QGIS API Documentation 3.29.0-Master (006c3c0232)
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
54class CORE_EXPORT QgsMapLayerRenderer
55{
56 public:
57
61 QgsMapLayerRenderer( const QString &layerID, QgsRenderContext *context = nullptr )
62 : mLayerID( layerID )
63 , mContext( context )
64 {}
65
67
74 virtual bool render() = 0;
75
92 virtual bool forceRasterRender() const { return false; }
93
98 virtual QgsFeedback *feedback() const { return nullptr; }
99
101 QStringList errors() const { return mErrors; }
102
104 QString layerId() const { return mLayerID; }
105
111 QgsRenderContext *renderContext() { return mContext; }
112
119 const QgsRenderContext *renderContext() const SIP_SKIP { return mContext; }
120
127 bool isReadyToCompose() const { return mReadyToCompose; }
128
139 virtual void setLayerRenderingTimeHint( int time ) SIP_SKIP { Q_UNUSED( time ) }
140
149 QList< QgsRenderedItemDetails * > takeRenderedItemDetails() SIP_TRANSFERBACK;
150
151 protected:
152 QStringList mErrors;
153 QString mLayerID;
154
155 // TODO QGIS 4.0 - make false as default
156
171 bool mReadyToCompose = true;
172
181 static constexpr int MAX_TIME_TO_USE_CACHED_PREVIEW_IMAGE = 3000 SIP_SKIP;
182
193 void appendRenderedItemDetails( QgsRenderedItemDetails *details SIP_TRANSFER );
194
195 private:
196
197 // TODO QGIS 4.0 - make reference instead of pointer!
198
204 QgsRenderContext *mContext = nullptr;
205
206 QList<QgsRenderedItemDetails *> mRenderedItemDetails;
207};
208
209#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