qgsmapcanvasitem.cpp

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/***************************************************************************
    qgsmapcanvasitem.h  - base class for map canvas items
    ----------------------
    begin                : February 2006
    copyright            : (C) 2006 by Martin Dobias
    email                : wonder.sk at gmail dot com
 ***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/
 
 
#include "qgsmapcanvasitem.h"
#include "qgsmapcanvas.h"
#include "qgsmaptopixel.h"
#include "qgsrendercontext.h"
#include <QGraphicsScene>
#include <QRect>
#include <QPen>
#include <QBrush>
#include <QPainter>
#include "qgslogger.h"
 
QgsMapCanvasItem::QgsMapCanvasItem( QgsMapCanvas *mapCanvas )
  : mMapCanvas( mapCanvas )
  , mRectRotation( 0.0 )
  , mItemSize( 0, 0 )
{
  Q_ASSERT( mapCanvas && mapCanvas->scene() );
  mapCanvas->scene()->addItem( this );
}
 
QgsMapCanvasItem::~QgsMapCanvasItem()
{
  update(); // schedule redraw of canvas
}
 
void QgsMapCanvasItem::paint( QPainter *painter,
                              const QStyleOptionGraphicsItem *option,
                              QWidget *widget )
{
  Q_UNUSED( option )
  Q_UNUSED( widget )
  if ( mMapCanvas->antiAliasingEnabled() )
  {
    painter->setRenderHint( QPainter::Antialiasing );
  }
  paint( painter ); // call the derived item's drawing routines
}
 
QgsPointXY QgsMapCanvasItem::toMapCoordinates( QPoint point ) const
{
  return mMapCanvas->getCoordinateTransform()->toMapCoordinates( point );
}
 
 
QPointF QgsMapCanvasItem::toCanvasCoordinates( const QgsPointXY &point ) const
{
  qreal x = point.x(), y = point.y();
  mMapCanvas->getCoordinateTransform()->transformInPlace( x, y );
  return QPointF( x, y );
}
 
QgsRectangle QgsMapCanvasItem::rect() const
{
  return mRect;
}
 
 
void QgsMapCanvasItem::setRect( const QgsRectangle &rect, bool resetRotation )
{
  mRect = rect;
  //updatePosition();
 
  QRectF r; // empty rect by default
  if ( !mRect.isEmpty() )
  {
    // rect encodes origin of the item (xMin,yMax from map to canvas units)
    // and size (rect size / map units per pixel)
    r.setTopLeft( toCanvasCoordinates( QPointF( mRect.xMinimum(), mRect.yMaximum() ) ) );
    const QgsMapToPixel *m2p = mMapCanvas->getCoordinateTransform();
    double res = m2p->mapUnitsPerPixel();
    r.setSize( QSizeF( mRect.width() / res, mRect.height() / res ) );
  }
 
  // set position in canvas where the item will have coordinate (0,0)
  prepareGeometryChange();
  setPos( r.topLeft() );
  mItemSize = QSizeF( r.width() + 2, r.height() + 2 );
 
  if ( resetRotation )
  {
    mRectRotation = mMapCanvas->rotation();
    setRotation( 0 );
  }
 
  // QgsDebugMsg(QString("[%1,%2]-[%3x%4]").arg((int) r.left()).arg((int) r.top()).arg((int) r.width()).arg((int) r.height()));
 
  update();
}
 
QRectF QgsMapCanvasItem::boundingRect() const
{
  return QRectF( QPointF( -1, -1 ), mItemSize );
}
 
 
void QgsMapCanvasItem::updateCanvas()
{
  update();
  // porting: update below should not be needed anymore
  //mMapCanvas->scene()->update(); //Contents();
}
 
bool QgsMapCanvasItem::setRenderContextVariables( QPainter *p, QgsRenderContext &context ) const
{
  if ( !mMapCanvas || !p )
  {
    return false;
  }
  const QgsMapSettings &ms = mMapCanvas->mapSettings();
 
  context.setPainter( p );
  context.setRendererScale( mMapCanvas->scale() );
  context.setScaleFactor( ms.outputDpi() / 25.4 );
 
  context.setForceVectorOutput( true );
  return true;
}
 
void QgsMapCanvasItem::updatePosition()
{
  // default implementation: recalculate position of the item
  setRect( mRect, false );
  setRotation( mMapCanvas->rotation() - mRectRotation );
}