Doc: Move touch examples around so they get included in docs

Task-number: QTBUG-59249
Change-Id: I71f1d2e28f0cadbad1d6bcf117198018eaf8e012
Reviewed-by: Topi Reiniö <topi.reinio@qt.io>

1 files changed, 95 insertions, 0 deletions

diff --git a/examples/widgets/touch/pinchzoom/graphicsview.cpp b/examples/widgets/touch/pinchzoom/graphicsview.cpp
new file mode 100644
index 0000000000..54e134aea2
--- /dev/null
+++ b/examples/widgets/touch/pinchzoom/graphicsview.cpp
@@ -0,0 +1,95 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the examples of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** 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.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "graphicsview.h"
+
+#include <QScrollBar>
+#include <QTouchEvent>
+
+GraphicsView::GraphicsView(QGraphicsScene *scene, QWidget *parent)
+    : QGraphicsView(scene, parent), totalScaleFactor(1)
+{
+    viewport()->setAttribute(Qt::WA_AcceptTouchEvents);
+    setDragMode(ScrollHandDrag);
+}
+
+bool GraphicsView::viewportEvent(QEvent *event)
+{
+    switch (event->type()) {
+    case QEvent::TouchBegin:
+    case QEvent::TouchUpdate:
+    case QEvent::TouchEnd:
+    {
+        QTouchEvent *touchEvent = static_cast<QTouchEvent *>(event);
+        QList<QTouchEvent::TouchPoint> touchPoints = touchEvent->touchPoints();
+        if (touchPoints.count() == 2) {
+            // determine scale factor
+            const QTouchEvent::TouchPoint &touchPoint0 = touchPoints.first();
+            const QTouchEvent::TouchPoint &touchPoint1 = touchPoints.last();
+            qreal currentScaleFactor =
+                    QLineF(touchPoint0.pos(), touchPoint1.pos()).length()
+                    / QLineF(touchPoint0.startPos(), touchPoint1.startPos()).length();
+            if (touchEvent->touchPointStates() & Qt::TouchPointReleased) {
+                // if one of the fingers is released, remember the current scale
+                // factor so that adding another finger later will continue zooming
+                // by adding new scale factor to the existing remembered value.
+                totalScaleFactor *= currentScaleFactor;
+                currentScaleFactor = 1;
+            }
+            setTransform(QTransform().scale(totalScaleFactor * currentScaleFactor,
+                                            totalScaleFactor * currentScaleFactor));
+        }
+        return true;
+    }
+    default:
+        break;
+    }
+    return QGraphicsView::viewportEvent(event);
+}