qwtplotcanvas.3

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.TH "QwtPlotCanvas" 3 "4 Nov 2003" "Qwt User's Guide" \" -*- nroff -*-
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.nh
.SH NAME
QwtPlotCanvas \- 
.SH SYNOPSIS
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.PP
.SH "Detailed Description"
.PP 
Canvas of a \fBQwtPlot\fP. 

\fBSee also:\fP
.RS 4
\fBQwtPlot\fP 
.RE
.PP

.PP
.SS "Public Types"

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.RI "enum \fBFocusIndicator\fP { \fBNoFocusIndicator\fP, \fBCanvasFocusIndicator\fP, \fBItemFocusIndicator\fP }"
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.SS "Public Member Functions"

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.RI "void \fBsetFocusIndicator\fP (\fBFocusIndicator\fP)"
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.RI "\fBFocusIndicator\fP \fBfocusIndicator\fP () const "
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.RI "void \fBsetCacheMode\fP (bool on)"
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.RI "bool \fBcacheMode\fP () const "
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.RI "const  QPixmap * \fBcache\fP () const "
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.RI "void \fBenableOutline\fP (bool tf)"
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.RI "bool \fBoutlineEnabled\fP () const "
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.RI "void \fBsetOutlinePen\fP (const  QPen &p)"
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.RI "const  QPen & \fBoutlinePen\fP () const "
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.RI "void \fBsetOutlineStyle\fP (Qwt::Shape os)"
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.RI "Qwt::Shape \fBoutlineStyle\fP () const "
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.SS "Protected Member Functions"

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.RI "\fBQwtPlotCanvas\fP (\fBQwtPlot\fP *)"
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.RI "QPixmap * \fBcache\fP ()"
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.RI "virtual void \fBframeChanged\fP ()"
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.RI "virtual void \fBdrawContents\fP (QPainter *)"
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.RI "virtual void \fBdrawFocusIndicator\fP (QPainter *, const  QRect &)"
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.RI "void \fBdrawCanvas\fP (QPainter *painter=NULL)"
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.RI "void \fBmousePressed\fP (const  QMouseEvent &e)"
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.RI "void \fBmouseReleased\fP (const  QMouseEvent &e)"
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.RI "void \fBmouseMoved\fP (const  QMouseEvent &e)"
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.RI "virtual void \fBmousePressEvent\fP (QMouseEvent *)"
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.RI "virtual void \fBmouseReleaseEvent\fP (QMouseEvent *)"
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.RI "virtual void \fBmouseMoveEvent\fP (QMouseEvent *)"
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.SS "Friends"

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.RI "class \fBQwtPlot\fP"
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.SH "Member Enumeration Documentation"
.PP 
.SS "enum \fBQwtPlotCanvas::FocusIndicator\fP"
.PP
Focus indicator. .IP "\(bu" 2
NoFocusIndicator
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 Don磘 paint a focus indicator
.IP "\(bu" 2
CanvasFocusIndicator
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 The focus is related to the complete canvas. Paint the focus indicator using paintFocus()
.IP "\(bu" 2
ItemFocusIndicator
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 The focus is related to an item (curve, point, ...) on the canvas. It is up to the application to display a focus indication using f.e. highlighting.
.PP
.PP
\fBSee also:\fP
.RS 4
\fBsetFocusIndicator()\fP, \fBfocusIndicator()\fP, paintFocus() 
.RE
.PP

.SH "Constructor & Destructor Documentation"
.PP 
.SS "QwtPlotCanvas::QwtPlotCanvas (\fBQwtPlot\fP *)\fC [protected]\fP"
.PP
Sets a cross cursor, and an invisible red outline. 
.SH "Member Function Documentation"
.PP 
.SS "QPixmap * QwtPlotCanvas::cache ()\fC [protected]\fP"
.PP
Return the paint cache, might be null. 
.SS "const  QPixmap * QwtPlotCanvas::cache () const"
.PP
Return the paint cache, might be null. 
.SS "bool QwtPlotCanvas::cacheMode () const"
.PP
\fBReturns:\fP
.RS 4
Cache mode 
.RE
.PP
\fBSee also:\fP
.RS 4
\fBsetCacheMode\fP 
.RE
.PP

.SS "void QwtPlotCanvas::drawCanvas (QPainter * painter = NULL)\fC [protected]\fP"
.PP
Draw the the canvas
.PP
Paints all plot items to the contentsRect(), using \fBQwtPlot::drawCanvas\fP and updates the cache.
.PP
\fBSee also:\fP
.RS 4
\fBQwtPlot::drawCanvas\fP, \fBsetCacheMode()\fP, \fBcacheMode()\fP 
.RE
.PP

.SS "void QwtPlotCanvas::drawContents (QPainter *)\fC [protected, virtual]\fP"
.PP
Redraw the canvas, and focus rect. 
.SS "void QwtPlotCanvas::enableOutline (bool tf)"
.PP
Enables or disables outline drawing. When the outline feature is enabled, a shape will be drawn in the plotting region when the user presses or drags the mouse. It can be used to implement crosshairs, mark a selected region, etc. \fBParameters:\fP
.RS 4
\fItf\fP \fCTRUE\fP (enabled) or \fCFALSE\fP (disabled) 
.RE
.PP
\fBWarning:\fP
.RS 4
An outline style has to be specified. 
.RE
.PP
\fBSee also:\fP
.RS 4
\fBQwtPlotCanvas::setOutlineStyle()\fP 
.RE
.PP

.SS "\fBQwtPlotCanvas::FocusIndicator\fP QwtPlotCanvas::focusIndicator () const"
.PP
\fBReturns:\fP
.RS 4
Focus indicator
.RE
.PP
\fBSee also:\fP
.RS 4
\fBFocusIndicator\fP, \fBsetFocusIndicator\fP 
.RE
.PP

.SS "void QwtPlotCanvas::frameChanged ()\fC [protected, virtual]\fP"
.PP
Requires layout updates of the parent plot. 
.SS "void QwtPlotCanvas::mouseMoved (const QMouseEvent & e)\fC [protected]\fP"
.PP
A signal which is emitted when the mouse is moved in the canvas. 
.PP
\fBParameters:\fP
.RS 4
\fIe\fP Mouse event object 
.RE
.PP

.SS "void QwtPlotCanvas::mouseMoveEvent (QMouseEvent *)\fC [protected, virtual]\fP"
.PP
mouseMoveEvent 
.SS "void QwtPlotCanvas::mousePressed (const QMouseEvent & e)\fC [protected]\fP"
.PP
A signal which is emitted when the mouse is pressed in the canvas. 
.PP
\fBParameters:\fP
.RS 4
\fIe\fP Mouse event object 
.RE
.PP

.SS "void QwtPlotCanvas::mousePressEvent (QMouseEvent *)\fC [protected, virtual]\fP"
.PP
mousePressEvent 
.SS "void QwtPlotCanvas::mouseReleased (const QMouseEvent & e)\fC [protected]\fP"
.PP
A signal which is emitted when a mouse button has been released in the canvas. 
.PP
\fBParameters:\fP
.RS 4
\fIe\fP Mouse event object 
.RE
.PP

.SS "void QwtPlotCanvas::mouseReleaseEvent (QMouseEvent *)\fC [protected, virtual]\fP"
.PP
mouseReleaseEvent 
.SS "bool QwtPlotCanvas::outlineEnabled () const"
.PP
\fBReturns:\fP
.RS 4
\fCTRUE\fP if the outline feature is enabled 
.RE
.PP
\fBSee also:\fP
.RS 4
\fBQwtPlotCanvas::enableOutline\fP 
.RE
.PP

.SS "const  QPen & QwtPlotCanvas::outlinePen () const"
.PP
\fBReturns:\fP
.RS 4
the pen used to draw outlines 
.RE
.PP
\fBSee also:\fP
.RS 4
\fBQwtPlotCanvas::setOutlinePen\fP 
.RE
.PP

.SS "Qwt::Shape QwtPlotCanvas::outlineStyle () const"
.PP
\fBReturns:\fP
.RS 4
the outline style 
.RE
.PP
\fBSee also:\fP
.RS 4
\fBQwtPlotCanvas::setOutlineStyle()\fP 
.RE
.PP

.SS "void QwtPlotCanvas::setCacheMode (bool on)"
.PP
En/Disable caching. When cache mode is enabled the canvas contents are copied to a pixmap that is used for trivial repaints. Such repaints happen when a plot gets unhidden, deiconified or changes the focus.
.PP
The win of caching depends on the costs of \fBQwtPlot::drawCanvas\fP. In case of plots with huge data it might be significant. The price of caching is wasting memory for the cache, what is a pixmap in size of contentsRect(). In case of \fBQwtPaintBuffer::isEnabled()\fP updating the cache produces no performance overhead as it reuses the temporary paintbuffer of the double buffering. Otherwise canvas updates have to painted twice to widget and cache.
.PP
\fBParameters:\fP
.RS 4
\fIon\fP Enable caching, when TRUE
.RE
.PP
\fBSee also:\fP
.RS 4
\fBcacheMode()\fP, \fBdrawCanvas()\fP, \fBdrawContents()\fP, \fBcache()\fP 
.RE
.PP

.SS "void QwtPlotCanvas::setFocusIndicator (\fBFocusIndicator\fP focusIndicator)"
.PP
Set the focus indicator
.PP
\fBSee also:\fP
.RS 4
\fBFocusIndicator\fP, \fBfocusIndicator\fP 
.RE
.PP

.SS "void QwtPlotCanvas::setOutlinePen (const QPen & pen)"
.PP
Specify a pen for the outline. \fBParameters:\fP
.RS 4
\fIpen\fP new pen 
.RE
.PP
\fBSee also:\fP
.RS 4
\fBQwtPlotCanvas::outlinePen\fP 
.RE
.PP

.SS "void QwtPlotCanvas::setOutlineStyle (Qwt::Shape os)"
.PP
Specify the style of the outline. The outline style determines which kind of shape is drawn in the plotting region when the user presses a mouse button or drags the mouse. Valid Styles are: 
.PP
\fBParameters:\fP
.RS 4
\fIos\fP Outline Style. Valid values are: \fCQwt::HLine\fP, \fCQwt::VLine\fP, \fCQwt::Cross\fP, \fCQwt::Rect\fP, \fCQwt::Ellipse\fP 
.IP "\fBQwt::Cros \fP" 1c
Cross hairs are drawn across the plotting area when the user presses a mouse button. The lines intersect at the point where the mouse was pressed and move with the mouse pointer. 
.IP "\fBQwt::HLine, Qwt::VLine \fP" 1c
A horizontal or vertical line appears when the user presses a mouse button. This is useful for moving line markers. 
.IP "\fBQwt::Rect \fP" 1c
A rectangle is displayed when the user drags the mouse. One corner is fixed at the point where the mouse was pressed, and the opposite corner moves with the mouse pointer. This can be used for selecting regions. 
.IP "\fBQwt::Ellipse \fP" 1c
Similar to Qwt::Rect, but with an ellipse inside a bounding rectangle. 
.PP
.RE
.PP
\fBSee also:\fP
.RS 4
\fBQwtPlotCanvas::enableOutline()\fP, \fBQwtPlotCanvas::outlineStyle()\fP 
.RE
.PP


.SH "Author"
.PP 
Generated automatically by Doxygen for Qwt User's Guide from the source code.