Quantum GIS API Documentation  1.8
Classes | Public Types | Public Slots | Signals | Public Member Functions | Protected Member Functions | Protected Attributes | Private Slots | Private Member Functions | Private Attributes
QgsMapCanvas Class Reference

Map canvas is a class for displaying all GIS data types on a canvas. More...

#include <qgsmapcanvas.h>

Collaboration diagram for QgsMapCanvas:
Collaboration graph
[legend]

List of all members.

Classes

class  CanvasProperties

Public Types

enum  WheelAction { WheelZoom, WheelZoomAndRecenter, WheelZoomToMouseCursor, WheelNothing }

Public Slots

void refresh ()
 Repaints the canvas map.
void selectionChangedSlot ()
 Receives signal about selection change, and pass it on with layer info.
void saveAsImage (QString theFileName, QPixmap *QPixmap=0, QString="PNG")
 Save the convtents of the map canvas to disk as an image.
void layerStateChange ()
 This slot is connected to the visibility change of one or more layers.
void setRenderFlag (bool theFlag)
 Whether to suppress rendering or not.
bool renderFlag ()
 State of render suppression flag.
bool hasCrsTransformEnabled ()
 A simple helper method to find out if on the fly projections are enabled or not.
void mapUnitsChanged ()
 The map units may have changed, so cope with that.
void updateMap ()
 updates pixmap on render progress
void showError (QgsMapLayer *mapLayer)
 show whatever error is exposed by the QgsMapLayer.
void readProject (const QDomDocument &)
 called to read map canvas settings from project
void writeProject (QDomDocument &)
 called to write map canvas settings to project

Signals

void setProgress (int, int)
 Let the owner know how far we are with render operations.
void xyCoordinates (const QgsPoint &p)
 emits current mouse position
void scaleChanged (double)
 Emitted when the scale of the map changes.
void extentsChanged ()
 Emitted when the extents of the map change.
void renderComplete (QPainter *)
 Emitted when the canvas has rendered.
void renderStarting ()
 Emitted when the canvas is about to be rendered.
void layersChanged ()
 Emitted when a new set of layers has been received.
void keyPressed (QKeyEvent *e)
 Emit key press event.
void keyReleased (QKeyEvent *e)
 Emit key release event.
void mapToolSet (QgsMapTool *tool)
 Emit map tool changed event.
void selectionChanged (QgsMapLayer *layer)
 Emitted when selection in any layer gets changed.
void zoomLastStatusChanged (bool)
 Emitted when zoom last status changed.
void zoomNextStatusChanged (bool)
 Emitted when zoom next status changed.

Public Member Functions

 QgsMapCanvas (QWidget *parent=0, const char *name=0)
 Constructor.
 ~QgsMapCanvas ()
 Destructor.
void setLayerSet (QList< QgsMapCanvasLayer > &layers)
void setCurrentLayer (QgsMapLayer *layer)
void updateOverview ()
void enableOverviewMode (QgsMapOverviewCanvas *overview)
QgsMapCanvasMapmap ()
QgsMapRenderermapRenderer ()
Q_DECL_DEPRECATED QPixmap & canvasPixmap ()
 Accessor for the canvas pixmap.
QPaintDevice & canvasPaintDevice ()
 Accessor for the canvas paint device.
double scale ()
 Get the last reported scale of the canvas.
void clear ()
 Clear the map canvas.
double mapUnitsPerPixel () const
 Returns the mapUnitsPerPixel (map units per pixel) for the canvas.
QgsRectangle extent () const
 Returns the current zoom exent of the map canvas.
QgsRectangle fullExtent () const
 Returns the combined exent for all layers on the map canvas.
void setExtent (QgsRectangle const &r)
 Set the extent of the map canvas.
void zoomToFullExtent ()
 Zoom to the full extent of all layers.
void zoomToPreviousExtent ()
 Zoom to the previous extent (view)
void zoomToNextExtent ()
 Zoom to the Next extent (view)
void clearExtentHistory ()
void zoomToSelected (QgsVectorLayer *layer=NULL)
 Zoom to the extent of the selected features of current (vector) layer.
void panToSelected (QgsVectorLayer *layer=NULL)
 Pan to the selected features of current (vector) layer keeping same extent.
void setMapTool (QgsMapTool *mapTool)
 Sets the map tool currently being used on the canvas.
void unsetMapTool (QgsMapTool *mapTool)
 Unset the current map tool or last non zoom tool.
QgsMapToolmapTool ()
 Returns the currently active tool.
virtual void setCanvasColor (const QColor &_newVal)
 Write property of QColor bgColor.
virtual QColor canvasColor () const
 Read property of QColor bgColor.
void updateScale ()
 Emits signal scalChanged to update scale in main window.
void updateFullExtent ()
 Updates the full extent.
QgsMapLayerlayer (int index)
 return the map layer at position index in the layer stack
int layerCount () const
 return number of layers on the map
QList< QgsMapLayer * > layers () const
 return list of layers within map canvas. Added in v1.5
void freeze (bool frz=true)
bool isFrozen ()
void setDirty (bool _dirty)
 Flag the canvas as dirty and needed a refresh.
bool isDirty () const
 Return the state of the canvas (dirty or not)
void setMapUnits (QGis::UnitType mapUnits)
 Set map units (needed by project properties dialog)
QGis::UnitType mapUnits () const
 Get the current canvas map units.
const QgsMapToPixelgetCoordinateTransform ()
 Get the current coordinate transform.
bool isDrawing ()
 true if canvas currently drawing
QgsMapLayercurrentLayer ()
 returns current layer (set by legend widget)
void setWheelAction (WheelAction action, double factor=2)
 set wheel action and zoom factor (should be greater than 1)
void zoomIn ()
 Zoom in with fixed factor.
void zoomOut ()
 Zoom out with fixed factor.
void zoomScale (double scale)
 Zoom to a specific scale.
void zoomByFactor (double scaleFactor)
 Zoom with the factor supplied. Factor > 1 zooms out, interval (0,1) zooms in.
void zoomWithCenter (int x, int y, bool zoomIn)
 Zooms in/out with a given center.
void enableAntiAliasing (bool theFlag)
 used to determine if anti-aliasing is enabled or not
bool antiAliasingEnabled () const
 true if antialising is enabled
void useImageToRender (bool theFlag)
 Select which Qt class to render with.
void panActionEnd (QPoint releasePoint)
 Ends pan action and redraws the canvas.
void panAction (QMouseEvent *event)
 Called when mouse is moving and pan is activated.
QPoint mouseLastXY ()
 returns last position of mouse cursor

Protected Member Functions

void keyPressEvent (QKeyEvent *e)
 Overridden key press event.
void keyReleaseEvent (QKeyEvent *e)
 Overridden key release event.
void mouseDoubleClickEvent (QMouseEvent *e)
 Overridden mouse double click event.
void mouseMoveEvent (QMouseEvent *e)
 Overridden mouse move event.
void mousePressEvent (QMouseEvent *e)
 Overridden mouse press event.
void mouseReleaseEvent (QMouseEvent *e)
 Overridden mouse release event.
void wheelEvent (QWheelEvent *e)
 Overridden mouse wheel event.
void resizeEvent (QResizeEvent *e)
 Overridden resize event.
void paintEvent (QPaintEvent *e)
 Overridden paint event.
void dragEnterEvent (QDragEnterEvent *e)
 Overridden drag enter event.
void moveCanvasContents (bool reset=false)
 called when panning is in action, reset indicates end of panning
void updateCanvasItemPositions ()
 called on resize or changed extent to notify canvas items to change their rectangle

Protected Attributes

std::auto_ptr< CanvasPropertiesmCanvasProperties
 Handle pattern for implementation object.

Private Slots

void mapToolDestroyed ()
 called when current maptool is destroyed
void crsTransformEnabled (bool)

Private Member Functions

 QgsMapCanvas (QgsMapCanvas const &)
 this class is non-copyable
void connectNotify (const char *signal)
 debugging member invoked when a connect() is made to this object

Private Attributes

QgsMapRenderermMapRenderer
 all map rendering is done in this class
QgsMapCanvasMapmMap
 owns pixmap with rendered map and controls rendering
QgsMapOverviewCanvasmMapOverview
 map overview widget - it's controlled by QgsMapCanvas
bool mDrawing
 Flag indicating a map refresh is in progress.
bool mFrozen
 Flag indicating if the map canvas is frozen.
bool mDirty
 Flag to track the state of the Map canvas.
bool mRenderFlag
 determines whether user has requested to suppress rendering
QList< QPair< int, int > > mResizeQueue
 Resize events that have been ignored because the canvas is busy with rendering may put their sizes into this list.
QgsMapLayermCurrentLayer
 current layer in legend
QGraphicsScene * mScene
 graphics scene manages canvas items
QgsMapToolmMapTool
 pointer to current map tool
QgsMapToolmLastNonZoomMapTool
 previous tool if current is for zooming/panning
QList< QgsRectanglemLastExtent
 recently used extent
int mLastExtentIndex
double mWheelZoomFactor
 Scale factor multiple for default zoom in/out.
WheelAction mWheelAction
 Mouse wheel action.
QSize mNewSize
 resize canvas size
bool mPainting
 currently in paint event
bool mAntiAliasing
 indicates whether antialiasing will be used for rendering

Detailed Description

Map canvas is a class for displaying all GIS data types on a canvas.

Definition at line 97 of file qgsmapcanvas.h.


Member Enumeration Documentation

Enumerator:
WheelZoom 
WheelZoomAndRecenter 
WheelZoomToMouseCursor 
WheelNothing 

Definition at line 103 of file qgsmapcanvas.h.


Constructor & Destructor Documentation

QgsMapCanvas::QgsMapCanvas ( QWidget *  parent = 0,
const char *  name = 0 
)

Destructor.

Definition at line 140 of file qgsmapcanvas.cpp.

References QgsMapTool::deactivate(), mLastNonZoomMapTool, mMapRenderer, mMapTool, and mScene.

QgsMapCanvas::QgsMapCanvas ( QgsMapCanvas const &  ) [private]

this class is non-copyable

Note:

Otherwise std::auto_ptr would pass the object responsiblity on to the copy like a hot potato leaving the copyer in a weird state.


Member Function Documentation

bool QgsMapCanvas::antiAliasingEnabled ( ) const [inline]

true if antialising is enabled

Definition at line 255 of file qgsmapcanvas.h.

Referenced by QgsMapCanvasItem::paint().

QColor QgsMapCanvas::canvasColor ( ) const [virtual]

Read property of QColor bgColor.

Definition at line 1236 of file qgsmapcanvas.cpp.

References mScene.

Referenced by QgsQuickPrint::setMapCanvas().

QPaintDevice & QgsMapCanvas::canvasPaintDevice ( )

Accessor for the canvas paint device.

Definition at line 1306 of file qgsmapcanvas.cpp.

References mMap, and QgsMapCanvasMap::paintDevice().

Referenced by canvasPixmap().

Accessor for the canvas pixmap.

Deprecated:
use canvasPaintDevice()

Definition at line 1281 of file qgsmapcanvas.cpp.

References canvasPaintDevice(), mMap, and QgsMapCanvasMap::paintDevice().

Clear the map canvas.

Definition at line 562 of file qgsmapcanvas.cpp.

References setDirty().

Referenced by refresh().

void QgsMapCanvas::connectNotify ( const char *  signal) [private]

debugging member invoked when a connect() is made to this object

Definition at line 1348 of file qgsmapcanvas.cpp.

References QgsDebugMsg.

void QgsMapCanvas::crsTransformEnabled ( bool  enabled) [private, slot]

Definition at line 1546 of file qgsmapcanvas.cpp.

References mMapRenderer, QgsDebugMsg, and refresh().

Referenced by QgsMapCanvas().

returns current layer (set by legend widget)

Definition at line 368 of file qgsmapcanvas.cpp.

References mCurrentLayer.

Referenced by setLayerSet(), QgsMapCanvasSnapper::snapToBackgroundLayers(), and QgsMapCanvasSnapper::snapToCurrentLayer().

void QgsMapCanvas::dragEnterEvent ( QDragEnterEvent *  e) [protected]

Overridden drag enter event.

Definition at line 1538 of file qgsmapcanvas.cpp.

void QgsMapCanvas::enableAntiAliasing ( bool  theFlag)

used to determine if anti-aliasing is enabled or not

Definition at line 169 of file qgsmapcanvas.cpp.

References QgsMapCanvasMap::enableAntiAliasing(), QgsMapOverviewCanvas::enableAntiAliasing(), mAntiAliasing, mMap, and mMapOverview.

Definition at line 332 of file qgsmapcanvas.cpp.

References hasCrsTransformEnabled(), mMapOverview, and mMapRenderer.

void QgsMapCanvas::extentsChanged ( ) [signal]

Emitted when the extents of the map change.

Referenced by paintEvent(), setExtent(), zoomToNextExtent(), and zoomToPreviousExtent().

void QgsMapCanvas::freeze ( bool  frz = true)

Freeze/thaw the map canvas. This is used to prevent the canvas from responding to events while layers are being added/removed etc.

Parameters:
frzBoolean specifying if the canvas should be frozen (true) or thawed (false). Default is true.

Definition at line 1270 of file qgsmapcanvas.cpp.

References mFrozen.

Returns the combined exent for all layers on the map canvas.

Definition at line 481 of file qgsmapcanvas.cpp.

References QgsMapRenderer::fullExtent(), and mMapRenderer.

Referenced by setLayerSet(), updateFullExtent(), and zoomToFullExtent().

A simple helper method to find out if on the fly projections are enabled or not.

Definition at line 651 of file qgsmapcanvas.cpp.

References QgsMapRenderer::hasCrsTransformEnabled(), and mMapRenderer.

Referenced by enableOverviewMode(), and QgsMapCanvas().

bool QgsMapCanvas::isDirty ( ) const

Return the state of the canvas (dirty or not)

Definition at line 219 of file qgsmapcanvas.cpp.

References mDirty.

true if canvas currently drawing

Definition at line 226 of file qgsmapcanvas.cpp.

References mDrawing.

Accessor for frozen status of canvas

Definition at line 1275 of file qgsmapcanvas.cpp.

References mFrozen.

void QgsMapCanvas::keyPressed ( QKeyEvent *  e) [signal]

Emit key press event.

Referenced by keyPressEvent().

void QgsMapCanvas::keyPressEvent ( QKeyEvent *  e) [protected]
void QgsMapCanvas::keyReleased ( QKeyEvent *  e) [signal]

Emit key release event.

Referenced by keyReleaseEvent().

void QgsMapCanvas::keyReleaseEvent ( QKeyEvent *  e) [protected]

Overridden key release event.

Definition at line 849 of file qgsmapcanvas.cpp.

References keyReleased(), QgsMapTool::keyReleaseEvent(), mCanvasProperties, mDrawing, mMapTool, panActionEnd(), and QgsDebugMsg.

QgsMapLayer * QgsMapCanvas::layer ( int  index)

return the map layer at position index in the layer stack

Definition at line 194 of file qgsmapcanvas.cpp.

References QgsMapLayerRegistry::instance(), layers(), QgsMapRenderer::layerSet(), QgsMapLayerRegistry::mapLayer(), and mMapRenderer.

Referenced by layers(), selectionChangedSlot(), setCurrentLayer(), and setLayerSet().

int QgsMapCanvas::layerCount ( ) const

return number of layers on the map

Definition at line 1241 of file qgsmapcanvas.cpp.

References QgsMapRenderer::layerSet(), and mMapRenderer.

Referenced by setLayerSet().

QList< QgsMapLayer * > QgsMapCanvas::layers ( ) const

return list of layers within map canvas. Added in v1.5

Definition at line 1247 of file qgsmapcanvas.cpp.

References QgsMapLayerRegistry::instance(), layer(), QgsMapRenderer::layerSet(), QgsMapLayerRegistry::mapLayer(), and mMapRenderer.

Referenced by layer(), and QgsFormAnnotationItem::updateVisibility().

void QgsMapCanvas::layersChanged ( ) [signal]

Emitted when a new set of layers has been received.

Referenced by setLayerSet().

This slot is connected to the visibility change of one or more layers.

Definition at line 1260 of file qgsmapcanvas.cpp.

References refresh().

Definition at line 183 of file qgsmapcanvas.cpp.

References mMap.

Returns the currently active tool.

Definition at line 1356 of file qgsmapcanvas.cpp.

References mMapTool.

void QgsMapCanvas::mapToolDestroyed ( ) [private, slot]

called when current maptool is destroyed

Definition at line 1558 of file qgsmapcanvas.cpp.

References mMapTool, and QgsDebugMsg.

Referenced by setMapTool().

void QgsMapCanvas::mapToolSet ( QgsMapTool tool) [signal]

Emit map tool changed event.

Referenced by setMapTool(), and unsetMapTool().

Get the current canvas map units.

Definition at line 1324 of file qgsmapcanvas.cpp.

References QgsMapRenderer::mapUnits(), and mMapRenderer.

The map units may have changed, so cope with that.

Definition at line 656 of file qgsmapcanvas.cpp.

References refresh(), and updateScale().

Returns the mapUnitsPerPixel (map units per pixel) for the canvas.

Definition at line 1311 of file qgsmapcanvas.cpp.

References QgsMapRenderer::mapUnitsPerPixel(), and mMapRenderer.

Referenced by saveAsImage().

void QgsMapCanvas::mouseDoubleClickEvent ( QMouseEvent *  e) [protected]

Overridden mouse double click event.

Definition at line 887 of file qgsmapcanvas.cpp.

References QgsMapTool::canvasDoubleClickEvent(), mDrawing, and mMapTool.

returns last position of mouse cursor

Definition at line 1480 of file qgsmapcanvas.cpp.

References mCanvasProperties.

void QgsMapCanvas::mouseMoveEvent ( QMouseEvent *  e) [protected]
void QgsMapCanvas::mousePressEvent ( QMouseEvent *  e) [protected]

Overridden mouse press event.

Definition at line 900 of file qgsmapcanvas.cpp.

References QgsMapTool::canvasPressEvent(), mCanvasProperties, mDrawing, and mMapTool.

void QgsMapCanvas::mouseReleaseEvent ( QMouseEvent *  e) [protected]
void QgsMapCanvas::moveCanvasContents ( bool  reset = false) [protected]

called when panning is in action, reset indicates end of panning

Definition at line 1425 of file qgsmapcanvas.cpp.

References mCanvasProperties, mDrawing, mMap, mScene, QgsMapCanvasMap::setPanningOffset(), QgsMapCanvasItem::setPanningOffset(), and updateCanvasItemPositions().

Referenced by panAction(), panActionEnd(), and QgsMapCanvas().

void QgsMapCanvas::paintEvent ( QPaintEvent *  e) [protected]
void QgsMapCanvas::panAction ( QMouseEvent *  event)

Called when mouse is moving and pan is activated.

Definition at line 1409 of file qgsmapcanvas.cpp.

References mDrawing, and moveCanvasContents().

Referenced by QgsMapToolPan::canvasMoveEvent(), QgsMapToolTouch::canvasMoveEvent(), and mouseMoveEvent().

void QgsMapCanvas::panActionEnd ( QPoint  releasePoint)
void QgsMapCanvas::panToSelected ( QgsVectorLayer layer = NULL)

Pan to the selected features of current (vector) layer keeping same extent.

Note:
added in 2.0

Definition at line 721 of file qgsmapcanvas.cpp.

References QgsVectorLayer::boundingBoxOfSelected(), QgsRectangle::center(), QgsMapRenderer::layerExtentToOutputExtent(), mCurrentLayer, mDrawing, mMapRenderer, refresh(), QgsVectorLayer::selectedFeatureCount(), and setExtent().

void QgsMapCanvas::readProject ( const QDomDocument &  doc) [slot]

called to read map canvas settings from project

Definition at line 1485 of file qgsmapcanvas.cpp.

References clearExtentHistory(), mMapRenderer, QgsDebugMsg, and QgsMapRenderer::readXML().

Referenced by QgsMapCanvas().

void QgsMapCanvas::refresh ( ) [slot]
void QgsMapCanvas::renderComplete ( QPainter *  ) [signal]

Emitted when the canvas has rendered.

Passes a pointer to the painter on which the map was drawn. This is useful for plugins that wish to draw on the map after it has been rendered. Passing the painter allows plugins to work when the map is being rendered onto a pixmap other than the mapCanvas own pixmap member.

Referenced by refresh(), and saveAsImage().

bool QgsMapCanvas::renderFlag ( ) [inline, slot]

State of render suppression flag.

Definition at line 288 of file qgsmapcanvas.h.

void QgsMapCanvas::renderStarting ( ) [signal]

Emitted when the canvas is about to be rendered.

Note:
Added in 1.5

Referenced by refresh().

void QgsMapCanvas::resizeEvent ( QResizeEvent *  e) [protected]

Overridden resize event.

Definition at line 980 of file qgsmapcanvas.cpp.

References mNewSize.

void QgsMapCanvas::saveAsImage ( QString  theFileName,
QPixmap *  QPixmap = 0,
QString  theFormat = "PNG" 
) [slot]
double QgsMapCanvas::scale ( void  )

Get the last reported scale of the canvas.

Definition at line 209 of file qgsmapcanvas.cpp.

References mMapRenderer, and QgsMapRenderer::scale().

Referenced by QgsMapCanvasItem::setRenderContextVariables(), updateScale(), and zoomScale().

void QgsMapCanvas::scaleChanged ( double  ) [signal]

Emitted when the scale of the map changes.

Referenced by updateScale().

void QgsMapCanvas::selectionChanged ( QgsMapLayer layer) [signal]

Emitted when selection in any layer gets changed.

Referenced by selectionChangedSlot(), and setLayerSet().

Receives signal about selection change, and pass it on with layer info.

Definition at line 1530 of file qgsmapcanvas.cpp.

References layer(), refresh(), and selectionChanged().

Referenced by setLayerSet().

void QgsMapCanvas::setCanvasColor ( const QColor &  theColor) [virtual]

Write property of QColor bgColor.

Definition at line 1218 of file qgsmapcanvas.cpp.

References mMap, mScene, and QgsMapCanvasMap::setBackgroundColor().

Definition at line 204 of file qgsmapcanvas.cpp.

References layer(), and mCurrentLayer.

void QgsMapCanvas::setDirty ( bool  _dirty)

Flag the canvas as dirty and needed a refresh.

Definition at line 214 of file qgsmapcanvas.cpp.

References mDirty.

Referenced by clear().

void QgsMapCanvas::setLayerSet ( QList< QgsMapCanvasLayer > &  layers)
void QgsMapCanvas::setMapTool ( QgsMapTool mapTool)

Sets the map tool currently being used on the canvas.

Definition at line 1167 of file qgsmapcanvas.cpp.

References QgsMapTool::activate(), QgsMapTool::deactivate(), QgsMapTool::isTransient(), mapToolDestroyed(), mapToolSet(), mLastNonZoomMapTool, and mMapTool.

Referenced by mouseReleaseEvent().

Set map units (needed by project properties dialog)

Definition at line 1317 of file qgsmapcanvas.cpp.

References mMapRenderer, QgsDebugMsg, and QgsMapRenderer::setMapUnits().

void QgsMapCanvas::setProgress ( int  ,
int   
) [signal]

Let the owner know how far we are with render operations.

void QgsMapCanvas::setRenderFlag ( bool  theFlag) [slot]

Whether to suppress rendering or not.

Definition at line 1330 of file qgsmapcanvas.cpp.

References mMapRenderer, mRenderFlag, refresh(), QgsMapRenderer::rendererContext(), and QgsRenderContext::setRenderingStopped().

void QgsMapCanvas::setWheelAction ( WheelAction  action,
double  factor = 2 
)

set wheel action and zoom factor (should be greater than 1)

Definition at line 1100 of file qgsmapcanvas.cpp.

References mWheelAction, and mWheelZoomFactor.

Referenced by QgsMapCanvas().

void QgsMapCanvas::showError ( QgsMapLayer mapLayer) [slot]

show whatever error is exposed by the QgsMapLayer.

Definition at line 1460 of file qgsmapcanvas.cpp.

References QgsMapLayer::lastError(), QgsMapLayer::lastErrorTitle(), QgsMapLayer::name(), and QgsMessageViewer::setMessageAsPlainText().

Referenced by QgsMapCanvas().

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.

Definition at line 1201 of file qgsmapcanvas.cpp.

References QgsMapTool::deactivate(), mapToolSet(), mLastNonZoomMapTool, and mMapTool.

Referenced by QgsMapTool::~QgsMapTool().

called on resize or changed extent to notify canvas items to change their rectangle

Definition at line 1031 of file qgsmapcanvas.cpp.

References mScene, and QgsMapCanvasItem::updatePosition().

Referenced by moveCanvasContents(), paintEvent(), setExtent(), zoomToNextExtent(), and zoomToPreviousExtent().

void QgsMapCanvas::updateMap ( ) [slot]

updates pixmap on render progress

Definition at line 412 of file qgsmapcanvas.cpp.

References mMap, and QgsMapCanvasMap::updateContents().

Referenced by setLayerSet().

Definition at line 358 of file qgsmapcanvas.cpp.

References mMapOverview, and QgsMapOverviewCanvas::refresh().

Referenced by setLayerSet(), and updateFullExtent().

Emits signal scalChanged to update scale in main window.

Definition at line 554 of file qgsmapcanvas.cpp.

References mMapRenderer, scale(), QgsMapRenderer::scale(), and scaleChanged().

Referenced by mapUnitsChanged(), paintEvent(), setExtent(), zoomToNextExtent(), and zoomToPreviousExtent().

void QgsMapCanvas::useImageToRender ( bool  theFlag)

Select which Qt class to render with.

Definition at line 177 of file qgsmapcanvas.cpp.

References mMap, refresh(), and QgsMapCanvasMap::useImageToRender().

void QgsMapCanvas::wheelEvent ( QWheelEvent *  e) [protected]
void QgsMapCanvas::writeProject ( QDomDocument &  doc) [slot]

called to write map canvas settings to project

Definition at line 1500 of file qgsmapcanvas.cpp.

References mMapRenderer, QgsDebugMsg, and QgsMapRenderer::writeXML().

Referenced by QgsMapCanvas().

void QgsMapCanvas::xyCoordinates ( const QgsPoint p) [signal]

emits current mouse position

Note:
changed in 1.3

Referenced by mouseMoveEvent().

void QgsMapCanvas::zoomByFactor ( double  scaleFactor)

Zoom with the factor supplied. Factor > 1 zooms out, interval (0,1) zooms in.

Definition at line 1517 of file qgsmapcanvas.cpp.

References QgsMapRenderer::extent(), mDrawing, mMapRenderer, refresh(), QgsRectangle::scale(), and setExtent().

Referenced by zoomIn(), zoomOut(), and zoomScale().

Zoom in with fixed factor.

Definition at line 1106 of file qgsmapcanvas.cpp.

References mWheelZoomFactor, and zoomByFactor().

Referenced by keyPressEvent(), and wheelEvent().

void QgsMapCanvas::zoomLastStatusChanged ( bool  ) [signal]

Emitted when zoom last status changed.

Note:
: this signal was added in version 1.4

Referenced by clearExtentHistory(), setExtent(), zoomToNextExtent(), and zoomToPreviousExtent().

void QgsMapCanvas::zoomNextStatusChanged ( bool  ) [signal]

Emitted when zoom next status changed.

Note:
: this signal was added in version 1.4

Referenced by clearExtentHistory(), setExtent(), zoomToNextExtent(), and zoomToPreviousExtent().

Zoom out with fixed factor.

Definition at line 1111 of file qgsmapcanvas.cpp.

References mWheelZoomFactor, and zoomByFactor().

Referenced by keyPressEvent(), QgsMapToolTouch::pinchTriggered(), and wheelEvent().

void QgsMapCanvas::zoomScale ( double  scale)

Zoom to a specific scale.

Definition at line 1116 of file qgsmapcanvas.cpp.

References scale(), and zoomByFactor().

Zoom to the full extent of all layers.

Definition at line 571 of file qgsmapcanvas.cpp.

References extent(), fullExtent(), QgsRectangle::isEmpty(), mDrawing, refresh(), QgsRectangle::scale(), and setExtent().

void QgsMapCanvas::zoomToSelected ( QgsVectorLayer layer = NULL)

Zoom to the extent of the selected features of current (vector) layer.

Added in version 1.2: optionally specify different than current layer

Definition at line 674 of file qgsmapcanvas.cpp.

References QgsVectorLayer::boundingBoxOfSelected(), QgsRectangle::center(), QgsRectangle::expand(), extent(), QgsRectangle::isEmpty(), QgsMapRenderer::layerExtentToOutputExtent(), mCurrentLayer, mDrawing, mMapRenderer, refresh(), QgsRectangle::scale(), QgsVectorLayer::selectedFeatureCount(), and setExtent().

void QgsMapCanvas::zoomWithCenter ( int  x,
int  y,
bool  zoomIn 
)

Member Data Documentation

indicates whether antialiasing will be used for rendering

Definition at line 492 of file qgsmapcanvas.h.

Referenced by enableAntiAliasing().

Handle pattern for implementation object.

Definition at line 406 of file qgsmapcanvas.h.

Referenced by keyPressEvent(), keyReleaseEvent(), mouseLastXY(), mouseMoveEvent(), mousePressEvent(), mouseReleaseEvent(), moveCanvasContents(), and panActionEnd().

current layer in legend

Definition at line 464 of file qgsmapcanvas.h.

Referenced by currentLayer(), mouseReleaseEvent(), panToSelected(), QgsMapCanvas(), setCurrentLayer(), and zoomToSelected().

bool QgsMapCanvas::mDirty [private]

Flag to track the state of the Map canvas.

The canvas is flagged as dirty by any operation that changes the state of the layers or the view extent. If the canvas is not dirty, paint events are handled by bit-blitting the stored canvas bitmap to the canvas. This improves performance by not reading the data source when no real change has occurred

Definition at line 448 of file qgsmapcanvas.h.

Referenced by isDirty(), QgsMapCanvas(), refresh(), and setDirty().

bool QgsMapCanvas::mDrawing [private]
bool QgsMapCanvas::mFrozen [private]

Flag indicating if the map canvas is frozen.

Definition at line 437 of file qgsmapcanvas.h.

Referenced by freeze(), isFrozen(), QgsMapCanvas(), and refresh().

recently used extent

Definition at line 476 of file qgsmapcanvas.h.

Referenced by clearExtentHistory(), setExtent(), zoomToNextExtent(), and zoomToPreviousExtent().

previous tool if current is for zooming/panning

Definition at line 473 of file qgsmapcanvas.h.

Referenced by mouseReleaseEvent(), QgsMapCanvas(), setMapTool(), unsetMapTool(), and ~QgsMapCanvas().

owns pixmap with rendered map and controls rendering

Definition at line 428 of file qgsmapcanvas.h.

Referenced by canvasPaintDevice(), canvasPixmap(), enableAntiAliasing(), map(), moveCanvasContents(), paintEvent(), QgsMapCanvas(), refresh(), saveAsImage(), setCanvasColor(), updateMap(), and useImageToRender().

QSize QgsMapCanvas::mNewSize [private]

resize canvas size

Definition at line 486 of file qgsmapcanvas.h.

Referenced by paintEvent(), and resizeEvent().

bool QgsMapCanvas::mPainting [private]

currently in paint event

Definition at line 489 of file qgsmapcanvas.h.

Referenced by paintEvent().

bool QgsMapCanvas::mRenderFlag [private]

determines whether user has requested to suppress rendering

Definition at line 451 of file qgsmapcanvas.h.

Referenced by QgsMapCanvas(), refresh(), and setRenderFlag().

QList< QPair<int, int> > QgsMapCanvas::mResizeQueue [private]

Resize events that have been ignored because the canvas is busy with rendering may put their sizes into this list.

The canvas then picks up the last entry in case a lot of resize events arrive in short time

Definition at line 456 of file qgsmapcanvas.h.

QGraphicsScene* QgsMapCanvas::mScene [private]

graphics scene manages canvas items

Definition at line 467 of file qgsmapcanvas.h.

Referenced by canvasColor(), moveCanvasContents(), paintEvent(), QgsMapCanvas(), setCanvasColor(), updateCanvasItemPositions(), and ~QgsMapCanvas().

Mouse wheel action.

Definition at line 483 of file qgsmapcanvas.h.

Referenced by setWheelAction(), and wheelEvent().

Scale factor multiple for default zoom in/out.

Definition at line 480 of file qgsmapcanvas.h.

Referenced by setWheelAction(), wheelEvent(), zoomIn(), zoomOut(), and zoomWithCenter().


The documentation for this class was generated from the following files:
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