[feature] Handy null painter device class to use with map renderer cu…

…stom painter jobs
qgis · Dec 30, 2021 · 6e60731 · 6e60731
1 parent 6c6e011
commit 6e60731
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diff --git a/python/core/auto_generated/qgsnullpainterdevice.sip.in b/python/core/auto_generated/qgsnullpainterdevice.sip.in
@@ -0,0 +1,53 @@
+/************************************************************************
+ * This file has been generated automatically from                      *
+ *                                                                      *
+ * src/core/qgsnullpainterdevice.h                                      *
+ *                                                                      *
+ * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
+ ************************************************************************/
+
+
+
+
+
+
+
+class QgsNullPaintDevice: QPaintDevice
+{
+%Docstring(signature="appended")
+Null painter device that can be used for map renderer jobs which use custom painters.
+
+.. versionadded:: 3.24
+%End
+
+%TypeHeaderCode
+#include "qgsnullpainterdevice.h"
+%End
+  public:
+
+    QgsNullPaintDevice();
+
+    virtual QPaintEngine *paintEngine() const;
+
+
+    virtual int metric( PaintDeviceMetric metric ) const;
+
+
+    void setOutputSize( const QSize &size );
+%Docstring
+Sets the ``size`` of the device in pixels.
+%End
+    void setOutputDpi( const int dpi );
+%Docstring
+Sets the ``dpi`` of the device.
+%End
+};
+
+
+/************************************************************************
+ * This file has been generated automatically from                      *
+ *                                                                      *
+ * src/core/qgsnullpainterdevice.h                                      *
+ *                                                                      *
+ * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
+ ************************************************************************/
diff --git a/python/core/core_auto.sip b/python/core/core_auto.sip
@@ -122,6 +122,7 @@
 %Include auto_generated/qgsmessageoutput.sip
 %Include auto_generated/qgsmimedatautils.sip
 %Include auto_generated/qgsmultirenderchecker.sip
+%Include auto_generated/qgsnullpainterdevice.sip
 %Include auto_generated/qgsobjectcustomproperties.sip
 %Include auto_generated/qgsofflineediting.sip
 %Include auto_generated/qgsogcutils.sip

diff --git a/src/core/CMakeLists.txt b/src/core/CMakeLists.txt
@@ -422,6 +422,7 @@ set(QGIS_CORE_SRCS
   qgsmessageoutput.cpp
   qgsmimedatautils.cpp
   qgsmultirenderchecker.cpp
+  qgsnullpainterdevice.cpp
   qgsobjectcustomproperties.cpp
   qgsofflineediting.cpp
   qgsogcutils.cpp
@@ -1063,6 +1064,7 @@ set(QGIS_CORE_HDRS
   qgsmessageoutput.h
   qgsmimedatautils.h
   qgsmultirenderchecker.h
+  qgsnullpainterdevice.h
   qgsobjectcustomproperties.h
   qgsofflineediting.h
   qgsogcutils.h

diff --git a/src/core/qgsnullpainterdevice.cpp b/src/core/qgsnullpainterdevice.cpp
@@ -0,0 +1,56 @@
+/***************************************************************************
+  qgsnullpainterdevice.cpp
+  --------------------------------------
+  Date                 : December 2021
+  Copyright            : (C) 2013 by Mathieu Pellerin
+  Email                : nirvn dot asia 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 "qgsnullpainterdevice.h"
+
+
+QgsNullPaintDevice::QgsNullPaintDevice()
+{
+  mPaintEngine = std::make_unique<QgsNullPaintEngine>();
+}
+
+QPaintEngine *QgsNullPaintDevice::paintEngine() const
+{
+  return mPaintEngine.get();
+}
+
+int QgsNullPaintDevice::metric( PaintDeviceMetric metric ) const
+{
+  switch ( metric )
+  {
+    case QPaintDevice::PdmWidth:
+      return mSize.width();
+    case QPaintDevice::PdmHeight:
+      return mSize.height();
+    case QPaintDevice::PdmWidthMM:
+      return mSize.width();
+    case QPaintDevice::PdmHeightMM:
+      return mSize.height();
+    case QPaintDevice::PdmNumColors:
+      return std::numeric_limits<int>::max();
+    case QPaintDevice::PdmDepth:
+      return 32;
+    case QPaintDevice::PdmDpiX:
+    case QPaintDevice::PdmDpiY:
+    case QPaintDevice::PdmPhysicalDpiX:
+    case QPaintDevice::PdmPhysicalDpiY:
+      return mDpi;
+    case QPaintDevice::PdmDevicePixelRatio:
+      return 1;
+    case QPaintDevice::PdmDevicePixelRatioScaled:
+      return 1;
+  }
+  return 0;
+}
diff --git a/src/core/qgsnullpainterdevice.h b/src/core/qgsnullpainterdevice.h
@@ -0,0 +1,98 @@
+/***************************************************************************
+  qgsnullpainterdevice.h
+  --------------------------------------
+  Date                 : December 2021
+  Copyright            : (C) 2013 by Mathieu Pellerin
+  Email                : nirvn dot asia 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.                                   *
+ *                                                                         *
+ ***************************************************************************/
+
+#ifndef QGSNULLPAINTERDEVICE_H
+#define QGSNULLPAINTERDEVICE_H
+
+#include "qgis_core.h"
+#include "qgis_sip.h"
+
+#include <QPaintDevice>
+#include <QPaintEngine>
+#include <memory>
+
+
+#ifndef SIP_RUN
+///@cond PRIVATE
+class QgsNullPaintEngine: public QPaintEngine
+{
+
+  public:
+
+    QgsNullPaintEngine() : QPaintEngine( QPaintEngine::AllFeatures ) {};
+
+    bool begin( QPaintDevice * ) override { return true; };
+    bool end() override { return true; };
+    QPaintEngine::Type type() const override { return QPaintEngine::User; };
+    void updateState( const QPaintEngineState & ) override { return; };
+
+    void drawRects( const QRect *, int ) override { return; };
+    void drawRects( const QRectF *, int ) override { return; };
+    void drawLines( const QLine *, int ) override { return; };
+    void drawLines( const QLineF *, int ) override { return; };
+    void drawEllipse( const QRectF & ) override { return; };
+    void drawEllipse( const QRect & ) override { return; };
+    void drawPath( const QPainterPath & ) override { return; };
+    void drawPoints( const QPointF *, int ) override { return; };
+    void drawPoints( const QPoint *, int ) override { return; };
+    void drawPolygon( const QPointF *, int, PolygonDrawMode ) override { return; };
+    void drawPolygon( const QPoint *, int, PolygonDrawMode ) override { return; };
+    void drawPixmap( const QRectF &, const QPixmap &, const QRectF & ) override { return; };
+    void drawTextItem( const QPointF &, const QTextItem & ) override { return; };
+    void drawTiledPixmap( const QRectF &, const QPixmap &, const QPointF & ) override { return; };
+    void drawImage( const QRectF &, const QImage &, const QRectF &, Qt::ImageConversionFlags ) override { return; };
+
+};
+///@endcond
+#endif
+
+
+/**
+ * \ingroup core
+ * \brief Null painter device that can be used for map renderer jobs which use custom painters.
+ * \since QGIS 3.24
+ */
+class CORE_EXPORT QgsNullPaintDevice: public QPaintDevice
+{
+
+  public:
+
+    QgsNullPaintDevice();
+
+    QPaintEngine *paintEngine() const override;
+
+    int metric( PaintDeviceMetric metric ) const override;
+
+    /**
+     * Sets the \a size of the device in pixels.
+     */
+    void setOutputSize( const QSize &size ) { mSize = size; };
+
+    /**
+     * Sets the \a dpi of the device.
+     */
+    void setOutputDpi( const int dpi ) { mDpi = dpi; };
+
+  private:
+
+    std::unique_ptr<QgsNullPaintEngine> mPaintEngine;
+
+    QSize mSize;
+    int mDpi = 96;
+
+};
+
+
+#endif // QGSNULLPAINTERDEVICE_H
diff --git a/tests/src/core/testqgsmaprendererjob.cpp b/tests/src/core/testqgsmaprendererjob.cpp
@@ -32,6 +32,8 @@
 #include "qgsfield.h"
 #include "qgis.h"
 #include "qgsmaprenderersequentialjob.h"
+#include "qgsmaprenderercustompainterjob.h"
+#include "qgsnullpainterdevice.h"
 #include "qgsmaplayer.h"
 #include "qgsreadwritecontext.h"
 #include "qgsproviderregistry.h"
@@ -96,6 +98,8 @@ class TestQgsMapRendererJob : public QObject
     void labelSink();
     void skipSymbolRendering();
 
+    void customNullPainterJob();
+
   private:
     bool imageCheck( const QString &type, const QImage &image, int mismatchCount = 0 );
 
@@ -1042,6 +1046,49 @@ void TestQgsMapRendererJob::skipSymbolRendering()
   QVERIFY( imageCheck( QStringLiteral( "skip_symbol_rendering" ), img ) );
 }
 
+void TestQgsMapRendererJob::customNullPainterJob()
+{
+  std::unique_ptr< QgsVectorLayer > pointsLayer = std::make_unique< QgsVectorLayer >( TEST_DATA_DIR + QStringLiteral( "/points.shp" ),
+      QStringLiteral( "points" ), QStringLiteral( "ogr" ) );
+  QVERIFY( pointsLayer->isValid() );
+
+  QgsPalLayerSettings settings;
+  settings.fieldName = QStringLiteral( "Class" );
+  QgsTextFormat format;
+  format.setFont( QgsFontUtils::getStandardTestFont( QStringLiteral( "Bold" ) ).family() );
+  format.setSize( 12 );
+  format.setNamedStyle( QStringLiteral( "Bold" ) );
+  format.setColor( QColor( 200, 0, 200 ) );
+  settings.setFormat( format );
+  settings.zIndex = 1;
+
+  pointsLayer->setLabeling( new QgsVectorLayerSimpleLabeling( settings ) );
+  pointsLayer->setLabelsEnabled( true );
+
+  QgsMapSettings mapSettings;
+  mapSettings.setDestinationCrs( pointsLayer->crs() );
+  mapSettings.setExtent( pointsLayer->extent() );
+  mapSettings.setOutputSize( QSize( 512, 512 ) );
+  mapSettings.setFlag( Qgis::MapSettingsFlag::DrawLabeling, true );
+  mapSettings.setOutputDpi( 96 );
+  mapSettings.setLayers( QList< QgsMapLayer * >() << pointsLayer.get() );
+
+  std::unique_ptr<QgsNullPaintDevice> nullPaintDevice = std::make_unique<QgsNullPaintDevice>();
+  nullPaintDevice->setOutputSize( QSize( 512, 512 ) );
+  nullPaintDevice->setOutputDpi( 96 );
+  std::unique_ptr<QPainter> painter = std::make_unique<QPainter>( nullPaintDevice.get() );
+
+  QgsMapRendererCustomPainterJob renderJob( mapSettings, painter.get() );
+
+  std::unique_ptr<TestLabelSink> labelSink = std::make_unique<TestLabelSink>();
+  renderJob.setLabelSink( labelSink.get() );
+
+  renderJob.start();
+  renderJob.waitForFinished();
+
+  QCOMPARE( labelSink->drawnCount, 17 );
+}
+
 bool TestQgsMapRendererJob::imageCheck( const QString &testName, const QImage &image, int mismatchCount )
 {
   mReport += "<h2>" + testName + "</h2>\n";