import java.awt.*;
import java.awt.image.*;
import utilities.*;
import utilities.gfx.*;

public class Dial extends Canvas {

protected Circle circle;		// we use Circles to render part of a Dial

protected int radius, diameter;
protected int dialWidth, dialHeight;
protected int divisions;

protected double heading;
protected boolean headingVisible;

protected boolean fixedFace;	// true= heading moves in relation to face

protected Image dialImage;		// off-screen image
protected Graphics gg;			// handle to off-screen Graphics context

//-------------------------------------------------------------------
// Dial Constructor
//-------------------------------------------------------------------
// default dial, diameter = 50 pixels
public Dial() {
	this(50);
}
// default dial, 8 divisions, heading 0 deg, heading not visible
public Dial(int diameter) {
	this(diameter, 8, 0.0, false);
}
// heading specified -> heading visible
public Dial(int diameter, int divisions, double heading) {
	this(diameter, divisions, heading, true);
}
public Dial(int diameter, int divisions, double heading, boolean visHeading) {

	this.diameter	= diameter;
	this.divisions	= divisions;
	this.heading	= heading;
	this.headingVisible = visHeading;
	this.fixedFace	= true;

	radius	  = diameter/2;
	dialWidth = diameter;
	dialHeight= diameter + extraHeight();

	circle = new Circle(radius, radius, radius);
	circle.useDegrees(true);
}
//-------------------------------------------------------------------
// set()/get() for 'Heading' property
//-------------------------------------------------------------------
public void setHeading(double value) {
	this.heading = value;
	reflectChanges();
}
public double getHeading() {
	return heading;
}
//-------------------------------------------------------------------
// set()/get() for 'Divisions' property
//-------------------------------------------------------------------
public void setDivisions(int value) {
	this.divisions = value;
	reflectChanges();
}
public int getDivisions() {
	return divisions;
}
//-------------------------------------------------------------------
// set()/get() for 'HeadingVisible' property
//-------------------------------------------------------------------
public void setHeadingVisible(boolean value) {
	this.headingVisible = value;
	reflectChanges();
}
public boolean getHeadingVisible() {
	return headingVisible;
}
public void showHeading() {
	setHeadingVisible(true);
}
public void hideHeading() {
	setHeadingVisible(false);
}
//-------------------------------------------------------------------
// set()/get() for 'FixedFace' property
//-------------------------------------------------------------------
public void setFixedFace(boolean value) {
	this.fixedFace = value;
}
public boolean getFixedFace() {
	return fixedFace;
}
//-------------------------------------------------------------------
// Some visible dial property changed. Reflect the change graphically
//-------------------------------------------------------------------
protected void reflectChanges() {
	renderDial();
	repaint();
}
//-------------------------------------------------------------------
// extraHeight lets subclasses reserve some extra height to render
// a dial label below the dial face.
//-------------------------------------------------------------------
protected int extraHeight() {
	return 0;					// default extra space = none.
}
//-------------------------------------------------------------------
// Render dial.
//-------------------------------------------------------------------
public void renderDial() {

	if ( dialImage == null ) {
		return;
	}

	GfxKit.wipeImage(dialImage, getBackground(), this);

	circle.draw(gg);
	circle.setRadialSize(0.90, 0.97);			// percentage of radius

	if ( fixedFace ) {
		circle.drawRadials(gg, divisions);
	} else {
		circle.drawRadials(gg, divisions, heading, heading + 360.0);
	}

	if ( headingVisible ) {
		renderHeading();
	}
	renderCustomFeatures(gg);
}
//-------------------------------------------------------------------
// Render any extra gadgets or embellishments to the dial.
// Another method for subclasses to override.
//-------------------------------------------------------------------
protected void renderCustomFeatures(Graphics g) {
	// empty, subclasses need to override
}
//-------------------------------------------------------------------
// Render heading as a small triangle pointing outwards
//-------------------------------------------------------------------
protected void renderHeading() {
	circle.setRadialSize(0.60, 0.85);
	circle.drawArrow(gg, heading, 16.0);	// n degree "wide" arrow base
}
//-------------------------------------------------------------------
// Initialize the off-screen dial image.
//-------------------------------------------------------------------
protected void allocImage() {
	dialImage = createImage(dialWidth, dialHeight);
	gg = dialImage.getGraphics();
}
//-------------------------------------------------------------------
// Overridden update()/paint()
//-------------------------------------------------------------------
public void update(Graphics g) {
	paint(g);
}
public void paint(Graphics g) {

	if ( dialImage == null ) {
		allocImage();
		renderDial();
	}

	g.drawImage(dialImage, 0,0, this);
}
//-------------------------------------------------------------------
// Overridden setSize()
//-------------------------------------------------------------------
public Dimension preferredSize() {
	return new Dimension(dialWidth, dialHeight);
}
public Dimension getPreferredSize() {
	return preferredSize();
}
//-------------------------------------------------------------------
// Dial self-test
//-------------------------------------------------------------------
public static void main (String[] args) {
Frame window = new Frame("Dial Test");
Dial aDial = new Dial();
Dial bDial = new Dial(80);
Dial cDial = new Dial(150);

	window.setLayout(new FlowLayout());
	window.add(aDial);
	window.add(bDial);
	window.add(cDial);
	window.pack();
	window.setVisible(true);

	MiscKit.delay(2000);

	aDial.showHeading();
	bDial.showHeading();
	cDial.showHeading();

	MiscKit.delay(2000);

	for (int i=0; i < 10; i++) {
		cDial.hideHeading();
		MiscKit.delay(200);

		cDial.showHeading();
		MiscKit.delay(200);
	}

	while ( true ) {
	for (int i=0; i < 90; i++) {
		aDial.setHeading((double) i);
		bDial.setHeading((double) i*2);
		cDial.setHeading((double) i*4);
		MiscKit.delay(100);
		cDial.setFixedFace( i > 50 );
	}
	}
}
} // End of Class Dial