<?xml version="1.0" encoding="iso-8859-1"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "DTD/xhtml1-strict.dtd"> <html><head><title>QStaticText Class Reference</title><style>h3.fn,span.fn { margin-left: 1cm; text-indent: -1cm } a:link { color: #004faf; text-decoration: none } a:visited { color: #672967; text-decoration: none } td.postheader { font-family: sans-serif } tr.address { font-family: sans-serif } body { background: #ffffff; color: black; } </style></head><body><table border="0" cellpadding="0" cellspacing="0" width="100%"><tr /><td align="left" valign="top" width="32"><img align="left" border="0" height="32" src="images/rb-logo.png" width="32" /></td><td width="1">  </td><td class="postheader" valign="center"><a href="index.html"><font color="#004faf">Home</font></a> · <a href="classes.html"><font color="#004faf">All Classes</font></a> · <a href="modules.html"><font color="#004faf">Modules</font></a></td></table><h1 align="center">QStaticText Class Reference<br /><sup><sup>[<a href="qtgui.html">QtGui</a> module]</sup></sup></h1><p>The QStaticText class enables optimized drawing of text when the text and its layout is updated rarely. <a href="#details">More...</a></p> <h3>Types</h3><ul><li><div class="fn" />enum <b><a href="qstatictext.html#PerformanceHint-enum">PerformanceHint</a></b> { ModerateCaching, AggressiveCaching }</li></ul><h3>Methods</h3><ul><li><div class="fn" /><b><a href="qstatictext.html#QStaticText">__init__</a></b> (<i>self</i>)</li><li><div class="fn" /><b><a href="qstatictext.html#QStaticText-2">__init__</a></b> (<i>self</i>, QString <i>text</i>)</li><li><div class="fn" /><b><a href="qstatictext.html#QStaticText-3">__init__</a></b> (<i>self</i>, QStaticText <i>other</i>)</li><li><div class="fn" />PerformanceHint <b><a href="qstatictext.html#performanceHint">performanceHint</a></b> (<i>self</i>)</li><li><div class="fn" /><b><a href="qstatictext.html#prepare">prepare</a></b> (<i>self</i>, QTransform <i>matrix</i> = QTransform(), QFont <i>font</i> = QFont())</li><li><div class="fn" /><b><a href="qstatictext.html#setPerformanceHint">setPerformanceHint</a></b> (<i>self</i>, PerformanceHint <i>performanceHint</i>)</li><li><div class="fn" /><b><a href="qstatictext.html#setText">setText</a></b> (<i>self</i>, QString <i>text</i>)</li><li><div class="fn" /><b><a href="qstatictext.html#setTextFormat">setTextFormat</a></b> (<i>self</i>, Qt.TextFormat <i>textFormat</i>)</li><li><div class="fn" /><b><a href="qstatictext.html#setTextOption">setTextOption</a></b> (<i>self</i>, QTextOption <i>textOption</i>)</li><li><div class="fn" /><b><a href="qstatictext.html#setTextWidth">setTextWidth</a></b> (<i>self</i>, float <i>textWidth</i>)</li><li><div class="fn" />QSizeF <b><a href="qstatictext.html#size">size</a></b> (<i>self</i>)</li><li><div class="fn" />QString <b><a href="qstatictext.html#text">text</a></b> (<i>self</i>)</li><li><div class="fn" />Qt.TextFormat <b><a href="qstatictext.html#textFormat">textFormat</a></b> (<i>self</i>)</li><li><div class="fn" />QTextOption <b><a href="qstatictext.html#textOption">textOption</a></b> (<i>self</i>)</li><li><div class="fn" />float <b><a href="qstatictext.html#textWidth">textWidth</a></b> (<i>self</i>)</li></ul><h3>Special Methods</h3><ul><li><div class="fn" />bool <b><a href="qstatictext.html#__eq__">__eq__</a></b> (<i>self</i>, QStaticText)</li><li><div class="fn" />bool <b><a href="qstatictext.html#__ne__">__ne__</a></b> (<i>self</i>, QStaticText)</li></ul><a name="details" /><hr /><h2>Detailed Description</h2><p>The QStaticText class enables optimized drawing of text when the text and its layout is updated rarely.</p> <p>QStaticText provides a way to cache layout data for a block of text so that it can be drawn more efficiently than by using <a href="qpainter.html#drawText">QPainter.drawText</a>() in which the layout information is recalculated with every call.</p> <p>The class primarily provides an optimization for cases where the text, its font and the transformations on the painter are static over several paint events. If the text or its layout is changed for every iteration, <a href="qpainter.html#drawText">QPainter.drawText</a>() is the more efficient alternative, since the static text's layout would have to be recalculated to take the new state into consideration.</p> <p>Translating the painter will not cause the layout of the text to be recalculated, but will cause a very small performance impact on drawStaticText(). Altering any other parts of the painter's transformation or the painter's font will cause the layout of the static text to be recalculated. This should be avoided as often as possible to maximize the performance benefit of using QStaticText.</p> <p>In addition, only affine transformations are supported by drawStaticText(). Calling drawStaticText() on a projected painter will perform slightly worse than using the regular drawText() call, so this should be avoided.</p> <pre class="cpp"> <span class="keyword">class</span> MyWidget: <span class="keyword">public</span> <span class="type"><a href="qwidget.html">QWidget</a></span> { <span class="keyword">public</span>: MyWidget(<span class="type"><a href="qwidget.html">QWidget</a></span> <span class="operator">*</span>parent <span class="operator">=</span> <span class="number">0</span>) : <span class="type"><a href="qwidget.html">QWidget</a></span>(parent)<span class="operator">,</span> m_staticText(<span class="string">"This is static text"</span>) <span class="keyword">protected</span>: <span class="type">void</span> paintEvent(<span class="type"><a href="qpaintevent.html">QPaintEvent</a></span> <span class="operator">*</span>) { <span class="type"><a href="qpainter.html">QPainter</a></span> painter(<span class="keyword">this</span>); painter<span class="operator">.</span>drawStaticText(<span class="number">0</span><span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> m_staticText); } <span class="keyword">private</span>: <span class="type">QStaticText</span> m_staticText; }; </pre> <p>The QStaticText class can be used to mimic the behavior of <a href="qpainter.html#drawText">QPainter.drawText</a>() to a specific point with no boundaries, and also when <a href="qpainter.html#drawText">QPainter.drawText</a>() is called with a bounding rectangle.</p> <p>If a bounding rectangle is not required, create a QStaticText object without setting a preferred text width. The text will then occupy a single line.</p> <p>If you set a text width on the QStaticText object, this will bound the text. The text will be formatted so that no line exceeds the given width. The text width set for QStaticText will not automatically be used for clipping. To achieve clipping in addition to line breaks, use <a href="qpainter.html#setClipRect">QPainter.setClipRect</a>(). The position of the text is decided by the argument passed to <a href="qpainter.html#drawStaticText">QPainter.drawStaticText</a>() and can change from call to call with a minimal impact on performance.</p> <p>For extra convenience, it is possible to apply formatting to the text using the HTML subset supported by <a href="qtextdocument.html">QTextDocument</a>. QStaticText will attempt to guess the format of the input text using <a href="qt.html#mightBeRichText">Qt.mightBeRichText</a>(), and interpret it as rich text if this function returns true. To force QStaticText to display its contents as either plain text or rich text, use the function <a href="qstatictext.html#setTextFormat">QStaticText.setTextFormat</a>() and pass in, respectively, <a href="qt.html#TextFormat-enum">Qt.PlainText</a> and <a href="qt.html#TextFormat-enum">Qt.RichText</a>.</p> <p>QStaticText can only represent text, so only HTML tags which alter the layout or appearance of the text will be respected. Adding an image to the input HTML, for instance, will cause the image to be included as part of the layout, affecting the positions of the text glyphs, but it will not be displayed. The result will be an empty area the size of the image in the output. Similarly, using tables will cause the text to be laid out in table format, but the borders will not be drawn.</p> <p>If it's the first time the static text is drawn, or if the static text, or the painter's font has been altered since the last time it was drawn, the text's layout has to be recalculated. On some paint engines, changing the matrix of the painter will also cause the layout to be recalculated. In particular, this will happen for any engine except for the OpenGL2 paint engine. Recalculating the layout will impose an overhead on the <a href="qpainter.html#drawStaticText">QPainter.drawStaticText</a>() call where it occurs. To avoid this overhead in the paint event, you can call <a href="qstatictext.html#prepare">prepare</a>() ahead of time to ensure that the layout is calculated.</p> <hr /><h2>Type Documentation</h2><h3 class="fn"><a name="PerformanceHint-enum" />QStaticText.PerformanceHint</h3><p>This enum the different performance hints that can be set on the <a href="qstatictext.html">QStaticText</a>. These hints can be used to indicate that the <a href="qstatictext.html">QStaticText</a> should use additional caches, if possible, to improve performance at the expense of memory. In particular, setting the performance hint AggressiveCaching on the <a href="qstatictext.html">QStaticText</a> will improve performance when using the OpenGL graphics system or when drawing to a <a href="qglwidget.html">QGLWidget</a>.</p> <table class="valuelist"> <tr class="odd" valign="top"> <th class="tblConst">Constant</th> <th class="tblval">Value</th> <th class="tbldscr">Description</th> </tr> <tr> <td class="topAlign"><tt>QStaticText.ModerateCaching</tt></td> <td class="topAlign"><tt>0</tt></td> <td class="topAlign">Do basic caching for high performance at a low memory cost.</td> </tr> <tr> <td class="topAlign"><tt>QStaticText.AggressiveCaching</tt></td> <td class="topAlign"><tt>1</tt></td> <td class="topAlign">Use additional caching when available. This may improve performance at a higher memory cost.</td> </tr> </table> <hr /><h2>Method Documentation</h2><h3 class="fn"><a name="QStaticText" />QStaticText.__init__ (<i>self</i>)</h3><p>Constructs an empty <a href="qstatictext.html">QStaticText</a></p> <h3 class="fn"><a name="QStaticText-2" />QStaticText.__init__ (<i>self</i>, QString <i>text</i>)</h3><p>Constructs a <a href="qstatictext.html">QStaticText</a> object with the given <i>text</i>.</p> <h3 class="fn"><a name="QStaticText-3" />QStaticText.__init__ (<i>self</i>, <a href="qstatictext.html">QStaticText</a> <i>other</i>)</h3><p>Constructs a <a href="qstatictext.html">QStaticText</a> object which is a copy of <i>other</i>.</p> <h3 class="fn"><a name="performanceHint" /><a href="qstatictext.html#PerformanceHint-enum">PerformanceHint</a> QStaticText.performanceHint (<i>self</i>)</h3><p>Returns which performance hint is set for the <a href="qstatictext.html">QStaticText</a>.</p> <p><b>See also</b> <a href="qstatictext.html#setPerformanceHint">setPerformanceHint</a>().</p> <h3 class="fn"><a name="prepare" />QStaticText.prepare (<i>self</i>, <a href="qtransform.html">QTransform</a> <i>matrix</i> = QTransform(), <a href="qfont.html">QFont</a> <i>font</i> = QFont())</h3><p>Prepares the <a href="qstatictext.html">QStaticText</a> object for being painted with the given <i>matrix</i> and the given <i>font</i> to avoid overhead when the actual drawStaticText() call is made.</p> <p>When drawStaticText() is called, the layout of the <a href="qstatictext.html">QStaticText</a> will be recalculated if any part of the <a href="qstatictext.html">QStaticText</a> object has changed since the last time it was drawn. It will also be recalculated if the painter's font is not the same as when the <a href="qstatictext.html">QStaticText</a> was last drawn, or, on any other paint engine than the OpenGL2 engine, if the painter's matrix has been altered since the static text was last drawn.</p> <p>To avoid the overhead of creating the layout the first time you draw the <a href="qstatictext.html">QStaticText</a> after making changes, you can use the prepare() function and pass in the <i>matrix</i> and <i>font</i> you expect to use when drawing the text.</p> <p><b>See also</b> <a href="qpainter.html#setFont">QPainter.setFont</a>() and <a class="obsolete" href="qpainter-obsolete.html#setMatrix">QPainter.setMatrix</a>().</p> <h3 class="fn"><a name="setPerformanceHint" />QStaticText.setPerformanceHint (<i>self</i>, <a href="qstatictext.html#PerformanceHint-enum">PerformanceHint</a> <i>performanceHint</i>)</h3><p>Sets the performance hint of the <a href="qstatictext.html">QStaticText</a> according to the <i>performanceHint</i> provided. The <i>performanceHint</i> is used to customize how much caching is done internally to improve performance.</p> <p>The default is <a href="qstatictext.html#PerformanceHint-enum">QStaticText.ModerateCaching</a>.</p> <p><b>Note:</b> This function will cause the layout of the text to require recalculation.</p> <p><b>See also</b> <a href="qstatictext.html#performanceHint">performanceHint</a>().</p> <h3 class="fn"><a name="setText" />QStaticText.setText (<i>self</i>, QString <i>text</i>)</h3><p>Sets the text of the <a href="qstatictext.html">QStaticText</a> to <i>text</i>.</p> <p><b>Note:</b> This function will cause the layout of the text to require recalculation.</p> <p><b>See also</b> <a href="qstatictext.html#text">text</a>().</p> <h3 class="fn"><a name="setTextFormat" />QStaticText.setTextFormat (<i>self</i>, <a href="qt.html#TextFormat-enum">Qt.TextFormat</a> <i>textFormat</i>)</h3><p>Sets the text format of the <a href="qstatictext.html">QStaticText</a> to <i>textFormat</i>. If <i>textFormat</i> is set to <a href="qt.html#TextFormat-enum">Qt.AutoText</a> (the default), the format of the text will try to be determined using the function <a href="qt.html#mightBeRichText">Qt.mightBeRichText</a>(). If the text format is <a href="qt.html#TextFormat-enum">Qt.PlainText</a>, then the text will be displayed as is, whereas it will be interpreted as HTML if the format is <a href="qt.html#TextFormat-enum">Qt.RichText</a>. HTML tags that alter the font of the text, its color, or its layout are supported by <a href="qstatictext.html">QStaticText</a>.</p> <p><b>Note:</b> This function will cause the layout of the text to require recalculation.</p> <p><b>See also</b> <a href="qstatictext.html#textFormat">textFormat</a>(), <a href="qstatictext.html#setText">setText</a>(), and <a href="qstatictext.html#text">text</a>().</p> <h3 class="fn"><a name="setTextOption" />QStaticText.setTextOption (<i>self</i>, <a href="qtextoption.html">QTextOption</a> <i>textOption</i>)</h3><p>Sets the text option structure that controls the layout process to the given <i>textOption</i>.</p> <p><b>See also</b> <a href="qstatictext.html#textOption">textOption</a>().</p> <h3 class="fn"><a name="setTextWidth" />QStaticText.setTextWidth (<i>self</i>, float <i>textWidth</i>)</h3><p>Sets the preferred width for this <a href="qstatictext.html">QStaticText</a>. If the text is wider than the specified width, it will be broken into multiple lines and grow vertically. If the text cannot be split into multiple lines, it will be larger than the specified <i>textWidth</i>.</p> <p>Setting the preferred text width to a negative number will cause the text to be unbounded.</p> <p>Use <a href="qstatictext.html#size">size</a>() to get the actual size of the text.</p> <p><b>Note:</b> This function will cause the layout of the text to require recalculation.</p> <p><b>See also</b> <a href="qstatictext.html#textWidth">textWidth</a>() and <a href="qstatictext.html#size">size</a>().</p> <h3 class="fn"><a name="size" /><a href="qsizef.html">QSizeF</a> QStaticText.size (<i>self</i>)</h3><p>Returns the size of the bounding rect for this <a href="qstatictext.html">QStaticText</a>.</p> <p><b>See also</b> <a href="qstatictext.html#textWidth">textWidth</a>().</p> <h3 class="fn"><a name="text" />QString QStaticText.text (<i>self</i>)</h3><p>Returns the text of the <a href="qstatictext.html">QStaticText</a>.</p> <p><b>See also</b> <a href="qstatictext.html#setText">setText</a>().</p> <h3 class="fn"><a name="textFormat" /><a href="qt.html#TextFormat-enum">Qt.TextFormat</a> QStaticText.textFormat (<i>self</i>)</h3><p>Returns the text format of the <a href="qstatictext.html">QStaticText</a>.</p> <p><b>See also</b> <a href="qstatictext.html#setTextFormat">setTextFormat</a>(), <a href="qstatictext.html#setText">setText</a>(), and <a href="qstatictext.html#text">text</a>().</p> <h3 class="fn"><a name="textOption" /><a href="qtextoption.html">QTextOption</a> QStaticText.textOption (<i>self</i>)</h3><p>Returns the current text option used to control the layout process.</p> <p><b>See also</b> <a href="qstatictext.html#setTextOption">setTextOption</a>().</p> <h3 class="fn"><a name="textWidth" />float QStaticText.textWidth (<i>self</i>)</h3><p>Returns the preferred width for this <a href="qstatictext.html">QStaticText</a>.</p> <p><b>See also</b> <a href="qstatictext.html#setTextWidth">setTextWidth</a>().</p> <h3 class="fn"><a name="__eq__" />bool QStaticText.__eq__ (<i>self</i>, <a href="qstatictext.html">QStaticText</a>)</h3><h3 class="fn"><a name="__ne__" />bool QStaticText.__ne__ (<i>self</i>, <a href="qstatictext.html">QStaticText</a>)</h3><address><hr /><div align="center"><table border="0" cellspacing="0" width="100%"><tr class="address"><td align="left" width="25%">PyQt 4.10.3 for X11</td><td align="center" width="50%">Copyright © <a href="http://www.riverbankcomputing.com">Riverbank Computing Ltd</a> and <a href="http://www.qtsoftware.com">Nokia</a> 2012</td><td align="right" width="25%">Qt 4.8.5</td></tr></table></div></address></body></html>