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diff --git a/doc/src/examples/symbianvibration.qdoc b/doc/src/examples/symbianvibration.qdoc new file mode 100644 index 0000000000..cd88ee2594 --- /dev/null +++ b/doc/src/examples/symbianvibration.qdoc @@ -0,0 +1,192 @@ +/**************************************************************************** +** +** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies). +** All rights reserved. +** Contact: Nokia Corporation (qt-info@nokia.com) +** +** This file is part of the documentation of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:FDL$ +** 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. +** +** Other Usage +** Alternatively, this file may be used in accordance with the terms +** and conditions contained in a signed written agreement between you +** and Nokia. +** +** +** +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +/*! \example widgets/symbianvibration + \group all-examples + \title Symbian Vibration Example + + The Symbian Vibrator example shows how to get fine-grained vibration + control on Symbian devices. + + Native Symbian APIs have to be used to enable vibration, since QtMobility + doesn't provide an interface for it yet. It is, however, planned to be + included in a future release. In anticipation for that, we make use of the + \c XQVibra class that was a part of the Mobile Extensions Technology Preview + API for Qt for Symbian. The pre-compiled libraries are no longer compatible + with Qt 4.6, but we can include the source code itself with the project. + + \image symbianvibration-example.png Screenshot of the Symbian Vibration example + + The example application divides the window into rectangles, which can be + pressed to make the device vibrate. Pressing different rectangles make the + device vibrate with different intensities. Each rectangle has a different + color and its intensity number is drawn on top of it. Moving the cursor + from one rectangle to another changes the vibration intensity to that of + the new one. Vibration stops when the mouse button has been released. It + is also possible to launch a short burst of vibration through the menu. + + The example consists of four classes: + + \list + \o \c XQVibra is the vibration interface class taken from the Mobile + Extensions for Qt for Symbian. + + \o \c XQVibraPrivate is the Symbian specific private implementation of the + vibration implementation. + + \o \c VibrationSurface is a custom widget that uses a XQVibra instance to + vibrate the device depending on where the user presses. + + \o \c MainWindow inherits from QMainWindow and contains a \c VibrationSurface + as its central widget, and also has a menu from which it is possible to + make the phone vibrate. + \endlist + + \section1 XQVibra Class Definition + + The \c XQVibra class uses the pimpl-idiom to hide the platform specific + implementation behind a common interface. Technically it would be possible + to support more target platforms, with only the addition of a private + implementation. The rest of the code would work the same, since only the + common interface is used. + + \snippet examples/widgets/symbianvibration/xqvibra.h 0 + + \c XQVibra provides a very simple interface for us to use. The interesting + part are the three slots \c start(), \c stop() and \c setIntensity(). Calling the start + method initiates vibration for the specified duration. Calling it while the + device is already vibrating causes it to stop the current one and start the + new one, even if the intensities are the same. The \c setIntensity() method + should be called before starting vibration. + + + \section1 VibrationSurface Class Definition + + \c VibrationSurface inherits from QWidget and acts like a controller for a + \c XQVibra object. It responds to mouse events and performs custom painting. + + \snippet examples/widgets/symbianvibration/vibrationsurface.h 0 + + The virtual event methods are reimplemented from QWidget. As can be seen, + there is no public programmable interface beyond what QWidget provides. + + + \section1 VibrationSurface Class Implementation + + Mouse events control the intensity of the vibration. + + \snippet examples/widgets/symbianvibration/vibrationsurface.cpp 0 + \codeline + \snippet examples/widgets/symbianvibration/vibrationsurface.cpp 1 + \codeline + \snippet examples/widgets/symbianvibration/vibrationsurface.cpp 2 + + Presses starts the vibration, movement changes the intensity and releases + stops the vibration. To set the right amount of vibration, the private + method \c applyIntensity() is used. It sets the vibration intensity according to + which rectangle the mouse currently resides in. + + \snippet examples/widgets/symbianvibration/vibrationsurface.cpp 3 + + We make sure only to change the intensity if it is different than last + time, so that the vibrator isn't stopped and restarted unnecessarily. + + The range of vibration intensity ranges from 0 to XQVibra::MaxIntensity. We + divide this range into a set of levels. The number of levels and the intensity + increase for each level are stored in two constants. + + \snippet examples/widgets/symbianvibration/vibrationsurface.cpp 4 + + Each rectangle has an intensity of one \c IntensityPerLevel more than the + previous one. + + \snippet examples/widgets/symbianvibration/vibrationsurface.cpp 5 + + The rectangles are either put in a row, if the widget's width is greater + than its height (landscape), otherwise they are put in a column (portrait). + Each rectangle's size is thus dependent on the length of the width or the + height of the widget, whichever is longer. The length is then divided by + the number of levels, which gets us either the height or the width of each + rectangle. The dx and dy specify the distance from one rectangle to the + next, which is the same as either the width or height of the rectangle. + + \snippet examples/widgets/symbianvibration/vibrationsurface.cpp 6 + + For each level of intensity, we draw a rectangle with increasing + brightness. On top of the rectangle a text label is drawn, specifying the + intesity of this level. We use the rectangle rect as a template for + drawing, and move it down or right at each iteration. + + The intensity is calculated by dividing the greater of the width and height + into \c NumberOfLevels slices. + + \snippet examples/widgets/symbianvibration/vibrationsurface.cpp 7 + + In case the widget's geometry is too small to fit all the levels, the user + interface will not work. For simplicity, we just return 0. + + When we know the axis along which the rectangles lie, we can find the one + in which the mouse cursor lie. + + \snippet examples/widgets/symbianvibration/vibrationsurface.cpp 8 + + The final clamp of the intensity value at the end is necessary in case the + mouse coordinate lies outside the widget's geometry. + + + \section1 MainWindow Class Definition + + Here's the definition of the \c MainWindow class: + + \snippet examples/widgets/symbianvibration/mainwindow.h 0 + + \c MainWindow is a top level window that uses a \c XQVibra and a + \c VibrationSurface. It also adds a menu option to the menu bar which can + start a short vibration. + + \section1 MainWindow Class Implementation + + In the \c MainWindow constructor the \c XQVibra and the \c VibrationSurface + are created. An action is added to the menu and is connected to the vibrate + slot. + + \snippet examples/widgets/symbianvibration/mainwindow.cpp 0 + + The \c vibrate() slot offers a way to invoke the vibration in case no + mouse is present on the device. + + \snippet examples/widgets/symbianvibration/mainwindow.cpp 1 + + \section1 Symbian Vibration Library + + The \c XQVibra class requires a platform library to be included. It is + included in the \c .pro file for the symbian target. + + \quotefromfile examples/widgets/symbianvibration/symbianvibration.pro + \skipto /^symbian \{/ + \printuntil /^\}/ +*/ |