Add support for external drag and drop in Quick items.

Add dragType enums with values of None, Automatic, Internal (default).
Setting to Automatic allows startDrag to be called automatically.
Setting to Internal (default) retains old behavior.

Add mimeData to Drag item to enable external drags.

Call startDrag to start drag manually or change from internal drag to
external drag. Added events dragStarted and dragFinished that get
invoked from startDrag.

Mime data must be specified in the mimeData property as
mime-type / data pairs.

Moved QQuickDrag from qquickmousearea* files to qquickdrag* files to
reduce header interdependencies that caused linking errors in other
modules and also to improve code organization.

Allow DropArea to receive and process external data.

Introduced new variable containsDrag to QQuickDropAreaPrivate. This
replaces mimeData which was previously being used to determine if a
drop operation was currently occurring. The problem was that mimeData
was being externally destructed.

Also introduced accessor methods for getting color, html, image, text,
and urls out of the drop. This facilitates dropping of external data of
those types onto a DropArea.

Added example quick/externaldraganddrop.

Task-number: QTBUG-27498
Change-Id: I1420df7c161ea3399e49a23305273e106baa246f
Reviewed-by: Alan Alpert (Personal) <416365416c@gmail.com>

8 files changed, 283 insertions, 0 deletions

diff --git a/examples/quick/externaldraganddrop/DragAndDropTextItem.qml b/examples/quick/externaldraganddrop/DragAndDropTextItem.qml
new file mode 100644
index 0000000000..390a4b3abe
--- /dev/null
+++ b/examples/quick/externaldraganddrop/DragAndDropTextItem.qml
@@ -0,0 +1,92 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the examples 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 2.2
+
+Rectangle {
+    id: item
+    property string display
+    color: "#EEE"
+    Text {
+        anchors.fill: parent
+        text: item.display
+        wrapMode: Text.WordWrap
+    }
+    DropArea {
+        anchors.fill: parent
+        keys: ["text/plain"]
+        onEntered: {
+            item.color = "#FCC"
+        }
+        onExited: {
+            item.color = "#EEE"
+        }
+        onDropped: {
+            item.color = "#EEE"
+            if (drop.hasText) {
+                if (drop.proposedAction == Qt.MoveAction || drop.proposedAction == Qt.CopyAction) {
+                    item.display = drop.text
+                    drop.acceptProposedAction()
+                }
+            }
+        }
+    }
+    MouseArea {
+        id: mouseArea
+        anchors.fill: parent
+        drag.target: draggable
+    }
+    Item {
+        id: draggable
+        anchors.fill: parent
+        Drag.active: mouseArea.drag.active
+        Drag.hotSpot.x: 0
+        Drag.hotSpot.y: 0
+        Drag.mimeData: { "text/plain": item.display }
+        Drag.dragType: Drag.Automatic
+        Drag.onDragStarted: {
+        }
+        Drag.onDragFinished: {
+            if (dropAction == Qt.MoveAction) {
+                item.display = ""
+            }
+        }
+    } // Item
+}
diff --git a/examples/quick/externaldraganddrop/doc/images/qml-dnd2-example.png b/examples/quick/externaldraganddrop/doc/images/qml-dnd2-example.png
new file mode 100644
index 0000000000..e657d81795
--- /dev/null
+++ b/examples/quick/externaldraganddrop/doc/images/qml-dnd2-example.png
diff --git a/examples/quick/externaldraganddrop/doc/src/externaldraganddrop.qdoc b/examples/quick/externaldraganddrop/doc/src/externaldraganddrop.qdoc
new file mode 100644
index 0000000000..1251e6e1eb
--- /dev/null
+++ b/examples/quick/externaldraganddrop/doc/src/externaldraganddrop.qdoc
@@ -0,0 +1,38 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the documentation of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:FDL$
+** 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 Free Documentation License Usage
+** Alternatively, this file may be used under the terms of the GNU Free
+** Documentation License version 1.3 as published by the Free Software
+** Foundation and appearing in the file included in the packaging of
+** this file.  Please review the following information to ensure
+** the GNU Free Documentation License version 1.3 requirements
+** will be met: http://www.gnu.org/copyleft/fdl.html.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+/*!
+    \title Qt Quick Examples - externaldraganddrop
+    \example externaldraganddrop
+    \brief This is an example of drag and drop between Qml and other applications
+    \image qml-dnd2-example.png
+    \ingroup qtquickexamples
+
+    This example shows you how to respond to do drag and drop using MouseArea and DropArea.
+
+    Drag text between boxes, out of boxes into other applications, and from other applications into the boxes. Use option/ctrl to copy rather than move text when dragging between boxes.
+
+*/
diff --git a/examples/quick/externaldraganddrop/externaldraganddrop.pro b/examples/quick/externaldraganddrop/externaldraganddrop.pro
new file mode 100644
index 0000000000..646781e7d1
--- /dev/null
+++ b/examples/quick/externaldraganddrop/externaldraganddrop.pro
@@ -0,0 +1,11 @@
+TEMPLATE = app
+
+QT += quick qml
+SOURCES += main.cpp
+RESOURCES += externaldraganddrop.qrc
+
+EXAMPLE_FILES = \
+    DragAndDropTextItem.qml
+
+target.path = $$[QT_INSTALL_EXAMPLES]/quick/externaldraganddrop
+INSTALLS += target
diff --git a/examples/quick/externaldraganddrop/externaldraganddrop.qml b/examples/quick/externaldraganddrop/externaldraganddrop.qml
new file mode 100644
index 0000000000..f39d33dda7
--- /dev/null
+++ b/examples/quick/externaldraganddrop/externaldraganddrop.qml
@@ -0,0 +1,79 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the examples 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 2.2
+import QtQuick.Layouts 1.0
+
+Item {
+    id: root
+    width: 320
+    height: 480
+
+    ColumnLayout {
+
+        anchors.fill: parent
+        anchors.margins: 8
+
+        Text {
+            Layout.fillWidth: true
+            text: "Drag text into, out of, and between the boxes below."
+            wrapMode: Text.WordWrap
+        }
+
+        DragAndDropTextItem {
+            Layout.fillWidth: true
+            height: 142
+            display: "Sample Text"
+        }
+
+        DragAndDropTextItem {
+            Layout.fillWidth: true
+            height: 142
+            display: "Option/ctrl drag to copy instead of move text."
+        }
+
+        DragAndDropTextItem {
+            Layout.fillWidth: true
+            height: 142
+            display: "Drag out into other applications."
+        }
+
+    }
+}
diff --git a/examples/quick/externaldraganddrop/externaldraganddrop.qmlproject b/examples/quick/externaldraganddrop/externaldraganddrop.qmlproject
new file mode 100644
index 0000000000..359efae597
--- /dev/null
+++ b/examples/quick/externaldraganddrop/externaldraganddrop.qmlproject
@@ -0,0 +1,16 @@
+import QmlProject 1.1
+
+Project {
+    mainFile: "externaldraganddrop.qml"
+
+    /* Include .qml, .js, and image files from current directory and subdirectories */
+    QmlFiles {
+        directory: "."
+    }
+    JavaScriptFiles {
+        directory: "."
+    }
+    ImageFiles {
+        directory: "."
+    }
+}
diff --git a/examples/quick/externaldraganddrop/externaldraganddrop.qrc b/examples/quick/externaldraganddrop/externaldraganddrop.qrc
new file mode 100644
index 0000000000..edac9820c9
--- /dev/null
+++ b/examples/quick/externaldraganddrop/externaldraganddrop.qrc
@@ -0,0 +1,6 @@
+<RCC>
+    <qresource prefix="/externaldraganddrop">
+        <file>externaldraganddrop.qml</file>
+        <file>DragAndDropTextItem.qml</file>
+    </qresource>
+</RCC>
diff --git a/examples/quick/externaldraganddrop/main.cpp b/examples/quick/externaldraganddrop/main.cpp
new file mode 100644
index 0000000000..33600e7983
--- /dev/null
+++ b/examples/quick/externaldraganddrop/main.cpp
@@ -0,0 +1,41 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the examples 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."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+#include "../shared/shared.h"
+DECLARATIVE_EXAMPLE_MAIN(externaldraganddrop/externaldraganddrop)