Class GradApplet

java.lang.Object
   |
   +----java.awt.Component
           |
           +----java.awt.Container
                   |
                   +----java.awt.Panel
                           |
                           +----java.applet.Applet
                                   |
                                   +----GradApplet

public class GradApplet

extends Applet

implements Runnable

Version:

1.1

Author:

Revathy Balaraman

GradApplet()

checkboundaries()

Tests the x,y coordinates of the image that is to be displayed.

drawimage(Graphics, Color)

Provides basic graphic methods to draw lines and fill ovals

init()

Initializes the variables.

mouseDown(Event, int, int)

The purpose of this method is to toggle between pausing and resuming the thread’s execution.

pausethread(int)

Causes the thread to sleep for the specified amount of time (msecs).

run()

Provides the applet’s thread activity.

start()

Checks the status of the thread.

stop()

Stops the thread and waits for it to really die! In general, the stop() causes a thread to leave its run() method and therefore end its thread activity.

 public GradApplet()

 public void init()

Initializes the variables.

Overrides:

init in class Applet

See Also:

init

 public void start()

Checks the status of the thread. If 'null', creates and starts the thread. This process in turn invokes the run() method.

Overrides:

start in class Applet

See Also:

start

 public void stop()

Stops the thread and waits for it to really die! In general, the stop() causes a thread to leave its run() method and therefore end its thread activity. It is accompanied by a join() call, which forces the calling thread to wait until the thread is really dead.

Overrides:

stop in class Applet

See Also:

stop

 public boolean mouseDown(Event ev,
                          int x,
                          int y)

The purpose of this method is to toggle between pausing and resuming the thread’s execution. The suspend() method suspends a thread’s execution; when a thread is suspended it will not continue its stream of execution until the complementary resume() method is invoked. Suspending a thread is accompanied by clearing out the applet’s drawing area (i.e. removing the previously drawn images) through the repaint() method. This occurs because the applet does not override the paint() method. The 'appRunning' variable is used to keep track of whether the thread is suspended. Due to the action performed by the mouseDown() method, the run() method gets repeatedly started and stopped.

Parameters:

ev - Traps any mouse-click events

x - The x coordinate of the mouseclick action/event

y - The y coordinate of the mouseclick action/event

Returns:

true Returns true to indicate mouseclick action

Overrides:

mouseDown in class Component

See Also:

mouseDown

 public void run()

Provides the applet’s thread activity. The method defines just what the thread is supposed to do when it is started. The thread enters a loop, randomly drawing animated images on each iteration. It runs until the applet is terminated or the thread is explicitly stopped. The method also displays a string message at the lower left side of the applet area.

See Also:

run

 public void checkboundaries()

Tests the x,y coordinates of the image that is to be displayed. If the randomly selected location is too close to the boundaries of the workarea, the location is changed. This avoids partially displayed images.

See Also:

checkboundaries

 public void drawimage(Graphics g,
                       Color c)

Provides basic graphic methods to draw lines and fill ovals

Parameters:

g - The graphics object needed to draw the image

c - The color selected to draw the image

See Also:

drawimage

 public void pausethread(int msecs)

Causes the thread to sleep for the specified amount of time (msecs). Thus, the GradApplet class uses the sleep() method to delay a little between the image drawing process. The method also requires catching Interrupted Exception objects. This is meant for situations in which a thread has been interrupted by another thread.

Parameters:

msecs - Causes the thread to sleep for specific number of milliseconds

See Also:

pausethread