QGIS API Documentation  2.99.0-Master (dcec6bb)
qgsmapcanvasmap.cpp
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1 /***************************************************************************
2  qgsmapcanvasmap.cpp - draws the map in map canvas
3  ----------------------
4  begin : February 2006
5  copyright : (C) 2006 by Martin Dobias
6  email : wonder.sk at gmail dot com
7  ***************************************************************************
8  * *
9  * This program is free software; you can redistribute it and/or modify *
10  * it under the terms of the GNU General Public License as published by *
11  * the Free Software Foundation; either version 2 of the License, or *
12  * (at your option) any later version. *
13  * *
14  ***************************************************************************/
15 
16 #include "qgslogger.h"
17 #include "qgsmapcanvas.h"
18 #include "qgsmapcanvasmap.h"
19 #include "qgsmaprendererjob.h"
20 #include "qgsmapsettings.h"
21 #include "qgsmaplayer.h"
22 
23 #include <QPainter>
24 
26 
27 QgsMapCanvasMap::QgsMapCanvasMap( QgsMapCanvas *canvas )
28  : QgsMapCanvasItem( canvas )
29 {
30  setZValue( -10 );
31 }
32 
33 void QgsMapCanvasMap::setContent( const QImage &image, const QgsRectangle &rect )
34 {
35  mPreviewImages.clear();
36 
37  mImage = image;
38 
39  // For true retro fans: this is approximately how the graphics looked like in 1990
40  if ( mMapCanvas->property( "retro" ).toBool() )
41  mImage = mImage.scaled( mImage.width() / 3, mImage.height() / 3 )
42  .convertToFormat( QImage::Format_Indexed8, Qt::OrderedDither | Qt::OrderedAlphaDither );
43 
44  setRect( rect );
45 }
46 
47 void QgsMapCanvasMap::addPreviewImage( const QImage &image, const QgsRectangle &rect )
48 {
49  mPreviewImages.append( qMakePair( image, rect ) );
50  update();
51 }
52 
53 QRectF QgsMapCanvasMap::boundingRect() const
54 {
55  double width = mItemSize.width();
56  double height = mItemSize.height();
57 
58  return QRectF( -width, -height, 3 * width, 3 * height );
59 }
60 
61 void QgsMapCanvasMap::paint( QPainter *painter )
62 {
63  int w = qRound( mItemSize.width() ) - 2, h = qRound( mItemSize.height() ) - 2; // setRect() makes the size +2 :-(
64  if ( mImage.size() != QSize( w, h ) )
65  {
66  QgsDebugMsg( QString( "map paint DIFFERENT SIZE: img %1,%2 item %3,%4" ).arg( mImage.width() ).arg( mImage.height() ).arg( w ).arg( h ) );
67  // This happens on zoom events when ::paint is called before
68  // the renderer has completed
69  }
70 
71  /*Offset between 0/0 and mRect.xMinimum/mRect.yMinimum.
72  We need to consider the offset, because mRect is not updated yet and there might be an offset*/
73  QgsPointXY pt = toMapCoordinates( QPoint( 0, 0 ) );
74  double offsetX = pt.x() - mRect.xMinimum();
75  double offsetY = pt.y() - mRect.yMaximum();
76 
77  //draw preview images first
78  QList< QPair< QImage, QgsRectangle > >::const_iterator imIt = mPreviewImages.constBegin();
79  for ( ; imIt != mPreviewImages.constEnd(); ++imIt )
80  {
81  QPointF ul = toCanvasCoordinates( QgsPoint( imIt->second.xMinimum() + offsetX, imIt->second.yMaximum() + offsetY ) );
82  QPointF lr = toCanvasCoordinates( QgsPoint( imIt->second.xMaximum() + offsetX, imIt->second.yMinimum() + offsetY ) );
83  painter->drawImage( QRectF( ul.x(), ul.y(), lr.x() - ul.x(), lr.y() - ul.y() ), imIt->first, QRect( 0, 0, imIt->first.width(), imIt->first.height() ) );
84  }
85 
86  painter->drawImage( QRect( 0, 0, w, h ), mImage );
87 
88  // For debugging:
89 #if 0
90  QRectF br = boundingRect();
91  QPointF c = br.center();
92  double rad = std::max( br.width(), br.height() ) / 10;
93  painter->drawRoundedRect( br, rad, rad );
94  painter->drawLine( QLineF( 0, 0, br.width(), br.height() ) );
95  painter->drawLine( QLineF( br.width(), 0, 0, br.height() ) );
96 
97  double nw = br.width() * 0.5;
98  double nh = br.height() * 0.5;
99  br = QRectF( c - QPointF( nw / 2, nh / 2 ), QSize( nw, nh ) );
100  painter->drawRoundedRect( br, rad, rad );
101 
102  nw = br.width() * 0.5;
103  nh = br.height() * 0.5;
104  br = QRectF( c - QPointF( nw / 2, nh / 2 ), QSize( nw, nh ) );
105  painter->drawRoundedRect( br, rad, rad );
106 #endif
107 }
108 
A rectangle specified with double values.
Definition: qgsrectangle.h:38
QgsRectangle rect() const
returns canvas item rectangle in map units
QgsPointXY toMapCoordinates(QPoint point) const
transformation from screen coordinates to map coordinates
#define QgsDebugMsg(str)
Definition: qgslogger.h:37
A class to represent a 2D point.
Definition: qgspointxy.h:42
An abstract class for items that can be placed on the map canvas.
Map canvas is a class for displaying all GIS data types on a canvas.
Definition: qgsmapcanvas.h:73
QSizeF mItemSize
cached size of the item (to return in boundingRect())
virtual QRectF boundingRect() const override
void setRect(const QgsRectangle &r, bool resetRotation=true)
sets canvas item rectangle in map units
QgsRectangle mRect
cached canvas item rectangle in map coordinates encodes position (xmin,ymax) and size (width/height) ...
Point geometry type, with support for z-dimension and m-values.
Definition: qgspoint.h:36
double ANALYSIS_EXPORT max(double x, double y)
Returns the maximum of two doubles or the first argument if both are equal.
Definition: MathUtils.cc:437
QgsMapCanvas * mMapCanvas
pointer to map canvas
double xMinimum() const
Returns the x minimum value (left side of rectangle).
Definition: qgsrectangle.h:96
double yMaximum() const
Returns the y maximum value (top side of rectangle).
Definition: qgsrectangle.h:101
QPointF toCanvasCoordinates(const QgsPointXY &point) const
transformation from map coordinates to screen coordinates