com.seanchenxi.gwt.effect.core.Fly.java Source code

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Here is the source code for com.seanchenxi.gwt.effect.core.Fly.java

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/*******************************************************************************
 * Copyright 2012 Xi CHEN
 *
 * 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 com.seanchenxi.gwt.effect.core;

import com.google.gwt.dom.client.Style.Position;
import com.google.gwt.dom.client.Style.Unit;
import com.google.gwt.user.client.Window;
import com.google.gwt.user.client.ui.Widget;
import com.seanchenxi.gwt.effect.api.EffectCallback;
import com.seanchenxi.gwt.effect.api.Effect;
import com.seanchenxi.gwt.effect.api.Parallelizable;

public class Fly extends Effect implements Parallelizable {

    private int startLeft, startTop, targetLeft, targetTop = -1;
    private double distL, distT;

    public Fly(Widget widget, int duration) {
        super(widget, duration);
    }

    public Fly(Widget widget) {
        this(widget, 700);
    }

    public void setTarget(int left, int top) {
        this.targetLeft = Math.max(left, 0);
        this.targetTop = Math.max(top, 0);
    }

    public void setTargetRelativeToCenter(int left, int top) {
        this.targetLeft = left + (Window.getClientWidth() - getWidget().getOffsetWidth()) >> 1;
        this.targetTop = top + (Window.getClientHeight() - getWidget().getOffsetHeight()) >> 1;
    }

    public void flyTo(int left, int top) {
        setTarget(left, top);
        this.play();
    }

    public void flyTo(int left, int top, EffectCallback callback) {
        setCallback(callback);
        flyTo(left, top);
    }

    public void center() {
        flyTo(-1, -1);
    }

    public void center(EffectCallback callback) {
        flyTo(-1, -1, callback);
    }

    @Override
    protected void play() {
        if (doPrepare())
            super.play();
    }

    @Override
    public void doUpdate(double progress) {
        getStyle().setTop(startTop + progress * distT, Unit.PX);
        getStyle().setLeft(startLeft + progress * distL, Unit.PX);
    }

    @Override
    public boolean doPrepare() {
        getStyle().setPosition(Position.ABSOLUTE);
        if (targetTop == -1) {
            targetLeft = (Window.getClientWidth() - getWidget().getOffsetWidth()) >> 1;
            targetTop = (Window.getClientHeight() - getWidget().getOffsetHeight()) >> 1;
        }
        startLeft = getWidget().getAbsoluteLeft();
        startTop = getWidget().getAbsoluteTop();
        distL = targetLeft - startLeft;
        distT = targetTop - startTop;
        return true;
    }

    @Override
    protected void onUpdate(double progress) {
        doUpdate(progress);
    }

}