Doc: tutorial for developing an Android app

This tutorial explains how to create an app
that uses Qt Sensors QML module to move an
SVG image based on the changing accelerometer
values.

Change-Id: Id4d9c8b389c5b8ebb330c6dba2dee783a475ba17
Reviewed-by: Topi Reiniö <topi.reinio@digia.com>
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@digia.com>

doc/snippets/qml/tutorial_finalmainqml.qml

+/****************************************************************************
+**
+** 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.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** 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 2.1
+import QtQuick.Controls 1.0
+
+//! [sensorimport]
+import QtSensors 5.0
+//! [sensorimport]
+
+
+ApplicationWindow {
+    title: "Accelerate Bubble"
+    id: mainWindow
+    width: 320
+    height: 480
+    visible: true
+
+    Accelerometer {
+        id: accel
+        dataRate: 100
+        active:true
+
+
+//! [readingchanged]
+        onReadingChanged: {
+            var newX = (bubble.x + calcRoll(accel.reading.x, accel.reading.y, accel.reading.z) * 0.1)
+            var newY = (bubble.y - calcPitch(accel.reading.x, accel.reading.y, accel.reading.z) * 0.1)
+
+            if (newX < 0)
+                newX = 0
+
+            if (newX > mainWindow.width - bubble.width)
+                newX = mainWindow.width - bubble.width
+
+            if (newY < 18)
+                newY = 18
+
+            if (newY > mainWindow.height - bubble.height)
+                newY = mainWindow.height - bubble.height
+
+                bubble.x = newX
+                bubble.y = newY
+        }
+//! [readingchanged]
+    }
+
+//! [jsfunctions]
+    function calcPitch(x, y, z) {
+        return -(Math.atan(y / Math.sqrt(x * x + z * z)) * 57.2957795);
+    }
+    function calcRoll(x, y, z) {
+         return -(Math.atan(x / Math.sqrt(y * y + z * z)) * 57.2957795);
+    }
+//! [jsfunctions]
+
+    Image {
+        id: bubble
+        source: "Bluebubble.svg"
+        smooth: true
+        property real centerX: mainWindow.width / 2
+        property real centerY: mainWindow.height / 2;
+        property real bubbleCenter: bubble.width / 2
+        x: centerX - bubbleCenter
+        y: centerY - bubbleCenter
+
+//! [smoothedanim]
+        Behavior on y {
+            SmoothedAnimation {
+                easing.type: Easing.Linear
+                duration: 100
+            }
+        }
+        Behavior on x {
+            SmoothedAnimation {
+                easing.type: Easing.Linear
+                duration: 100
+            }
+        }
+//! [smoothedanim]
+   }
+}

doc/snippets/qml/tutorial_initialqml.qml

+/****************************************************************************
+**
+** 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.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** 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."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+//! [initialcode]
+import QtQuick 2.0
+
+Rectangle {
+    width: 100
+    height: 62
+}
+//! [initialcode]

doc/snippets/qml/tutorial_updatedmainview.qml

+/****************************************************************************
+**
+** 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.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** 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."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+//! [imports]
+import QtQuick 2.1
+import QtQuick.Controls 1.0
+//! [imports]
+
+ApplicationWindow {
+    title: "Accelerate Bubble"
+    id: mainWindow
+    width: 320
+    height: 480
+    visible: true
+
+    Image {
+        id: bubble
+        source: "Bluebubble.svg"
+        smooth: true
+        property real centerX: mainWindow.width / 2
+        property real centerY: mainWindow.height / 2
+        property real bubbleCenter: bubble.width / 2
+        x: centerX - bubbleCenter
+        y: centerY - bubbleCenter
+    }
+}

doc/snippets/tutorial_accelbubble.pro

+RESOURCES += \
+    accelbubble.qrc
+
+SOURCES += \
+    main.cpp
+
+QT += quick sensors svg xml

doc/snippets/tutorial_main.cpp

+/****************************************************************************
+**
+** 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.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** 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 <QtGui/QGuiApplication>
+#include <QtQml/QQmlApplicationEngine>
+
+int main(int argc, char *argv[])
+{
+    QGuiApplication app(argc, argv);
+    QQmlApplicationEngine engine(QUrl("qrc:///accelbubble.qml"));
+
+    return app.exec();
+}
+

doc/src/android/creator-android-app-tutorial.qdoc

+/****************************************************************************
+**
+** Copyright (c) 2013 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of Qt Creator
+**
+**
+** GNU Free Documentation License
+**
+** 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.
+**
+**
+****************************************************************************/
+
+// **********************************************************************
+// NOTE: the sections are not ordered by their logical order to avoid
+// reshuffling the file each time the index order changes (i.e., often).
+// Run the fixnavi.pl script to adjust the links to the index order.
+// **********************************************************************
+
+/*!
+    \contentspage index.html
+    \previouspage creator-writing-program.html
+    \page creator-android-app-tutorial.html
+    \nextpage creator-project-managing.html
+
+    \title Creating an Android Application
+
+    This tutorial describes developing Qt Quick applications for Android devices
+    using Qt Quick Controls.
+
+    This tutorial describes how to use \QC to implement a Qt Quick application
+    that accelerates an SVG (Scalable Vector Graphics) image based on the
+    changing accelerometer values.
+
+    \image creator_android_tutorial_ex_app.png
+
+    \section1 Creating the Project
+
+    Let us start with creating an empty Qt project.
+
+    \list 1
+
+        \li Select \gui{File > New File or Project > Other Project >
+            Empty Qt Project > Choose}.
+
+        \li In the \gui{Name} field, type \b{accelbubble}.
+
+        \li In the \gui {Create in} field, enter the path for the project files.
+            For example, \c {C:\Qt\examples}, and then click \gui{Next} (on
+            Mac OS X, it is \gui Continue).
+
+        \li Select an Android \l{glossary-buildandrun-kit}{kit} for arm,
+            and click \gui{Next}.
+
+            \note Kits are listed if they have been specified in \gui Tools >
+            \gui Options > \gui{Build & Run} > \gui Kits.
+
+        \li Select \gui Next in the following dialogs to use the default
+            settings.
+
+        \li Review the project settings, and click \gui{Finish} (on Mac OS X,
+            it is \gui Done).
+    \endlist
+
+    \QC creates the project and displays its contents under the \gui Projects
+    view on the sidebar. You can only see a .pro file under the project as we
+    created an empty project, but the remaining bits will be added
+    during the course of this tutorial.
+
+    \section1 Creating the Main View
+
+    The main view of the application displays an SVG bubble image at the center
+    of the main window.
+
+    \list 1
+
+        \li In the \gui Edit mode, right-click on the \b{accelbubble} project
+            and select \gui{Add new} to open the \gui{New File} dialog.
+
+        \li Select \gui{Qt > QML File (Qt Quick 2)} and click \gui Choose to
+            give a name to the QML file.
+
+        \li In the \gui Name field, type "accelbubble" and select \gui Next.
+
+        \li Select \gui Finish to add accelbubble.qml to the project.
+    \endlist
+
+    \QC adds a default QML file containing a Rectangle. Here is how the QML
+    file looks:
+
+    \snippet qml/tutorial_initialqml.qml initialcode
+
+    Now let us edit accelbubble.qml to add the bits required for our
+    application.
+
+    \list 1
+
+        \li Replace the existing import statement with the following:
+
+            \snippet qml/tutorial_updatedmainview.qml imports
+
+        \li Replace the Rectangle type with ApplicationWindow, which
+            will be the top-level window for our application.
+
+        \li Set the \a id, \a title, \a visible, and the window dimension
+            properties (width and height) with the values given in the
+            following snippet:
+
+            \quotefromfile qml/tutorial_updatedmainview.qml
+            \skipto ApplicationWindow
+            \printuntil true
+            \skipto /^\}/
+            \printuntil }
+    \endlist
+
+    \section1 Adding an SVG Image
+
+    SVG is an XML-based image format that enables you to combine vector
+    graphics, raster graphics, and text into one image. It is based on
+    an open standard developed and maintained by \l{http://www.w3.org/}{W3C}.
+
+    Qt supports the \l{http://www.w3.org/TR/SVGTiny12/}{SVGT} v1.2, which is a
+    trimmed version of the \l{http://www.w3.org/TR/SVG12/}{SVG Full v1.2}
+    specification, for mobile devices.
+
+    You can copy the Bluebubble.svg used by the Qt Sensors example, Accel
+    Bubble, to your project directory or find an SVG image that uses SVGT v1.2.
+
+    \note If you choose to create a new SVG image, ensure that the \a svg root
+    element has the \a version attribute with the value 1.1 or 1.2, and baseProfile
+    with \c tiny.
+
+    \list 1
+        \li Open accelbubble.qml in \gui Edit mode and add an Image type
+            within the ApplicationWindow.
+        \li Set the image \a id, \a source, and \a smooth properties as shown
+            in the following code block:
+
+            \quotefromfile qml/tutorial_updatedmainview.qml
+            \skipto Image
+            \printuntil true
+
+        \li Add the following new properties to the image:
+
+            \dots
+            \printuntil bubbleCenter:
+
+            \note These properties are used to position the image
+             at the center of ApplicationWindow when the application starts.
+        \li Set the x and y position of the image based on the new
+            properties.
+
+            \dots
+            \printuntil }
+    \endlist
+
+    Here is how the accelbubble.qml file looks after making the changes
+    mentioned earlier in this section:
+
+    \quotefromfile qml/tutorial_updatedmainview.qml
+    \skipto import QtQuick
+    \printuntil 1.0
+    \codeline
+    \skipto ApplicationWindow
+    \printuntil true
+
+    \skipto Image
+    \printuntil /^\}\
+
+
+    \section1 Moving the Bubble
+
+    Now that the visual elements are in place, let us move the bubble based on
+    Accelerometer sensor values.
+
+    \list 1
+        \li Add the following import statement to accelbubble.qml:
+
+            \snippet qml/tutorial_finalmainqml.qml sensorimport
+
+        \li Add the Accelerometer type with the necessary properties as shown
+            in the following code block:
+
+            \quotefromfile qml/tutorial_finalmainqml.qml
+            \skipto Accelerometer
+            \printuntil true
+            \skipto }
+            \printuntil }
+
+        \li Add the following JavaScript functions that calculate the
+            x and y position of the bubble based on the current Accelerometer
+            values:
+
+            \snippet qml/tutorial_finalmainqml.qml jsfunctions
+
+        \li Add the following JavaScript code for \a onReadingChanged signal of
+            Accelerometer type to make the bubble move when the Accelerometer
+            values change:
+
+            \snippet qml/tutorial_finalmainqml.qml readingchanged
+
+        \li Add SmoothedAnimation behavior on the \a x and \a y properties of
+            the bubble to make its movement look smoother.
+
+            \snippet qml/tutorial_finalmainqml.qml smoothedanim
+     \endlist
+
+
+    \section1 Running the Application
+
+    The main view is complete but the application is not ready yet. This
+    section provides instructions to add a few lines of C++ code that loads the
+    QML file when you try to run the application on an Android device.
+
+    \list 1
+        \li Right-click on the project in \gui Edit mode and select
+            \gui{Add New > Qt > Qt Resource File}.
+
+        \li Name the resource file as \a accelbubble.qrc and click \gui Next.
+
+        \li Select \gui Finish in the following dialog to add the resource file
+            to the project and open it in \gui Edit mode.
+
+        \li Select \gui {Add > Add Prefix} and add \c / as the prefix.
+
+            \note The prefix is used every time you refer to the .qrc file
+                  contents from the C++ code.
+
+        \li Select \gui {Add > Add Files} and add accelbubble.qml and Bluebubble.svg
+            to the resource file.
+
+        \li Right-click on the project in \gui Edit mode and select
+            \gui {Add New} to open the \gui {New File} dialog.
+
+        \li Select \gui {C++ > C++ Source File > Choose}
+
+        \li Name the file as \a main.cpp and click \gui Next.
+
+        \li Select \gui Finish to add main.cpp to the project and open it in
+            edit mode.
+
+        \li Add the following lines of C++ code to main.cpp to load the
+            accelbubble.qml file from accelbubble.qrc:
+
+            \quotefromfile tutorial_main.cpp
+            \skipto #include
+            \printuntil }
+
+        \li Update the accelbubble.pro file with the following library
+            dependency information:
+
+            \code
+              QT += quick sensors svg xml
+            \endcode
+    \endlist
+
+    The application is complete and ready to be deployed to the device.
+    Enable "USB Debugging" on your Android device and connect it to your PC.
+    If you are using a device running Android v4.2.2, it should prompt you to
+    verify the connection to allow USB debugging from the PC it is connected
+    to. To avoid such prompts every time you connect the device, check
+    "Always allow from the computer" and select \gui OK.
+
+    To run the application on the device, press CTRL + R keys in \QC
+    \gui Edit mode.
+
+    \section1 Example Code
+
+    When you have completed the steps mentioned in the earlier sections, the
+    accelbubble.qml, main.cpp, and accelbubble.pro files look as follows:
+
+    \section2 accelbubble.qml
+
+    \quotefile qml/tutorial_finalmainqml.qml
+
+    \section2 main.cpp
+
+    \quotefile tutorial_main.cpp
+
+    \section2 accelbubble.pro
+
+    \quotefile tutorial_accelbubble.pro
+*/

doc/src/overview/creator-tutorials.qdoc

@@ -46,6 +46,11 @@
 
             Learn how to create a Qt widget based application for the desktop.
 
+       \li \l{Creating an Android Application}
+
+            Learn how to create a Qt Quick application using Qt Quick Controls
+            for Android devices.
+
     \endlist
 
 */

doc/src/projects/creator-projects-overview.qdoc

@@ -24,7 +24,7 @@
 
 /*!
     \contentspage index.html
-    \previouspage creator-writing-program.html
+    \previouspage creator-android-app-tutorial.html
     \page creator-project-managing.html
     \nextpage creator-project-creating.html
 

doc/src/qtcreator.qdoc

@@ -154,6 +154,7 @@
             \list
                 \li \l{Creating a Qt Quick Application}
                 \li \l{Creating a Qt Widget Based Application}
+                \li \l{Creating an Android Application}
             \endlist
         \endlist
         \li \l{Managing Projects}

doc/src/widgets/qtdesigner-app-tutorial.qdoc

@@ -26,7 +26,7 @@
     \contentspage index.html
     \previouspage creator-qml-application.html
     \page creator-writing-program.html
-    \nextpage creator-project-managing.html
+    \nextpage creator-android-app-tutorial.html
 
     \title Creating a Qt Widget Based Application