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Improved docs for QgsMapCanvas::setTheme, handle setLayers and 
setLayerStyleOverrides when canvas is following a map theme
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@nyalldawson
nyalldawson committed Mar 12, 2017
1 parent 7b7c3e1 commit af532ecdf396ade589d40cb2cc13959418cdcd68
Unified Split
Showing with 118 additions and 251 deletions.
  1. +25 −241 python/gui/qgsmapcanvas.sip
  2. +27 −2 src/gui/qgsmapcanvas.cpp
  3. +44 −8 src/gui/qgsmapcanvas.h
  4. +22 −0 tests/src/python/test_qgsmapcanvas.py
266 python/gui/qgsmapcanvas.sip
View file
@@ -18,298 +18,82 @@ class QgsMapCanvas : QGraphicsView
public:

//! Constructor
QgsMapCanvas( QWidget * parent /TransferThis/ = 0 );

QgsMapCanvas( QWidget *parent /TransferThis/ = 0 );
~QgsMapCanvas();

//! Returns the magnification factor
//! @note added in 2.16
double magnificationFactor() const;

//! Set list of layers that should be shown in the canvas
//! @note added in 3.0
void setLayers( const QList<QgsMapLayer*>& layers );

void setCurrentLayer( QgsMapLayer* layer );

//! Get access to properties used for map rendering
//! @note added in 2.4
const QgsMapSettings& mapSettings() const /KeepReference/;

//! sets destination coordinate reference system
//! @note added in 2.4
void setDestinationCrs( const QgsCoordinateReferenceSystem& crs );

//! Get access to the labeling results (may be null)
//! @note added in 2.4
const QgsLabelingResults* labelingResults() const;

//! Set whether to cache images of rendered layers
//! @note added in 2.4
void setLayers( const QList<QgsMapLayer *> &layers );
void setCurrentLayer( QgsMapLayer *layer );
const QgsMapSettings &mapSettings() const /KeepReference/;
void setDestinationCrs( const QgsCoordinateReferenceSystem &crs );
const QgsLabelingResults *labelingResults() const;
void setCachingEnabled( bool enabled );

//! Check whether images of rendered layers are curerently being cached
//! @note added in 2.4
bool isCachingEnabled() const;

//! Make sure to remove any rendered images from cache (does nothing if cache is not enabled)
//! @note added in 2.4
void clearCache();

//! Reload all layers, clear the cache and refresh the canvas
//! @note added in 2.9
void refreshAllLayers();

//! Set whether the layers are rendered in parallel or sequentially
//! @note added in 2.4
void setParallelRenderingEnabled( bool enabled );

//! Check whether the layers are rendered in parallel or sequentially
//! @note added in 2.4
bool isParallelRenderingEnabled() const;

//! Set how often map preview should be updated while it is being rendered (in milliseconds)
//! @note added in 2.4
void setMapUpdateInterval( int timeMilliseconds );

//! Find out how often map preview should be updated while it is being rendered (in milliseconds)
//! @note added in 2.4
int mapUpdateInterval() const;

//! Get the last reported scale of the canvas
double scale();

//! Returns the mapUnitsPerPixel (map units per pixel) for the canvas
double mapUnitsPerPixel() const;

//! Returns the current zoom extent of the map canvas
QgsRectangle extent() const;
//! Returns the combined extent for all layers on the map canvas
QgsRectangle fullExtent() const;

//! Set the extent of the map canvas
void setExtent( const QgsRectangle &r, bool magnified = false );

//! Get the current map canvas rotation in clockwise degrees
//! @note added in 2.8
double rotation() const;

//! Set the rotation of the map canvas in clockwise degrees
//! @note added in 2.8
void setRotation( double degrees );

//! Set the center of the map canvas, in geographical coordinates
//! @note added in 2.8
void setCenter( const QgsPoint& center );

//! Get map center, in geographical coordinates
//! @note added in 2.8
void setCenter( const QgsPoint &center );
QgsPoint center() const;

//! Zoom to the full extent of all layers
void zoomToFullExtent();

//! Zoom to the previous extent (view)
void zoomToPreviousExtent();

//! Zoom to the next extent (view)
void zoomToNextExtent();

// ! Clears the list of extents and sets current extent as first item
void clearExtentHistory();

/** Zoom to the extent of the selected features of current (vector) layer.
* @param layer optionally specify different than current layer
*/
void zoomToSelected( QgsVectorLayer* layer = 0 );

/** Set canvas extent to the bounding box of a set of features
@param layer the vector layer
@param ids the feature ids*/
void zoomToFeatureIds( QgsVectorLayer* layer, const QgsFeatureIds& ids );

/** Centers canvas extent to feature ids
@param layer the vector layer
@param ids the feature ids*/
void panToFeatureIds( QgsVectorLayer* layer, const QgsFeatureIds& ids );

//! Pan to the selected features of current (vector) layer keeping same extent.
void panToSelected( QgsVectorLayer* layer = 0 );

//! \brief Sets the map tool currently being used on the canvas
void setMapTool( QgsMapTool* mapTool );

/** \brief Unset the current map tool or last non zoom tool
*
* This is called from destructor of map tools to make sure
* that this map tool won't be used any more.
* You don't have to call it manualy, QgsMapTool takes care of it.
*/
void unsetMapTool( QgsMapTool* mapTool );

//! Returns the currently active tool
QgsMapTool* mapTool();

//! Write property of QColor bgColor.
void setCanvasColor( const QColor & _newVal );
//! Read property of QColor bgColor.
void zoomToSelected( QgsVectorLayer *layer = 0 );
void zoomToFeatureIds( QgsVectorLayer *layer, const QgsFeatureIds &ids );
void panToFeatureIds( QgsVectorLayer *layer, const QgsFeatureIds &ids );
void panToSelected( QgsVectorLayer *layer = 0 );
void setMapTool( QgsMapTool *mapTool );
void unsetMapTool( QgsMapTool *mapTool );
QgsMapTool *mapTool();
void setCanvasColor( const QColor &_newVal );
QColor canvasColor() const;

//! Set color of selected vector features
//! @note added in 2.4
void setSelectionColor( const QColor& color );

//! Emits signal scaleChanged to update scale in main window
void setSelectionColor( const QColor &color );
void updateScale();

//! return the map layer at position index in the layer stack
QgsMapLayer *layer( int index );

//! return number of layers on the map
int layerCount() const;

//! return list of layers within map canvas.
QList<QgsMapLayer*> layers() const;
QList<QgsMapLayer *> layers() const;
void freeze( bool frozen = true );
bool isFrozen() const;
bool renderFlag() const;

//! Get the current canvas map units
QgsUnitTypes::DistanceUnit mapUnits() const;

//! Getter for stored overrides of styles for layers.
//! @note added in 2.12
QMap<QString, QString> layerStyleOverrides() const;

//! Setter for stored overrides of styles for layers.
//! @note added in 2.12
void setLayerStyleOverrides( const QMap<QString, QString>& overrides );

void setLayerStyleOverrides( const QMap<QString, QString> &overrides );
void setTheme( const QString &theme );
QString theme() const;
const QgsMapToPixel *getCoordinateTransform();
bool isDrawing();
QgsMapLayer *currentLayer();
void setWheelFactor( double factor );

//! Zoom to a specific scale
void zoomScale( double scale );

//! Zoom with the factor supplied. Factor > 1 zooms out, interval (0,1) zooms in
//! If point is given, re-center on it
void zoomByFactor( double scaleFactor, const QgsPoint *center = 0 );

//! Zooms in/out with a given center
void zoomWithCenter( int x, int y, bool zoomIn );

//! Zooms to feature extent. Adds a small margin around the extent
//! and does a pan if rect is empty (point extent)
void zoomToFeatureExtent( QgsRectangle& rect );

//! Returns whether the scale is locked, so zooming can be performed using magnication.
//! @note added in 2.16
//! @see setScaleLocked()
void zoomToFeatureExtent( QgsRectangle &rect );
bool scaleLocked() const;

//! used to determine if anti-aliasing is enabled or not
void enableAntiAliasing( bool flag );

//! true if antialising is enabled
bool antiAliasingEnabled() const;

//! sets map tile rendering flag
void enableMapTileRendering( bool flag );

// following 2 methods should be moved elsewhere or changed to private
// currently used by pan map tool
//! Ends pan action and redraws the canvas.
void panActionEnd( QPoint releasePoint );

//! Called when mouse is moving and pan is activated
void panAction( QMouseEvent * event );

//! returns last position of mouse cursor
void panAction( QMouseEvent *event );
QPoint mouseLastXY();

/** Enables a preview mode for the map canvas
* @param previewEnabled set to true to enable a preview mode
* @see setPreviewMode
* @note added in 2.3 */
void setPreviewModeEnabled( bool previewEnabled );

/** Returns whether a preview mode is enabled for the map canvas
* @returns true if a preview mode is currently enabled
* @see setPreviewModeEnabled
* @see previewMode
* @note added in 2.3 */
bool previewModeEnabled() const;

/** Sets a preview mode for the map canvas. This setting only has an effect if
* previewModeEnabled is true.
* @param mode preview mode for the canvas
* @see previewMode
* @see setPreviewModeEnabled
* @see previewModeEnabled
* @note added in 2.3 */
void setPreviewMode( QgsPreviewEffect::PreviewMode mode );

/** Returns the current preview mode for the map canvas. This setting only has an effect if
* previewModeEnabled is true.
* @returns preview mode for map canvas
* @see setPreviewMode
* @see previewModeEnabled
* @note added in 2.3 */
QgsPreviewEffect::PreviewMode previewMode() const;

/** Return snapping utility class that is associated with map canvas.
* If no snapping utils instance has been associated previously, an internal will be created for convenience
* (so map tools do not need to test for existence of the instance).
*
* Main canvas in QGIS returns an instance which is always up-to-date with the project's snapping configuration.
* @note added in 2.8
*/
QgsSnappingUtils* snappingUtils() const;

/** Assign an instance of snapping utils to the map canvas.
* The instance is not owned by the canvas, so it is possible to use one instance in multiple canvases.
*
* For main canvas in QGIS, do not associate a different instance from the existing one (it is updated from
* the project's snapping configuration).
* @note added in 2.8
*/
void setSnappingUtils( QgsSnappingUtils* utils );

/** Sets an expression context scope for the map canvas. This scope is injected into the expression
* context used for rendering the map, and can be used to apply specific variable overrides for
* expression evaluation for the map canvas render. This method will overwrite the existing expression
* context scope for the canvas.
* @param scope new expression context scope
* @note added in QGIS 2.12
* @see expressionContextScope()
*/
void setExpressionContextScope( const QgsExpressionContextScope& scope );

/** Returns a reference to the expression context scope for the map canvas. This scope is injected
* into the expression context used for rendering the map, and can be used to apply specific variable
* overrides for expression evaluation for the map canvas render.
* @note added in QGIS 2.12
* @see setExpressionContextScope()
*/
QgsExpressionContextScope& expressionContextScope();

/** Returns a const reference to the expression context scope for the map canvas.
* @note added in QGIS 2.12
* @see setExpressionContextScope()
* @note not available in python bindings
*/
// const QgsExpressionContextScope& expressionContextScope() const;

/** Sets the segmentation tolerance applied when rendering curved geometries
@param tolerance the segmentation tolerance*/
QgsSnappingUtils *snappingUtils() const;
void setSnappingUtils( QgsSnappingUtils *utils );
void setExpressionContextScope( const QgsExpressionContextScope &scope );
QgsExpressionContextScope &expressionContextScope();
// const QgsExpressionContextScope &expressionContextScope() const;
void setSegmentationTolerance( double tolerance );

/** Sets segmentation tolerance type (maximum angle or maximum difference between curve and approximation)
@param type the segmentation tolerance typename*/
void setSegmentationToleranceType( QgsAbstractGeometry::SegmentationToleranceType type );

public slots:
29 src/gui/qgsmapcanvas.cpp
View file
@@ -291,6 +291,15 @@ const QgsMapToPixel *QgsMapCanvas::getCoordinateTransform()
}

void QgsMapCanvas::setLayers( const QList<QgsMapLayer *> &layers )
{
// following a theme => request denied!
if ( !mTheme.isEmpty() )
return;

setLayersPrivate( layers );
}

void QgsMapCanvas::setLayersPrivate( const QList<QgsMapLayer *> &layers )
{
QList<QgsMapLayer *> oldLayers = mSettings.layers();

@@ -487,6 +496,12 @@ void QgsMapCanvas::refreshMap()

if ( !mTheme.isEmpty() )
{
// IMPORTANT: we MUST set the layer style overrides here! (At the time of writing this
// comment) retrieving layer styles from the theme collection gives an XML snapshot of the
// current state of the style. If we had stored the style overrides earlier (such as in
// mapThemeChanged slot) then this xml could be out of date...
// TODO: if in future QgsMapThemeCollection::mapThemeStyleOverrides is changed to
// just return the style name, we can instead set the overrides in mapThemeChanged and not here
mSettings.setLayerStyleOverrides( QgsProject::instance()->mapThemeCollection()->mapThemeStyleOverrides( mTheme ) );
}

@@ -530,7 +545,17 @@ void QgsMapCanvas::mapThemeChanged( const QString &theme )
{
if ( theme == mTheme )
{
setLayers( QgsProject::instance()->mapThemeCollection()->mapThemeVisibleLayers( mTheme ) );
// set the canvas layers to match the new layers contained in the map theme
// NOTE: we do this when the theme layers change and not when we are refreshing the map
// as setLayers() sets up necessary connections to handle changes to the layers
setLayersPrivate( QgsProject::instance()->mapThemeCollection()->mapThemeVisibleLayers( mTheme ) );
// IMPORTANT: we don't set the layer style overrides here! (At the time of writing this
// comment) retrieving layer styles from the theme collection gives an XML snapshot of the
// current state of the style. If changes were made to the style then this xml
// snapshot goes out of sync...
// TODO: if in future QgsMapThemeCollection::mapThemeStyleOverrides is changed to
// just return the style name, we can instead set the overrides here and not in refreshMap()

clearCache();
refresh();
}
@@ -1628,7 +1653,7 @@ void QgsMapCanvas::setTheme( const QString &theme )
else
{
mTheme = theme;
setLayers( QgsProject::instance()->mapThemeCollection()->mapThemeVisibleLayers( mTheme ) );
setLayersPrivate( QgsProject::instance()->mapThemeCollection()->mapThemeVisibleLayers( mTheme ) );
emit themeChanged( theme );
}
}

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