[Chapter 2] 2.3 Dimension

#

| Chapter 2 Simple Graphics |

## 2.3 Dimension

The `Dimension` class is similar to the `Point` class, except it encapsulates a width and height in a single object. Like `Point`, `Dimension` is somewhat underused; it is used primarily by methods that need to return a width and a height as a single object; for example, `getSize()` returns a `Dimension` object.

### Dimension Methods

Variables

A `Dimension` instance has two variables, one for width and one for height. They are accessible directly or through use of the `getSize()` method.

public int width

  The width variable represents the size of an object along the x axis (left to right). Width should not be negative; however, there is nothing within the class to prevent this from happening.

public int height

  The height variable represents the size of an object along the y axis (top to bottom). Height should not be negative; however, there is nothing within the class to prevent this from happening.

Constructors

public Dimension ()

  This constructor creates a `Dimension` instance with a width and height of 0.

public Dimension (Dimension dim)

  This constructor creates a copy of `dim`. The initial width is `dim.width`. The initial height is `dim.height`.

public Dimension (int width, int height)

  This constructor creates a `Dimension` with an initial width of `width` and an initial height of `height`.

Sizing

public Dimension getSize ()

  The `getSize()` method retrieves the current size as a new `Dimension`, even though the instance variables are public.

public void setSize (int width, int height)

  The `setSize()` method changes the dimension's size to `width` x `height`.

public void setSize (Dimension d)

  The `setSize()` method changes the dimension's size to `d.width` x `d.height`.

Miscellaneous methods

public boolean equals (Object object)

  The `equals()` method overrides the `Object.equals()` method to define equality for dimensions. Two `Dimension` objects are equal if their width and height values are equal.

public String toString ()

  The `toString()` method of `Dimension` returns a string showing the current width and height settings. For example:

      java.awt.Dimension[width=0,height=0]

Point |  | Shape