acm.graphics

Interface Summary
Interface	Description
GContainer	Defines the functionality of an object that can serve as the parent of a `GObject`.
GFillable	Specifies the characteristics of a graphical object that supports filling.
GResizable	Specifies the characteristics of a graphical object that supports the `setSize` and `setBounds` methods.
GScalable	Specifies the characteristics of a graphical object that supports the `scale` method.

Class Summary
Class	Description
G3DRect	The `G3DRect` class is used to represent a rectangle whose borders are drawn to create a three-dimensional effect.
GArc	The `GArc` class is a graphical object whose appearance consists of an arc.
GCanvas	The `GCanvas` class is a lightweight component that also serves as a container for graphical objects.
GCompound	This class defines a graphical object that consists of a collection of other graphical objects.
GDimension	This class is a double-precision version of the `Dimension` class in `java.awt`.
GImage	The `GImage` class is a graphical object whose appearance is defined by an image.
GLabel	The `GLabel` class is a graphical object whose appearance consists of a text string.
GLine	The `GLine` class is a graphical object whose appearance consists of a line segment.
GMath	This class defines a variety of static mathematical methods that are useful for the `acm.graphics` package.
GObject	This class is the common superclass of all graphical objects that can be displayed on a `GCanvas`.
GOval	The `GOval` class is a graphical object whose appearance consists of an oval.
GPen	The `GPen` class simulates a pen drawing on a canvas.
GPoint	This class is a double-precision version of the `Point` class in `java.awt`.
GPolygon	The `GPolygon` class is a graphical object whose appearance consists of a polygon.
GRect	The `GRect` class is a graphical object whose appearance consists of a rectangular box.
GRectangle	This class is a double-precision version of the `Rectangle` class in `java.awt`.
GRoundRect	The `GRoundRect` class is a graphical object whose appearance consists of a rounded rectangle.
GTurtle	The `GTurtle` class simulates a turtle moving on a canvas.

Package acm.graphics Description

This package provides a set of classes that support the creation of simple, object-oriented graphical displays. The basic model is that of a felt board of the sort one might use as a child. The felt board itself is represented by the GCanvas class, which is a lightweight container that supports the addition of graphical objects that correspond to the shapes attached to the board. These graphical objects come from a variety of classes that represent geometrical shapes and other graphical entities including lines, ovals, rectangles, images, and strings.

The standard approach to using the acm.graphics package consists of the following steps:

Allocate a new GCanvas object to serve as the surface to which subsequent graphical objects are attached.
Make the canvas appear on the screen by adding it to some component that is displayed. The simplest strategy, for example, is to create a JFrame object and then add the GCanvas at the center of that frame.
Use the add method in GCanvas to add new graphical objects from the GObject hierarchy.

As an example, the following main program follows this outline to display a red square on the screen:


public static void main(String[] args) {
   GCanvas gc = new GCanvas();
   JFrame frame = new JFrame();
   frame.getContentPane().add(BorderLayout.CENTER, gc);
   GRectangle square = new GRectangle(100, 100, 200, 200);
   square.setFilled(true);
   square.setColor(Color.RED);
   gc.add(square);
   frame.show();
}

Much of this boilerplate can be eliminated by using the GraphicsProgram class in the acm.program package.

The public classes in the acm.graphics package can be diagrammed as follows: