList() << "One" << "Two" << "Three");
+    list->selectionModel()->select(list->model()->index(0, 0), QItemSelectionModel::Select);
+    list->viewport()->setAttribute(Qt::WA_MacNoClickThrough);
+    vbox->addWidget(list);
+    w.setLayout(vbox);
+    w.show();
+    return a.exec();
+}

tests/manual/cocoa/noclickthrough/noclickthrough.pro

@@ -0,0 +1,4 @@
+QT += widgets
+TEMPLATE = app
+TARGET = noclickthrough
+SOURCES += main.cpp