Packageflash.geom
Classpublic class Rectangle
InheritanceRectangle Inheritance Object

A Rectangle object is an area defined by its position, as indicated by its top-left corner point (x, y), and by its width and its height.

The x, y, width, and height properties of the Rectangle class are independent of each other; changing the value of one property has no effect on the others. However, the right and bottom properties are integrally related to those four properties. For example, if you change the value of the right property, the value of the width property changes; if you change the bottom property, the value of the height property changes.

Rectangle objects are used in the following:

You can use the new Rectangle() constructor to create a Rectangle object.

Note: The Rectangle class does not define a rectangular Shape display object. To draw a rectangle Shape onscreen, use the drawRect() method of the flash.display.Graphics class.

View the examples.

See also
flash.display.DisplayObject.scrollRect, flash.display.BitmapData, flash.display.DisplayObject, flash.text.TextField.getCharBoundaries(), flash.geom.Transform.pixelBounds, flash.display.Sprite.startDrag(), flash.printing.PrintJob.addPage()

Public Properties
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 PropertyDefined by
  bottom : Number
The sum of the y and height properties.
Rectangle
  bottomRight : Point
The location of the Rectangle object's bottom-right corner, determined by the values of the right and bottom properties.
Rectangle
 Inheritedconstructor : Object
A reference to the class object or constructor function for a given object instance.
Object
  height : Number
The height of the rectangle, in pixels.
Rectangle
  left : Number
The x coordinate of the top-left corner of the rectangle.
Rectangle
 Inheritedprototype : Object
[static] A reference to the prototype object of a class or function object.
Object
  right : Number
The sum of the x and width properties.
Rectangle
  size : Point
The size of the Rectangle object, expressed as a Point object with the values of the width and height properties.
Rectangle
  top : Number
The y coordinate of the top-left corner of the rectangle.
Rectangle
  topLeft : Point
The location of the Rectangle object's top-left corner, determined by the x and y coordinates of the point.
Rectangle
  width : Number
The width of the rectangle in pixels.
Rectangle
  x : Number
The x coordinate of the top-left corner of the rectangle.
Rectangle
  y : Number
The y coordinate of the top-left corner of the rectangle.
Rectangle
Public Methods
Hide Inherited Public Methods
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 FunctionDefined by
  
Rectangle(x:Number = 0, y:Number = 0, width:Number = 0, height:Number = 0)
Creates a new Rectangle object with the top-left corner specified by the x and y parameters and with the specified width and height.
Rectangle
  
clone():Rectangle
Returns a new Rectangle object with the same values for the x, y, width, and height properties as the original Rectangle object.
Rectangle
  
contains(x:Number, y:Number):Boolean
Determines whether the specified point is contained within the rectangular region defined by this Rectangle object.
Rectangle
  
containsPoint(point:Point):Boolean
Determines whether the specified point is contained within the rectangular region defined by this Rectangle object.
Rectangle
  
containsRect(rect:Rectangle):Boolean
Determines whether the Rectangle object specified by the rect parameter is contained within this Rectangle object.
Rectangle
  
equals(toCompare:Rectangle):Boolean
Determines whether the object specified in the toCompare parameter is equal to this Rectangle object.
Rectangle
 Inherited
hasOwnProperty(name:String):Boolean
Indicates whether an object has a specified property defined.
Object
  
inflate(dx:Number, dy:Number):void
Increases the size of the Rectangle object by the specified amounts, in pixels.
Rectangle
  
inflatePoint(point:Point):void
Increases the size of the Rectangle object.
Rectangle
  
intersection(toIntersect:Rectangle):Rectangle
If the Rectangle object specified in the toIntersect parameter intersects with this Rectangle object, the intersection() method returns the area of intersection as a Rectangle object.
Rectangle
  
intersects(toIntersect:Rectangle):Boolean
Determines whether the object specified in the toIntersect parameter intersects with this Rectangle object.
Rectangle
  
isEmpty():Boolean
Determines whether or not this Rectangle object is empty.
Rectangle
 Inherited
isPrototypeOf(theClass:Object):Boolean
Indicates whether an instance of the Object class is in the prototype chain of the object specified as the parameter.
Object
  
offset(dx:Number, dy:Number):void
Adjusts the location of the Rectangle object, as determined by its top-left corner, by the specified amounts.
Rectangle
  
offsetPoint(point:Point):void
Adjusts the location of the Rectangle object using a Point object as a parameter.
Rectangle
 Inherited
propertyIsEnumerable(name:String):Boolean
Indicates whether the specified property exists and is enumerable.
Object
  
setEmpty():void
Sets all of the Rectangle object's properties to 0.
Rectangle
 Inherited
setPropertyIsEnumerable(name:String, isEnum:Boolean = true):void
Sets the availability of a dynamic property for loop operations.
Object
  
toString():String
Builds and returns a string that lists the horizontal and vertical positions and the width and height of the Rectangle object.
Rectangle
  
union(toUnion:Rectangle):Rectangle
Adds two rectangles together to create a new Rectangle object, by filling in the horizontal and vertical space between the two rectangles.
Rectangle
 Inherited
valueOf():Object
Returns the primitive value of the specified object.
Object
Property detail
bottom property
bottom:Number  [read-write]

The sum of the y and height properties.



Implementation
    public function get bottom():Number
    public function set bottom(value:Number):void

See also
y, height
bottomRight property
bottomRight:Point  [read-write]

The location of the Rectangle object's bottom-right corner, determined by the values of the right and bottom properties.



Implementation
    public function get bottomRight():Point
    public function set bottomRight(value:Point):void

See also
flash.geom.Point
height property
public var height:Number

The height of the rectangle, in pixels. Changing the height value of a Rectangle object has no effect on the x, y, and width properties.

See also
x, y, height
left property
left:Number  [read-write]

The x coordinate of the top-left corner of the rectangle. Changing the left property of a Rectangle object has no effect on the y and height properties. However it does affect the width property; whereas changing the x value does not affect the width property.

The value of the left property is equal to the value of the x property.



Implementation
    public function get left():Number
    public function set left(value:Number):void

See also
x, y, width, height
right property
right:Number  [read-write]

The sum of the x and width properties.



Implementation
    public function get right():Number
    public function set right(value:Number):void

See also
x, width
size property
size:Point  [read-write]

The size of the Rectangle object, expressed as a Point object with the values of the width and height properties.

Implementation
    public function get size():Point
    public function set size(value:Point):void

See also
flash.geom.Point
top property
top:Number  [read-write]

The y coordinate of the top-left corner of the rectangle. Changing the top property of a Rectangle object has no effect on the x and width properties. However it does affect the height property; whereas changing the y value does not affect the height property.

The value of the top property is equal to the value of the y property.



Implementation
    public function get top():Number
    public function set top(value:Number):void

See also
x, y, width, height
topLeft property
topLeft:Point  [read-write]

The location of the Rectangle object's top-left corner, determined by the x and y coordinates of the point.



Implementation
    public function get topLeft():Point
    public function set topLeft(value:Point):void

See also
flash.geom.Point, x, y
width property
public var width:Number

The width of the rectangle in pixels. Changing the width value of a Rectangle object has no effect on the x, y, or height properties.

See also
x, y, height
x property
public var x:Number

The x coordinate of the top-left corner of the rectangle. Changing the value of the x property of a Rectangle object has no effect on the y, width, and height properties.

The value of the x property is equal to the value of the left property.

See also
left
y property
public var y:Number

The y coordinate of the top-left corner of the rectangle. Changing the value of the y property of a Rectangle object has no effect on the x, width, and height properties.

The value of the y property is equal to the value of the top property.

See also
x, width, height, top
Constructor detail
Rectangle constructor

public function Rectangle(x:Number = 0, y:Number = 0, width:Number = 0, height:Number = 0)

Creates a new Rectangle object with the top-left corner specified by the x and y parameters and with the specified width and height. If you call this constructor function without parameters, a rectangle with x, y, width, and height properties set to 0 is created.

Parameters
x:Number (default = 0) — The x coordinate of the top-left corner of the rectangle.
y:Number (default = 0) — The y coordinate of the top-left corner of the rectangle.
width:Number (default = 0) — The width of the rectangle, in pixels.
height:Number (default = 0) — The height of the rectangle, in pixels.

See also
x, y, width, height
Method detail
clone method

public function clone():Rectangle

Returns a new Rectangle object with the same values for the x, y, width, and height properties as the original Rectangle object.

Returns
Rectangle — A new Rectangle object with the same values for the x, y, width, and height properties as the original Rectangle object.

See also
x, y, width, height
contains method

public function contains(x:Number, y:Number):Boolean

Determines whether the specified point is contained within the rectangular region defined by this Rectangle object.

Parameters
x:Number — The x coordinate (horizontal position) of the point.
y:Number — The y coordinate (vertical position) of the point.

Returns
Boolean — A value of true if the Rectangle object contains the specified point; otherwise false.

See also
flash.geom.Point
containsPoint method

public function containsPoint(point:Point):Boolean

Determines whether the specified point is contained within the rectangular region defined by this Rectangle object. This method is similar to the Rectangle.contains() method, except that it takes a Point object as a parameter.

Parameters
point:Point — The point, as represented by its x and y coordinates.

Returns
Boolean — A value of true if the Rectangle object contains the specified point; otherwise false.

See also
contains(), flash.geom.Point
containsRect method

public function containsRect(rect:Rectangle):Boolean

Determines whether the Rectangle object specified by the rect parameter is contained within this Rectangle object. A Rectangle object is said to contain another if the second Rectangle object falls entirely within the boundaries of the first.

Parameters
rect:Rectangle — The Rectangle object being checked.

Returns
Boolean — A value of true if the Rectangle object that you specify is contained by this Rectangle object; otherwise false.
equals method

public function equals(toCompare:Rectangle):Boolean

Determines whether the object specified in the toCompare parameter is equal to this Rectangle object. This method compares the x, y, width, and height properties of an object against the same properties of this Rectangle object.

Parameters
toCompare:Rectangle — The rectangle to compare to this Rectangle object.

Returns
Boolean — A value of true if the object has exactly the same values for the x, y, width, and height properties as this Rectangle object; otherwise false.

See also
x, y, width, height
inflate method

public function inflate(dx:Number, dy:Number):void

Increases the size of the Rectangle object by the specified amounts, in pixels. The center point of the Rectangle object stays the same, and its size increases to the left and right by the dx value, and to the top and the bottom by the dy value.

Parameters
dx:Number — The value to be added to the left and the right of the Rectangle object. The following equation is used to calculate the new width and position of the rectangle: 
 x -= dx;
 width += 2 * dx;
dy:Number — The value to be added to the top and the bottom of the Rectangle. The following equation is used to calculate the new height and position of the rectangle: 
 y -= dy;
 height += 2 * dy;

See also
x, y
inflatePoint method

public function inflatePoint(point:Point):void

Increases the size of the Rectangle object. This method is similar to the Rectangle.inflate() method except it takes a Point object as a parameter.

The following two code examples give the same result:

  rect1=new flash.geom.Rectangle(0,0,2,5);
  rect1.inflate(2,2)
  
  rect1=new flash.geom.Rectangle(0,0,2,5);
  pt1=new flash.geom.Point(2,2);
  rect1.inflatePoint(pt1)

Parameters
point:Point — The x property of this Point object is used to increase the horizontal dimension of the Rectangle object. The y property of this Point object is used to increase the vertical dimension of the Rectangle object.

See also
flash.geom.Point
intersection method

public function intersection(toIntersect:Rectangle):Rectangle

If the Rectangle object specified in the toIntersect parameter intersects with this Rectangle object, the intersection() method returns the area of intersection as a Rectangle object. If the rectangles do not intersect, this method returns an empty Rectangle object with its properties set to 0.

Parameters
toIntersect:Rectangle — The Rectangle object to compare against to see if it intersects with this Rectangle object.

Returns
Rectangle — A Rectangle object that equals the area of intersection. If the rectangles do not intersect, this method returns an empty Rectangle object; that is, a rectangle with its x, y, width, and height properties set to 0.
intersects method

public function intersects(toIntersect:Rectangle):Boolean

Determines whether the object specified in the toIntersect parameter intersects with this Rectangle object. This method checks the x, y, width, and height properties of the specified Rectangle object to see if it intersects with this Rectangle object.

Parameters
toIntersect:Rectangle — The Rectangle object to compare against this Rectangle object.

Returns
Boolean — A value of true if the specified object intersects with this Rectangle object; otherwise false.

See also
x, y, width, height
isEmpty method

public function isEmpty():Boolean

Determines whether or not this Rectangle object is empty.

Returns
Boolean — A value of true if the Rectangle object's width or height is less than or equal to 0; otherwise false.
offset method

public function offset(dx:Number, dy:Number):void

Adjusts the location of the Rectangle object, as determined by its top-left corner, by the specified amounts.

Parameters
dx:Number — Moves the x value of the Rectangle object by this amount.
dy:Number — Moves the y value of the Rectangle object by this amount.
offsetPoint method

public function offsetPoint(point:Point):void

Adjusts the location of the Rectangle object using a Point object as a parameter. This method is similar to the Rectangle.offset() method, except that it takes a Point object as a parameter.

Parameters
point:Point — A Point object to use to offset this Rectangle object.

See also
flash.geom.Point
setEmpty method

public function setEmpty():void

Sets all of the Rectangle object's properties to 0. A Rectangle object is empty if its width or height is less than or equal to 0.

This method sets the values of the x, y, width, and height properties to 0.

See also
x, y, width, height
toString method

public function toString():String

Builds and returns a string that lists the horizontal and vertical positions and the width and height of the Rectangle object.

Returns
String — A string listing the value of each of the following properties of the Rectangle object: x, y, width, and height.

See also
x, y, width, height
union method

public function union(toUnion:Rectangle):Rectangle

Adds two rectangles together to create a new Rectangle object, by filling in the horizontal and vertical space between the two rectangles.

Parameters
toUnion:Rectangle — A Rectangle object to add to this Rectangle object.

Returns
Rectangle — A new Rectangle object that is the union of the two rectangles.
Class examples

The following example uses the class RectangleExample to create three new Rectangle objects at various x,y coordinates and with various heights and widths and then uses the trace() method to confirm that the Rectangle instances were successfully created. Then a Boolean variable isContained is assigned to the result of the call to the containsRect() method, which determines that the second rectangle does not fully enclose the third rectangle. 
package {
    import flash.display.Sprite;
    import flash.geom.Rectangle;

    public class RectangleExample extends Sprite {

        public function RectangleExample() {
            var firstRect:Rectangle = new Rectangle();
            trace(firstRect);  // (x=0, y=0, w=0, h=0)
            var secondRect:Rectangle = new Rectangle(1, 3, 11, 13);
            trace(secondRect); // (x=1, y=3, w=11, h=13)
            var thirdRect:Rectangle = new Rectangle(5, 8, 17, 19);
            trace(thirdRect);  // (x=5, y=8, w=17, h=19)
            var isContained:Boolean = secondRect.containsRect(thirdRect);
            trace(isContained); // false
        }
    }
}



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Fri Apr 21 2006, 12:34 PDT

 

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