/*
* Copyright 2010 Hao Nguyen
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package gwt.g2d.client.demo;
import gwt.g2d.client.graphics.KnownColor;
import gwt.g2d.client.graphics.LineCap;
import gwt.g2d.client.graphics.LineJoin;
import gwt.g2d.client.graphics.Surface;
import gwt.g2d.client.graphics.shapes.ShapeBuilder;
import gwt.g2d.client.math.Vector2;
import com.google.gwt.dom.client.NativeEvent;
import com.google.gwt.event.dom.client.MouseDownEvent;
import com.google.gwt.event.dom.client.MouseDownHandler;
import com.google.gwt.event.dom.client.MouseMoveEvent;
import com.google.gwt.event.dom.client.MouseMoveHandler;
import com.google.gwt.event.dom.client.MouseUpEvent;
import com.google.gwt.event.dom.client.MouseUpHandler;
import com.google.gwt.user.client.ui.Label;
import com.google.gwt.user.client.ui.Panel;
/**
* Demo on how to draw on a canvas using the mouse manager.
*
* @author hao1300@gmail.com
*/
public class DrawingPadDemo extends AbstractDemo implements MouseDownHandler,
MouseMoveHandler, MouseUpHandler {
private Vector2 lastPosition = new Vector2();
private boolean isLeftButtonDown, isRightButtonDown;
public DrawingPadDemo(Panel parentContainer) {
super("Drawing Pad Demo", parentContainer);
getPrimarySurface().addMouseDownHandler(this);
getPrimarySurface().addMouseMoveHandler(this);
getPrimarySurface().addMouseUpHandler(this);
}
@Override
public void initialize() {
add(new Label("Use the mouse to draw on the canvas below:"));
add(getPrimarySurface());
}
@Override
public void update() {
}
@Override
public void onMouseDown(MouseDownEvent event) {
switch (event.getNativeButton()) {
case NativeEvent.BUTTON_LEFT:
isLeftButtonDown = true;
break;
case NativeEvent.BUTTON_RIGHT:
isRightButtonDown = true;
break;
}
lastPosition.set(event.getX(), event.getY());
event.preventDefault();
event.stopPropagation();
}
@Override
public void onMouseMove(MouseMoveEvent event) {
if (isLeftButtonDown || isRightButtonDown) {
Surface surface = getPrimarySurface();
surface.save().setLineCap(LineCap.ROUND).setLineJoin(LineJoin.ROUND);
if (isLeftButtonDown) {
surface.setStrokeStyle(KnownColor.BLACK).setLineWidth(5);
} else if (isRightButtonDown) {
surface.setStrokeStyle(KnownColor.WHITE).setLineWidth(20);
}
surface.strokeShape(new ShapeBuilder()
.drawLineSegment(lastPosition, new Vector2(event.getX(), event.getY()))
.build());
surface.restore();
lastPosition.set(event.getX(), event.getY());
}
}
@Override
public void onMouseUp(MouseUpEvent event) {
switch (event.getNativeButton()) {
case NativeEvent.BUTTON_LEFT:
isLeftButtonDown = false;
break;
case NativeEvent.BUTTON_RIGHT:
isRightButtonDown = false;
break;
}
event.preventDefault();
event.stopPropagation();
}
}