QGIS API Documentation  3.6.0-Noosa (5873452)
qgslayoutitemnodeitem.cpp
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1 /***************************************************************************
2  qgslayoutitemnodeitem.cpp
3  begin : March 2016
4  copyright : (C) 2016 Paul Blottiere, Oslandia
5  email : paul dot blottiere at oslandia dot com
6  ***************************************************************************/
7 
8 /***************************************************************************
9  * *
10  * This program is free software; you can redistribute it and/or modify *
11  * it under the terms of the GNU General Public License as published by *
12  * the Free Software Foundation; either version 2 of the License, or *
13  * (at your option) any later version. *
14  * *
15  ***************************************************************************/
16 
17 #include "qgslayoutitemnodeitem.h"
18 #include "qgssymbollayerutils.h"
19 #include "qgssymbol.h"
20 #include "qgsmapsettings.h"
21 #include "qgslayout.h"
22 #include "qgslayoututils.h"
23 #include <limits>
24 #include <cmath>
25 #include <QStyleOptionGraphicsItem>
26 
27 void QgsLayoutNodesItem::setNodes( const QPolygonF &nodes )
28 {
29  mPolygon = nodes;
31 }
32 
34 {
35  return mCurrentRectangle;
36 }
37 
39 {
40  return mMaxSymbolBleed;
41 }
42 
44  : QgsLayoutItem( layout )
45 {
46  init();
47 }
48 
49 QgsLayoutNodesItem::QgsLayoutNodesItem( const QPolygonF &polygon,
50  QgsLayout *layout )
51  : QgsLayoutItem( layout )
52 {
53  init();
54 
55  const QRectF boundingRect = polygon.boundingRect();
56  attemptSetSceneRect( boundingRect );
57 
58  const QPointF topLeft = boundingRect.topLeft();
59  mPolygon = polygon.translated( -topLeft );
60 }
61 
62 void QgsLayoutNodesItem::init()
63 {
64  // no cache - the node based items cannot reliably determine their real bounds (e.g. due to mitred corners).
65  // this blocks use of the pixmap based cache for these
66  setCacheMode( QGraphicsItem::NoCache );
67  setBackgroundEnabled( false );
68  setFrameEnabled( false );
69 
71 }
72 
74 {
75  QPainter *painter = context.renderContext().painter();
76  painter->setPen( Qt::NoPen );
77  painter->setBrush( Qt::NoBrush );
78 
79  context.renderContext().setForceVectorOutput( true );
81  _draw( context );
82 
83  if ( mDrawNodes && layout()->renderContext().isPreviewRender() )
84  drawNodes( context );
85 }
86 
88  QPointF pt2 ) const
89 {
90  return std::sqrt( std::pow( pt1.x() - pt2.x(), 2 ) + std::pow( pt1.y() - pt2.y(), 2 ) );
91 }
92 
93 bool QgsLayoutNodesItem::addNode( QPointF pt,
94  const bool checkArea,
95  const double radius )
96 {
97  const QPointF start = mapFromScene( pt );
98  double minDistance = std::numeric_limits<double>::max();
99  double maxDistance = ( checkArea ) ? radius : minDistance;
100  bool rc = false;
101  int idx = -1;
102 
103  for ( int i = 0; i != mPolygon.size(); i++ )
104  {
105  // get nodes of polyline
106  const QPointF pt1 = mPolygon.at( i );
107  QPointF pt2 = mPolygon.at( 0 );
108  if ( ( i + 1 ) != mPolygon.size() )
109  pt2 = mPolygon.at( i + 1 );
110 
111  // compute line eq
112  const double coef = ( pt2.y() - pt1.y() ) / ( pt2.x() - pt1.x() );
113  const double b = pt1.y() - coef * pt1.x();
114 
115  double distance = std::numeric_limits<double>::max();
116  if ( std::isinf( coef ) )
117  distance = std::fabs( pt1.x() - start.x() );
118  else
119  {
120  const double coef2 = ( -1 / coef );
121  const double b2 = start.y() - coef2 * start.x();
122 
123  QPointF inter;
124  if ( std::isinf( coef2 ) )
125  {
126  distance = std::fabs( pt1.y() - start.y() );
127  inter.setX( start.x() );
128  inter.setY( pt1.y() );
129  }
130  else
131  {
132  const double interx = ( b - b2 ) / ( coef2 - coef );
133  const double intery = interx * coef2 + b2;
134  inter.setX( interx );
135  inter.setY( intery );
136  }
137 
138  // check if intersection is within the line
139  const double length1 = computeDistance( inter, pt1 );
140  const double length2 = computeDistance( inter, pt2 );
141  const double length3 = computeDistance( pt1, pt2 );
142  const double length4 = length1 + length2;
143 
144  if ( std::fabs( length3 - length4 ) < std::numeric_limits<float>::epsilon() )
145  distance = computeDistance( inter, start );
146  }
147 
148  if ( distance < minDistance && distance < maxDistance )
149  {
150  minDistance = distance;
151  idx = i;
152  }
153  }
154 
155  if ( idx >= 0 )
156  {
157  rc = _addNode( idx, start, maxDistance );
158  updateSceneRect();
159  }
160 
161  return rc;
162 }
163 
164 void QgsLayoutNodesItem::drawNodes( QgsLayoutItemRenderContext &context ) const
165 {
166  context.renderContext().painter()->setRenderHint( QPainter::Antialiasing, false );
167 
168  double rectSize = 9.0 / context.viewScaleFactor();
169 
170  QgsStringMap properties;
171  properties.insert( QStringLiteral( "name" ), QStringLiteral( "cross" ) );
172  properties.insert( QStringLiteral( "color_border" ), QStringLiteral( "red" ) );
173 
174  std::unique_ptr<QgsMarkerSymbol> symbol;
175  symbol.reset( QgsMarkerSymbol::createSimple( properties ) );
176  symbol->setSize( rectSize );
177  symbol->setAngle( 45 );
178 
179  symbol->startRender( context.renderContext() );
180  for ( QPointF pt : mPolygon )
181  symbol->renderPoint( pt * context.viewScaleFactor(), nullptr, context.renderContext() );
182  symbol->stopRender( context.renderContext() );
183 
184  if ( mSelectedNode >= 0 && mSelectedNode < mPolygon.size() )
185  drawSelectedNode( context );
186 }
187 
188 void QgsLayoutNodesItem::drawSelectedNode( QgsLayoutItemRenderContext &context ) const
189 {
190  double rectSize = 9.0 / context.viewScaleFactor();
191 
192  QgsStringMap properties;
193  properties.insert( QStringLiteral( "name" ), QStringLiteral( "square" ) );
194  properties.insert( QStringLiteral( "color" ), QStringLiteral( "0, 0, 0, 0" ) );
195  properties.insert( QStringLiteral( "color_border" ), QStringLiteral( "blue" ) );
196  properties.insert( QStringLiteral( "width_border" ), QStringLiteral( "4" ) );
197 
198  std::unique_ptr<QgsMarkerSymbol> symbol;
199  symbol.reset( QgsMarkerSymbol::createSimple( properties ) );
200  symbol->setSize( rectSize );
201 
202  symbol->startRender( context.renderContext() );
203  symbol->renderPoint( mPolygon.at( mSelectedNode ) * context.viewScaleFactor(), nullptr, context.renderContext() );
204  symbol->stopRender( context.renderContext() );
205 }
206 
208  const bool searchInRadius,
209  const double radius ) const
210 {
211  const QPointF pt = mapFromScene( node );
212  double nearestDistance = std::numeric_limits<double>::max();
213  double maxDistance = ( searchInRadius ) ? radius : nearestDistance;
214  double distance = 0;
215  int idx = -1;
216 
217  int i = 0;
218  for ( QPointF polyPt : mPolygon )
219  {
220  distance = computeDistance( pt, polyPt );
221  if ( distance < nearestDistance && distance < maxDistance )
222  {
223  nearestDistance = distance;
224  idx = i;
225  }
226  i++;
227  }
228 
229  return idx;
230 }
231 
232 bool QgsLayoutNodesItem::nodePosition( const int index, QPointF &position ) const
233 {
234  bool rc( false );
235 
236  if ( index >= 0 && index < mPolygon.size() )
237  {
238  position = mapToScene( mPolygon.at( index ) );
239  rc = true;
240  }
241 
242  return rc;
243 }
244 
245 bool QgsLayoutNodesItem::removeNode( const int index )
246 {
247  bool rc = _removeNode( index );
248  if ( rc )
249  updateSceneRect();
250  return rc;
251 }
252 
253 bool QgsLayoutNodesItem::moveNode( const int index, QPointF pt )
254 {
255  bool rc( false );
256 
257  if ( index >= 0 && index < mPolygon.size() )
258  {
259  QPointF nodeItem = mapFromScene( pt );
260  mPolygon.replace( index, nodeItem );
261  updateSceneRect();
262 
263  rc = true;
264  }
265 
266  return rc;
267 }
268 
269 bool QgsLayoutNodesItem::readPropertiesFromElement( const QDomElement &itemElem,
270  const QDomDocument &, const QgsReadWriteContext &context )
271 {
272  // restore style
273  QDomElement styleSymbolElem = itemElem.firstChildElement( QStringLiteral( "symbol" ) );
274  if ( !styleSymbolElem.isNull() )
275  _readXmlStyle( styleSymbolElem, context );
276 
277  // restore nodes
278  mPolygon.clear();
279  QDomNodeList nodesList = itemElem.elementsByTagName( QStringLiteral( "node" ) );
280  for ( int i = 0; i < nodesList.size(); i++ )
281  {
282  QDomElement nodeElem = nodesList.at( i ).toElement();
283  QPointF newPt;
284  newPt.setX( nodeElem.attribute( QStringLiteral( "x" ) ).toDouble() );
285  newPt.setY( nodeElem.attribute( QStringLiteral( "y" ) ).toDouble() );
286  mPolygon.append( newPt );
287  }
288 
289  emit changed();
290  return true;
291 }
292 
294 {
295  // get the bounding rect for the polygon currently displayed
296  const QRectF boundingRect = mPolygon.boundingRect();
297 
298  // compute x/y ratio
299  const float ratioX = !qgsDoubleNear( boundingRect.width(), 0.0 )
300  ? rect().width() / boundingRect.width() : 0;
301  const float ratioY = !qgsDoubleNear( boundingRect.height(), 0.0 )
302  ? rect().height() / boundingRect.height() : 0;
303 
304  // scaling
305  QTransform trans;
306  trans = trans.scale( ratioX, ratioY );
307  mPolygon = trans.map( mPolygon );
308 }
309 
310 bool QgsLayoutNodesItem::setSelectedNode( const int index )
311 {
312  bool rc = false;
313 
314  if ( index >= 0 && index < mPolygon.size() )
315  {
316  mSelectedNode = index;
317  rc = true;
318  }
319 
320  return rc;
321 }
322 
324 {
325  // set the new scene rectangle
326  const QRectF br = mPolygon.boundingRect();
327 
328  const QPointF topLeft = mapToScene( br.topLeft() );
329  //will trigger updateBoundingRect if necessary
330  attemptSetSceneRect( QRectF( topLeft.x(), topLeft.y(), br.width(), br.height() ) );
331 
332  // update polygon position
333  mPolygon.translate( -br.topLeft().x(), -br.topLeft().y() );
334 }
335 
337 {
338  QRectF br = rect();
340  mCurrentRectangle = br;
341 
342  // update
343  prepareGeometryChange();
344  update();
345 }
346 
347 bool QgsLayoutNodesItem::writePropertiesToElement( QDomElement &elem, QDomDocument &doc, const QgsReadWriteContext &context ) const
348 {
349  // style
350  _writeXmlStyle( doc, elem, context );
351 
352  // write nodes
353  QDomElement nodesElem = doc.createElement( QStringLiteral( "nodes" ) );
354  for ( QPointF pt : mPolygon )
355  {
356  QDomElement nodeElem = doc.createElement( QStringLiteral( "node" ) );
357  nodeElem.setAttribute( QStringLiteral( "x" ), QString::number( pt.x() ) );
358  nodeElem.setAttribute( QStringLiteral( "y" ), QString::number( pt.y() ) );
359  nodesElem.appendChild( nodeElem );
360  }
361  elem.appendChild( nodesElem );
362 
363  return true;
364 }
virtual void _writeXmlStyle(QDomDocument &doc, QDomElement &elmt, const QgsReadWriteContext &context) const =0
Method called in writeXml.
double computeDistance(QPointF pt1, QPointF pt2) const
Compute an euclidian distance between 2 nodes.
void setForceVectorOutput(bool force)
The class is used as a container of context for various read/write operations on other objects...
double viewScaleFactor() const
Returns the current view zoom (scale factor).
Definition: qgslayoutitem.h:94
void updateSceneRect()
Update the current scene rectangle for this item.
bool readPropertiesFromElement(const QDomElement &element, const QDomDocument &document, const QgsReadWriteContext &context) override
Sets item state from a DOM element.
Base class for graphical items within a QgsLayout.
QRectF mCurrentRectangle
Current bounding rectangle of shape.
virtual void _draw(QgsLayoutItemRenderContext &context, const QStyleOptionGraphicsItem *itemStyle=nullptr)=0
Method called in paint.
bool qgsDoubleNear(double a, double b, double epsilon=4 *std::numeric_limits< double >::epsilon())
Compare two doubles (but allow some difference)
Definition: qgis.h:265
double mMaxSymbolBleed
Max symbol bleed.
bool nodePosition(int index, QPointF &position) const
Gets the position of a node in scene coordinates.
bool writePropertiesToElement(QDomElement &element, QDomDocument &document, const QgsReadWriteContext &context) const override
Stores item state within an XML DOM element.
virtual bool _removeNode(int nodeIndex)=0
Method called in removeNode.
QPolygonF mPolygon
Shape&#39;s nodes.
virtual void updateBoundingRect()
Called when the bounding rect of the item should recalculated.
int nodeAtPosition(QPointF point, bool searchInRadius=true, double radius=10) const
Search for the nearest node in the shape within a maximal area.
QMap< QString, QString > QgsStringMap
Definition: qgis.h:587
void sizePositionChanged()
Emitted when the item&#39;s size or position changes.
const QgsLayout * layout() const
Returns the layout the object is attached to.
void attemptSetSceneRect(const QRectF &rect, bool includesFrame=false)
Attempts to update the item&#39;s position and size to match the passed rect in layout coordinates...
QgsRenderContext & renderContext()
Returns a reference to the context&#39;s render context.
Definition: qgslayoutitem.h:72
QgsLayoutNodesItem(QgsLayout *layout)
Constructor for QgsLayoutNodesItem, attached to the specified layout.
QRectF boundingRect() const override
Base class for layouts, which can contain items such as maps, labels, scalebars, etc.
Definition: qgslayout.h:49
void setNodes(const QPolygonF &nodes)
Sets the nodes the shape consists of.
bool setSelectedNode(int index)
Selects a node by index.
void setBackgroundEnabled(bool drawBackground)
Sets whether this item has a background drawn under it or not.
Contains settings and helpers relating to a render of a QgsLayoutItem.
Definition: qgslayoutitem.h:44
bool removeNode(int index)
Remove a node with specified index from the shape.
double estimatedFrameBleed() const override
Returns the estimated amount the item&#39;s frame bleeds outside the item&#39;s actual rectangle.
QPainter * painter()
Returns the destination QPainter for the render operation.
QPolygonF nodes() const
Returns the nodes the shape consists of.
virtual void setFrameEnabled(bool drawFrame)
Sets whether this item has a frame drawn around it or not.
bool addNode(QPointF point, bool checkArea=true, double radius=10)
Add a node in current shape.
static QgsMarkerSymbol * createSimple(const QgsStringMap &properties)
Create a marker symbol with one symbol layer: SimpleMarker with specified properties.
Definition: qgssymbol.cpp:1126
bool moveNode(int index, QPointF node)
Moves a node to a new position.
void changed()
Emitted when the object&#39;s properties change.
virtual void _readXmlStyle(const QDomElement &elmt, const QgsReadWriteContext &context)=0
Method called in readXml.
virtual bool _addNode(int nodeIndex, QPointF newNode, double radius)=0
Method called in addNode.
void draw(QgsLayoutItemRenderContext &context) override
Draws the item&#39;s contents using the specified item render context.
void rescaleToFitBoundingBox()
Rescale the current shape according to the item&#39;s bounding box.