Sources_For_Linux/Qwt/doc/man/man3/QwtTextEngine.3

.TH "QwtTextEngine" 3 "Mon Dec 28 2020" "Version 6.1.6" "Qwt User's Guide" \" -*- nroff -*-
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.SH NAME
QwtTextEngine \- Abstract base class for rendering text strings\&.  

.SH SYNOPSIS
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.PP
.PP
\fC#include <qwt_text_engine\&.h>\fP
.PP
Inherited by \fBQwtMathMLTextEngine\fP, \fBQwtPlainTextEngine\fP, and \fBQwtRichTextEngine\fP\&.
.SS "Public Member Functions"

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.RI "virtual \fB~QwtTextEngine\fP ()"
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.RI "Destructor\&. "
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.RI "virtual double \fBheightForWidth\fP (const QFont &font, int flags, const QString &text, double width) const =0"
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.RI "virtual QSizeF \fBtextSize\fP (const QFont &font, int flags, const QString &text) const =0"
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.RI "virtual bool \fBmightRender\fP (const QString &text) const =0"
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.RI "virtual void \fBtextMargins\fP (const QFont &font, const QString &text, double &left, double &right, double &top, double &bottom) const =0"
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.RI "virtual void \fBdraw\fP (QPainter *painter, const QRectF &rect, int flags, const QString &text) const =0"
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.SS "Protected Member Functions"

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.RI "\fBQwtTextEngine\fP ()"
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.RI "Constructor\&. "
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.SH "Detailed Description"
.PP 
Abstract base class for rendering text strings\&. 

A text engine is responsible for rendering texts for a specific text format\&. They are used by \fBQwtText\fP to render a text\&.
.PP
\fBQwtPlainTextEngine\fP and \fBQwtRichTextEngine\fP are part of the Qwt library\&. The implementation of \fBQwtMathMLTextEngine\fP uses code from the Qt solution package\&. Because of license implications it is built into a separate library\&.
.PP
\fBSee also\fP
.RS 4
\fBQwtText::setTextEngine()\fP 
.RE
.PP

.SH "Member Function Documentation"
.PP 
.SS "virtual void QwtTextEngine::draw (QPainter * painter, const QRectF & rect, int flags, const QString & text) const\fC [pure virtual]\fP"
Draw the text in a clipping rectangle
.PP
\fBParameters\fP
.RS 4
\fIpainter\fP Painter 
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\fIrect\fP Clipping rectangle 
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\fIflags\fP Bitwise OR of the flags like in for QPainter::drawText() 
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\fItext\fP Text to be rendered 
.RE
.PP

.PP
Implemented in \fBQwtMathMLTextEngine\fP, \fBQwtRichTextEngine\fP, and \fBQwtPlainTextEngine\fP\&.
.SS "virtual double QwtTextEngine::heightForWidth (const QFont & font, int flags, const QString & text, double width) const\fC [pure virtual]\fP"
Find the height for a given width
.PP
\fBParameters\fP
.RS 4
\fIfont\fP Font of the text 
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\fIflags\fP Bitwise OR of the flags used like in QPainter::drawText 
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\fItext\fP Text to be rendered 
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\fIwidth\fP Width
.RE
.PP
\fBReturns\fP
.RS 4
Calculated height 
.RE
.PP

.PP
Implemented in \fBQwtMathMLTextEngine\fP, \fBQwtRichTextEngine\fP, and \fBQwtPlainTextEngine\fP\&.
.SS "virtual bool QwtTextEngine::mightRender (const QString & text) const\fC [pure virtual]\fP"
Test if a string can be rendered by this text engine
.PP
\fBParameters\fP
.RS 4
\fItext\fP Text to be tested 
.RE
.PP
\fBReturns\fP
.RS 4
true, if it can be rendered 
.RE
.PP

.PP
Implemented in \fBQwtMathMLTextEngine\fP, \fBQwtRichTextEngine\fP, and \fBQwtPlainTextEngine\fP\&.
.SS "virtual void QwtTextEngine::textMargins (const QFont & font, const QString & text, double & left, double & right, double & top, double & bottom) const\fC [pure virtual]\fP"
Return margins around the texts
.PP
The textSize might include margins around the text, like QFontMetrics::descent()\&. In situations where texts need to be aligned in detail, knowing these margins might improve the layout calculations\&.
.PP
\fBParameters\fP
.RS 4
\fIfont\fP Font of the text 
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\fItext\fP Text to be rendered 
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\fIleft\fP Return value for the left margin 
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\fIright\fP Return value for the right margin 
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\fItop\fP Return value for the top margin 
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\fIbottom\fP Return value for the bottom margin 
.RE
.PP

.PP
Implemented in \fBQwtMathMLTextEngine\fP, \fBQwtRichTextEngine\fP, and \fBQwtPlainTextEngine\fP\&.
.SS "virtual QSizeF QwtTextEngine::textSize (const QFont & font, int flags, const QString & text) const\fC [pure virtual]\fP"
Returns the size, that is needed to render text
.PP
\fBParameters\fP
.RS 4
\fIfont\fP Font of the text 
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\fIflags\fP Bitwise OR of the flags like in for QPainter::drawText 
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\fItext\fP Text to be rendered
.RE
.PP
\fBReturns\fP
.RS 4
Calculated size 
.RE
.PP

.PP
Implemented in \fBQwtMathMLTextEngine\fP, \fBQwtRichTextEngine\fP, and \fBQwtPlainTextEngine\fP\&.

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