add support for color ramps to raster layers

src/gui/raster/qgssinglebandpseudocolorrendererwidget.cpp

@@ -18,6 +18,11 @@
 #include "qgssinglebandpseudocolorrendererwidget.h"
 #include "qgssinglebandpseudocolorrenderer.h"
 #include "qgsrasterlayer.h"
+
+// for color ramps - todo add rasterStyle and refactor raster vs. vector ramps
+#include "qgsstylev2.h"
+#include "qgsvectorcolorrampv2.h"
+
 #include <QColorDialog>
 #include <QFileDialog>
 #include <QMessageBox>
@@ -29,6 +34,8 @@ QgsSingleBandPseudoColorRendererWidget::QgsSingleBandPseudoColorRendererWidget(
 {
   setupUi( this );
 
+  mColorRampComboBox->populate( QgsStyleV2::defaultStyle() );
+
   if ( !mRasterLayer )
   {
     return;
@@ -213,19 +220,45 @@ void QgsSingleBandPseudoColorRendererWidget::on_mClassifyButton_clicked()
     }
   }
 
+#if 0
   //hard code color range from blue -> red for now. Allow choice of ramps in future
   int colorDiff = 0;
   if ( numberOfEntries != 0 )
   {
     colorDiff = ( int )( 255 / numberOfEntries );
   }
-
   for ( int i = 0; i < numberOfEntries; ++i )
   {
     QColor currentColor;
     currentColor.setRgb( colorDiff*i, 0, 255 - colorDiff * i );
     entryColors.push_back( currentColor );
   }
+#endif
+
+  QgsVectorColorRampV2* colorRamp = mColorRampComboBox->currentColorRamp();
+  if ( ! colorRamp )
+  {
+    //hard code color range from blue -> red (previous default) 
+    int colorDiff = 0;
+    if ( numberOfEntries != 0 )
+    {
+      colorDiff = ( int )( 255 / numberOfEntries );
+    }
+
+    for ( int i = 0; i < numberOfEntries; ++i )
+    {
+      QColor currentColor;
+      currentColor.setRgb( colorDiff*i, 0, 255 - colorDiff * i );
+      entryColors.push_back( currentColor );
+    }   
+  }
+  else
+  {
+    for ( int i = 0; i < numberOfEntries; ++i )
+    {
+      entryColors.push_back( colorRamp->color( ( ( double ) i ) / numberOfEntries  ) );
+    }   
+  }
 
   mColormapTreeWidget->clear();
 

src/ui/qgssinglebandpseudocolorrendererwidgetbase.ui

@@ -6,7 +6,7 @@
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>505</width>
+    <width>584</width>
     <height>400</height>
    </rect>
   </property>
@@ -146,7 +146,7 @@
       <item row="0" column="0">
        <widget class="QLabel" name="mNumberOfEntriesLabel">
         <property name="text">
-         <string>Number of entries</string>
+         <string>Classes</string>
         </property>
        </widget>
       </item>
@@ -163,28 +163,84 @@
         </property>
        </widget>
       </item>
-      <item row="0" column="2">
+      <item row="0" column="3">
        <widget class="QLabel" name="mClassificationModeLabel">
         <property name="text">
-         <string>Classification mode</string>
+         <string>Mode</string>
         </property>
        </widget>
       </item>
-      <item row="0" column="3">
+      <item row="0" column="4">
        <widget class="QComboBox" name="mClassificationModeComboBox"/>
       </item>
-      <item row="0" column="4">
+      <item row="0" column="9">
        <widget class="QPushButton" name="mClassifyButton">
         <property name="text">
          <string>Classify</string>
         </property>
        </widget>
       </item>
+      <item row="0" column="5">
+       <spacer name="horizontalSpacer_3">
+        <property name="orientation">
+         <enum>Qt::Horizontal</enum>
+        </property>
+        <property name="sizeHint" stdset="0">
+         <size>
+          <width>40</width>
+          <height>20</height>
+         </size>
+        </property>
+       </spacer>
+      </item>
+      <item row="0" column="6">
+       <widget class="QLabel" name="label">
+        <property name="text">
+         <string>Color ramp</string>
+        </property>
+       </widget>
+      </item>
+      <item row="0" column="2">
+       <spacer name="horizontalSpacer_2">
+        <property name="orientation">
+         <enum>Qt::Horizontal</enum>
+        </property>
+        <property name="sizeHint" stdset="0">
+         <size>
+          <width>40</width>
+          <height>20</height>
+         </size>
+        </property>
+       </spacer>
+      </item>
+      <item row="0" column="7">
+       <widget class="QgsColorRampComboBox" name="mColorRampComboBox"/>
+      </item>
+      <item row="0" column="8">
+       <spacer name="horizontalSpacer_4">
+        <property name="orientation">
+         <enum>Qt::Horizontal</enum>
+        </property>
+        <property name="sizeHint" stdset="0">
+         <size>
+          <width>40</width>
+          <height>20</height>
+         </size>
+        </property>
+       </spacer>
+      </item>
      </layout>
     </widget>
    </item>
   </layout>
  </widget>
+ <customwidgets>
+  <customwidget>
+   <class>QgsColorRampComboBox</class>
+   <extends>QComboBox</extends>
+   <header>qgscolorrampcombobox.h</header>
+  </customwidget>
+ </customwidgets>
  <resources>
   <include location="../../images/images.qrc"/>
  </resources>

tests/src/core/testqgsrasterlayer.cpp

@@ -35,6 +35,7 @@
 #include <qgsmaprenderer.h>
 #include <qgsmaplayerregistry.h>
 #include "qgssinglebandpseudocolorrenderer.h"
+#include "qgsvectorcolorrampv2.h"
 
 //qgis unit test includes
 #include <qgsrenderchecker.h>
@@ -54,6 +55,8 @@ class TestQgsRasterLayer: public QObject
 
     void isValid();
     void pseudoColor();
+    void colorRamp1();
+    void colorRamp2();
     void landsatBasic();
     void landsatBasic875Qml();
     void checkDimensions();
@@ -63,6 +66,11 @@ class TestQgsRasterLayer: public QObject
   private:
     bool render( QString theFileName );
     bool setQml( QString theType );
+    void populateColorRampShader( QgsColorRampShader* colorRampShader,
+                                  QgsVectorColorRampV2* colorRamp,
+                                  int numberOfEntries );
+    bool testColorRamp( QString name, QgsVectorColorRampV2* colorRamp,
+                        QgsColorRampShader::ColorRamp_TYPE type, int numberOfEntries );
     QString mTestDataDir;
     QgsRasterLayer * mpRasterLayer;
     QgsRasterLayer * mpLandsatRasterLayer;
@@ -162,6 +170,87 @@ void TestQgsRasterLayer::pseudoColor()
   QVERIFY( render( "raster_pseudo" ) );
 }
 
+void TestQgsRasterLayer::populateColorRampShader( QgsColorRampShader* colorRampShader,
+    QgsVectorColorRampV2* colorRamp,
+    int numberOfEntries )
+
+{
+  // adapted from QgsSingleBandPseudoColorRendererWidget::on_mClassifyButton_clicked()
+  // and TestQgsRasterLayer::pseudoColor()
+  // would be better to add a more generic function to api that does this
+  int bandNr = 1;
+  QgsRasterBandStats myRasterBandStats = mpRasterLayer->dataProvider()->bandStatistics( bandNr );
+
+  QList<double> entryValues;
+  QList<QColor> entryColors;
+  double currentValue = myRasterBandStats.minimumValue;
+  double intervalDiff;
+  if ( numberOfEntries > 1 )
+  {
+    //because the highest value is also an entry, there are (numberOfEntries - 1)
+    //intervals
+    intervalDiff = ( myRasterBandStats.maximumValue - myRasterBandStats.minimumValue ) /
+                   ( numberOfEntries - 1 );
+  }
+  else
+  {
+    intervalDiff = myRasterBandStats.maximumValue - myRasterBandStats.minimumValue;
+  }
+
+  for ( int i = 0; i < numberOfEntries; ++i )
+  {
+    entryValues.push_back( currentValue );
+    currentValue += intervalDiff;
+    entryColors.push_back( colorRamp->color((( double ) i ) / numberOfEntries ) );
+  }
+
+  //items to imitate old pseudo color renderer
+  QList<QgsColorRampShader::ColorRampItem> colorRampItems;
+  QList<double>::const_iterator value_it = entryValues.begin();
+  QList<QColor>::const_iterator color_it = entryColors.begin();
+  for ( ; value_it != entryValues.end(); ++value_it, ++color_it )
+  {
+    colorRampItems.append( QgsColorRampShader::ColorRampItem( *value_it, *color_it ) );
+  }
+  colorRampShader->setColorRampItemList( colorRampItems );
+}
+
+bool TestQgsRasterLayer::testColorRamp( QString name, QgsVectorColorRampV2* colorRamp,
+                                        QgsColorRampShader::ColorRamp_TYPE type, int numberOfEntries )
+{
+  QgsRasterShader* rasterShader = new QgsRasterShader();
+  QgsColorRampShader* colorRampShader = new QgsColorRampShader();
+  colorRampShader->setColorRampType( type );
+
+  populateColorRampShader( colorRampShader, colorRamp, numberOfEntries );
+
+  rasterShader->setRasterShaderFunction( colorRampShader );
+  QgsSingleBandPseudoColorRenderer* r = new QgsSingleBandPseudoColorRenderer( mpRasterLayer->dataProvider(), 1, rasterShader );
+  mpRasterLayer->setRenderer( r );
+  mpMapRenderer->setExtent( mpRasterLayer->extent() );
+  return render( name );
+}
+
+void TestQgsRasterLayer::colorRamp1()
+{
+  // gradient ramp
+  QgsVectorGradientColorRampV2* colorRamp = new QgsVectorGradientColorRampV2( QColor( Qt::red ), QColor( Qt::black ) );
+  QgsVectorGradientColorRampV2::StopsMap stops;
+  stops[ 0.5 ] = QColor( Qt::white );
+  colorRamp->setStops( stops );
+
+  // QVERIFY( testColorRamp( "raster_colorRamp1", colorRamp, QgsColorRampShader::INTERPOLATED, 5 ) );
+  QVERIFY( testColorRamp( "raster_colorRamp1", colorRamp, QgsColorRampShader::DISCRETE, 10 ) );
+}
+
+void TestQgsRasterLayer::colorRamp2()
+{
+  // ColorBrewer ramp
+  QgsVectorColorBrewerColorRampV2* cb2Ramp = new QgsVectorColorBrewerColorRampV2( "BrBG", 10 );
+
+  QVERIFY( testColorRamp( "raster_colorRamp2", cb2Ramp, QgsColorRampShader::DISCRETE, 10 ) );
+}
+
 void TestQgsRasterLayer::landsatBasic()
 {
   mpLandsatRasterLayer->setContrastEnhancementAlgorithm( QgsContrastEnhancement::StretchToMinimumMaximum, false );