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diff --git a/doc/src/examples/wheel.qdoc b/doc/src/examples/wheel.qdoc deleted file mode 100644 index 995ff87..0000000 --- a/doc/src/examples/wheel.qdoc +++ /dev/null @@ -1,109 +0,0 @@ -/**************************************************************************** -** -** Copyright (C) 2011 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. -** -** $QT_BEGIN_LICENSE:FDL$ -** No Commercial Usage -** This file contains pre-release code and may not be distributed. -** You may use this file in accordance with the terms and conditions -** contained in the Technology Preview License Agreement accompanying -** this package. -** -** 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. -** -** If you have questions regarding the use of this file, please contact -** Nokia at qt-info@nokia.com. -** $QT_END_LICENSE$ -** -****************************************************************************/ - -/*! - \example scroller/wheel - \title Wheel Scroller Example - - The Wheel Scroller Example shows how to use QScroller, QScrollEvent - and QScrollPrepareEvent to implement smooth scrolling for a - custom Widget. - - \section1 Basics - - The QScroller class is the main part of the smooth scrolling - mechanism in Qt. It keeps track of the current scroll position and - speed and updates the object through events. - QScroller will get touch events via the QFlickGesture. - It will query the target object through a QScrollPrepareEvent for - the scroll area and other information. - QScroller will send QScrollEvents to inform the target object about - the current scroll position. - The target object (usually a QWidget or a QGraphicsObject) will - then need to update it's graphical representation to reflect the - new scroll position. - - \section1 The Wheel Widget class - - To demonstrate how to use the QScroller we implement a QWidget that - looks and works like the wheel of a slot machine. - The wheel can be started via touch events and will continue getting - slower. - Additionally the wheel should appear as if no border exists (which - would seem unnatural) and the scrolling should snap to center one - item. - - In the widget we need to grab the QFlickGesture. The gesture itself - will setAcceptTouchEvents for us, so we don't need to do that here. - - \snippet examples/scroller/wheel/wheelwidget.cpp 0 - - The widget will get gesture events but in addition we also will - get the events from QScroller. - We will need to accept the QScrollPrepareEvent to indicate that - a scrolling should really be started from the given position. - - \snippet examples/scroller/wheel/wheelwidget.cpp 1 - - We should call all three set functions form QScrollPrepareEvent. - - \list - \o \c setViewportSize to indicate our viewport size. Actually the - given code could be improved by giving our size minus the borders. - \o \c setMaxContentPos to indicate the maximum values for the scroll - position. The minimum values are implicitely set to 0. - In our example we give a very high number here and hope that the user - is not patient enough to scroll until the very end. - \o \c setContentPos to indicate the current scroll position. - We give a position in the middle of the huge scroll area. - Actually we give this position every time a new scroll is started so - the user will only reach the end if he continuously scrolls in one - direction which is not very likely. - \endlist - - The handling of the QScrollEvent is a lengthly code not fully shown here. - \snippet examples/scroller/wheel/wheelwidget.cpp 2 - - In principle it does three steps. - \list - \o It calculates and updates the current scroll position as given by - QScroller. - \o It repaints the widget so that the new position is shown. - \o It centers the item as soon as the scrolling stopps. - \endlist - - The following code does the centering. - \snippet examples/scroller/wheel/wheelwidget.cpp 3 - - We check if the scrolling is finished which is indicated in the - QScrollEvent by the \c isLast flag. - We then check if the item is not already centered and if not start a new - scroll by calling QScroller::scrollTo. - - As you can see the QScroller can be used for other things besides simple - scroll areas. -*/ |