Add internal QQuickAnimatedNode helper

This handles the timers, signals, updates etc. so that the animated
node implementations for busy indicators and indeterminate progress
bars become a bit simpler. The implementation is based on
qtdeclarative/examples/quick/scenegraph/threadedanimation.

Task-number: QTBUG-56601
Change-Id: Ibd82060aa103e6447ee16814c3e0d6ff2c14d608
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>

3 files changed, 277 insertions, 0 deletions

diff --git a/src/quickcontrols2/qquickanimatednode.cpp b/src/quickcontrols2/qquickanimatednode.cpp
new file mode 100644
index 00000000..2c5cdc67
--- /dev/null
+++ b/src/quickcontrols2/qquickanimatednode.cpp
@@ -0,0 +1,163 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the Qt Quick Controls 2 module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL3$
+** 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 http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://www.qt.io/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 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPLv3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or later 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 2.0 requirements will be
+** met: http://www.gnu.org/licenses/gpl-2.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qquickanimatednode_p.h"
+
+#include <QtQuick/qquickitem.h>
+#include <QtQuick/qquickwindow.h>
+
+// based on qtdeclarative/examples/quick/scenegraph/threadedanimation
+
+QT_BEGIN_NAMESPACE
+
+QQuickAnimatedNode::QQuickAnimatedNode(QQuickItem *target)
+    : m_running(false),
+      m_duration(0),
+      m_loopCount(1),
+      m_currentTime(0),
+      m_currentLoop(0),
+      m_window(target->window())
+{
+}
+
+bool QQuickAnimatedNode::isRunning() const
+{
+    return m_running;
+}
+
+int QQuickAnimatedNode::currentTime() const
+{
+    int time = m_currentTime;
+    if (m_running)
+        time += m_timer.elapsed();
+    return time;
+}
+
+void QQuickAnimatedNode::setCurrentTime(int time)
+{
+    m_currentTime = time;
+    m_timer.restart();
+}
+
+int QQuickAnimatedNode::duration() const
+{
+    return m_duration;
+}
+
+void QQuickAnimatedNode::setDuration(int duration)
+{
+    m_duration = duration;
+}
+
+int QQuickAnimatedNode::loopCount() const
+{
+    return m_loopCount;
+}
+
+void QQuickAnimatedNode::setLoopCount(int count)
+{
+    m_loopCount = count;
+}
+
+void QQuickAnimatedNode::sync(QQuickItem *target)
+{
+    Q_UNUSED(target);
+}
+
+QQuickWindow *QQuickAnimatedNode::window() const
+{
+    return m_window;
+}
+
+void QQuickAnimatedNode::start(int duration)
+{
+    if (m_running)
+        return;
+
+    m_running = true;
+    m_currentLoop = 0;
+    m_timer.restart();
+    if (duration > 0)
+        m_duration = duration;
+    connect(m_window, &QQuickWindow::beforeRendering, this, &QQuickAnimatedNode::advance);
+    connect(m_window, &QQuickWindow::frameSwapped, this, &QQuickAnimatedNode::update);
+    emit started();
+}
+
+void QQuickAnimatedNode::restart()
+{
+    stop();
+    start();
+}
+
+void QQuickAnimatedNode::stop()
+{
+    if (!m_running)
+        return;
+
+    m_running = false;
+    disconnect(m_window, &QQuickWindow::beforeRendering, this, &QQuickAnimatedNode::advance);
+    disconnect(m_window, &QQuickWindow::frameSwapped, this, &QQuickAnimatedNode::update);
+    emit stopped();
+}
+
+void QQuickAnimatedNode::updateCurrentTime(int time)
+{
+    Q_UNUSED(time);
+}
+
+void QQuickAnimatedNode::advance()
+{
+    int time = currentTime();
+    if (time > m_duration) {
+        time = 0;
+        setCurrentTime(0);
+
+        if (m_loopCount > 0 && ++m_currentLoop >= m_loopCount) {
+            time = m_duration; // complete
+            stop();
+        }
+    }
+    updateCurrentTime(time);
+}
+
+void QQuickAnimatedNode::update()
+{
+    if (m_running)
+        m_window->update();
+}
+
+QT_END_NAMESPACE
diff --git a/src/quickcontrols2/qquickanimatednode_p.h b/src/quickcontrols2/qquickanimatednode_p.h
new file mode 100644
index 00000000..24b404c9
--- /dev/null
+++ b/src/quickcontrols2/qquickanimatednode_p.h
@@ -0,0 +1,112 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the Qt Quick Controls 2 module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL3$
+** 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 http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://www.qt.io/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 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPLv3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or later 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 2.0 requirements will be
+** met: http://www.gnu.org/licenses/gpl-2.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QQUICKANIMATEDNODE_P_H
+#define QQUICKANIMATEDNODE_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <QtQuick/qsgnode.h>
+#include <QtCore/qelapsedtimer.h>
+#include <QtQuickControls2/private/qtquickcontrols2global_p.h>
+
+QT_BEGIN_NAMESPACE
+
+class QQuickItem;
+class QQuickWindow;
+
+class Q_QUICKCONTROLS2_PRIVATE_EXPORT QQuickAnimatedNode : public QObject, public QSGTransformNode
+{
+    Q_OBJECT
+
+public:
+    explicit QQuickAnimatedNode(QQuickItem *target);
+
+    bool isRunning() const;
+
+    int currentTime() const;
+    void setCurrentTime(int time);
+
+    int duration() const;
+    void setDuration(int duration);
+
+    enum LoopCount { Infinite = -1 };
+
+    int loopCount() const;
+    void setLoopCount(int count);
+
+    virtual void sync(QQuickItem *target);
+
+    QQuickWindow *window() const;
+
+    // must be called from sync() or updatePaintNode()
+    void start(int duration = 0);
+    void restart();
+    void stop();
+
+Q_SIGNALS:
+    void started();
+    void stopped();
+
+protected:
+    virtual void updateCurrentTime(int time);
+
+private Q_SLOTS:
+    void advance();
+    void update();
+
+private:
+    bool m_running;
+    int m_duration;
+    int m_loopCount;
+    int m_currentTime;
+    int m_currentLoop;
+    QElapsedTimer m_timer;
+    QQuickWindow *m_window;
+};
+
+QT_END_NAMESPACE
+
+#endif // QQUICKANIMATEDNODE_P_H
diff --git a/src/quickcontrols2/quickcontrols2.pri b/src/quickcontrols2/quickcontrols2.pri
index 8e4e0046..eddd14d2 100644
--- a/src/quickcontrols2/quickcontrols2.pri
+++ b/src/quickcontrols2/quickcontrols2.pri
@@ -1,4 +1,5 @@
 HEADERS += \
+    $$PWD/qquickanimatednode_p.h \
     $$PWD/qquickcolorimageprovider_p.h \
     $$PWD/qquickproxytheme_p.h \
     $$PWD/qquickstyle.h \
@@ -11,6 +12,7 @@ HEADERS += \
     $$PWD/qquicktumblerview_p.h
 
 SOURCES += \
+    $$PWD/qquickanimatednode.cpp \
     $$PWD/qquickcolorimageprovider.cpp \
     $$PWD/qquickproxytheme.cpp \
     $$PWD/qquickstyle.cpp \