QGIS API Documentation 3.32.0-Lima (311a8cb8a6)
qgsmaplayerrenderer.h
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1/***************************************************************************
2 qgsmaplayerrenderer.h
3 --------------------------------------
4 Date : December 2013
5 Copyright : (C) 2013 by Martin Dobias
6 Email : wonder dot 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#ifndef QGSMAPLAYERRENDERER_H
17#define QGSMAPLAYERRENDERER_H
18
19#include <QStringList>
20
21#include "qgis_core.h"
22#include "qgis_sip.h"
23
24class QgsFeedback;
27
51class CORE_EXPORT QgsMapLayerRenderer
52{
53 public:
54
58 QgsMapLayerRenderer( const QString &layerID, QgsRenderContext *context = nullptr )
59 : mLayerID( layerID )
60 , mContext( context )
61 {}
62
64
71 virtual bool render() = 0;
72
89 virtual bool forceRasterRender() const { return false; }
90
95 virtual QgsFeedback *feedback() const { return nullptr; }
96
98 QStringList errors() const { return mErrors; }
99
101 QString layerId() const { return mLayerID; }
102
108 QgsRenderContext *renderContext() { return mContext; }
109
116 const QgsRenderContext *renderContext() const SIP_SKIP { return mContext; }
117
124 bool isReadyToCompose() const { return mReadyToCompose; }
125
136 virtual void setLayerRenderingTimeHint( int time ) SIP_SKIP { Q_UNUSED( time ) }
137
146 QList< QgsRenderedItemDetails * > takeRenderedItemDetails() SIP_TRANSFERBACK;
147
148 protected:
149 QStringList mErrors;
150 QString mLayerID;
151
152 // TODO QGIS 4.0 - make false as default
153
168 bool mReadyToCompose = true;
169
178 static constexpr int MAX_TIME_TO_USE_CACHED_PREVIEW_IMAGE = 3000 SIP_SKIP;
179
190 void appendRenderedItemDetails( QgsRenderedItemDetails *details SIP_TRANSFER );
191
192 private:
193
194 // TODO QGIS 4.0 - make reference instead of pointer!
195
201 QgsRenderContext *mContext = nullptr;
202
203 QList<QgsRenderedItemDetails *> mRenderedItemDetails;
204};
205
206#endif // QGSMAPLAYERRENDERER_H
Base class for feedback objects to be used for cancellation of something running in a worker thread.
Definition: qgsfeedback.h:45
Base class for utility classes that encapsulate information necessary for rendering of map layers.
const QgsRenderContext * renderContext() const
Returns the render context associated with the renderer.
virtual bool render()=0
Do the rendering (based on data stored in the class).
bool isReadyToCompose() const
Returns whether the renderer has already drawn (at least partially) some data.
QString layerId() const
Gets access to the ID of the layer rendered by this class.
virtual bool forceRasterRender() const
Returns true if the renderer must be rendered to a raster paint device (e.g.
virtual ~QgsMapLayerRenderer()
QgsRenderContext * renderContext()
Returns the render context associated with the renderer.
QStringList errors() const
Returns list of errors (problems) that happened during the rendering.
QgsMapLayerRenderer(const QString &layerID, QgsRenderContext *context=nullptr)
Constructor for QgsMapLayerRenderer, with the associated layerID and render context.
virtual void setLayerRenderingTimeHint(int time)
Sets approximate render time (in ms) for the layer to render.
virtual QgsFeedback * feedback() const
Access to feedback object of the layer renderer (may be nullptr)
Contains information about the context of a rendering operation.
Base class for detailed information about a rendered item.
#define SIP_SKIP
Definition: qgis_sip.h:126
#define SIP_TRANSFER
Definition: qgis_sip.h:36
#define SIP_TRANSFERBACK
Definition: qgis_sip.h:48