QGIS API Documentation 3.29.0-Master (ade4f0cf0f)
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 "qgsrendercontext.h"
20#include <QDomDocument>
21#include <QPainter>
22
24 : QgsAnnotation( parent )
25 , mDocument( new QTextDocument( QString() ) )
26{
27 mDocument->setUseDesignMetrics( true );
28}
29
31{
32 std::unique_ptr< QgsTextAnnotation > c( new QgsTextAnnotation() );
33 copyCommonProperties( c.get() );
34 c->setDocument( mDocument.get() );
35 return c.release();
36}
37
38const QTextDocument *QgsTextAnnotation::document() const
39{
40 return mDocument.get();
41}
42
43void QgsTextAnnotation::setDocument( const QTextDocument *doc )
44{
45 if ( doc )
46 mDocument.reset( doc->clone() );
47 else
48 mDocument.reset();
49 emit appearanceChanged();
50}
51
52void QgsTextAnnotation::renderAnnotation( QgsRenderContext &context, QSizeF size ) const
53{
54 QPainter *painter = context.painter();
55 if ( !mDocument )
56 {
57 return;
58 }
59
60 // scale painter back to 96 dpi, so layout prints match screen rendering
61 const QgsScopedQPainterState painterState( context.painter() );
62 const double scaleFactor = context.painter()->device()->logicalDpiX() / 96.0;
63 context.painter()->scale( scaleFactor, scaleFactor );
64 size /= scaleFactor;
65
66 mDocument->setTextWidth( size.width() );
67
68 QRectF clipRect = QRectF( 0, 0, size.width(), size.height() );
69 if ( painter->hasClipping() )
70 {
71 //QTextDocument::drawContents will draw text outside of the painter's clip region
72 //when it is passed a clip rectangle. So, we need to intersect it with the
73 //painter's clip region to prevent text drawn outside clipped region (e.g., outside layout maps, see #10400)
74 clipRect = clipRect.intersected( painter->clipRegion().boundingRect() );
75 }
76 //draw text document
77 mDocument->drawContents( painter, clipRect );
78}
79
80void QgsTextAnnotation::writeXml( QDomElement &elem, QDomDocument &doc, const QgsReadWriteContext &context ) const
81{
82 QDomElement annotationElem = doc.createElement( QStringLiteral( "TextAnnotationItem" ) );
83 if ( mDocument )
84 {
85 annotationElem.setAttribute( QStringLiteral( "document" ), mDocument->toHtml() );
86 }
87 _writeXml( annotationElem, doc, context );
88 elem.appendChild( annotationElem );
89}
90
91void QgsTextAnnotation::readXml( const QDomElement &itemElem, const QgsReadWriteContext &context )
92{
93 mDocument.reset( new QTextDocument );
94 mDocument->setHtml( itemElem.attribute( QStringLiteral( "document" ), QString() ) );
95 const QDomElement annotationElem = itemElem.firstChildElement( QStringLiteral( "AnnotationItem" ) );
96 if ( !annotationElem.isNull() )
97 {
98 _readXml( annotationElem, context );
99 }
100}
Abstract base class for annotation items which are drawn over a map.
Definition: qgsannotation.h:54
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.
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.
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