From 084306783828839b957ef5073a477122f7aed679 Mon Sep 17 00:00:00 2001 From: Christiaan Janssen Date: Tue, 18 Dec 2012 13:00:29 +0100 Subject: Qt Gui Examples: Fixed QDoc files Change-Id: I160d8d186a1078f20f2b779bfbdae90459c27641 Reviewed-by: Jerome Pasion --- examples/gui/doc/rasterwindow.qdoc | 161 ------------------------------------- 1 file changed, 161 deletions(-) delete mode 100644 examples/gui/doc/rasterwindow.qdoc (limited to 'examples/gui/doc/rasterwindow.qdoc') diff --git a/examples/gui/doc/rasterwindow.qdoc b/examples/gui/doc/rasterwindow.qdoc deleted file mode 100644 index f246533c4f..0000000000 --- a/examples/gui/doc/rasterwindow.qdoc +++ /dev/null @@ -1,161 +0,0 @@ -**************************************************************************** -** -** Copyright (C) 2012 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. -** $QT_END_LICENSE$ -** -****************************************************************************/ - -/*! - \example rasterwindow - \title Raster Window Example - - \brief This example shows how to create a minimal QWindow based - application using QPainter for rendering. - - - \section1 Application Entry Point - - \snippet rasterwindow/main.cpp 1 - - The entry point for a QWindow based application is the \l - QGuiApplication class. It manages the GUI application's control - flow and main settings. We pass the command line arguments which - can be used to pick up certain system wide options. - - From there, we go on to create our window instance and then call - the \l QWindow::show() function to tell the windowing system that - this window should now be made visible on screen. - - Once this is done, we enter the application's event loop so the - application can run. - - - \section1 RasterWindow Declaration - - \snippet rasterwindow/rasterwindow.h 1 - - We first start by including the the QtGui headers. This means we - can use all classes in the Qt GUI module. Classes can also be - included individually if that is preferred. - - The RasterWindow class subclasses QWindow directly and provides a - constructor which allows the window to be a sub-window of another - QWindow. Parent-less QWindows show up in the windowing system as - top-level windows. - - The class declares a QBackingStore which is what we use to manage - the window's back buffer for QPainter based graphics. - - \e {The raster window is also reused in a few other examples and adds - a few helper functions, like renderLater().} - - - \section1 RasterWindow Implementation - - \snippet rasterwindow/rasterwindow.cpp 1 - - The constructor first of all calls \l QWindow::create(). This will - create the window in the windowing system. Without calling create, - the window will not get events and will not be visible in the - windowing system. The call to create does not show the window. We - then set the geometry to be something reasonable. - - Then we create the backingstore and pass it the window instance it - is supposed to manage. - - \snippet rasterwindow/rasterwindow.cpp 2 - - Shortly after calling \l QWindow::show() on a created window, the - virtual function \l QWindow::exposeEvent() will be called to - notify us that the window's exposure in the windowing system has - changed. The event contains the exposed sub-region, but since we - will anyway draw the entire window every time, we do not make use - of that. - - The function \l QWindow::isExposed() will tell us if the window is - showing or not. We need this as the exposeEvent is called also - when the window becomes obscured in the windowing system. If the - window is showing, we call renderNow() to draw the window - immediately. We want to draw right away so we can present the - system with some visual content. - - - \snippet rasterwindow/rasterwindow.cpp 5 - - The resize event is guaranteed to be called prior to the window - being shown on screen and will also be called whenever the window - is resized while on screen. We use this to resize the back buffer - and call renderNow() if we are visible to immediately update the - visual representation of the window on screen. - - \snippet rasterwindow/rasterwindow.cpp 3 - - The renderNow function sets up what is needed for a \l QWindow to - render its content using QPainter. As obscured windows have will - not be visible, we abort if the window is not exposed in the - windowing system. This can for instance happen when another window - fully obscures this window. - - We start the drawing by calling \l QBackingStore::beginPaint() on - the region we want to draw. Then we get the \l QPaintDevice of the - back buffer and create a QPainter to render to that paint device. - - To void leaving traces from the previous rendering and start with a - clean buffer, we fill the entire buffer with the color white. Then - we call the virtual render() function which does the actual - drawing of this window. - - After drawing is complete, we call endPaint() to signal that we - are done rendering and present the contents in the back buffer - using \l QBackingStore::flush(). - - - \snippet rasterwindow/rasterwindow.cpp 4 - - The render function contains the drawing code for the window. In - this minial example, we only draw the string "QWindow" in the - center. - - - \section1 Rendering Asynchronously - - - \snippet rasterwindow/rasterwindow.cpp 6 - - We went through a few places where the window needed to repainted - immediately. There are some cases where this is not desierable, - but rather let the application return to the event loop and - later. We acheive this by posting an even to ourself which will - then be delivered when the application returns to the \l - QGuiApplication event loop. To avoid posting new requests when one - is already pending, we store this state in the \c m_update_pending - variable. - - \snippet rasterwindow/rasterwindow.cpp 7 - - We reimplement the virtual \l QObject::event() function to handle - the update event we posted to ourselves. When the event comes in - we reset the pending update flag and call renderNow() to render - the window right away. - - */ -- cgit v1.2.3