Yes, of course"
I did not post it before because I thought it was not the right place
to do it. The class is an extended class from GWTCanvas, but I was
asking about mouse events and about the disappearing of a
function :) and because of that I posted here.
The class is:
/**
*
*/
package com.mapvs.client;
import com.google.gwt.i18n.client.NumberFormat;
import com.google.gwt.user.client.Event;
import com.google.gwt.user.client.ui.ClickListener;
import com.google.gwt.user.client.ui.ClickListenerCollection;
import com.google.gwt.user.client.ui.Label;
import com.google.gwt.user.client.ui.MouseListener;
import com.google.gwt.user.client.ui.MouseListenerCollection;
import com.google.gwt.user.client.ui.Widget;
import com.google.gwt.widgetideas.graphics.client.Color;
import com.google.gwt.widgetideas.graphics.client.GWTCanvas;
/**
* @author raulsan
*
*/
@SuppressWarnings("deprecation")
public class CompassCanvas extends GWTCanvas {
private MouseListenerCollection mouseListeners;
private ClickListenerCollection clickListeners;
private Label angleLab = new Label("0");
/**
* the size of the canvas
*/
private int x = 90;
private int y = 90;
/**
* the size of the compass
*/
private float radius = x/2 -5;
/**
* distance from the top of the arrow
* to the top of the stick
*/
private int distArr = (int)radius/5;
/**
* the size of the arrow
*/
private int arrSize = (int)radius-distArr;
/**
* The angle to draw the arrow
*/
private double alfa = 0;
/**
* the with of the lines
*/
private int lineW = 7;
/**
* the colors
*/
private Color c1 = Color.YELLOW;
private Color c2 = Color.BLUE;
/**
* Constructor
*/
public CompassCanvas() {
super(90,90);
// draw
drawCompass(alfa,c1,c1);
// the listeners
this.sinkEvents(Event.MOUSEEVENTS | Event.ONCLICK);
this.addMouseListener(new MouseListener(){
// variable
boolean dragging = false;
public void onMouseDown(Widget sender, int x, int y) {
drawCompass(x, y, c2, c2);
dragging = true;
}
public void onMouseEnter(Widget sender) {
drawCompass(alfa, c2, c1);
}
public void onMouseLeave(Widget sender) {
drawCompass(alfa, c1, c1);
dragging = false;
}
public void onMouseMove(Widget sender, int x, int y) {
if (dragging)
drawCompass(x,y,c2,c2);
else
drawCompass(alfa,c2,c1);
}
public void onMouseUp(Widget sender, int x, int y) {
drawCompass(x,y,c2,c1);
dragging = false;
}
});
}
/**
* Handling events
*/
public void onBrowserEvent(Event event) {
event.preventDefault();
super.onBrowserEvent(event);
if (mouseListeners != null) {
int x = Event.getRelativeX(event, this.getElement());
int y = Event.getRelativeY(event, this.getElement());
switch (event.getTypeInt()) {
case Event.ONCLICK:
if (clickListeners != null) {
clickListeners.fireClick(this);
}
break;
case Event.ONMOUSEDOWN:
if (mouseListeners != null) {
mouseListeners.fireMouseDown(this, x, y);
}
break;
case Event.ONMOUSEMOVE:
if (mouseListeners != null) {
mouseListeners.fireMouseMove(this, x, y);
}
break;
case Event.ONMOUSEUP:
if (mouseListeners != null) {
mouseListeners.fireMouseUp(this, x, y);
}
break;
case Event.ONMOUSEOUT:
if (mouseListeners != null) {
mouseListeners.fireMouseLeave(this);
}
break;
}
}
}
/**
*
* @param listener
*/
public void addClickListener(ClickListener listener) {
if (clickListeners == null) {
clickListeners = new ClickListenerCollection();
sinkEvents(Event.ONCLICK);
}
clickListeners.add(listener);
}
/**
*
* @param listener
*/
public void addMouseListener(MouseListener listener) {
if (mouseListeners == null) {
mouseListeners = new MouseListenerCollection();
sinkEvents(Event.MOUSEEVENTS);
}
mouseListeners.add(listener);
}
public void removeClickListener(ClickListener listener) {
if (clickListeners != null) {
clickListeners.remove(listener);
}
}
public void removeMouseListener(MouseListener listener) {
if (mouseListeners != null) {
mouseListeners.remove(listener);
}
}
/**
*
*/
public void drawCompass(int w,int h, Color c1, Color c2){
this.clear();
double i = getDistance(w,h,x/2,h);
double j = getDistance(w,h,w,y/2);
alfa = correctAngle(Math.atan2(i, j),w,h,x/2,y/2);
alfa = (alfa==-0)?0:alfa;
alfa = (alfa==-180)?180:alfa;
// call to the function to draw with alfa
drawCompass(alfa, c1, c2);
}
/**
*
*/
public void drawCompass(double alfa, Color c1, Color c2){
this.clear();
// the circumference
this.saveContext();
this.setFillStyle(Color.WHITE);
this.setStrokeStyle(c1);
this.setLineWidth(lineW);
float startAngle = 0;
float endAngle = (float)Math.PI*2;
this.beginPath();
this.arc(x/2, y/2, radius, startAngle, endAngle, true);
this.stroke();
this.fill();
this.restoreContext();
// the arrow
this.saveContext();
this.translate(x/2, y/2);
this.rotate(-Math.PI/2 + alfa);
this.setLineCap("round");
this.setLineWidth(lineW/2);
this.setStrokeStyle(c2);
this.beginPath();
this.moveTo(0, 0);
this.lineTo(arrSize, 0);
this.stroke();
this.closePath();
// the corner of the arrow
this.setStrokeStyle(c2);
this.setFillStyle(c2);
this.beginPath();
this.moveTo(arrSize+distArr-(lineW/2), 0);
this.lineTo(arrSize-distArr, distArr);
this.lineTo(arrSize, 0);
this.lineTo(arrSize-distArr, -distArr);
this.lineTo(arrSize+distArr-(lineW/2), 0);
this.stroke();
this.fill();
this.closePath();
this.restoreContext();
// The angle
angleLab.setText(NumberFormat.getFormat("#,##0").format(alfa*360/
(2*Math.PI)));
}
/**
* Gives the distance between 2 points
*/
public double getDistance(int x, int y,int i,int j){
return Math.sqrt(Math.pow(x-i, 2)+Math.pow(y-j, 2));
}
/**
* Gives the right angle inside the compass
*/
public double correctAngle(double alfa,int w,int h,int x,int y){
double beta = 0;
boolean a = w>x;
boolean b = h<y;
if (a&&b){
//1st quadrant
beta = alfa;
}else if (!a&&b){
//2nd quadrant
beta = -alfa;
}else if (!a&&!b){
//3er quadrant
beta = -Math.PI+alfa;
}else if (a&&!b){
//4th quadrant
beta = Math.PI-alfa;
}
return beta;
}
}
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