draw.model

Class Element

java.lang.Object

draw.model.Element

Direct Known Subclasses:

Group, OvalElt, RectangleElt

public abstract class Element
extends java.lang.Object

Element that can appear in drawing.

Field Summary

Fields

Modifier and Type	Field and Description
static int	anchorSize Default anchor size in pixels.
static java.awt.Rectangle	EmptyRectangle Empty rectangle.

Method Summary

Modifier and Type	Method and Description
void	accept(Visitor visitor) Accept a visitor and dispatch.
abstract Element	clone() Make an exact copy, delegated to subclasses.
abstract boolean	contains(java.awt.Point p) Does this element contain the given point.
void	draw(java.awt.Graphics g) Draw self into the given graphics context using the drawElement method.
abstract void	drawElement(java.awt.Graphics g) Draw self into the given graphics context.
java.awt.Rectangle[]	getAnchors() Access anchors for element.
java.awt.Rectangle	getBoundingBox() Returns bounding box of the given element.
Element	getParent() Return parent of Element.
Style	getStyle() Retrieve style for this element
boolean	hasParent() Check if element is part of a group.
boolean	isSelected() Query selected status of element.
Element	outermostGroup() When elements are contained in a Group, this can be used to find the outermost group.
Element	removeParent() Clear parent reference.
void	resetAnchors() Reset anchors; useful as a catch-all mechanism to force recalculation when changes occur.
void	setBoundingBox(java.awt.Rectangle r) Update the bounding box.
Element	setParent(Group parent) Set the enclosing element (a group) for this element.
Element	setSelected(boolean flag) Set whether element is selected.
Element	setStyle(Style style) Update style for this element.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

EmptyRectangle

public static final java.awt.Rectangle EmptyRectangle

Empty rectangle.

anchorSize

public static final int anchorSize

Default anchor size in pixels.

See Also:

Constant Field Values

Method Detail

setParent

public Element setParent(Group parent)

Set the enclosing element (a group) for this element. Return self for programming convenience

Parameters:

parent - place this into a group identified by this element

Returns:

self

removeParent

public Element removeParent()

Clear parent reference. Returns self for programming convenience

Returns:

self

hasParent

public boolean hasParent()

Check if element is part of a group.

Returns:

whether element is part of a group.

getParent

public Element getParent()
                  throws java.util.NoSuchElementException

Return parent of Element. If caller doesn't first validate by calling hasParent(), will get NoSuchElementException Exception.

Returns:

parent should it exist

Throws:

java.util.NoSuchElementException - If did not validate that a parent exists, this exception will be thrown.

outermostGroup

public Element outermostGroup()

When elements are contained in a Group, this can be used to find the outermost group.

Returns:

outermost group

getAnchors

public java.awt.Rectangle[] getAnchors()

Access anchors for element. note: A potential risk since these rectangles could be modified by caller. Please avoid doing so!

Returns:

anchors for this element. Anchors are returned in order SouthWest, SouthEast, NorthWest, NorthEast

resetAnchors

public void resetAnchors()

Reset anchors; useful as a catch-all mechanism to force recalculation when changes occur.

getBoundingBox

public java.awt.Rectangle getBoundingBox()

Returns bounding box of the given element. The upper left corner of this bounding box rectangle is the 'anchor' for the element, and all drawing is relative to it. A copy of the current bounding box is returned for protection, so it isn't inadvertently modified by code external to this class.

Returns:

bounding box for element.

setBoundingBox

public void setBoundingBox(java.awt.Rectangle r)

Update the bounding box. Resets anchors to force re-computation when needed.

Parameters:

r - new bounding rectangle for the element.

isSelected

public boolean isSelected()

Query selected status of element.

Returns:

whether element is selected.

setSelected

public Element setSelected(boolean flag)

Set whether element is selected.

Parameters:

flag - determines whether element should be selected.

Returns:

this element, for programmer convenience

accept

public void accept(Visitor visitor)

Accept a visitor and dispatch.

Parameters:

visitor - Visitor that performs necessary operations.

getStyle

public Style getStyle()

Retrieve style for this element

Returns:

Style associated with element

Since:

draw.3

setStyle

public Element setStyle(Style style)

Update style for this element. Return self for programming convenience

Parameters:

style - new style to associate with element

Returns:

self

Since:

draw.3

clone

public abstract Element clone()

Make an exact copy, delegated to subclasses.

Overrides:

clone in class java.lang.Object

Returns:

copy of the current element.

drawElement

public abstract void drawElement(java.awt.Graphics g)

Draw self into the given graphics context.

Parameters:

g - Graphics object into which to draw

draw

public void draw(java.awt.Graphics g)

Draw self into the given graphics context using the drawElement method. This will store the relevant graphics properties to free up the individual draw elements from saving them.

Parameters:

g - Graphics object into which to draw

contains

public abstract boolean contains(java.awt.Point p)

Does this element contain the given point.

Parameters:

p - point to query

Returns:

true if element contains the point