ShapeItem Class Reference

#include <ShapeItem.hpp>

Inheritance diagram for ShapeItem:

Public Member Functions
virtual void	paint ()
Public Member Functions inherited from Item
	Item (const Item &)=delete
virtual	~Item ()
void	addChild (Item *child)
const vector< Item * > &	children () const
virtual void	clearItemListProperty (const PropertyDef *property)
void	destroyChild (Item *child)
virtual bool	getBoolProperty (const PropertyDef *property) const
virtual vector< double >	getDoubleListProperty (const PropertyDef *property) const
virtual double	getDoubleProperty (const PropertyDef *property) const
virtual string	getEnumProperty (const PropertyDef *property) const
virtual int	getIntProperty (const PropertyDef *property) const
virtual vector< Item * >	getItemListProperty (const PropertyDef *property) const
virtual Item *	getItemProperty (const PropertyDef *property) const
virtual string	getStringProperty (const PropertyDef *property) const
int	getUtilityProperty (string name) const
virtual void	insertIntoItemListProperty (const PropertyDef *property, int index, Item *item)
Item &	operator= (const Item &)=delete
Item *	parent () const
virtual void	removeFromItemListProperty (const PropertyDef *property, int index)
virtual void	setBoolProperty (const PropertyDef *property, bool value)
virtual void	setDoubleListProperty (const PropertyDef *property, vector< double > value)
virtual void	setDoubleProperty (const PropertyDef *property, double value)
virtual void	setEnumProperty (const PropertyDef *property, string value)
virtual void	setIntProperty (const PropertyDef *property, int value)
virtual void	setItemProperty (const PropertyDef *property, Item *item)
virtual void	setStringProperty (const PropertyDef *property, string value)
void	setUtilityProperty (string name, int value)
virtual string	type () const

Protected Member Functions
	ShapeItem ()
virtual void	drawLine (double x1, double y1, double x2, double y2)
virtual void	paintSelf ()
virtual void	popState ()
virtual void	pushState ()
virtual void	setColor (double r, double g, double b)
virtual void	setWidth (double w)
Protected Member Functions inherited from Item
	Item ()

Private Types
using	BaseType = Item
using	ItemType = ShapeItem

Friends
class	ItemRegistry

Detailed Description

The ShapeItem class is the abstract base class for all items in the 'shapes' program. It inherits from the Item class to offer discovery and resurrection capabilities. In addition, it offers facilities to handle drawing of shapes in coordination with its subclasses. The root of a run-time shape hierarchy must be an instance of the ShapeCanvas class, which inherits ShapeItem.

Constructor & Destructor Documentation

ShapeItem()

ShapeItem::ShapeItem ( )

inlineprotected

Default constructor for abstract Item subclass ShapeItem : "an abstract shape item" .

Member Function Documentation

drawLine()

virtual void ShapeItem::drawLine ( double  x1, double  y1, double  x2, double  y2  )

protectedvirtual

This function can be invoked from a subclass to draw a line on the canvas held by the root of the run-time shape hierarchy. The line is drawn using the current graphics state color and width from the point (x1,y1) to the point (x2,y2). The coordinates are specified in in a frame where the lower left corner of the canvas is at (0 m, 0 m) and the upper right corner of the canvas is at (1 m, 1 m). Segments of the line lying outside of the canvas are clipped away. The implementation in this base class forwards the message to its parent in the run-time hierarchy until the root shape has been reached.

Reimplemented in ShapeCanvas.

paint()

virtual void ShapeItem::paint ( )

virtual

This function causes the receiving shape and its children to be painted on the canvas held by the root of the run-time shape hierarchy. Specifically, the function calls the pushState() function to save the graphics state, calls its own paintSelf() function, forwards the paint() message to all its children (recursively) and finally calls the popState() function to restore the graphics state.

paintSelf()

virtual void ShapeItem::paintSelf ( )

protectedvirtual

This function must be implemented by Shape subclasses to paint the appropriate marks for the shape on the canvas held by the root of the run-time shape hierarchy. This can be accomplished by calling one or more of the drawing functions offered by this class. The implementation in this base class does nothing, which may be appropriate for subclasses such as transparent groups.

Reimplemented in ColorDecorator, PolygonShape, RectangleShape, and WidthDecorator.

popState()

virtual void ShapeItem::popState ( )

protectedvirtual

This function is invoked by the paint() function to restore the graphics state of the canvas held by the root of the run-time shape hierarchy to the most recently saved state. The implementation in this base class forwards the message to its parent in the run-time hierarchy until the root shape has been reached.

Reimplemented in ShapeCanvas.

pushState()

virtual void ShapeItem::pushState ( )

protectedvirtual

This function is invoked by the paint() function to save the graphics state of the canvas held by the root of the run-time shape hierarchy. The implementation in this base class forwards the message to its parent in the run-time hierarchy until the root shape has been reached.

Reimplemented in ShapeCanvas.

setColor()

virtual void ShapeItem::setColor ( double  r, double  g, double  b  )

protectedvirtual

This function can be invoked from a subclass to set the color in the graphics state. The color is specified as three RGB components ranging from 0 (no intensity) to 1 (maximum intensity). If a component value is out of range, the result is undefined. The implementation in this base class forwards the message to its parent in the run-time hierarchy until the root shape has been reached.

Reimplemented in ShapeCanvas.

setWidth()

virtual void ShapeItem::setWidth ( double  w )

protectedvirtual

This function can be invoked from a subclass to set the line width in the graphics state. The line width is specified in units where the canvas size equals 1, and should be greater than 0 and smaller than 1. If the value is out of range, the result is undefined. The implementation in this base class forwards the message to its parent in the run-time hierarchy until the root shape has been reached.

Reimplemented in ShapeCanvas.

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

• ShapeItem.hpp