I'm having a hard time finding where exactly addMouseListener is defined.
On a side note, I approached this problem in a different way by simply
adding an event preview handler Event#addNativePreviewHandler. Also, you
should use handlers rather than listeners (not super important, but the
listeners are deprecated).
I'd recommend looking at how some of the native GWT widgets do their event
handling to get an idea of how to write your own.
On Wed, Apr 15, 2009 at 9:20 PM, raulsan <ufreeurs...@gmail.com> wrote:
>
>
>
> 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;
> }
> }
>
> >
>
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Google Web Toolkit" group.
To post to this group, send email to Google-Web-Toolkit@googlegroups.com
To unsubscribe from this group, send email to
google-web-toolkit+unsubscr...@googlegroups.com
For more options, visit this group at
http://groups.google.com/group/Google-Web-Toolkit?hl=en
-~----------~----~----~----~------~----~------~--~---
