Say hello to QQuickItem::grabToImage().

[ChangeLog][QtQuick][Item] Added functions QQuickItem::grabToImage()
and Item::grabToImage() to allow grabbing of items into
system-memory images.

Change-Id: I76cd73bb62f7440569c6fce63d63528559845721
Reviewed-by: Michael Brasser <michael.brasser@live.com>

src/quick/doc/snippets/qml/itemGrab.qml

@@ -0,0 +1,87 @@
+/****************************************************************************
+**
+** Copyright (C) 2014 Jolla Ltd, author: <gunnar.sletta@jollamobile.com>
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the documentation of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** 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 Digia Plc and its Subsidiary(-ies) 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."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+import QtQuick 2.4
+
+Item {
+    width: 320
+    height: 480
+
+//! [grab-source]
+Rectangle {
+    id: source
+    width: 100
+    height: 100
+    gradient: Gradient {
+        GradientStop { position: 0; color: "steelblue" }
+        GradientStop { position: 1; color: "black" }
+    }
+}
+//! [grab-source]
+
+//! [grab-image-target]
+Image {
+    id: image
+}
+//! [grab-image-target]
+    Timer {
+        repeat: false
+        running: true
+        interval: 1000
+        onTriggered: {
+//! [grab-to-file]
+
+    // ...
+    source.grabToImage(function(result) {
+                           result.save("something.png");
+                       });
+//! [grab-to-file]
+
+//! [grab-to-cache]
+
+    // ...
+    source.grabToImage(function(result) {
+                           image.source = result.url;
+                       },
+                       Qt.size(50, 50));
+//! [grab-to-cache]
+        }
+    }
+}

src/quick/items/items.pri

@@ -75,7 +75,8 @@ HEADERS += \
     $$PWD/qquickitemviewtransition_p.h \
     $$PWD/qquickscreen_p.h \
     $$PWD/qquickwindowmodule_p.h \
-    $$PWD/qquickframebufferobject.h
+    $$PWD/qquickframebufferobject.h \
+    $$PWD/qquickitemgrabresult.h
 
 SOURCES += \
     $$PWD/qquickevents.cpp \
@@ -128,7 +129,8 @@ SOURCES += \
     $$PWD/qquickitemviewtransition.cpp \
     $$PWD/qquickwindowmodule.cpp \
     $$PWD/qquickscreen.cpp \
-    $$PWD/qquickframebufferobject.cpp
+    $$PWD/qquickframebufferobject.cpp \
+    $$PWD/qquickitemgrabresult.cpp
 
 SOURCES += \
     $$PWD/qquickshadereffect.cpp \

src/quick/items/qquickitem.h

@@ -43,6 +43,7 @@
 #define QQUICKITEM_H
 
 #include <QtQuick/qtquickglobal.h>
+#include <QtQuick/qquickitemgrabresult.h>
 #include <QtQml/qqml.h>
 #include <QtQml/qqmlcomponent.h>
 
@@ -52,6 +53,7 @@
 #include <QtGui/qfont.h>
 #include <QtGui/qaccessible.h>
 
+
 QT_BEGIN_NAMESPACE
 
 class QQuickItem;
@@ -92,6 +94,7 @@ class QTouchEvent;
 class QSGNode;
 class QSGTransformNode;
 class QSGTextureProvider;
+class QQuickItemGrabResult;
 
 class Q_QUICK_EXPORT QQuickItem : public QObject, public QQmlParserStatus
 {
@@ -310,6 +313,10 @@ class Q_QUICK_EXPORT QQuickItem : public QObject, public QQmlParserStatus
     bool keepTouchGrab() const;
     void setKeepTouchGrab(bool);
 
+    // implemented in qquickitemgrabresult.cpp
+    Q_REVISION(4) Q_INVOKABLE bool grabToImage(const QJSValue &callback, const QSize &targetSize = QSize());
+    QSharedPointer<QQuickItemGrabResult> grabToImage(const QSize &targetSize = QSize());
+
     Q_INVOKABLE virtual bool contains(const QPointF &point) const;
 
     QTransform itemTransform(QQuickItem *, bool *) const;