/*
* Copyright (C) 2013 Red Hat, Inc. and/or its affiliates.
*
* 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 org.jboss.errai.demo.mobile.client.local;
import com.google.gwt.dom.client.Element;
import org.jboss.errai.orientation.client.shared.OrientationEvent;
public class PerspectiveAnimator {
/**
* Number of degrees along each axis that the animation can progress in each frame.
*/
private static final double MAX_CHANGE_PER_FRAME = 5;
private final Element element;
private double x;
private double y;
private double z;
private double targetX;
private double targetY;
private double targetZ;
public PerspectiveAnimator(Element element) {
this.element = element;
}
public void updateTargets(OrientationEvent e) {
targetX = e.getX();
targetY = e.getY();
targetZ = e.getZ();
}
public void nextFrame() {
x += Math.min(MAX_CHANGE_PER_FRAME, targetX - x);
y += Math.min(MAX_CHANGE_PER_FRAME, targetY - y);
z += Math.min(MAX_CHANGE_PER_FRAME, targetZ - z);
String transform = "rotateX(" + (x - 90.0) + "deg) " + "rotateY(" + (-y) + "deg)";
// rotating the main rectangle with the compass direction is annoying,
// because then what you see on screen doesn't relate to what how you see
// your phone in front of you. So we rotate a compass rose instead:
String compassTransform = "rotate( " + (360.0 - z) + "deg)";
// could use deferred binding for this, but it's probably overkill
element.getStyle().setProperty("MozTransform", transform);
element.getStyle().setProperty("WebkitTransform", transform);
element.getStyle().setProperty("transform", transform);
// XXX this is fragile because it assumes a certain layout of the div contents
Element rotateMeCompass = element.getFirstChildElement().getNextSiblingElement();
rotateMeCompass.getStyle().setProperty("MozTransform", compassTransform);
rotateMeCompass.getStyle().setProperty("WebkitTransform", compassTransform);
rotateMeCompass.getStyle().setProperty("transform", compassTransform);
}
}