Add examples.

These are mostly former manual tests that seem useful for
demonstrating some feature to learners.

Change-Id: I06d895ebdee1280699416cf4930a08602951aaf7
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>

6 files changed, 354 insertions, 0 deletions

diff --git a/examples/collidingmice/collidingmice.qbs b/examples/collidingmice/collidingmice.qbs
new file mode 100644
index 000000000..9df92b74c
--- /dev/null
+++ b/examples/collidingmice/collidingmice.qbs
@@ -0,0 +1,19 @@
+import qbs 1.0
+
+Application {
+    name : "CollidingMice"
+    destinationDirectory: "bin"
+
+    Depends {
+        name: "Qt"
+        submodules: ["widgets"]
+    }
+
+    files : [
+        "main.cpp",
+        "mouse.cpp",
+        "mouse.h",
+        "mice.qrc"
+    ]
+}
+
diff --git a/examples/collidingmice/images/cheese.jpg b/examples/collidingmice/images/cheese.jpg
new file mode 100644
index 000000000..dea5795fd
--- /dev/null
+++ b/examples/collidingmice/images/cheese.jpg
diff --git a/examples/collidingmice/main.cpp b/examples/collidingmice/main.cpp
new file mode 100644
index 000000000..633a1f003
--- /dev/null
+++ b/examples/collidingmice/main.cpp
@@ -0,0 +1,84 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the Qt Build Suite.
+**
+** 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.
+**
+****************************************************************************/
+
+#include "mouse.h"
+
+#include <QApplication>
+#include <QGraphicsScene>
+#include <QGraphicsView>
+#include <QTime>
+#include <QTimer>
+
+#include <math.h>
+
+static const int MouseCount = 7;
+
+//! [0]
+int main(int argc, char **argv)
+{
+    QApplication app(argc, argv);
+    qsrand(QTime(0,0,0).secsTo(QTime::currentTime()));
+//! [0]
+
+//! [1]
+    QGraphicsScene scene;
+    scene.setSceneRect(-300, -300, 600, 600);
+//! [1] //! [2]
+    scene.setItemIndexMethod(QGraphicsScene::NoIndex);
+//! [2]
+
+//! [3]
+    for (int i = 0; i < MouseCount; ++i) {
+        Mouse *mouse = new Mouse;
+        mouse->setPos(::sin((i * 6.28) / MouseCount) * 200,
+                      ::cos((i * 6.28) / MouseCount) * 200);
+        scene.addItem(mouse);
+    }
+//! [3]
+
+//! [4]
+    QGraphicsView view(&scene);
+    view.setRenderHint(QPainter::Antialiasing);
+    view.setBackgroundBrush(QPixmap(":/images/cheese.jpg"));
+//! [4] //! [5]
+    view.setCacheMode(QGraphicsView::CacheBackground);
+    view.setViewportUpdateMode(QGraphicsView::BoundingRectViewportUpdate);
+    view.setDragMode(QGraphicsView::ScrollHandDrag);
+//! [5] //! [6]
+    view.setWindowTitle(QT_TRANSLATE_NOOP(QGraphicsView, "Colliding Mice"));
+    view.resize(400, 300);
+    view.show();
+
+    QTimer timer;
+    QObject::connect(&timer, SIGNAL(timeout()), &scene, SLOT(advance()));
+    timer.start(1000 / 33);
+
+    return app.exec();
+}
+//! [6]
diff --git a/examples/collidingmice/mice.qrc b/examples/collidingmice/mice.qrc
new file mode 100644
index 000000000..accdb4d0a
--- /dev/null
+++ b/examples/collidingmice/mice.qrc
@@ -0,0 +1,5 @@
+<RCC>
+    <qresource prefix="/" >
+        <file>images/cheese.jpg</file>
+    </qresource>
+</RCC>
diff --git a/examples/collidingmice/mouse.cpp b/examples/collidingmice/mouse.cpp
new file mode 100644
index 000000000..fb263b49a
--- /dev/null
+++ b/examples/collidingmice/mouse.cpp
@@ -0,0 +1,189 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the Qt Build Suite.
+**
+** 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.
+**
+****************************************************************************/
+
+#include "mouse.h"
+
+#include <QGraphicsScene>
+#include <QPainter>
+#include <QStyleOption>
+
+#include <math.h>
+
+static const double Pi = 3.14159265358979323846264338327950288419717;
+static double TwoPi = 2.0 * Pi;
+
+static qreal normalizeAngle(qreal angle)
+{
+    while (angle < 0)
+        angle += TwoPi;
+    while (angle > TwoPi)
+        angle -= TwoPi;
+    return angle;
+}
+
+//! [0]
+Mouse::Mouse()
+    : angle(0), speed(0), mouseEyeDirection(0),
+      color(qrand() % 256, qrand() % 256, qrand() % 256)
+{
+    setRotation(qrand() % (360 * 16));
+}
+//! [0]
+
+//! [1]
+QRectF Mouse::boundingRect() const
+{
+    qreal adjust = 0.5;
+    return QRectF(-18 - adjust, -22 - adjust,
+                  36 + adjust, 60 + adjust);
+}
+//! [1]
+
+//! [2]
+QPainterPath Mouse::shape() const
+{
+    QPainterPath path;
+    path.addRect(-10, -20, 20, 40);
+    return path;
+}
+//! [2]
+
+//! [3]
+void Mouse::paint(QPainter *painter, const QStyleOptionGraphicsItem *, QWidget *)
+{
+    // Body
+    painter->setBrush(color);
+    painter->drawEllipse(-10, -20, 20, 40);
+
+    // Eyes
+    painter->setBrush(Qt::white);
+    painter->drawEllipse(-10, -17, 8, 8);
+    painter->drawEllipse(2, -17, 8, 8);
+
+    // Nose
+    painter->setBrush(Qt::black);
+    painter->drawEllipse(QRectF(-2, -22, 4, 4));
+
+    // Pupils
+    painter->drawEllipse(QRectF(-8.0 + mouseEyeDirection, -17, 4, 4));
+    painter->drawEllipse(QRectF(4.0 + mouseEyeDirection, -17, 4, 4));
+
+    // Ears
+    painter->setBrush(scene()->collidingItems(this).isEmpty() ? Qt::darkYellow : Qt::red);
+    painter->drawEllipse(-17, -12, 16, 16);
+    painter->drawEllipse(1, -12, 16, 16);
+
+    // Tail
+    QPainterPath path(QPointF(0, 20));
+    path.cubicTo(-5, 22, -5, 22, 0, 25);
+    path.cubicTo(5, 27, 5, 32, 0, 30);
+    path.cubicTo(-5, 32, -5, 42, 0, 35);
+    painter->setBrush(Qt::NoBrush);
+    painter->drawPath(path);
+}
+//! [3]
+
+//! [4]
+void Mouse::advance(int step)
+{
+    if (!step)
+        return;
+//! [4]
+    // Don't move too far away
+//! [5]
+    QLineF lineToCenter(QPointF(0, 0), mapFromScene(0, 0));
+    if (lineToCenter.length() > 150) {
+        qreal angleToCenter = ::acos(lineToCenter.dx() / lineToCenter.length());
+        if (lineToCenter.dy() < 0)
+            angleToCenter = TwoPi - angleToCenter;
+        angleToCenter = normalizeAngle((Pi - angleToCenter) + Pi / 2);
+
+        if (angleToCenter < Pi && angleToCenter > Pi / 4) {
+            // Rotate left
+            angle += (angle < -Pi / 2) ? 0.25 : -0.25;
+        } else if (angleToCenter >= Pi && angleToCenter < (Pi + Pi / 2 + Pi / 4)) {
+            // Rotate right
+            angle += (angle < Pi / 2) ? 0.25 : -0.25;
+        }
+    } else if (::sin(angle) < 0) {
+        angle += 0.25;
+    } else if (::sin(angle) > 0) {
+        angle -= 0.25;
+//! [5] //! [6]
+    }
+//! [6]
+
+    // Try not to crash with any other mice
+//! [7]
+    QList<QGraphicsItem *> dangerMice = scene()->items(QPolygonF()
+                                                       << mapToScene(0, 0)
+                                                       << mapToScene(-30, -50)
+                                                       << mapToScene(30, -50));
+    foreach (QGraphicsItem *item, dangerMice) {
+        if (item == this)
+            continue;
+        
+        QLineF lineToMouse(QPointF(0, 0), mapFromItem(item, 0, 0));
+        qreal angleToMouse = ::acos(lineToMouse.dx() / lineToMouse.length());
+        if (lineToMouse.dy() < 0)
+            angleToMouse = TwoPi - angleToMouse;
+        angleToMouse = normalizeAngle((Pi - angleToMouse) + Pi / 2);
+
+        if (angleToMouse >= 0 && angleToMouse < Pi / 2) {
+            // Rotate right
+            angle += 0.5;
+        } else if (angleToMouse <= TwoPi && angleToMouse > (TwoPi - Pi / 2)) {
+            // Rotate left
+            angle -= 0.5;
+//! [7] //! [8]
+        }
+//! [8] //! [9]
+    }
+//! [9]
+
+    // Add some random movement
+//! [10]
+    if (dangerMice.size() > 1 && (qrand() % 10) == 0) {
+        if (qrand() % 1)
+            angle += (qrand() % 100) / 500.0;
+        else
+            angle -= (qrand() % 100) / 500.0;
+    }
+//! [10]
+
+//! [11]
+    speed += (-50 + qrand() % 100) / 100.0;
+
+    qreal dx = ::sin(angle) * 10;
+    mouseEyeDirection = (qAbs(dx / 5) < 1) ? 0 : dx / 5;
+
+    setRotation(rotation() + dx);
+    setPos(mapToParent(0, -(3 + sin(speed) * 3)));
+}
+//! [11]
diff --git a/examples/collidingmice/mouse.h b/examples/collidingmice/mouse.h
new file mode 100644
index 000000000..cf3f06d03
--- /dev/null
+++ b/examples/collidingmice/mouse.h
@@ -0,0 +1,57 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the Qt Build Suite.
+**
+** 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.
+**
+****************************************************************************/
+
+#ifndef MOUSE_H
+#define MOUSE_H
+
+#include <QGraphicsItem>
+
+//! [0]
+class Mouse : public QGraphicsItem
+{
+public:
+    Mouse();
+
+    QRectF boundingRect() const;
+    QPainterPath shape() const;
+    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option,
+               QWidget *widget);
+
+protected:
+    void advance(int step);
+
+private:
+    qreal angle;
+    qreal speed;
+    qreal mouseEyeDirection;
+    QColor color;
+};
+//! [0]
+
+#endif