QGIS API Documentation  3.14.0-Pi (9f7028fd23)
qgsmaptoolextent.cpp
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1 /***************************************************************************
2  qgsmaptoolextent.h - map tool that emits an extent
3  ---------------------
4  begin : July 2017
5  copyright : (C) 2017 by Mathieu Pellerin
6  email : nirvn dot asia 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 
17 
18 #include "qgsmaptoolextent.h"
19 #include "qgsmapcanvas.h"
20 #include "qgswkbtypes.h"
21 #include "qgsmapmouseevent.h"
22 
23 
25  : QgsMapTool( canvas )
26 {
28 }
29 
31 {
33 }
34 
36 {
37  mRubberBand->reset( QgsWkbTypes::PolygonGeometry );
38 
40 }
41 
43 {
44  if ( !mDraw )
45  return;
46 
47 
48  QgsPointXY p = toMapCoordinates( e->pos() );
49  if ( mRatio.width() > 0 && mRatio.height() > 0 )
50  {
51  double width = std::fabs( p.x() - mStartPoint.x() );
52  double height = width * ( mRatio.width() / mRatio.height() );
53  if ( p.y() - mStartPoint.y() < 0 )
54  height *= -1;
55  p.setY( mStartPoint.y() + height );
56  }
57 
58  mEndPoint = toMapCoordinates( e->pos() );
59  calculateEndPoint( mEndPoint );
60  drawExtent();
61 }
62 
64 {
65  mStartPoint = toMapCoordinates( e->pos() );
66  mEndPoint = mStartPoint;
67  drawExtent();
68 
69  mDraw = true;
70 }
71 
73 {
74  if ( !mDraw )
75  return;
76 
77  mEndPoint = toMapCoordinates( e->pos() );
78  calculateEndPoint( mEndPoint );
79  drawExtent();
80 
81  emit extentChanged( extent() );
82 
83  mDraw = false;
84 }
85 
87 {
88  if ( mStartPoint.x() != mEndPoint.x() && mStartPoint.y() != mEndPoint.y() )
89  {
90  return QgsRectangle( mStartPoint, mEndPoint );
91  }
92  else
93  {
94  return QgsRectangle();
95  }
96 }
97 
98 void QgsMapToolExtent::calculateEndPoint( QgsPointXY &point )
99 {
100  if ( mRatio.width() > 0 && mRatio.height() > 0 )
101  {
102  double width = std::fabs( point.x() - mStartPoint.x() );
103  double height = width * mRatio.height() / mRatio.width();
104  if ( point.y() - mStartPoint.y() < 0 )
105  height *= -1;
106  point.setY( mStartPoint.y() + height );
107  }
108 }
109 
110 void QgsMapToolExtent::drawExtent()
111 {
112  if ( qgsDoubleNear( mStartPoint.x(), mEndPoint.x() ) && qgsDoubleNear( mStartPoint.y(), mEndPoint.y() ) )
113  return;
114 
115  mRubberBand->reset( QgsWkbTypes::PolygonGeometry );
116 
117  QgsRectangle rect( mStartPoint, mEndPoint );
118 
119  mRubberBand->reset( QgsWkbTypes::PolygonGeometry );
120  mRubberBand->addPoint( QgsPointXY( rect.xMinimum(), rect.yMinimum() ), false );
121  mRubberBand->addPoint( QgsPointXY( rect.xMaximum(), rect.yMinimum() ), false );
122  mRubberBand->addPoint( QgsPointXY( rect.xMaximum(), rect.yMaximum() ), false );
123  mRubberBand->addPoint( QgsPointXY( rect.xMinimum(), rect.yMaximum() ), true );
124 
125  mRubberBand->show();
126 }
QgsMapToolExtent::extentChanged
void extentChanged(const QgsRectangle &extent)
signal emitted on extent change
QgsPointXY::y
double y
Definition: qgspointxy.h:48
QObjectUniquePtr::reset
void reset(T *p=nullptr)
Will reset the managed pointer to p.
Definition: qobjectuniqueptr.h:176
QgsMapToolExtent::extent
QgsRectangle extent() const
Returns the current extent drawn onto the canvas.
Definition: qgsmaptoolextent.cpp:86
qgsmapcanvas.h
QgsMapToolExtent::deactivate
void deactivate() override
called when map tool is being deactivated
Definition: qgsmaptoolextent.cpp:35
QgsRubberBand
Definition: qgsrubberband.h:49
QgsMapCanvas
Definition: qgsmapcanvas.h:83
QgsMapTool::deactivate
virtual void deactivate()
called when map tool is being deactivated
Definition: qgsmaptool.cpp:99
QgsMapToolExtent::activate
void activate() override
called when set as currently active map tool
Definition: qgsmaptoolextent.cpp:30
QgsMapTool::canvas
QgsMapCanvas * canvas() const
returns pointer to the tool's map canvas
Definition: qgsmaptool.cpp:198
QgsRectangle
Definition: qgsrectangle.h:41
QgsWkbTypes::PolygonGeometry
@ PolygonGeometry
Definition: qgswkbtypes.h:143
QgsRubberBand::reset
void reset(QgsWkbTypes::GeometryType geometryType=QgsWkbTypes::LineGeometry)
Clears all the geometries in this rubberband.
Definition: qgsrubberband.cpp:102
QgsMapTool
Definition: qgsmaptool.h:63
qgsDoubleNear
bool qgsDoubleNear(double a, double b, double epsilon=4 *std::numeric_limits< double >::epsilon())
Compare two doubles (but allow some difference)
Definition: qgis.h:315
QgsMapToolExtent::canvasMoveEvent
void canvasMoveEvent(QgsMapMouseEvent *e) override
Mouse move event for overriding. Default implementation does nothing.
Definition: qgsmaptoolextent.cpp:42
QgsMapToolExtent::canvasReleaseEvent
void canvasReleaseEvent(QgsMapMouseEvent *e) override
Mouse release event for overriding. Default implementation does nothing.
Definition: qgsmaptoolextent.cpp:72
QgsPointXY::setY
void setY(double y)
Sets the y value of the point.
Definition: qgspointxy.h:117
QgsRubberBand::addPoint
void addPoint(const QgsPointXY &p, bool doUpdate=true, int geometryIndex=0, int ringIndex=0)
Adds a vertex to the rubberband and update canvas.
Definition: qgsrubberband.cpp:110
QgsMapTool::activate
virtual void activate()
called when set as currently active map tool
Definition: qgsmaptool.cpp:83
QgsPointXY
Definition: qgspointxy.h:43
QgsMapMouseEvent
Definition: qgsmapmouseevent.h:35
QgsPointXY::x
double x
Definition: qgspointxy.h:47
qgsmaptoolextent.h
QgsMapToolExtent::canvasPressEvent
void canvasPressEvent(QgsMapMouseEvent *e) override
Mouse press event for overriding. Default implementation does nothing.
Definition: qgsmaptoolextent.cpp:63
QgsMapToolExtent::QgsMapToolExtent
QgsMapToolExtent(QgsMapCanvas *canvas)
constructor
Definition: qgsmaptoolextent.cpp:24
qgsmapmouseevent.h
qgswkbtypes.h
QgsMapTool::toMapCoordinates
QgsPointXY toMapCoordinates(QPoint point)
transformation from screen coordinates to map coordinates
Definition: qgsmaptool.cpp:42