From 1794c3b7a1f2b27aaadfc20cea587284e336080e Mon Sep 17 00:00:00 2001 From: Casper van Donderen Date: Tue, 8 May 2012 11:13:18 +0200 Subject: Doc: Modularize QtPrintSupport documentation. This change moves the snippets and images to the modularized directories. Change-Id: Ib8f8556bcef13593ee40ac1122d765ed307ecb93 Reviewed-by: Marius Storm-Olsen --- src/printsupport/doc/src/printing.qdoc | 189 +++++++++++++++++++++++++++++++++ 1 file changed, 189 insertions(+) create mode 100644 src/printsupport/doc/src/printing.qdoc (limited to 'src/printsupport/doc/src/printing.qdoc') diff --git a/src/printsupport/doc/src/printing.qdoc b/src/printsupport/doc/src/printing.qdoc new file mode 100644 index 0000000000..cc79b41704 --- /dev/null +++ b/src/printsupport/doc/src/printing.qdoc @@ -0,0 +1,189 @@ +/**************************************************************************** +** +** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies). +** Contact: http://www.qt-project.org/ +** +** 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. +** +** +** +** +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +/*! + \group printing + \title Printer and Printing APIs + \brief Classes for producing printed output + \ingroup groups +*/ + +/*! + \page printing.html + \title Printing with Qt + \ingroup qt-graphics + + \previouspage Styling + \contentspage The Paint System + + \brief A guide to producing printed output with Qt's paint system and widgets. + + Qt provides extensive cross-platform support for printing. Using the printing + systems on each platform, Qt applications can print to attached printers and + across networks to remote printers. Qt's printing system also enables PostScript + and PDF files to be generated, providing the foundation for basic report + generation facilities. + + \tableofcontents + + \section1 Classes Supporting Printing + + The following classes support the selecting and setting up of printers and + printing output. + + \annotatedlist printing + + \section1 Paint Devices and Printing + + In Qt, printers are represented by QPrinter, a paint device that provides + functionality specific to printing, such as support for multiple pages and + double-sided output. As a result, printing involves using a QPainter to paint + onto a series of pages in the same way that you would paint onto a custom + widget or image. + + \section2 Creating a QPrinter + + Although QPrinter objects can be constructed and set up without requiring user + input, printing is often performed as a result of a request by the user; + for example, when the user selects the \gui{File|Print...} menu item in a GUI + application. In such cases, a newly-constructed QPrinter object is supplied to + a QPrintDialog, allowing the user to specify the printer to use, paper size, and + other printing properties. + + \snippet richtext/orderform/mainwindow.cpp 18 + + It is also possible to set certain default properties by modifying the QPrinter + before it is supplied to the print dialog. For example, applications that + generate batches of reports for printing may set up the QPrinter to + \l{QPrinter::setOutputFileName()}{write to a local file} by default rather than + to a printer. + + \section2 Painting onto a Page + + Once a QPrinter object has been constructed and set up, a QPainter can be used + to perform painting operations on it. We can construct and set up a painter in + the following way: + + \snippet printing-qprinter/object.cpp 0 + + Since the QPrinter starts with a blank page, we only need to call the + \l{QPrinter::}{newPage()} function after drawing each page, except for the + last page. + + The document is sent to the printer, or written to a local file, when we call + \l{QPainter::}{end()}. + + \section2 Coordinate Systems + + QPrinter provides functions that can be used to obtain information about the + dimensions of the paper (the paper rectangle) and the dimensions of the + printable area (the page rectangle). These are given in logical device + coordinates that may differ from the physical coordinates used by the device + itself, indicating that the printer is able to render text and graphics at a + (typically higher) resolution than the user's display. + + Although we do not need to handle the conversion between logical and physical + coordinates ourselves, we still need to apply transformations to painting + operations because the pixel measurements used to draw on screen are often + too small for the higher resolutions of typical printers. + + \table + \row \li \b{Printer and Painter Coordinate Systems} + + The \l{QPrinter::}{paperRect()} and \l{QPrinter::}{pageRect()} functions + provide information about the size of the paper used for printing and the + area on it that can be painted on. + + The rectangle returned by \l{QPrinter::}{pageRect()} usually lies inside + the rectangle returned by \l{QPrinter::}{paperRect()}. You do not need to + take the positions and sizes of these area into account when using a QPainter + with a QPrinter as the underlying paint device; the origin of the painter's + coordinate system will coincide with the top-left corner of the page + rectangle, and painting operations will be clipped to the bounds of the + drawable part of the page. + + \li \inlineimage printer-rects.png + \endtable + + The paint system automatically uses the correct device metrics when painting + text but, if you need to position text using information obtained from + font metrics, you need to ensure that the print device is specified when + you construct QFontMetrics and QFontMetricsF objects, or ensure that each QFont + used is constructed using the form of the constructor that accepts a + QPaintDevice argument. + + \section1 Printing Widgets + + To print a widget, you can use the QWidget::render() function. As mentioned, + the printer's resolution is usually higher than the screen resolution, so you + will have to scale the painter. You may also want to position the widget on the + page. The following code sample shows how this may look. + + \snippet widgetprinting.cpp 0 + + This will center the widget on the page and scale it so that it fits the page. + + \section1 Printing from Complex Widgets + + Certain widgets, such as QTextEdit and QGraphicsView, display rich content + that is typically managed by instances of other classes, such as QTextDocument + and QGraphicsScene. As a result, it is these content handling classes that + usually provide printing functionality, either via a function that can be used + to perform the complete task, or via a function that accepts an existing + QPainter object. Some widgets provide convenience functions to expose underlying + printing features, avoiding the need to obtain the content handler just to call + a single function. + + The following table shows which class and function are responsible for + printing from a selection of different widgets. For widgets that do not expose + printing functionality directly, the content handling classes containing this + functionality can be obtained via a function in the corresponding widget's API. + + \table + \header \li Widget \li Printing function \li Accepts + \row \li QGraphicsView \li QGraphicsView::render() \li QPainter + \row \li QSvgWidget \li QSvgRenderer::render() \li QPainter + \row \li QTextEdit \li QTextDocument::print() \li QPrinter + \row \li QTextLayout \li QTextLayout::draw() \li QPainter + \row \li QTextLine \li QTextLine::draw() \li QPainter + \endtable + + QTextEdit requires a QPrinter rather than a QPainter because it uses information + about the configured page dimensions in order to insert page breaks at the most + appropriate places in printed documents. +*/ + +/*! + \page pdf-licensing.html + \title Notes about PDF Licensing + \ingroup licensing + \brief Details of restrictions on the use of PDF-related trademarks. + + Please note that Adobe\reg places restrictions on the use of its trademarks + (including logos) in conjunction with PDF; e.g. "Adobe PDF". Please refer + to \l{http://www.adobe.com}{www.adobe.com} for guidelines. +*/ -- cgit v1.2.3