Construct a new frame with the
* {@link CanvasPanel CanvasPanel} panel as its component.
*
* @param width the width of the panel
* @param height the height of the panel
* @param title the title of the panel
*/
public Canvas(int width, int height, String title){
this.width = width;
this.height = height;
// Label the frame as "Canvas" and set up the layout
f = new JFrame(title);
f.setLayout(new BorderLayout());
// End the application when the last window closes
f.addWindowListener(winapt);
// if the user closes the Canvas window
// it will only hide and can be reopened by invoking 'show'
f.setDefaultCloseOperation(WindowConstants.HIDE_ON_CLOSE);
// set up the panel and the graphics
panel = new CanvasPanel(width, height);
panel.addNotify();
f.getContentPane().add(panel, BorderLayout.CENTER);
f.pack();
Graphics g = panel.getGraphics();
f.update(g);
f.setVisible(false);
// update the counter of open windows
// WINDOWS_OPEN = WINDOWS_OPEN + 1;
}
/**
* A WindowAdapter that allows us to close a window and re-open,
* provided there is at least one open window. The program ends
* when all windows have been closed.
*/
protected WindowAdapter winapt = new WindowAdapter(){
public void windowClosing(WindowEvent e) {
//System.out.println("hiding the window");
WINDOWS_OPEN = WINDOWS_OPEN - 1;
//closeCanvas();
panel.clearPanel();
if (WINDOWS_OPEN == 0)
System.exit(0);
}
};
/**
* Create a new canvas with the default title "Canvas"
*
* @param width the width of the canvas
* @param height the height of the canvas
*/
public Canvas(int width, int height){
this(width, height, "Canvas");
}
/////////////////////////////////////////////////////////////////////////
// Methods for drawing and erasing shapes and text //
/////////////////////////////////////////////////////////////////////////
/**
* Draw a circle with the given center,
* radius, and color.
*
* @param center the center
* @param radius the radius of the disk
* @param color the color of the circle
*/
public void drawCircle(Posn center, int radius, Color color){
((CanvasPanel)panel).drawCircle(center, radius, color);
}
public void drawCircle(Posn center, int radius, IColor color){
this.drawCircle(center, radius, color.thisColor());
}
/**
* Draw a disk with the center at the given position with the given
* radius and color.
*
* @param center the position of the center
* @param radius the radius of the disk
* @param color the color of the disk
*/
public void drawDisk(Posn center, int radius, Color color){
((CanvasPanel)panel).drawDisk(center, radius, color);
}
public void drawDisk(Posn center, int radius, IColor color){
this.drawDisk(center, radius, color.thisColor());
}
/**
* Draw a rectangle with the NW corner at nw with the given
* width, height, and color.
*
* @param nw the NW corner
* @param width the width of the rectangle
* @param height the height of the rectangle
* @param color the color of the rectangle
*/
public void drawRect(Posn nw, int width, int height, Color color){
((CanvasPanel)panel).drawRect(nw, width, height, color);
}
public void drawRect(Posn nw, int width, int height, IColor color){
this.drawRect(nw, width, height, color.thisColor());
}
/**
* Draw a line from p1 to
* p2 in the given color.
*
* @param p1 the position of the start of the line
* @param p2 the position of the end of the line
* @param color the color of the line
*/
public void drawLine(Posn p1, Posn p2, Color color){
((CanvasPanel)panel).drawLine(p1, p2, color);
}
public void drawLine(Posn p1, Posn p2, IColor color){
this.drawLine(p1, p2, color.thisColor());
}
/**
* Draw a String with p
* identifying the bottom left position.
*
* @param p the position of the bottom left of the String
* @param s the String to display
*/
public void drawString(Posn p, String s){
((CanvasPanel)panel).drawString(p, s);
}
/////////////////////////////////////////////////////////////////////////
// Methods for showing and hiding the canvas //
/////////////////////////////////////////////////////////////////////////
/**
* Show the window with the canvas cleared
*/
public void show(){
// check if the widow is already open
if (!f.isVisible()){
// account for the open window, make it appear
WINDOWS_OPEN = WINDOWS_OPEN + 1;
f.setVisible(true);
// redraw the background
}
else{
// do nothing if the window is open already
//System.out.println("The window is shown already");
}
}
/**
* Close the window - if it is currently open, do nothing otherwise
*/
public void close(){
if (f.isVisible()){
WINDOWS_OPEN = WINDOWS_OPEN - 1;
f.setVisible(false);
panel.clearPanel();
}
}
/**
* Clear the canvas before painting the next scene
*/
protected void clear(){
this.panel.clearPanel();
}
/**
* Helper method to display a message and await RETURN before proceeding
*
* @param message the message to display
*/
private static void nextStep(String message){
try{
System.out.println(message);
System.out.println("Press RETURN");
// no input needed - the default input is a valid integer
int n = System.in.read();
}
catch(IOException e){
System.out.println("Next step");
}
}
/**
* Produce a String representation of this color
*/
public String toString(){
return "new Canvas(" + this.width + ", " + this.height + ")";
}
/**
* Self test for the Canvas class
*
* @param argv
*/
public static void main(String[] argv){
nextStep("Canvas with default name is constructed");
Canvas sm1 = new Canvas(200, 200);
nextStep("To show the canvas ... ");
sm1.show();
nextStep("Canvas shown - should be blank - add red and blue disk");
sm1.drawCircle(new Posn(50, 50), 20, new Red());
sm1.drawCircle(new Posn(150, 50), 50, new Blue());
nextStep("Show the canvas again - it should not do anything");
sm1.show();
nextStep("Draw a green disk");
sm1.drawCircle(new Posn(50, 150), 50, new Green());
nextStep("Close the Canvas");
sm1.close();
nextStep("Show the canvas again - it should be cleared");
sm1.show();
nextStep("Paint one disks on the canvas");
sm1.drawCircle(new Posn(50, 150), 25, new Black());
nextStep("Construct a second canvas with the name Smiley");
Canvas sm2 = new Canvas(200, 200, "Smiley");
nextStep("Show the second canvas");
sm2.show();
nextStep("Paint two disks on the Smiley canvas");
sm2.drawCircle(new Posn(50, 50), 20, new Red());
sm2.drawCircle(new Posn(150, 150), 50, new Blue());
nextStep("Manually close the 'Canvas' window\n" +
"and see if we can bring it back to life");
sm1.show();
nextStep("The first canvas should be shown - cleared");
sm1.drawCircle(new Posn(50, 50), 30, new Red());
sm1.drawCircle(new Posn(150, 50), 30, new Blue());
sm1.drawCircle(new Posn(50, 150), 30, new Green());
nextStep("The first canvas has three disks drawn");
System.out.println("Close both canvas windows to end the program");
}
}