[mesh] [feature] App widgets for styling mesh layers

- Adding datasets to mesh layer from properties panel
- Information and source panel in properties panel
- Selection of active dataset (properties or styling panel)
- Styling of contours/scalars (properties or styling panel)
- Styling of mesh frame (properties or styling panel)
- Styling of vector arrows (properties or styling panel)

python/core/auto_generated/mesh/qgsmeshdataprovider.sip.in

@@ -227,6 +227,8 @@ or read on demand
     virtual bool addDataset( const QString &uri ) = 0;
 %Docstring
 Associate dataset with the mesh
+
+emits dataChanged when successful
 %End
 
     virtual int datasetCount() const = 0;

python/core/auto_generated/mesh/qgsmeshrenderersettings.sip.in

@@ -10,6 +10,7 @@
 
 
 
+
 class QgsMeshRendererMeshSettings
 {
 %Docstring
@@ -73,54 +74,19 @@ Represents a mesh renderer settings for scalar datasets
 #include "qgsmeshrenderersettings.h"
 %End
   public:
-    QColor maxColor() const;
-%Docstring
-Returns color representing maximum scalar value in the dataset
-%End
-    void setMaxColor( const QColor &maxColor );
-%Docstring
-Sets color representing maximum scalar value in the dataset
-%End
-
-    QColor minColor() const;
+    QgsColorRampShader colorRampShader() const;
 %Docstring
-Returns color representing minimum scalar value in the dataset
+Returns color ramp shader function
 %End
-    void setMinColor( const QColor &minColor );
+    void setColorRampShader( const QgsColorRampShader &shader );
 %Docstring
-Sets color representing maximum scalar value in the dataset
+Sets color ramp shader function
 %End
 
-    double minValue() const;
-%Docstring
-Returns min scalar value that represents minColor()
-
-if set to numerical_limits<double>.quiet_NaN(), value for minColor() is
-taken from minimum value of active scalar dataset
-%End
-
-    void setMinValue( double minValue );
-%Docstring
-Sets min scalar value that represents minColor()
-
-.. seealso:: :py:func:`QgsMeshRendererScalarSettings.minValue`
-%End
-
-    double maxValue() const;
-%Docstring
-Returns max scalar value that represents maxColor()
-
-if set to numerical_limits<double>.quiet_NaN(), value for maxColor() is
-taken from maximum value of active scalar dataset
-%End
-
-    void setMaxValue( double maxValue );
+    bool isEnabled() const;
 %Docstring
-Sets min scalar value that represents minColor()
-
-.. seealso:: :py:func:`QgsMeshRendererScalarSettings.maxValue`
+Returns whether color ramp has any items assigned
 %End
-
 };
 
 class QgsMeshRendererVectorSettings

python/core/auto_generated/raster/qgscolorrampshader.sip.in

@@ -92,6 +92,13 @@ Returns the color ramp type as a string.
     void setColorRampType( QgsColorRampShader::Type colorRampType );
 %Docstring
 Sets the color ramp type
+%End
+
+    bool isEmpty() const;
+%Docstring
+Whether the color ramp contains any items
+
+.. versionadded:: 3.4
 %End
 
     QgsColorRamp *sourceColorRamp() const /Factory/;

python/gui/auto_generated/raster/qgssinglebandpseudocolorrendererwidget.sip.in

@@ -23,12 +23,22 @@ class QgsSingleBandPseudoColorRendererWidget: QgsRasterRendererWidget
     static QgsRasterRendererWidget *create( QgsRasterLayer *layer, const QgsRectangle &extent ) /Factory/;
     virtual QgsRasterRenderer *renderer();
 
+
+    QgsColorRampShader *shaderFunction() const /Factory/;
+%Docstring
+Returns shader function used in the renderer. Caller takes ownership and deletes it.
+%End
     virtual void setMapCanvas( QgsMapCanvas *canvas );
 
     virtual void doComputations();
 
     virtual QgsRasterMinMaxWidget *minMaxWidget();
 
+    int currentBand() const;
+%Docstring
+Returns the current raster band number
+%End
+
     void setFromRenderer( const QgsRasterRenderer *r );
 
   public slots:

src/app/CMakeLists.txt

@@ -210,6 +210,14 @@ SET(QGIS_APP_SRCS
   qgssettingstree.cpp
   qgsvariantdelegate.cpp
   qgscrashhandler.cpp
+
+  mesh/qgsmeshlayerproperties.cpp
+  mesh/qgsrenderermeshpropertieswidget.cpp
+  mesh/qgsmeshrenderermeshsettingswidget.cpp
+  mesh/qgsmeshrendererscalarsettingswidget.cpp
+  mesh/qgsmeshrenderervectorsettingswidget.cpp
+  mesh/qgsmeshrendereractivedatasetwidget.cpp
+  mesh/qgsmeshdatasetgrouptreeview.cpp
 )
 
 SET (QGIS_APP_MOC_HDRS
@@ -410,6 +418,14 @@ SET (QGIS_APP_MOC_HDRS
 
   qgssettingstree.h
   qgsvariantdelegate.h
+
+  mesh/qgsmeshlayerproperties.h
+  mesh/qgsrenderermeshpropertieswidget.h
+  mesh/qgsmeshrenderermeshsettingswidget.h
+  mesh/qgsmeshrendererscalarsettingswidget.h
+  mesh/qgsmeshrenderervectorsettingswidget.h
+  mesh/qgsmeshrendereractivedatasetwidget.h
+  mesh/qgsmeshdatasetgrouptreeview.h
   )
 
 
@@ -584,6 +600,7 @@ INCLUDE_DIRECTORIES(
   ${CMAKE_SOURCE_DIR}/src/app/pluginmanager
   ${CMAKE_SOURCE_DIR}/src/app/gps
   ${CMAKE_SOURCE_DIR}/src/app/dwg
+  ${CMAKE_SOURCE_DIR}/src/app/mesh
   ${CMAKE_SOURCE_DIR}/src/app/locator
   ${CMAKE_SOURCE_DIR}/src/analysis/raster
   ${CMAKE_SOURCE_DIR}/src/core
@@ -660,6 +677,7 @@ INCLUDE_DIRECTORIES(
   ../core/processing
   ../core/providers/memory
   ../core/raster
+  ../core/mesh
   ../core/scalebar
   ../core/symbology
   ../gui