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| author | Timothy Pearson <[email protected]> | 2012-01-26 23:32:43 -0600 |
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| committer | Timothy Pearson <[email protected]> | 2012-01-26 23:32:43 -0600 |
| commit | ea318d1431c89e647598c510c4245c6571aa5f46 (patch) | |
| tree | 996d29b80c30d453dda86d1a23162d441628f169 /doc/html/qcanvas.html | |
| parent | aaf89d4b48f69c9293feb187db26362e550b5561 (diff) | |
| download | tqt3-ea318d1431c89e647598c510c4245c6571aa5f46.tar.gz tqt3-ea318d1431c89e647598c510c4245c6571aa5f46.zip | |
Update to latest tqt3 automated conversion
Diffstat (limited to 'doc/html/qcanvas.html')
| -rw-r--r-- | doc/html/qcanvas.html | 588 |
1 files changed, 0 insertions, 588 deletions
diff --git a/doc/html/qcanvas.html b/doc/html/qcanvas.html deleted file mode 100644 index fbfdbd12e..000000000 --- a/doc/html/qcanvas.html +++ /dev/null @@ -1,588 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> -<!-- /home/espenr/tmp/qt-3.3.8-espenr-2499/qt-x11-free-3.3.8/src/canvas/qcanvas.cpp:435 --> -<html> -<head> -<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> -<title>TQCanvas Class</title> -<style type="text/css"><!-- -fn { margin-left: 1cm; text-indent: -1cm; } -a:link { color: #004faf; text-decoration: none } -a:visited { color: #672967; text-decoration: none } -body { background: #ffffff; color: black; } ---></style> -</head> -<body> - -<table border="0" cellpadding="0" cellspacing="0" width="100%"> -<tr bgcolor="#E5E5E5"> -<td 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="mainclasses.html"> -<font color="#004faf">Main Classes</font></a> - | <a href="annotated.html"> -<font color="#004faf">Annotated</font></a> - | <a href="groups.html"> -<font color="#004faf">Grouped Classes</font></a> - | <a href="functions.html"> -<font color="#004faf">Functions</font></a> -</td> -<td align="right" valign="center"><img src="logo32.png" align="right" width="64" height="32" border="0"></td></tr></table><h1 align=center>TQCanvas Class Reference<br><small>[<a href="canvas.html">canvas module</a>]</small></h1> - -<p>The TQCanvas class provides a 2D area that can contain TQCanvasItem objects. -<a href="#details">More...</a> -<p><tt>#include <<a href="qcanvas-h.html">qcanvas.h</a>></tt> -<p>Inherits <a href="qobject.html">TQObject</a>. -<p><a href="qcanvas-members.html">List of all member functions.</a> -<h2>Public Members</h2> -<ul> -<li class=fn><a href="#TQCanvas"><b>TQCanvas</b></a> ( TQObject * parent = 0, const char * name = 0 )</li> -<li class=fn><a href="#TQCanvas-2"><b>TQCanvas</b></a> ( int w, int h )</li> -<li class=fn><a href="#TQCanvas-3"><b>TQCanvas</b></a> ( TQPixmap p, int h, int v, int tilewidth, int tileheight )</li> -<li class=fn>virtual <a href="#~TQCanvas"><b>~TQCanvas</b></a> ()</li> -<li class=fn>virtual void <a href="#setTiles"><b>setTiles</b></a> ( TQPixmap p, int h, int v, int tilewidth, int tileheight )</li> -<li class=fn>virtual void <a href="#setBackgroundPixmap"><b>setBackgroundPixmap</b></a> ( const TQPixmap & p )</li> -<li class=fn>TQPixmap <a href="#backgroundPixmap"><b>backgroundPixmap</b></a> () const</li> -<li class=fn>virtual void <a href="#setBackgroundColor"><b>setBackgroundColor</b></a> ( const TQColor & c )</li> -<li class=fn>TQColor <a href="#backgroundColor"><b>backgroundColor</b></a> () const</li> -<li class=fn>virtual void <a href="#setTile"><b>setTile</b></a> ( int x, int y, int tilenum )</li> -<li class=fn>int <a href="#tile"><b>tile</b></a> ( int x, int y ) const</li> -<li class=fn>int <a href="#tilesHorizontally"><b>tilesHorizontally</b></a> () const</li> -<li class=fn>int <a href="#tilesVertically"><b>tilesVertically</b></a> () const</li> -<li class=fn>int <a href="#tileWidth"><b>tileWidth</b></a> () const</li> -<li class=fn>int <a href="#tileHeight"><b>tileHeight</b></a> () const</li> -<li class=fn>virtual void <a href="#resize"><b>resize</b></a> ( int w, int h )</li> -<li class=fn>int <a href="#width"><b>width</b></a> () const</li> -<li class=fn>int <a href="#height"><b>height</b></a> () const</li> -<li class=fn>TQSize <a href="#size"><b>size</b></a> () const</li> -<li class=fn>TQRect <a href="#rect"><b>rect</b></a> () const</li> -<li class=fn>bool <a href="#onCanvas"><b>onCanvas</b></a> ( int x, int y ) const</li> -<li class=fn>bool <a href="#onCanvas-2"><b>onCanvas</b></a> ( const TQPoint & p ) const</li> -<li class=fn>bool <a href="#validChunk"><b>validChunk</b></a> ( int x, int y ) const</li> -<li class=fn>bool <a href="#validChunk-2"><b>validChunk</b></a> ( const TQPoint & p ) const</li> -<li class=fn>int <a href="#chunkSize"><b>chunkSize</b></a> () const</li> -<li class=fn>virtual void <a href="#retune"><b>retune</b></a> ( int chunksze, int mxclusters = 100 )</li> -<li class=fn>virtual void <a href="#setAllChanged"><b>setAllChanged</b></a> ()</li> -<li class=fn>virtual void <a href="#setChanged"><b>setChanged</b></a> ( const TQRect & area )</li> -<li class=fn>virtual void <a href="#setUnchanged"><b>setUnchanged</b></a> ( const TQRect & area )</li> -<li class=fn>TQCanvasItemList <a href="#allItems"><b>allItems</b></a> ()</li> -<li class=fn>TQCanvasItemList <a href="#collisions"><b>collisions</b></a> ( const TQPoint & p ) const</li> -<li class=fn>TQCanvasItemList <a href="#collisions-2"><b>collisions</b></a> ( const TQRect & r ) const</li> -<li class=fn>TQCanvasItemList <a href="#collisions-3"><b>collisions</b></a> ( const TQPointArray & chunklist, const TQCanvasItem * item, bool exact ) const</li> -<li class=fn>void <a href="#drawArea"><b>drawArea</b></a> ( const TQRect & clip, TQPainter * painter, bool dbuf = FALSE )</li> -<li class=fn>virtual void <a href="#setAdvancePeriod"><b>setAdvancePeriod</b></a> ( int ms )</li> -<li class=fn>virtual void <a href="#setUpdatePeriod"><b>setUpdatePeriod</b></a> ( int ms )</li> -<li class=fn>virtual void <a href="#setDoubleBuffering"><b>setDoubleBuffering</b></a> ( bool y )</li> -</ul> -<h2>Public Slots</h2> -<ul> -<li class=fn>virtual void <a href="#advance"><b>advance</b></a> ()</li> -<li class=fn>virtual void <a href="#update"><b>update</b></a> ()</li> -</ul> -<h2>Signals</h2> -<ul> -<li class=fn>void <a href="#resized"><b>resized</b></a> ()</li> -</ul> -<h2>Protected Members</h2> -<ul> -<li class=fn>virtual void <a href="#drawBackground"><b>drawBackground</b></a> ( TQPainter & painter, const TQRect & clip )</li> -<li class=fn>virtual void <a href="#drawForeground"><b>drawForeground</b></a> ( TQPainter & painter, const TQRect & clip )</li> -</ul> -<hr><a name="details"></a><h2>Detailed Description</h2> - - -The TQCanvas class provides a 2D area that can contain <a href="qcanvasitem.html">TQCanvasItem</a> objects. - -<p> - - - - -<p> The TQCanvas class manages its 2D graphic area and all the canvas -items the area contains. The canvas has no visual appearance of -its own. Instead, it is displayed on screen using a <a href="qcanvasview.html">TQCanvasView</a>. -Multiple TQCanvasView widgets may be associated with a canvas to -provide multiple views of the same canvas. -<p> The canvas is optimized for large numbers of items, particularly -where only a small percentage of the items change at any -one time. If the entire display changes very frequently, you should -consider using your own custom <a href="qscrollview.html">TQScrollView</a> subclass. -<p> TQt provides a rich -set of canvas item classes, e.g. <a href="qcanvasellipse.html">TQCanvasEllipse</a>, <a href="qcanvasline.html">TQCanvasLine</a>, -<a href="qcanvaspolygon.html">TQCanvasPolygon</a>, <a href="qcanvaspolygonalitem.html">TQCanvasPolygonalItem</a>, <a href="qcanvasrectangle.html">TQCanvasRectangle</a>, <a href="qcanvasspline.html">TQCanvasSpline</a>, -<a href="qcanvassprite.html">TQCanvasSprite</a> and <a href="qcanvastext.html">TQCanvasText</a>. You can subclass to create your own -canvas items; TQCanvasPolygonalItem is the most common base class used -for this purpose. -<p> Items appear on the canvas after their <a href="qcanvasitem.html#show">show()</a> function has been called (or <a href="qcanvasitem.html#setVisible">setVisible(TRUE)</a>), and <em>after</em> -<a href="#update">update</a>() has been called. The canvas only shows items that are -<a href="qcanvasitem.html#setVisible">visible</a>, and then only if -<a href="#update">update</a>() is called. (By default the canvas is white and so are -canvas items, so if nothing appears try changing colors.) -<p> If you created the canvas without passing a width and height to -the constructor you must also call <a href="#resize">resize</a>(). -<p> Although a canvas may appear to be similar to a widget with child -widgets, there are several notable differences: -<p> <ul> -<li> Canvas items are usually much faster to manipulate and redraw than -child widgets, with the speed advantage becoming especially great when -there are <em>many</em> canvas items and non-rectangular items. In most -situations canvas items are also a lot more memory efficient than child -widgets. -<p> <li> It's easy to detect overlapping items (collision detection). -<p> <li> The canvas can be larger than a widget. A million-by-million canvas -is perfectly possible. At such a size a widget might be very -inefficient, and some window systems might not support it at all, -whereas TQCanvas scales well. Even with a billion pixels and a million -items, finding a particular canvas item, detecting collisions, etc., -is still fast (though the memory consumption may be prohibitive -at such extremes). -<p> <li> Two or more <a href="qcanvasview.html">TQCanvasView</a> objects can view the same canvas. -<p> <li> An arbitrary <a href="qwmatrix.html#TransformationMode">transformation matrix</a> can be set on each TQCanvasView -which makes it easy to zoom, rotate or shear the viewed canvas. -<p> <li> Widgets provide a lot more functionality, such as input (<a href="qkeyevent.html">TQKeyEvent</a>, -<a href="qmouseevent.html">TQMouseEvent</a> etc.) and layout management (<a href="qgridlayout.html">TQGridLayout</a> etc.). -<p> </ul> -<p> A canvas consists of a background, a number of canvas items organized by -x, y and z coordinates, and a foreground. A canvas item's z coordinate -can be treated as a layer number -- canvas items with a higher z -coordinate appear in front of canvas items with a lower z coordinate. -<p> The background is white by default, but can be set to a different color -using <a href="#setBackgroundColor">setBackgroundColor</a>(), or to a repeated pixmap using -<a href="#setBackgroundPixmap">setBackgroundPixmap</a>() or to a mosaic of smaller pixmaps using -<a href="#setTiles">setTiles</a>(). Individual tiles can be set with <a href="#setTile">setTile</a>(). There -are corresponding get functions, e.g. <a href="#backgroundColor">backgroundColor</a>() and -<a href="#backgroundPixmap">backgroundPixmap</a>(). -<p> Note that TQCanvas does not inherit from <a href="qwidget.html">TQWidget</a>, even though it has some -functions which provide the same functionality as those in TQWidget. One -of these is setBackgroundPixmap(); some others are <a href="#resize">resize</a>(), <a href="#size">size</a>(), -<a href="#width">width</a>() and <a href="#height">height</a>(). <a href="qcanvasview.html">TQCanvasView</a> is the widget used to display a -canvas on the screen. -<p> Canvas items are added to a canvas by constructing them and passing the -canvas to the canvas item's constructor. An item can be moved to a -different canvas using <a href="qcanvasitem.html#setCanvas">TQCanvasItem::setCanvas</a>(). -<p> Canvas items are movable (and in the case of TQCanvasSprites, animated) -objects that inherit <a href="qcanvasitem.html">TQCanvasItem</a>. Each canvas item has a position on the -canvas (x, y coordinates) and a height (z coordinate), all of which are -held as floating-point numbers. Moving canvas items also have x and y -velocities. It's possible for a canvas item to be outside the canvas -(for example <a href="qcanvasitem.html#x">TQCanvasItem::x</a>() is greater than width()). When a canvas -item is off the canvas, <a href="#onCanvas">onCanvas</a>() returns FALSE and the canvas -disregards the item. (Canvas items off the canvas do not slow down any -of the common operations on the canvas.) -<p> Canvas items can be moved with <a href="qcanvasitem.html#move">TQCanvasItem::move</a>(). The <a href="#advance">advance</a>() -function moves all <a href="qcanvasitem.html#animated">TQCanvasItem::animated</a>() canvas items and -<a href="#setAdvancePeriod">setAdvancePeriod</a>() makes TQCanvas move them automatically on a periodic -basis. In the context of the TQCanvas classes, to `animate' a canvas item -is to set it in motion, i.e. using <a href="qcanvasitem.html#setVelocity">TQCanvasItem::setVelocity</a>(). Animation -of a canvas item itself, i.e. items which change over time, is enabled -by calling <a href="qcanvassprite.html#setFrameAnimation">TQCanvasSprite::setFrameAnimation</a>(), or more generally by -subclassing and reimplementing <a href="qcanvasitem.html#advance">TQCanvasItem::advance</a>(). To detect collisions -use one of the <a href="qcanvasitem.html#collisions">TQCanvasItem::collisions</a>() functions. -<p> The changed parts of the canvas are redrawn (if they are visible in a -canvas view) whenever <a href="#update">update</a>() is called. You can either call update() -manually after having changed the contents of the canvas, or force -periodic updates using <a href="#setUpdatePeriod">setUpdatePeriod</a>(). If you have moving objects on -the canvas, you must call <a href="#advance">advance</a>() every time the objects should -move one step further. Periodic calls to advance() can be forced using -<a href="#setAdvancePeriod">setAdvancePeriod</a>(). The advance() function will call -TQCanvasItem::advance() on every item that is <a href="qcanvasitem.html#animated">animated</a> and trigger an update of the -affected areas afterwards. (A canvas item that is `animated' is simply -a canvas item that is in motion.) -<p> TQCanvas organizes its canvas items into <em>chunks</em>; these are areas on -the canvas that are used to speed up most operations. Many operations -start by eliminating most chunks (i.e. those which haven't changed) -and then process only the canvas items that are in the few interesting -(i.e. changed) chunks. A valid chunk, <a href="#validChunk">validChunk</a>(), is one which is on -the canvas. -<p> The chunk size is a key factor to TQCanvas's speed: if there are too many -chunks, the speed benefit of grouping canvas items into chunks is -reduced. If the chunks are too large, it takes too long to process each -one. The TQCanvas constructor tries to pick a suitable size, but you -can call <a href="#retune">retune</a>() to change it at any time. The <a href="#chunkSize">chunkSize</a>() function -returns the current chunk size. The canvas items always make sure -they're in the right chunks; all you need to make sure of is that -the canvas uses the right chunk size. A good rule of thumb is that -the size should be a bit smaller than the average canvas item -size. If you have moving objects, the chunk size should be a bit -smaller than the average size of the moving items. -<p> The foreground is normally nothing, but if you reimplement -<a href="#drawForeground">drawForeground</a>(), you can draw things in front of all the canvas -items. -<p> Areas can be set as changed with <a href="#setChanged">setChanged</a>() and set unchanged with -<a href="#setUnchanged">setUnchanged</a>(). The entire canvas can be set as changed with -<a href="#setAllChanged">setAllChanged</a>(). A list of all the items on the canvas is returned by -<a href="#allItems">allItems</a>(). -<p> An area can be copied (painted) to a <a href="qpainter.html">TQPainter</a> with <a href="#drawArea">drawArea</a>(). -<p> If the canvas is resized it emits the <a href="#resized">resized</a>() signal. -<p> The examples/canvas application and the 2D graphics page of the -examples/demo application demonstrate many of TQCanvas's facilities. -<p> <p>See also <a href="qcanvasview.html">TQCanvasView</a>, <a href="qcanvasitem.html">TQCanvasItem</a>, <a href="abstractwidgets.html">Abstract Widget Classes</a>, <a href="graphics.html">Graphics Classes</a>, and <a href="images.html">Image Processing Classes</a>. - -<hr><h2>Member Function Documentation</h2> -<h3 class=fn><a name="TQCanvas"></a>TQCanvas::TQCanvas ( <a href="qobject.html">TQObject</a> * parent = 0, const char * name = 0 ) -</h3> -Create a TQCanvas with no size. <em>parent</em> and <em>name</em> are passed to -the <a href="qobject.html">TQObject</a> superclass. -<p> <b>Warning:</b> You <em>must</em> call <a href="#resize">resize</a>() at some time after creation to -be able to use the canvas. - -<h3 class=fn><a name="TQCanvas-2"></a>TQCanvas::TQCanvas ( int w, int h ) -</h3> -Constructs a TQCanvas that is <em>w</em> pixels wide and <em>h</em> pixels high. - -<h3 class=fn><a name="TQCanvas-3"></a>TQCanvas::TQCanvas ( <a href="qpixmap.html">TQPixmap</a> p, int h, int v, int tilewidth, int tileheight ) -</h3> -Constructs a TQCanvas which will be composed of <em>h</em> tiles -horizontally and <em>v</em> tiles vertically. Each tile will be an image -<em>tilewidth</em> by <em>tileheight</em> pixels taken from pixmap <em>p</em>. -<p> The pixmap <em>p</em> is a list of tiles, arranged left to right, (and -in the case of pixmaps that have multiple rows of tiles, top to -bottom), with tile 0 in the top-left corner, tile 1 next to the -right, and so on, e.g. -<p> <center><table cellpadding="4" cellspacing="2" border="0"> -<tr bgcolor="#f0f0f0"> <td valign="top">0 <td valign="top">1 <td valign="top">2 <td valign="top">3 -<tr bgcolor="#d0d0d0"> <td valign="top">4 <td valign="top">5 <td valign="top">6 <td valign="top">7 -</table></center> -<p> The TQCanvas is initially sized to show exactly the given number of -tiles horizontally and vertically. If it is resized to be larger, -the entire matrix of tiles will be repeated as often as necessary -to cover the area. If it is smaller, tiles to the right and bottom -will not be visible. -<p> <p>See also <a href="#setTiles">setTiles</a>(). - -<h3 class=fn><a name="~TQCanvas"></a>TQCanvas::~TQCanvas ()<tt> [virtual]</tt> -</h3> -Destroys the canvas and all the canvas's canvas items. - -<h3 class=fn>void <a name="advance"></a>TQCanvas::advance ()<tt> [virtual slot]</tt> -</h3> -Moves all <a href="qcanvasitem.html#animated">TQCanvasItem::animated</a>() canvas items on the canvas and -refreshes all changes to all views of the canvas. (An `animated' -item is an item that is in motion; see setVelocity().) -<p> The advance takes place in two phases. In phase 0, the -<a href="qcanvasitem.html#advance">TQCanvasItem::advance</a>() function of each TQCanvasItem::animated() -canvas item is called with paramater 0. Then all these canvas -items are called again, with parameter 1. In phase 0, the canvas -items should not change position, merely examine other items on -the canvas for which special processing is required, such as -collisions between items. In phase 1, all canvas items should -change positions, ignoring any other items on the canvas. This -two-phase approach allows for considerations of "fairness", -although no <a href="qcanvasitem.html">TQCanvasItem</a> subclasses supplied with TQt do anything -interesting in phase 0. -<p> The canvas can be configured to call this function periodically -with <a href="#setAdvancePeriod">setAdvancePeriod</a>(). -<p> <p>See also <a href="#update">update</a>(). - -<h3 class=fn><a href="qcanvasitemlist.html">TQCanvasItemList</a> <a name="allItems"></a>TQCanvas::allItems () -</h3> -Returns a list of all the items in the canvas. - -<h3 class=fn><a href="qcolor.html">TQColor</a> <a name="backgroundColor"></a>TQCanvas::backgroundColor () const -</h3> -Returns the color set by <a href="#setBackgroundColor">setBackgroundColor</a>(). By default, this is -white. -<p> This function is not a reimplementation of -<a href="qwidget.html#backgroundColor">TQWidget::backgroundColor</a>() (TQCanvas is not a subclass of <a href="qwidget.html">TQWidget</a>), -but all TQCanvasViews that are viewing the canvas will set their -backgrounds to this color. -<p> <p>See also <a href="#setBackgroundColor">setBackgroundColor</a>() and <a href="#backgroundPixmap">backgroundPixmap</a>(). - -<h3 class=fn><a href="qpixmap.html">TQPixmap</a> <a name="backgroundPixmap"></a>TQCanvas::backgroundPixmap () const -</h3> -Returns the pixmap set by <a href="#setBackgroundPixmap">setBackgroundPixmap</a>(). By default, -this is a null pixmap. -<p> <p>See also <a href="#setBackgroundPixmap">setBackgroundPixmap</a>() and <a href="#backgroundColor">backgroundColor</a>(). - -<h3 class=fn>int <a name="chunkSize"></a>TQCanvas::chunkSize () const -</h3> - -<p> Returns the chunk size of the canvas. -<p> <p>See also <a href="#retune">retune</a>(). - -<h3 class=fn><a href="qcanvasitemlist.html">TQCanvasItemList</a> <a name="collisions"></a>TQCanvas::collisions ( const <a href="qpoint.html">TQPoint</a> & p ) const -</h3> -Returns a list of canvas items that collide with the point <em>p</em>. -The list is ordered by z coordinates, from highest z coordinate -(front-most item) to lowest z coordinate (rear-most item). - -<h3 class=fn><a href="qcanvasitemlist.html">TQCanvasItemList</a> <a name="collisions-2"></a>TQCanvas::collisions ( const <a href="qrect.html">TQRect</a> & r ) const -</h3> -This is an overloaded member function, provided for convenience. It behaves essentially like the above function. -<p> Returns a list of items which collide with the rectangle <em>r</em>. The -list is ordered by z coordinates, from highest z coordinate -(front-most item) to lowest z coordinate (rear-most item). - -<h3 class=fn><a href="qcanvasitemlist.html">TQCanvasItemList</a> <a name="collisions-3"></a>TQCanvas::collisions ( const <a href="qpointarray.html">TQPointArray</a> & chunklist, const <a href="qcanvasitem.html">TQCanvasItem</a> * item, bool exact ) const -</h3> -This is an overloaded member function, provided for convenience. It behaves essentially like the above function. -<p> Returns a list of canvas items which intersect with the chunks -listed in <em>chunklist</em>, excluding <em>item</em>. If <em>exact</em> is TRUE, -only those which actually <a href="qcanvasitem.html#collidesWith">collide with</a> <em>item</em> are returned; otherwise canvas items -are included just for being in the chunks. -<p> This is a utility function mainly used to implement the simpler -<a href="qcanvasitem.html#collisions">TQCanvasItem::collisions</a>() function. - -<h3 class=fn>void <a name="drawArea"></a>TQCanvas::drawArea ( const <a href="qrect.html">TQRect</a> & clip, <a href="qpainter.html">TQPainter</a> * painter, bool dbuf = FALSE ) -</h3> -Paints all canvas items that are in the area <em>clip</em> to <em>painter</em>, using double-buffering if <em>dbuf</em> is TRUE. -<p> e.g. to print the canvas to a printer: -<pre> - <a href="qprinter.html">TQPrinter</a> pr; - if ( pr.<a href="qprinter.html#setup">setup</a>() ) { - <a href="qpainter.html">TQPainter</a> p(&pr); - canvas.drawArea( canvas.rect(), &p ); - } - </pre> - - -<p>Example: <a href="canvas-example.html#x2908">canvas/canvas.cpp</a>. -<h3 class=fn>void <a name="drawBackground"></a>TQCanvas::drawBackground ( <a href="qpainter.html">TQPainter</a> & painter, const <a href="qrect.html">TQRect</a> & clip )<tt> [virtual protected]</tt> -</h3> -This virtual function is called for all updates of the canvas. It -renders any background graphics using the painter <em>painter</em>, in -the area <em>clip</em>. If the canvas has a background pixmap or a tiled -background, that graphic is used, otherwise the canvas is cleared -using the background color. -<p> If the graphics for an area change, you must explicitly call -<a href="#setChanged">setChanged</a>(const <a href="qrect.html">TQRect</a>&) for the result to be visible when -<a href="#update">update</a>() is next called. -<p> <p>See also <a href="#setBackgroundColor">setBackgroundColor</a>(), <a href="#setBackgroundPixmap">setBackgroundPixmap</a>(), and <a href="#setTiles">setTiles</a>(). - -<h3 class=fn>void <a name="drawForeground"></a>TQCanvas::drawForeground ( <a href="qpainter.html">TQPainter</a> & painter, const <a href="qrect.html">TQRect</a> & clip )<tt> [virtual protected]</tt> -</h3> -This virtual function is called for all updates of the canvas. It -renders any foreground graphics using the painter <em>painter</em>, in -the area <em>clip</em>. -<p> If the graphics for an area change, you must explicitly call -<a href="#setChanged">setChanged</a>(const <a href="qrect.html">TQRect</a>&) for the result to be visible when -<a href="#update">update</a>() is next called. -<p> The default is to draw nothing. - -<h3 class=fn>int <a name="height"></a>TQCanvas::height () const -</h3> - -<p> Returns the height of the canvas, in pixels. - -<p>Example: <a href="canvas-example.html#x2909">canvas/canvas.cpp</a>. -<h3 class=fn>bool <a name="onCanvas"></a>TQCanvas::onCanvas ( int x, int y ) const -</h3> - -<p> Returns TRUE if the pixel position (<em>x</em>, <em>y</em>) is on the canvas; -otherwise returns FALSE. -<p> <p>See also <a href="#validChunk">validChunk</a>(). - -<h3 class=fn>bool <a name="onCanvas-2"></a>TQCanvas::onCanvas ( const <a href="qpoint.html">TQPoint</a> & p ) const -</h3> - -This is an overloaded member function, provided for convenience. It behaves essentially like the above function. -<p> Returns TRUE if the pixel position <em>p</em> is on the canvas; -otherwise returns FALSE. -<p> <p>See also <a href="#validChunk">validChunk</a>(). - -<h3 class=fn><a href="qrect.html">TQRect</a> <a name="rect"></a>TQCanvas::rect () const -</h3> - -<p> Returns a rectangle the size of the canvas. - -<h3 class=fn>void <a name="resize"></a>TQCanvas::resize ( int w, int h )<tt> [virtual]</tt> -</h3> -Changes the size of the canvas to have a width of <em>w</em> and a -height of <em>h</em>. This is a slow operation. - -<p>Examples: <a href="canvas-example.html#x2910">canvas/canvas.cpp</a> and <a href="canvas-chart-example.html#x2876">chart/chartform.cpp</a>. -<h3 class=fn>void <a name="resized"></a>TQCanvas::resized ()<tt> [signal]</tt> -</h3> - -<p> This signal is emitted whenever the canvas is resized. Each -<a href="qcanvasview.html">TQCanvasView</a> connects to this signal to keep the scrollview's size -correct. - -<h3 class=fn>void <a name="retune"></a>TQCanvas::retune ( int chunksze, int mxclusters = 100 )<tt> [virtual]</tt> -</h3> -Change the efficiency tuning parameters to <em>mxclusters</em> clusters, -each of size <em>chunksze</em>. This is a slow operation if there are -many objects on the canvas. -<p> The canvas is divided into chunks which are rectangular areas <em>chunksze</em> wide by <em>chunksze</em> high. Use a chunk size which is about -the average size of the canvas items. If you choose a chunk size -which is too small it will increase the amount of calculation -required when drawing since each change will affect many chunks. -If you choose a chunk size which is too large the amount of -drawing required will increase because for each change, a lot of -drawing will be required since there will be many (unchanged) -canvas items which are in the same chunk as the changed canvas -items. -<p> Internally, a canvas uses a low-resolution "chunk matrix" to keep -track of all the items in the canvas. A 64x64 chunk matrix is the -default for a 1024x1024 pixel canvas, where each chunk collects -canvas items in a 16x16 pixel square. This default is also -affected by <a href="#setTiles">setTiles</a>(). You can tune this default using this -function. For example if you have a very large canvas and want to -trade off speed for memory then you might set the chunk size to 32 -or 64. -<p> The <em>mxclusters</em> argument is the number of rectangular groups of -chunks that will be separately drawn. If the canvas has a large -number of small, dispersed items, this should be about that -number. Our testing suggests that a large number of clusters is -almost always best. -<p> -<h3 class=fn>void <a name="setAdvancePeriod"></a>TQCanvas::setAdvancePeriod ( int ms )<tt> [virtual]</tt> -</h3> -Sets the canvas to call <a href="#advance">advance</a>() every <em>ms</em> milliseconds. Any -previous setting by <a href="#setAdvancePeriod">setAdvancePeriod</a>() or <a href="#setUpdatePeriod">setUpdatePeriod</a>() is -overridden. -<p> If <em>ms</em> is less than 0 advancing will be stopped. - -<p>Example: <a href="canvas-example.html#x2962">canvas/main.cpp</a>. -<h3 class=fn>void <a name="setAllChanged"></a>TQCanvas::setAllChanged ()<tt> [virtual]</tt> -</h3> -Marks the whole canvas as changed. -All views of the canvas will be entirely redrawn when -<a href="#update">update</a>() is called next. - -<h3 class=fn>void <a name="setBackgroundColor"></a>TQCanvas::setBackgroundColor ( const <a href="qcolor.html">TQColor</a> & c )<tt> [virtual]</tt> -</h3> -Sets the solid background to be the color <em>c</em>. -<p> <p>See also <a href="#backgroundColor">backgroundColor</a>(), <a href="#setBackgroundPixmap">setBackgroundPixmap</a>(), and <a href="#setTiles">setTiles</a>(). - -<h3 class=fn>void <a name="setBackgroundPixmap"></a>TQCanvas::setBackgroundPixmap ( const <a href="qpixmap.html">TQPixmap</a> & p )<tt> [virtual]</tt> -</h3> -Sets the solid background to be the pixmap <em>p</em> repeated as -necessary to cover the entire canvas. -<p> <p>See also <a href="#backgroundPixmap">backgroundPixmap</a>(), <a href="#setBackgroundColor">setBackgroundColor</a>(), and <a href="#setTiles">setTiles</a>(). - -<h3 class=fn>void <a name="setChanged"></a>TQCanvas::setChanged ( const <a href="qrect.html">TQRect</a> & area )<tt> [virtual]</tt> -</h3> -Marks <em>area</em> as changed. This <em>area</em> will be redrawn in all -views that are showing it when <a href="#update">update</a>() is called next. - -<h3 class=fn>void <a name="setDoubleBuffering"></a>TQCanvas::setDoubleBuffering ( bool y )<tt> [virtual]</tt> -</h3> -If <em>y</em> is TRUE (the default) double-buffering is switched on; -otherwise double-buffering is switched off. -<p> Turning off double-buffering causes the redrawn areas to flicker a -little and also gives a (usually small) performance improvement. - -<p>Example: <a href="canvas-example.html#x2911">canvas/canvas.cpp</a>. -<h3 class=fn>void <a name="setTile"></a>TQCanvas::setTile ( int x, int y, int tilenum )<tt> [virtual]</tt> -</h3> -Sets the tile at (<em>x</em>, <em>y</em>) to use tile number <em>tilenum</em>, which -is an index into the tile pixmaps. The canvas will update -appropriately when <a href="#update">update</a>() is next called. -<p> The images are taken from the pixmap set by <a href="#setTiles">setTiles</a>() and are -arranged left to right, (and in the case of pixmaps that have -multiple rows of tiles, top to bottom), with tile 0 in the -top-left corner, tile 1 next to the right, and so on, e.g. -<p> <center><table cellpadding="4" cellspacing="2" border="0"> -<tr bgcolor="#f0f0f0"> <td valign="top">0 <td valign="top">1 <td valign="top">2 <td valign="top">3 -<tr bgcolor="#d0d0d0"> <td valign="top">4 <td valign="top">5 <td valign="top">6 <td valign="top">7 -</table></center> -<p> <p>See also <a href="#tile">tile</a>() and <a href="#setTiles">setTiles</a>(). - -<h3 class=fn>void <a name="setTiles"></a>TQCanvas::setTiles ( <a href="qpixmap.html">TQPixmap</a> p, int h, int v, int tilewidth, int tileheight )<tt> [virtual]</tt> -</h3> -Sets the TQCanvas to be composed of <em>h</em> tiles horizontally and <em>v</em> tiles vertically. Each tile will be an image <em>tilewidth</em> by <em>tileheight</em> pixels from pixmap <em>p</em>. -<p> The pixmap <em>p</em> is a list of tiles, arranged left to right, (and -in the case of pixmaps that have multiple rows of tiles, top to -bottom), with tile 0 in the top-left corner, tile 1 next to the -right, and so on, e.g. -<p> <center><table cellpadding="4" cellspacing="2" border="0"> -<tr bgcolor="#f0f0f0"> <td valign="top">0 <td valign="top">1 <td valign="top">2 <td valign="top">3 -<tr bgcolor="#d0d0d0"> <td valign="top">4 <td valign="top">5 <td valign="top">6 <td valign="top">7 -</table></center> -<p> If the canvas is larger than the matrix of tiles, the entire -matrix is repeated as necessary to cover the whole canvas. If it -is smaller, tiles to the right and bottom are not visible. -<p> The width and height of <em>p</em> must be a multiple of <em>tilewidth</em> -and <em>tileheight</em>. If they are not the function will do nothing. -<p> If you want to unset any tiling set, then just pass in a null -pixmap and 0 for <em>h</em>, <em>v</em>, <em>tilewidth</em>, and -<em>tileheight</em>. - -<h3 class=fn>void <a name="setUnchanged"></a>TQCanvas::setUnchanged ( const <a href="qrect.html">TQRect</a> & area )<tt> [virtual]</tt> -</h3> -Marks <em>area</em> as <em>unchanged</em>. The area will <em>not</em> be redrawn in -the views for the next <a href="#update">update</a>(), unless it is marked or changed -again before the next call to update(). - -<h3 class=fn>void <a name="setUpdatePeriod"></a>TQCanvas::setUpdatePeriod ( int ms )<tt> [virtual]</tt> -</h3> -Sets the canvas to call <a href="#update">update</a>() every <em>ms</em> milliseconds. Any -previous setting by <a href="#setAdvancePeriod">setAdvancePeriod</a>() or <a href="#setUpdatePeriod">setUpdatePeriod</a>() is -overridden. -<p> If <em>ms</em> is less than 0 automatic updating will be stopped. - -<h3 class=fn><a href="qsize.html">TQSize</a> <a name="size"></a>TQCanvas::size () const -</h3> - -<p> Returns the size of the canvas, in pixels. - -<h3 class=fn>int <a name="tile"></a>TQCanvas::tile ( int x, int y ) const -</h3> - -<p> Returns the tile at position (<em>x</em>, <em>y</em>). Initially, all tiles -are 0. -<p> The parameters must be within range, i.e. -0 < <em>x</em> < <a href="#tilesHorizontally">tilesHorizontally</a>() and -0 < <em>y</em> < <a href="#tilesVertically">tilesVertically</a>(). -<p> <p>See also <a href="#setTile">setTile</a>(). - -<h3 class=fn>int <a name="tileHeight"></a>TQCanvas::tileHeight () const -</h3> - -<p> Returns the height of each tile. - -<h3 class=fn>int <a name="tileWidth"></a>TQCanvas::tileWidth () const -</h3> - -<p> Returns the width of each tile. - -<h3 class=fn>int <a name="tilesHorizontally"></a>TQCanvas::tilesHorizontally () const -</h3> - -<p> Returns the number of tiles horizontally. - -<h3 class=fn>int <a name="tilesVertically"></a>TQCanvas::tilesVertically () const -</h3> - -<p> Returns the number of tiles vertically. - -<h3 class=fn>void <a name="update"></a>TQCanvas::update ()<tt> [virtual slot]</tt> -</h3> -Repaints changed areas in all views of the canvas. -<p> <p>See also <a href="#advance">advance</a>(). - -<h3 class=fn>bool <a name="validChunk"></a>TQCanvas::validChunk ( int x, int y ) const -</h3> - -<p> Returns TRUE if the chunk position (<em>x</em>, <em>y</em>) is on the canvas; -otherwise returns FALSE. -<p> <p>See also <a href="#onCanvas">onCanvas</a>(). - -<h3 class=fn>bool <a name="validChunk-2"></a>TQCanvas::validChunk ( const <a href="qpoint.html">TQPoint</a> & p ) const -</h3> - -This is an overloaded member function, provided for convenience. It behaves essentially like the above function. -<p> Returns TRUE if the chunk position <em>p</em> is on the canvas; otherwise -returns FALSE. -<p> <p>See also <a href="#onCanvas">onCanvas</a>(). - -<h3 class=fn>int <a name="width"></a>TQCanvas::width () const -</h3> - -<p> Returns the width of the canvas, in pixels. - -<p>Example: <a href="canvas-example.html#x2912">canvas/canvas.cpp</a>. -<!-- eof --> -<hr><p> -This file is part of the <a href="index.html">TQt toolkit</a>. -Copyright © 1995-2007 -<a href="http://www.trolltech.com/">Trolltech</a>. All Rights Reserved.<p><address><hr><div align=center> -<table width=100% cellspacing=0 border=0><tr> -<td>Copyright © 2007 -<a href="troll.html">Trolltech</a><td align=center><a href="trademarks.html">Trademarks</a> -<td align=right><div align=right>TQt 3.3.8</div> -</table></div></address></body> -</html> |