QGIS/python/core/qgscomposeritem.sip

/** \ingroup MapComposer
 * A item that forms part of a map composition.
 */
class QgsComposerItem: QGraphicsRectItem
{
%TypeHeaderCode
#include <qgscomposeritem.h>
%End

  public:

    /**Describes the action (move or resize in different directon) to be done during mouse move*/
    enum MouseMoveAction
    {
      MoveItem,
      ResizeUp,
      ResizeDown,
      ResizeLeft,
      ResizeRight,
      ResizeLeftUp,
      ResizeRightUp,
      ResizeLeftDown,
      ResizeRightDown
    };

    enum ItemPositionMode
    {
      UpperLeft,
      UpperMiddle,
      UpperRight,
      MiddleLeft,
      Middle,
      MiddleRight,
      LowerLeft,
      LowerMiddle,
      LowerRight
    };

    /**Constructor
     @param manageZValue true if the z-Value of this object should be managed by mComposition*/
    QgsComposerItem( QgsComposition* composition, bool manageZValue = true );
    /**Constructor with box position and composer object
     @param manageZValue true if the z-Value of this object should be managed by mComposition*/
    QgsComposerItem( qreal x, qreal y, qreal width, qreal height, QgsComposition* composition, bool manageZValue = true );
    virtual ~QgsComposerItem();

    /** \brief Set selected, selected item should be highlighted */
    virtual void setSelected( bool s );

    /** \brief Is selected */
    virtual bool selected();

    /** stores state in project */
    virtual bool writeSettings();

    /** read state from project */
    virtual bool readSettings();

    /** delete settings from project file  */
    virtual bool removeSettings();

    /**Moves item in canvas coordinates*/
    void move( double dx, double dy );

    /**Move Content of item. Does nothing per default (but implemented in composer map)
       @param dx move in x-direction (canvas coordinates)
       @param dy move in y-direction(canvas coordinates)*/
    virtual void moveContent( double dx, double dy );

    /**Zoom content of item. Does nothing per default (but implemented in composer map)
     @param delta value from wheel event that describes magnitude and direction (positive /negative number)
    @param x x-position of mouse cursor (in item coordinates)
    @param y y-position of mouse cursor (in item coordinates)*/
    virtual void zoomContent( int delta, double x, double y );

    /**Moves the item to a new position (in canvas coordinates)*/
    void setItemPosition( double x, double y, ItemPositionMode itemPoint = UpperLeft );

    /**Sets this items bound in scene coordinates such that 1 item size units
     corresponds to 1 scene size unit*/
    virtual void setSceneRect( const QRectF& rectangle );

    /** stores state in Dom node
     * @param node is Dom node corresponding to 'Composer' tag
     * @param temp write template file
     */
    virtual bool writeXML( QDomElement& elem, QDomDocument & doc ) const = 0;

    /**Writes parameter that are not subclass specific in document. Usually called from writeXML methods of subclasses*/
    bool _writeXML( QDomElement& itemElem, QDomDocument& doc ) const;

    /** sets state from Dom document
     * @param itemElem is Dom node corresponding to item tag
     */
    virtual bool readXML( const QDomElement& itemElem, const QDomDocument& doc ) = 0;

    /**Reads parameter that are not subclass specific in document. Usually called from readXML methods of subclasses*/
    bool _readXML( const QDomElement& itemElem, const QDomDocument& doc );



    bool frame() const;
    void setFrame( bool drawFrame );

    /**Composite operations for item groups do nothing per default*/
    virtual void addItem( QgsComposerItem* item );
    virtual void removeItems();

    const QgsComposition* composition() const;

    //functions that encapsulate the workaround for the Qt font bug (that is to scale the font size up and then scale the
    //painter down by the same factor for drawing

    /**Draws Text. Takes care about all the composer specific issues (calculation to pixel, scaling of font and painter
     to work arount the Qt font bug)*/
    void drawText( QPainter* p, int x, int y, const QString& text, const QFont& font ) const;

    /**Like the above, but with a rectangle for multiline text*/
    void drawText( QPainter* p, const QRectF& rect, const QString& text, const QFont& font ) const;

    /**Returns the font width in Millimeters (considers upscaling and downscaling with FONT_WORKAROUND_SCALE*/
    double textWidthMillimeters( const QFont& font, const QString& text ) const;

    /**Returns the font ascent in Millimeters (considers upscaling and downscaling with FONT_WORKAROUND_SCALE*/
    double fontAscentMillimeters( const QFont& font ) const;

    /**Calculates font to from point size to pixel size*/
    double pixelFontSize( double pointSize ) const;

    /**Returns a font where size is in pixel and font size is upscaled with FONT_WORKAROUND_SCALE*/
    QFont scaledFontPixelSize( const QFont& font ) const;

  protected:

    //event handlers
    virtual void mouseMoveEvent( QGraphicsSceneMouseEvent * event );
    virtual void mousePressEvent( QGraphicsSceneMouseEvent * event );
    virtual void mouseReleaseEvent( QGraphicsSceneMouseEvent * event );

    virtual void hoverMoveEvent( QGraphicsSceneHoverEvent * event );

    /**Finds out the appropriate cursor for the current mouse position in the widget (e.g. move in the middle, resize at border)*/
    Qt::CursorShape cursorForPosition( const QPointF& itemCoordPos );

    /**Finds out which mouse move action to choose depending on the cursor position inside the widget*/
    QgsComposerItem::MouseMoveAction mouseMoveActionForPosition( const QPointF& itemCoordPos );

    /**Changes the rectangle of an item depending on current mouse action (resize or move)
     @param currentPosition current position of mouse cursor
     @param mouseMoveStartPos cursor position at the start of the current mouse action
     @param originalItem Item position at the start of the mouse action
     @param dx x-Change of mouse cursor
     @param dy y-Change of mouse cursor
     @param changeItem Item to change size (can be the same as originalItem or a differen one)
    */
    void changeItemRectangle( const QPointF& currentPosition, const QPointF& mouseMoveStartPos, const QGraphicsRectItem* originalItem, double dx, double dy, QGraphicsRectItem* changeItem );

    /**Draw selection boxes around item*/
    virtual void drawSelectionBoxes( QPainter* p );

    /**Draw black frame around item*/
    virtual void drawFrame( QPainter* p );

    /**Draw background*/
    virtual void drawBackground( QPainter* p );
};