qt-creator/doc/src/qtquick/creator-mobile-app-tutorial.qdoc

/****************************************************************************
**
** Copyright (c) 2014 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 {Qt Creator Manual}
    \previouspage creator-writing-program.html
    \page creator-mobile-app-tutorial.html
    \nextpage creator-project-managing.html

    \title Creating a Mobile Application

    This tutorial describes developing Qt Quick applications for Android and iOS
    devices using Qt Quick Controls.
    We 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 Setting up the Development Environment

    To be able to build and run the application on a mobile device, you must
    set up the development environment for the device platform and configure a
    connection between \QC and the mobile device.

    To develop for Android  devices, you must download and install
    the latest Android NDK and SDK, and update the SDK to get the API and tools
    needed for development. In addition, you must install the
    Java SE Development Kit (JDK) and Apache Ant. After you have installed all
    these tools, you must specify the paths to them in \QC.
    For detailed instructions, see \l{Qt for Android} and
    \l{Connecting Android Devices}.

    To develop for iOS devices, you must install Xcode and use it to configure
    a device. For this, you need an Apple developer account and iOS Developer
    Program certificate that you receive from Apple. For more information, see
    \l{Connecting iOS Devices}.

    \section1 Creating the Project

    \list 1

        \li Select \uicontrol File > \uicontrol {New File or Project} > \uicontrol Application >
            \uicontrol {Qt Quick Application} > \uicontrol Choose.

        \li In the \uicontrol{Name} field, type \b{accelbubble}.

        \li In the \uicontrol {Create in} field, enter the path for the project files.
            For example, \c {C:\Qt\examples}, and then click \uicontrol{Next} (or
            \uicontrol Continue on OS X).

        \li In the \uicontrol {Qt Quick component set} field, select
            \uicontrol {Qt Quick Controls 1.1}.

        \li Select \l{glossary-buildandrun-kit}{kits} for Android ARM and iPhone
            OS, and click \uicontrol{Next}.

            \note Kits are listed if they have been specified in \uicontrol Tools >
            \uicontrol Options > \uicontrol {Build & Run} > \uicontrol Kits (on Windows and Linux)
            or in \uicontrol {Qt Creator} > \uicontrol Preferences \uicontrol {Build & Run} >
            \uicontrol Kits (on OS X).

        \li Select \uicontrol Next in the following dialogs to use the default
            settings.

        \li Review the project settings, and click \uicontrol{Finish} (or \uicontrol Done on
            OS X).

    \endlist

    \QC generates a default QML file that you can modify to create the main view
    of the application.

    \section1 Creating the Main View

    The main view of the application displays an SVG bubble image at the center
    of the main window.

    To use the Bluebubble.svg used by the Qt Sensors example, Accel Bubble, in
    your project, you must copy it to the project directory (same subdirectory
    as the QML file) from the examples directory in the Qt installation
    directory. For example:
    \c {C:\Qt\Qt5.2.0\5.2.0\msvc2010\examples\sensors\accelbubble\content}.
    The image appears in \uicontrol Resources. You can also use any other
    image or a QML type, instead.

    \list 1

        \li In the \uicontrol Projects view, double-click the main.qml file
            to open it in the code editor.

        \li Modify the properties of the ApplicationWindow type to specify the
            application name, give the ApplicationWindow an id, and to set it
            visible, as illustrated by the following code snippet:

            \quotefromfile accelbubble/main.qml
            \skipto ApplicationWindow
            \printuntil visible
            \skipto /^\}/
            \printuntil }

        \li Click \uicontrol Design to open the file in \QMLD.

        \li In the \uicontrol Navigator, select \uicontrol Label and press \key Delete
            to delete it.

        \li In \uicontrol Library > \uicontrol Resources, select Bluebubble.svg
            and drag and drop it to the canvas.

        \li In the \uicontrol Properties pane, \uicontrol Id field, enter \e bubble to be
            able to reference the image from other places.

        \li In the code editor, add the following new properties to the image to
            position the image at the center of ApplicationWindow when the
            application starts:

            \quotefromfile accelbubble/main.qml
            \skipto Image
            \printuntil bubble.width

         \li Set the x and y position of the image based on the new
            properties:

            \dots
            \printuntil centerY
            \skipto /^\}/
            \printuntil }
    \endlist

    Here is how the accelbubble.qml file looks after you made the changes:

    \quotefromfile accelbubble/main.qml
    \skipto import QtQuick
    \printuntil 1.1
    \codeline
    \skipto ApplicationWindow
    \printuntil true
    \skipto Image
    \printuntil y:
    \skipto /^\}/
    \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 main.qml:

            \code
            import QtSensors 5.0
            \endcode

        \li Add the \l{Accelerometer} type with the necessary properties:

            \quotefromfile accelbubble/main.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:

            \quotefromfile accelbubble/main.qml
            \skipto function
            \printuntil Math.atan(x
            \printuntil }

        \li Add the following JavaScript code for \a onReadingChanged signal of
            Accelerometer type to make the bubble move when the Accelerometer
            values change:

            \quotefromfile accelbubble/main.qml
            \skipto onReadingChanged
            \printuntil }

            We want to ensure that the position of the bubble is always within
            the bounds of the screen. If the Accelerometer returns not a number
            (NaN), the value is ignored and the bubble position is not updated.
        \li Add SmoothedAnimation behavior on the \a x and \a y properties of
            the bubble to make its movement look smoother.

            \quotefromfile accelbubble/main.qml
            \skipto Behavior
            \printuntil x
            \printuntil }
            \printuntil }
     \endlist

     \section1 Locking Device Orientation

     The device display is rotated by default when the device orientation
     changes between portrait and landscape. For this example, it would be
     better for the screen orientation to be fixed.

    To lock the orientation to portrait or landscape on Android, specify it in
    an AndroidManifest.xml that you can generate in \QC. For more information,
    see \l{Editing Manifest Files}.

    On iOS, you can lock the device orientation in a Info.plist file that you
    specify in the .pro file as the value of the QMAKE_INFO_PLIST variable.

    \section1 Adding Dependencies

    Update the accelbubble.pro file with the following library dependency
    information:

    \code
    QT += quick sensors svg xml
    \endcode

    On iOS, you must link to the above libraries statically, by adding the
    plugin names explicitly as values of the QTPLUGIN variable. Specify a
    qmake scope for iOS builds (which can also contain the QMAKE_INFO_PLIST
    variable):

    \code
    ios {
    QTPLUGIN += qsvg qsvgicon qtsensors_ios
    QMAKE_INFO_PLIST = Info.plist
    }
    \endcode

    After adding the dependencies, select \uicontrol Build > \uicontrol {Run qmake} to apply
    the changes to the Makefile of the project.

    \section1 Adding Resources

    You need to add the Bluebubble.svg image file to the application resources
    for deployment to mobile devices:

    \list 1

        \li In the \uicontrol Projects view, double-click the qml.qrc file to open it
            in the resource editor.

        \li Select \uicontrol Add to add Bluebubble.svg.

    \endlist

    \section1 Running the Application

    The application is complete and ready to be deployed to a device:

    \list 1

        \li Enable \e{USB Debugging} on the Android device or \e{developer mode}
            on the iOS device.

        \li Connect the device to the development 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 \uicontrol OK.

        \li To run the application on the device, press \key {Ctrl+R}.

    \endlist

    \section1 Example Code

    When you have completed the steps, the main.qml file should look as follows:

    \quotefromfile accelbubble/main.qml
    \skipto import
    \printuntil /^\}/

*/