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<?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>QGradient 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">&#160;&#160;</td><td class="postheader" valign="center"><a href="../pyqt4ref.html"><font color="#004faf">Home</font></a>&#160;&#183; <a href="classes.html"><font color="#004faf">All Classes</font></a>&#160;&#183; <a href="modules.html"><font color="#004faf">Modules</font></a></td></table><h1 align="center">QGradient Class Reference<br /><sup><sup>[<a href="qtgui.html">QtGui</a> module]</sup></sup></h1><p>The QGradient class is used in combination with <a href="qbrush.html">QBrush</a> to specify gradient fills. <a href="#details">More...</a></p>
<p>Inherited by <a href="qconicalgradient.html">QConicalGradient</a>, <a href="qlineargradient.html">QLinearGradient</a> and <a href="qradialgradient.html">QRadialGradient</a>.</p><h3>Types</h3><ul><li><div class="fn" />enum <b><a href="qgradient.html#Spread-enum">Spread</a></b> { PadSpread, ReflectSpread, RepeatSpread }</li><li><div class="fn" />enum <b><a href="qgradient.html#Type-enum">Type</a></b> { LinearGradient, RadialGradient, ConicalGradient, NoGradient }</li></ul><h3>Methods</h3><ul><li><div class="fn" /><b><a href="qgradient.html#QGradient">__init__</a></b> (<i>self</i>)</li><li><div class="fn" /><b><a href="qgradient.html#QGradient-2">__init__</a></b> (<i>self</i>, QGradient)</li><li><div class="fn" /><b><a href="qgradient.html#setColorAt">setColorAt</a></b> (<i>self</i>, float&#160;<i>pos</i>, QColor&#160;<i>color</i>)</li><li><div class="fn" /><b><a href="qgradient.html#setSpread">setSpread</a></b> (<i>self</i>, Spread&#160;<i>aspread</i>)</li><li><div class="fn" /><b><a href="qgradient.html#setStops">setStops</a></b> (<i>self</i>, float-QColor-tuple-list&#160;<i>stops</i>)</li><li><div class="fn" />Spread <b><a href="qgradient.html#spread">spread</a></b> (<i>self</i>)</li><li><div class="fn" />float-QColor-tuple-list <b><a href="qgradient.html#stops">stops</a></b> (<i>self</i>)</li><li><div class="fn" />Type <b><a href="qgradient.html#type">type</a></b> (<i>self</i>)</li></ul><h3>Special Methods</h3><ul><li><div class="fn" />bool <b><a href="qgradient.html#__eq__">__eq__</a></b> (<i>self</i>, QGradient&#160;<i>gradient</i>)</li></ul><a name="details" /><hr /><h2>Detailed Description</h2><p>The QGradient class is used in combination with <a href="qbrush.html">QBrush</a> to specify gradient fills.</p>
<p>Qt currently supports three types of gradient fills:</p>
<ul>
<li><i>Linear</i> gradients interpolate colors between start and end points.</li>
<li><i>Radial</i> gradients interpolate colors between a focal point and end points on a circle surrounding it.</li>
<li><i>Conical</i> gradients interpolate colors around a center point.</li>
</ul>
<p>A gradient's type can be retrieved using the <a href="qgradient.html#type">type</a>() function. Each of the types is represented by a subclass of QGradient:</p>
<table align="center" border="0" cellpadding="2" cellspacing="1">
<tr bgcolor="#F0F0F0" valign="top">
<td><img src="images/qgradient-linear.png" /></td>
<td><img src="images/qgradient-radial.png" /></td>
<td><img src="images/qgradient-conical.png" /></td>
</tr>
<tr bgcolor="#A2C511" valign="top">
<th><a href="qlineargradient.html">QLinearGradient</a></th>
<th><a href="qradialgradient.html">QRadialGradient</a></th>
<th><a href="qconicalgradient.html">QConicalGradient</a></th>
</tr>
</table>
<br />
<br />
<p>The colors in a gradient is defined using stop points of the <a href="qgradient.html#QGradientStop-typedef">QGradientStop</a> type, i.e. a position and a color. Use the <a href="qgradient.html#setColorAt">setColorAt</a>() function to define a single stop point. Alternatively, use the <a href="qgradient.html#setStops">setStops</a>() function to define several stop points in one go. Note that the latter function <i>replaces</i> the current set of stop points.</p>
<p>It is the gradient's complete set of stop points (accessible through the <a href="qgradient.html#stops">stops</a>() function) that describes how the gradient area should be filled. If no stop points have been specified, a gradient of black at 0 to white at 1 is used.</p>
<p>A diagonal linear gradient from black at (100, 100) to white at (200, 200) could be specified like this:</p>
<pre>
        QLinearGradient linearGrad(QPointF(100, 100), QPointF(200, 200));
        linearGrad.setColorAt(0, Qt.black);
        linearGrad.setColorAt(1, Qt.white);
</pre>
<p>A gradient can have an arbitrary number of stop points. The following would create a radial gradient starting with red in the center, blue and then green on the edges:</p>
<pre>
        QRadialGradient radialGrad(QPointF(100, 100), 100);
        radialGrad.setColorAt(0, Qt.red);
        radialGrad.setColorAt(0.5, Qt.blue);
        radialGrad.setColorAt(1, Qt.green);
</pre>
<p>It is possible to repeat or reflect the gradient outside its area by specifiying the <a href="qgradient.html#Spread-enum">spread method</a> using the <a href="qgradient.html#setSpread">setSpread</a>() function. The default is to pad the outside area with the color at the closest stop point. The currently set <a href="qgradient.html#Spread-enum">spread method</a> can be retrieved using the <a href="qgradient.html#spread">spread</a>() function. The <a href="qgradient.html#Spread-enum">QGradient.Spread</a> enum defines three different methods:</p>
<table align="center" border="0" cellpadding="2" cellspacing="1">
<tr bgcolor="#F0F0F0" valign="top">
<td><img src="images/qradialgradient-pad.png" /></td>
<td><img src="images/qradialgradient-repeat.png" /></td>
<td><img src="images/qradialgradient-reflect.png" /></td>
</tr>
<tr bgcolor="#E0E0E0" valign="top">
<td><a href="qgradient.html#Spread-enum">PadSpread</a></td>
<td><a href="qgradient.html#Spread-enum">RepeatSpread</a></td>
<td><a href="qgradient.html#Spread-enum">ReflectSpread</a></td>
</tr>
</table>
<br />
<br />
<p>Note that the <a href="qgradient.html#setSpread">setSpread</a>() function only has effect for linear and radial gradients. The reason is that the conical gradient is closed by definition, i.e. the <i>conical</i> gradient fills the entire circle from 0 - 360 degrees, while the boundary of a radial or a linear gradient can be specified through its radius or final stop points, respectively.</p>
<p>See also <a href="demos-gradients.html">The Gradients Demo</a> and <a href="qbrush.html">QBrush</a>.</p>
<hr /><h2>Type Documentation</h2><h3 class="fn"><a name="Spread-enum" />QGradient.Spread</h3><p>Specifies how the area outside the gradient area should be filled.</p>
<table border="1" cellpadding="2" cellspacing="1" width="100%">
<tr>
<th width="25%">Constant</th>
<th width="15%">Value</th>
<th width="60%">Description</th>
</tr>
<tr>
<td valign="top"><tt>QGradient.PadSpread</tt></td>
<td align="center" valign="top"><tt>0</tt></td>
<td valign="top">The area is filled with the closest stop color. This is the default.</td>
</tr>
<tr>
<td valign="top"><tt>QGradient.RepeatSpread</tt></td>
<td align="center" valign="top"><tt>2</tt></td>
<td valign="top">The gradient is repeated outside the gradient area.</td>
</tr>
<tr>
<td valign="top"><tt>QGradient.ReflectSpread</tt></td>
<td align="center" valign="top"><tt>1</tt></td>
<td valign="top">The gradient is reflected outside the gradient area.</td>
</tr>
</table>
<br />
<br />
<p>See also <a href="qgradient.html#spread">spread</a>() and <a href="qgradient.html#setSpread">setSpread</a>().</p>
<h3 class="fn"><a name="Type-enum" />QGradient.Type</h3><p>Specifies the type of gradient.</p>
<table border="1" cellpadding="2" cellspacing="1" width="100%">
<tr>
<th width="25%">Constant</th>
<th width="15%">Value</th>
<th width="60%">Description</th>
</tr>
<tr>
<td valign="top"><tt>QGradient.LinearGradient</tt></td>
<td align="center" valign="top"><tt>0</tt></td>
<td valign="top">Interpolates colors between start and end points (<a href="qlineargradient.html">QLinearGradient</a>).</td>
</tr>
<tr>
<td valign="top"><tt>QGradient.RadialGradient</tt></td>
<td align="center" valign="top"><tt>1</tt></td>
<td valign="top">Interpolate colors between a focal point and end points on a circle surrounding it (<a href="qradialgradient.html">QRadialGradient</a>).</td>
</tr>
<tr>
<td valign="top"><tt>QGradient.ConicalGradient</tt></td>
<td align="center" valign="top"><tt>2</tt></td>
<td valign="top">Interpolate colors around a center point (<a href="qconicalgradient.html">QConicalGradient</a>).</td>
</tr>
<tr>
<td valign="top"><tt>QGradient.NoGradient</tt></td>
<td align="center" valign="top"><tt>3</tt></td>
<td valign="top">No gradient is used.</td>
</tr>
</table>
<br />
<br />
<p>See also <a href="qgradient.html#type">type</a>().</p>
<hr /><h2>Method Documentation</h2><h3 class="fn"><a name="QGradient" />QGradient.__init__ (<i>self</i>)</h3><h3 class="fn"><a name="QGradient-2" />QGradient.__init__ (<i>self</i>, <a href="qgradient.html">QGradient</a>)</h3><h3 class="fn"><a name="setColorAt" />QGradient.setColorAt (<i>self</i>, float&#160;<i>pos</i>, <a href="qcolor.html">QColor</a>&#160;<i>color</i>)</h3><p>Creates a stop point at the given <i>position</i> with the given <i>color</i>. The given <i>position</i> must be in the range 0 to 1.</p>
<p>See also <a href="qgradient.html#setStops">setStops</a>() and <a href="qgradient.html#stops">stops</a>().</p>
<h3 class="fn"><a name="setSpread" />QGradient.setSpread (<i>self</i>, <a href="qgradient.html#Spread-enum">Spread</a>&#160;<i>aspread</i>)</h3><p>Specifies the spread <i>method</i> that should be used for this gradient.</p>
<p>Note that this function only has effect for linear and radial gradients.</p>
<p>See also <a href="qgradient.html#spread">spread</a>().</p>
<h3 class="fn"><a name="setStops" />QGradient.setStops (<i>self</i>, float-QColor-tuple-list&#160;<i>stops</i>)</h3><p>Replaces the current set of stop points with the given <i>stopPoints</i>. The positions of the points must be in the range 0 to 1, and must be sorted with the lowest point first.</p>
<p>See also <a href="qgradient.html#setColorAt">setColorAt</a>() and <a href="qgradient.html#stops">stops</a>().</p>
<h3 class="fn"><a name="spread" /><a href="qgradient.html#Spread-enum">Spread</a> QGradient.spread (<i>self</i>)</h3><p>Returns the spread method use by this gradient. The default is <a href="qgradient.html#Spread-enum">PadSpread</a>.</p>
<p>See also <a href="qgradient.html#setSpread">setSpread</a>().</p>
<h3 class="fn"><a name="stops" />float-QColor-tuple-list QGradient.stops (<i>self</i>)</h3><p>Returns the stop points for this gradient.</p>
<p>If no stop points have been specified, a gradient of black at 0 to white at 1 is used.</p>
<p>See also <a href="qgradient.html#setStops">setStops</a>() and <a href="qgradient.html#setColorAt">setColorAt</a>().</p>
<h3 class="fn"><a name="type" /><a href="qgradient.html#Type-enum">Type</a> QGradient.type (<i>self</i>)</h3><p>Returns the type of gradient.</p>
<h3 class="fn"><a name="__eq__" />bool QGradient.__eq__ (<i>self</i>, <a href="qgradient.html">QGradient</a>&#160;<i>gradient</i>)</h3><address><hr /><div align="center"><table border="0" cellspacing="0" width="100%"><tr class="address"><td width="25%">PyQt&#160;4.0.1 for X11</td><td align="center" width="50%">Copyright &#169; <a href="http://www.riverbankcomputing.com">Riverbank&#160;Computing&#160;Ltd</a> and <a href="http://www.trolltech.com">Trolltech&#160;AS</a> 2006</td><td align="right" width="25%">Qt&#160;4.1.4</td></tr></table></div></address></body></html>