Added python bindings for QgsMapRendererJob + subclasses and QgsMapRendererCache

Author: wonder-sk

python/core/core.sip

@@ -48,6 +48,8 @@
 %Include qgsmaplayerregistry.sip
 %Include qgsmaplayerrenderer.sip
 %Include qgsmaprenderer.sip
+%Include qgsmaprenderercache.sip
+%Include qgsmaprendererjob.sip
 %Include qgsmapsettings.sip
 %Include qgsmaptopixel.sip
 %Include qgsmessagelog.sip

python/core/qgsmaprenderercache.sip

@@ -0,0 +1,39 @@
+
+/**
+ * This class is responsible for keeping cache of rendered images of individual layers.
+ *
+ * Once a layer has rendered image stored in the cache (using setCacheImage(...)),
+ * the cache listens to repaintRequested() signals from layer. If triggered, the cache
+ * removes the rendered image (and disconnects from the layer).
+ *
+ * The class is thread-safe (multiple classes can access the same instance safely). 
+ *
+ * @note added in 2.4
+ */
+class QgsMapRendererCache : QObject
+{
+%TypeHeaderCode
+#include <qgsmaprenderercache.h>
+%End
+
+  public:
+
+    QgsMapRendererCache();
+
+    //! invalidate the cache contents
+    void clear();
+
+    //! initialize cache: set new parameters and erase cache if parameters have changed
+    //! @return flag whether the parameters are the same as last time
+    bool init( QgsRectangle extent, double scale );
+
+    //! set cached image for the specified layer ID
+    void setCacheImage( QString layerId, const QImage& img );
+
+    //! get cached image for the specified layer ID. Returns null image if it is not cached.
+    QImage cacheImage( QString layerId );
+
+    //! remove layer from the cache
+    void clearCacheImage( QString layerId );
+
+};

python/core/qgsmaprendererjob.sip

@@ -0,0 +1,156 @@
+
+/** abstract base class renderer jobs that asynchronously start map rendering */
+class QgsMapRendererJob : QObject
+{
+%TypeHeaderCode
+#include <qgsmaprendererjob.h>
+%End
+
+  public:
+
+    QgsMapRendererJob( const QgsMapSettings& settings );
+
+    virtual ~QgsMapRendererJob();
+
+    //! Start the rendering job and immediately return.
+    //! Does nothing if the rendering is already in progress.
+    virtual void start() = 0;
+
+    //! Stop the rendering job - does not return until the job has terminated.
+    //! Does nothing if the rendering is not active.
+    virtual void cancel() = 0;
+
+    //! Block until the job has finished.
+    virtual void waitForFinished() = 0;
+
+    //! Tell whether the rendering job is currently running in background.
+    virtual bool isActive() const = 0;
+
+    //! Get pointer to internal labeling engine (in order to get access to the results)
+    virtual QgsLabelingResults* takeLabelingResults() = 0 /Transfer/;
+
+    struct Error
+    {
+      Error( const QString& lid, const QString& msg );
+
+      QString layerID;
+      QString message;
+    };
+
+    typedef QList<QgsMapRendererJob::Error> Errors;
+
+    //! List of errors that happened during the rendering job - available when the rendering has been finished
+    Errors errors() const;
+
+
+    //! Assign a cache to be used for reading and storing rendered images of individual layers.
+    //! Does not take ownership of the object.
+    void setCache( QgsMapRendererCache* cache );
+
+    //! Set which vector layers should be cached while rendering
+    //! @note The way how geometries are cached is really suboptimal - this method may be removed in future releases
+    void setRequestedGeometryCacheForLayers( const QStringList& layerIds );
+
+    //! Find out how log it took to finish the job (in miliseconds)
+    int renderingTime() const;
+
+  signals:
+
+    //! emitted when asynchronous rendering is finished (or canceled).
+    void finished();
+
+};
+
+
+/** Intermediate base class adding functionality that allows client to query the rendered image.
+ *  The image can be queried even while the rendering is still in progress to get intermediate result
+ */
+class QgsMapRendererQImageJob : QgsMapRendererJob
+{
+%TypeHeaderCode
+#include <qgsmaprendererjob.h>
+%End
+
+  public:
+    QgsMapRendererQImageJob( const QgsMapSettings& settings );
+
+    //! Get a preview/resulting image
+    virtual QImage renderedImage() = 0;
+};
+
+
+
+/** job implementation that renders everything sequentially in one thread */
+class QgsMapRendererSequentialJob : QgsMapRendererQImageJob
+{
+%TypeHeaderCode
+#include <qgsmaprendererjob.h>
+%End
+
+  public:
+    QgsMapRendererSequentialJob( const QgsMapSettings& settings );
+    ~QgsMapRendererSequentialJob();
+
+    virtual void start();
+    virtual void cancel();
+    virtual void waitForFinished();
+    virtual bool isActive() const;
+
+    virtual QgsLabelingResults* takeLabelingResults() /Transfer/;
+
+    // from QgsMapRendererJobWithPreview
+    virtual QImage renderedImage();
+
+  public slots:
+
+    void internalFinished();
+};
+
+
+
+
+/** job implementation that renders all layers in parallel */
+class QgsMapRendererParallelJob : QgsMapRendererQImageJob
+{
+%TypeHeaderCode
+#include <qgsmaprendererjob.h>
+%End
+
+  public:
+    QgsMapRendererParallelJob( const QgsMapSettings& settings );
+    ~QgsMapRendererParallelJob();
+
+    virtual void start();
+    virtual void cancel();
+    virtual void waitForFinished();
+    virtual bool isActive() const;
+
+    virtual QgsLabelingResults* takeLabelingResults() /Transfer/;
+
+    // from QgsMapRendererJobWithPreview
+    virtual QImage renderedImage();
+};
+
+
+
+/** job implementation that renders everything sequentially using a custom painter.
+ *  The returned image is always invalid (because there is none available).
+ */
+class QgsMapRendererCustomPainterJob : QgsMapRendererJob
+{
+%TypeHeaderCode
+#include <qgsmaprendererjob.h>
+%End
+
+  public:
+    QgsMapRendererCustomPainterJob( const QgsMapSettings& settings, QPainter* painter );
+    ~QgsMapRendererCustomPainterJob();
+
+    virtual void start();
+    virtual void cancel();
+    virtual void waitForFinished();
+    virtual bool isActive() const;
+    virtual QgsLabelingResults* takeLabelingResults() /Transfer/;
+
+    // TODO wrap??? const LayerRenderJobs& jobs() const;
+};