QGIS API Documentation 3.41.0-Master (fda2aa46e9a)
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qgstextannotation.cpp
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1/***************************************************************************
2 qgstextannotation.cpp
3 ------------------------
4begin : February 9, 2010
5copyright : (C) 2010 by Marco Hugentobler
6email : marco dot hugentobler at hugis dot net
7***************************************************************************/
8
9/***************************************************************************
10 * *
11 * This program is free software; you can redistribute it and/or modify *
12 * it under the terms of the GNU General Public License as published by *
13 * the Free Software Foundation; either version 2 of the License, or *
14 * (at your option) any later version. *
15 * *
16 ***************************************************************************/
17
18#include "qgstextannotation.h"
19#include "moc_qgstextannotation.cpp"
20#include "qgsrendercontext.h"
21#include <QDomDocument>
22#include <QPainter>
23
25 : QgsAnnotation( parent )
26 , mDocument( new QTextDocument( QString() ) )
27{
28 mDocument->setUseDesignMetrics( true );
29}
30
32{
33 std::unique_ptr< QgsTextAnnotation > c( new QgsTextAnnotation() );
34 copyCommonProperties( c.get() );
35 c->setDocument( mDocument.get() );
36 return c.release();
37}
38
39const QTextDocument *QgsTextAnnotation::document() const
40{
41 return mDocument.get();
42}
43
44void QgsTextAnnotation::setDocument( const QTextDocument *doc )
45{
46 if ( doc )
47 mDocument.reset( doc->clone() );
48 else
49 mDocument.reset();
50 emit appearanceChanged();
51}
52
53void QgsTextAnnotation::renderAnnotation( QgsRenderContext &context, QSizeF size ) const
54{
55 QPainter *painter = context.painter();
56 if ( !mDocument || ! painter || ( context.feedback() && context.feedback()->isCanceled() ) )
57 {
58 return;
59 }
60
61 // scale painter back to 96 dpi, so layout prints match screen rendering
62 const QgsScopedQPainterState painterState( context.painter() );
63 const double scaleFactor = context.painter()->device()->logicalDpiX() / 96.0;
64 context.painter()->scale( scaleFactor, scaleFactor );
65 size /= scaleFactor;
66
67 mDocument->setTextWidth( size.width() );
68
69 QRectF clipRect = QRectF( 0, 0, size.width(), size.height() );
70 if ( painter->hasClipping() )
71 {
72 //QTextDocument::drawContents will draw text outside of the painter's clip region
73 //when it is passed a clip rectangle. So, we need to intersect it with the
74 //painter's clip region to prevent text drawn outside clipped region (e.g., outside layout maps, see #10400)
75 clipRect = clipRect.intersected( painter->clipRegion().boundingRect() );
76 }
77 //draw text document
78 mDocument->drawContents( painter, clipRect );
79}
80
81void QgsTextAnnotation::writeXml( QDomElement &elem, QDomDocument &doc, const QgsReadWriteContext &context ) const
82{
83 QDomElement annotationElem = doc.createElement( QStringLiteral( "TextAnnotationItem" ) );
84 if ( mDocument )
85 {
86 annotationElem.setAttribute( QStringLiteral( "document" ), mDocument->toHtml() );
87 }
88 _writeXml( annotationElem, doc, context );
89 elem.appendChild( annotationElem );
90}
91
92void QgsTextAnnotation::readXml( const QDomElement &itemElem, const QgsReadWriteContext &context )
93{
94 mDocument.reset( new QTextDocument );
95 mDocument->setHtml( itemElem.attribute( QStringLiteral( "document" ), QString() ) );
96 const QDomElement annotationElem = itemElem.firstChildElement( QStringLiteral( "AnnotationItem" ) );
97 if ( !annotationElem.isNull() )
98 {
99 _readXml( annotationElem, context );
100 }
101}
Abstract base class for annotation items which are drawn over a map.
void appearanceChanged()
Emitted whenever the annotation's appearance changes.
void _writeXml(QDomElement &itemElem, QDomDocument &doc, const QgsReadWriteContext &context) const
Writes common annotation properties to a DOM element.
void _readXml(const QDomElement &annotationElem, const QgsReadWriteContext &context)
Reads common annotation properties from a DOM element.
void copyCommonProperties(QgsAnnotation *target) const
Copies common annotation properties to the targe annotation.
bool isCanceled() const
Tells whether the operation has been canceled already.
Definition qgsfeedback.h:53
The class is used as a container of context for various read/write operations on other objects.
Contains information about the context of a rendering operation.
QPainter * painter()
Returns the destination QPainter for the render operation.
QgsFeedback * feedback() const
Returns the feedback object that can be queried regularly during rendering to check if rendering shou...
Scoped object for saving and restoring a QPainter object's state.
An annotation item that displays formatted text from a QTextDocument document.
QgsTextAnnotation * clone() const override
Clones the annotation, returning a new copy of the annotation reflecting the annotation's current sta...
void writeXml(QDomElement &elem, QDomDocument &doc, const QgsReadWriteContext &context) const override
Writes the annotation state to a DOM element.
void readXml(const QDomElement &itemElem, const QgsReadWriteContext &context) override
Restores the annotation's state from a DOM element.
const QTextDocument * document() const
Returns the text document which will be rendered within the annotation.
void renderAnnotation(QgsRenderContext &context, QSizeF size) const override
Renders the annotation's contents to a target /a context at the specified /a size.
void setDocument(const QTextDocument *doc)
Sets the text document which will be rendered within the annotation.
QgsTextAnnotation(QObject *parent=nullptr)
Constructor for QgsTextAnnotation.
As part of the API refactoring and improvements which landed in the Processing API was substantially reworked from the x version This was done in order to allow much of the underlying Processing framework to be ported into c