Finish flipping a lot of methods to take const references for

non-trivial types

python/core/qgsapplication.sip

@@ -292,9 +292,9 @@ static void qtgui_UpdatePyArgv(PyObject *argvlist, int argc, char **argv)
     static void registerOgrDrivers();
 
     /** Converts absolute path to path relative to target */
-    static QString absolutePathToRelativePath( QString apath, QString targetPath );
+    static QString absolutePathToRelativePath( const QString& apath, const QString& targetPath );
     /** Converts path relative to target to an absolute path */
-    static QString relativePathToAbsolutePath( QString rpath, QString targetPath );
+    static QString relativePathToAbsolutePath( const QString& rpath, const QString& targetPath );
 
     /** Indicates whether running from build directory (not installed) */
     static bool isRunningFromBuildDir();

python/core/qgsdataitem.sip

@@ -95,7 +95,7 @@ class QgsDataItem : QObject
     typedef QFlags<QgsDataItem::Capability> Capabilities;
 
     // This will _write_ selected crs in data source
-    virtual bool setCrs( QgsCoordinateReferenceSystem crs );
+    virtual bool setCrs( const QgsCoordinateReferenceSystem& crs );
 
     //! @deprecated since 2.8, returned type this will changed to Capabilities
     virtual Capability capabilities() /Deprecated/;

python/core/qgsdataprovider.sip

@@ -82,7 +82,7 @@ class QgsDataProvider : QObject
      * that can be used by the data provider to create a subset.
      * Must be implemented in the dataprovider.
      */
-    virtual bool setSubsetString( QString subset, bool updateFeatureCount = true );
+    virtual bool setSubsetString( const QString& subset, bool updateFeatureCount = true );
 
     /** Provider supports setting of subset strings */
     virtual bool supportsSubsetString();

python/core/qgsproject.sip

@@ -343,7 +343,7 @@ class QgsProjectBadLayerHandler
 %End
 
   public:
-    virtual void handleBadLayers( QList<QDomNode> layers, QDomDocument projectDom ) = 0;
+    virtual void handleBadLayers( const QList<QDomNode>& layers, const QDomDocument& projectDom ) = 0;
     virtual ~QgsProjectBadLayerHandler();
 };
 
@@ -356,6 +356,6 @@ class QgsProjectBadLayerDefaultHandler : QgsProjectBadLayerHandler
 %End
 
   public:
-    virtual void handleBadLayers( QList<QDomNode> layers, QDomDocument projectDom );
+    virtual void handleBadLayers( const QList<QDomNode>& layers, const QDomDocument& projectDom );
 
 };

python/core/qgspythonrunner.sip

@@ -25,7 +25,7 @@ class QgsPythonRunner
     QgsPythonRunner();
     virtual ~QgsPythonRunner();
 
-    virtual bool runCommand( QString command, QString messageOnError = QString() ) = 0;
+    virtual bool runCommand( const QString& command, const QString& messageOnError = QString() ) = 0;
 
-    virtual bool evalCommand( QString command, QString& result ) = 0;
+    virtual bool evalCommand( const QString& command, QString& result ) = 0;
 };

python/core/qgsrenderchecker.sip

@@ -93,7 +93,7 @@ class QgsRenderChecker
      * @param theRenderedImageFile to optionally override the output filename
      * @note: make sure to call setExpectedImage and setRenderedImage first.
      */
-    bool compareImages( const QString& theTestName, unsigned int theMismatchCount = 0, QString theRenderedImageFile = "" );
+    bool compareImages( const QString& theTestName, unsigned int theMismatchCount = 0, const QString& theRenderedImageFile = "" );
     /** Get a list of all the anomalies. An anomaly is a rendered difference
       * file where there is some red pixel content (indicating a render check
       * mismatch), but where the output was still acceptible. If the render

python/core/raster/qgsrasterdataprovider.sip

@@ -159,7 +159,7 @@ class QgsRasterDataProvider : QgsDataProvider, QgsRasterInterface
      * ACTUALLY exists you need to look at the existsFlag member in each struct stored in the
      * list.
      */
-    virtual QList<QgsRasterPyramid> buildPyramidList( QList<int> overviewList = QList<int>() );
+    virtual QList<QgsRasterPyramid> buildPyramidList( const QList<int>& overviewList = QList<int>() );
 
     /** \brief Returns true if raster has at least one populated histogram. */
     bool hasPyramids();
@@ -261,7 +261,7 @@ class QgsRasterDataProvider : QgsDataProvider, QgsRasterInterface
     /** Validates creation options for a specific dataset and destination format.
      * @note used by GDAL provider only
      * @note see also validateCreationOptionsFormat() in gdal provider for validating options based on format only */
-    virtual QString validateCreationOptions( const QStringList& createOptions, QString format );
+    virtual QString validateCreationOptions( const QStringList& createOptions, const QString& format );
 
     /** Validates pyramid creation options for a specific dataset and destination format
      * @note used by GDAL provider only */

python/gui/qgisinterface.sip

@@ -49,16 +49,16 @@ class QgisInterface : QObject
     virtual void zoomToActiveLayer() = 0;
 
     //! Add a vector layer
-    virtual QgsVectorLayer* addVectorLayer( QString vectorLayerPath, QString baseName, QString providerKey ) = 0;
+    virtual QgsVectorLayer* addVectorLayer( const QString& vectorLayerPath, const QString& baseName, const QString& providerKey ) = 0;
 
     //! Add a raster layer given a raster layer file name
-    virtual QgsRasterLayer* addRasterLayer( QString rasterLayerPath, QString baseName = QString() ) = 0;
+    virtual QgsRasterLayer* addRasterLayer( const QString& rasterLayerPath, const QString& baseName = QString() ) = 0;
 
     //! Add a WMS layer
     virtual QgsRasterLayer* addRasterLayer( const QString& url, const QString& layerName, const QString& providerKey ) = 0;
 
     //! Add a project
-    virtual bool addProject( QString theProject ) = 0;
+    virtual bool addProject( const QString& theProject ) = 0;
     //! Start a blank project
     virtual void newProject( bool thePromptToSaveFlag = false ) = 0;
 
@@ -150,7 +150,7 @@ class QgisInterface : QObject
     virtual void removeWebToolBarIcon( QAction *qAction ) = 0;
 
     //! Add toolbar with specified name
-    virtual QToolBar *addToolBar( QString name ) = 0 /Factory/;
+    virtual QToolBar *addToolBar( const QString& name ) = 0 /Factory/;
 
     //! Add a toolbar
     //! @note added in 2.3
@@ -181,15 +181,15 @@ class QgisInterface : QObject
      * @return pointer to composer's view
      * @note new composer window will be shown and activated
      */
-    virtual QgsComposerView* createNewComposer( QString title = QString() ) = 0;
+    virtual QgsComposerView* createNewComposer( const QString& title = QString() ) = 0;
 
     /** Duplicate an existing parent composer from composer view
      * @param composerView pointer to existing composer view
      * @param title window title for duplicated composer (one will be generated if empty)
      * @return pointer to duplicate composer's view
      * @note dupicate composer window will be hidden until loaded, then shown and activated
      */
-    virtual QgsComposerView* duplicateComposer( QgsComposerView* composerView, QString title = QString() ) = 0;
+    virtual QgsComposerView* duplicateComposer( QgsComposerView* composerView, const QString& title = QString() ) = 0;
 
     /** Deletes parent composer of composer view, after closing composer window */
     virtual void deleteComposer( QgsComposerView* composerView ) = 0;
@@ -209,10 +209,10 @@ class QgisInterface : QObject
     virtual QFont defaultStyleSheetFont() = 0;
 
     /** Add action to the plugins menu */
-    virtual void addPluginToMenu( QString name, QAction* action ) = 0;
+    virtual void addPluginToMenu( const QString& name, QAction* action ) = 0;
 
     /** Remove action from the plugins menu */
-    virtual void removePluginMenu( QString name, QAction* action ) = 0;
+    virtual void removePluginMenu( const QString& name, QAction* action ) = 0;
 
     /** Add "add layer" action to layer menu */
     virtual void insertAddLayerAction( QAction *action ) = 0;
@@ -221,28 +221,28 @@ class QgisInterface : QObject
     virtual void removeAddLayerAction( QAction *action ) = 0;
 
     /** Add action to the Database menu */
-    virtual void addPluginToDatabaseMenu( QString name, QAction* action ) = 0;
+    virtual void addPluginToDatabaseMenu( const QString& name, QAction* action ) = 0;
 
     /** Remove action from the Database menu */
-    virtual void removePluginDatabaseMenu( QString name, QAction* action ) = 0;
+    virtual void removePluginDatabaseMenu( const QString& name, QAction* action ) = 0;
 
     /** Add action to the Raster menu */
-    virtual void addPluginToRasterMenu( QString name, QAction* action ) = 0;
+    virtual void addPluginToRasterMenu( const QString& name, QAction* action ) = 0;
 
     /** Remove action from the Raster menu */
-    virtual void removePluginRasterMenu( QString name, QAction* action ) = 0;
+    virtual void removePluginRasterMenu( const QString& name, QAction* action ) = 0;
 
     /** Add action to the Vector menu */
-    virtual void addPluginToVectorMenu( QString name, QAction* action ) = 0;
+    virtual void addPluginToVectorMenu( const QString& name, QAction* action ) = 0;
 
     /** Remove action from the Vector menu */
-    virtual void removePluginVectorMenu( QString name, QAction* action ) = 0;
+    virtual void removePluginVectorMenu( const QString& name, QAction* action ) = 0;
 
     /** Add action to the Web menu */
-    virtual void addPluginToWebMenu( QString name, QAction* action ) = 0;
+    virtual void addPluginToWebMenu( const QString& name, QAction* action ) = 0;
 
     /** Remove action from the Web menu */
-    virtual void removePluginWebMenu( QString name, QAction* action ) = 0;
+    virtual void removePluginWebMenu( const QString& name, QAction* action ) = 0;
 
     /** Add a dock widget to the main window */
     virtual void addDockWidget( Qt::DockWidgetArea area, QDockWidget * dockwidget ) = 0;
@@ -270,7 +270,7 @@ class QgisInterface : QObject
     virtual void removeWindow( QAction *action ) = 0;
 
     /** Register action to the shortcuts manager so its shortcut can be changed in GUI */
-    virtual bool registerMainWindowAction( QAction* action, QString defaultShortcut ) = 0;
+    virtual bool registerMainWindowAction( QAction* action, const QString& defaultShortcut ) = 0;
 
     /** Unregister a previously registered action. (e.g. when plugin is going to be unloaded) */
     virtual bool unregisterMainWindowAction( QAction* action ) = 0;
@@ -284,7 +284,7 @@ class QgisInterface : QObject
      * url to the QGIS documentation directory path (prefix/share/doc)
      * @deprecated
      */
-    virtual void openURL( QString url, bool useQgisDocDirectory = true ) = 0 /Deprecated/;
+    virtual void openURL( const QString& url, bool useQgisDocDirectory = true ) = 0 /Deprecated/;
 
     /** Accessors for inserting items into menus and toolbars.
      * An item can be inserted before any existing action.
@@ -488,7 +488,7 @@ class QgisInterface : QObject
      *
      * More information here: http://qt-project.org/forums/viewthread/27098/
      */
-    virtual void preloadForm( QString uifile ) = 0;
+    virtual void preloadForm( const QString& uifile ) = 0;
 
     /** Return vector layers in edit mode
      * @param modified whether to return only layers that have been modified

python/gui/qgsprojectbadlayerguihandler.sip

@@ -14,7 +14,7 @@ class QgsProjectBadLayerGuiHandler : QObject, QgsProjectBadLayerHandler
     QgsProjectBadLayerGuiHandler();
 
     /** Implementation of the handler */
-    virtual void handleBadLayers( QList<QDomNode> layers, QDomDocument projectDom );
+    virtual void handleBadLayers( const QList<QDomNode>& layers, const QDomDocument& projectDom );
 
     /** Flag to store the Ignore button press of MessageBox used by QgsLegend */
     static bool mIgnore;

src/app/qgisapp.cpp

@@ -7876,7 +7876,7 @@ class QgsPythonRunnerImpl : public QgsPythonRunner
   public:
     explicit QgsPythonRunnerImpl( QgsPythonUtils* pythonUtils ) : mPythonUtils( pythonUtils ) {}
 
-    virtual bool runCommand( QString command, QString messageOnError = QString() ) override
+    virtual bool runCommand( const QString& command, const QString& messageOnError = QString() ) override
     {
       if ( mPythonUtils && mPythonUtils->isEnabled() )
       {
@@ -7885,7 +7885,7 @@ class QgsPythonRunnerImpl : public QgsPythonRunner
       return false;
     }
 
-    virtual bool evalCommand( QString command, QString &result ) override
+    virtual bool evalCommand( const QString& command, QString &result ) override
     {
       if ( mPythonUtils && mPythonUtils->isEnabled() )
       {