Using Mouse Wheel Handler (Smart GWT)
/*
* SmartGWT (GWT for SmartClient)
* Copyright 2008 and beyond, Isomorphic Software, Inc.
*
* SmartGWT is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License version 3
* as published by the Free Software Foundation. SmartGWT is also
* available under typical commercial license terms - see
* http://smartclient.com/license
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*/
package com.smartgwt.sample.showcase.client;
import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.user.client.ui.RootPanel;
import com.smartgwt.client.types.Alignment;
import com.smartgwt.client.types.Overflow;
import com.smartgwt.client.util.EventHandler;
import com.smartgwt.client.widgets.Canvas;
import com.smartgwt.client.widgets.Label;
import com.smartgwt.client.widgets.events.MouseMoveEvent;
import com.smartgwt.client.widgets.events.MouseMoveHandler;
import com.smartgwt.client.widgets.events.MouseOutEvent;
import com.smartgwt.client.widgets.events.MouseOutHandler;
import com.smartgwt.client.widgets.events.MouseStillDownEvent;
import com.smartgwt.client.widgets.events.MouseStillDownHandler;
import com.smartgwt.client.widgets.events.MouseUpEvent;
import com.smartgwt.client.widgets.events.MouseUpHandler;
import com.smartgwt.client.widgets.events.MouseWheelEvent;
import com.smartgwt.client.widgets.events.MouseWheelHandler;
public class Showcase implements EntryPoint{
public void onModuleLoad() {
RootPanel.get().add(getViewPanel());
}
public Canvas getViewPanel() {
Canvas canvas = new Canvas();
final TrackerLabel eventTrackerLabel = new TrackerLabel();
eventTrackerLabel.setContents("<nobr>Last event: (mouse over the canvas below...)</nobr>");
eventTrackerLabel.setHeight(20);
final MouserLabel label = new MouserLabel();
label.setContents("<b>Mouse Me</b>");
label.setAlign(Alignment.CENTER);
label.setOverflow(Overflow.HIDDEN);
label.setShowEdges(true);
label.setBackgroundColor("lightblue");
label.setWidth(200);
label.setHeight(200);
label.setTop(40);
label.addMouseWheelHandler(new MouseWheelHandler() {
public void onMouseWheel(MouseWheelEvent event) {
int wheelDelta = EventHandler.getWheelDelta();
int newSize = label.getWidth() + wheelDelta * label.getZoomMultiplier();
if (newSize < label.getMinSize()) {
newSize = label.getMinSize();
} else if (newSize > label.getMaxSize()) {
newSize = label.getMaxSize();
}
label.setWidth(newSize);
label.setHeight(newSize);
eventTrackerLabel.setLastEvent("mouseWheel", label);
}
});
label.addMouseStillDownHandler(new MouseStillDownHandler() {
public void onMouseStillDown(MouseStillDownEvent event) {
Integer opacity = label.getOpacity();
if (opacity == null) opacity = 100;
label.setOpacity(Math.max(0, opacity - 5));
eventTrackerLabel.setLastEvent("mouseStillDown", label);
}
});
label.addMouseUpHandler(new MouseUpHandler() {
public void onMouseUp(MouseUpEvent event) {
label.setOpacity(100);
eventTrackerLabel.setLastEvent("mouseUp", label);
}
});
label.addMouseMoveHandler(new MouseMoveHandler() {
public void onMouseMove(MouseMoveEvent event) {
//scale to 1
float xScale = (label.getOffsetX() * 1f) / label.getWidth();
float yScale = (label.getOffsetY() * 1f) / label.getHeight();
// increasing red intensity on the x axis, green on the y axis. Blue stays at zero.
label.setBackgroundColor("rgb(0," + Math.round(255 * xScale) + "," + Math.round(255 * yScale) + ")");
eventTrackerLabel.setLastEvent("mouseMove", label);
}
});
label.addMouseOutHandler(new MouseOutHandler() {
public void onMouseOut(MouseOutEvent event) {
//restore settings
label.setBackgroundColor("lightblue");
label.setOpacity(100);
eventTrackerLabel.setLastEvent("mouseOut", label);
}
});
canvas.addChild(eventTrackerLabel);
canvas.addChild(label);
return canvas;
}
class TrackerLabel extends Label {
public void setLastEvent(String eventName, MouserLabel label) {
int localX = label.getOffsetX();
int localY = label.getOffsetY();
setContents("<nobr>Last event: <b>" + eventName + "</b> (" + localX + ", " + localY + ")</nobr>");
}
}
class MouserLabel extends Label {
private int minSize = 40;
private int maxSize = 400;
private int zoomMultiplier = 15;
public int getMinSize() {
return minSize;
}
public void setMinSize(int minSize) {
this.minSize = minSize;
}
public int getMaxSize() {
return maxSize;
}
public void setMaxSize(int maxSize) {
this.maxSize = maxSize;
}
public int getZoomMultiplier() {
return zoomMultiplier;
}
public void setZoomMultiplier(int zoomMultiplier) {
this.zoomMultiplier = zoomMultiplier;
}
}
}
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