next.i.view.widgets.XSlider.java Source code

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Here is the source code for next.i.view.widgets.XSlider.java

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/*
 * Copyright 2011 Vancouver Ywebb Consulting Ltd
 * 
 * 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 next.i.view.widgets;

import next.i.XStyle;
import next.i.mobile.DragController;
import next.i.mobile.DragEvent;
import next.i.mobile.DragEventsHandler;

import com.google.gwt.dom.client.Element;
import com.google.gwt.dom.client.Style.Unit;
import com.google.gwt.event.logical.shared.HasValueChangeHandlers;
import com.google.gwt.event.logical.shared.ValueChangeEvent;
import com.google.gwt.event.logical.shared.ValueChangeHandler;
import com.google.gwt.event.shared.HandlerRegistration;
import com.google.gwt.user.client.Event;
import com.google.gwt.user.client.ui.Composite;
import com.google.gwt.user.client.ui.FlowPanel;
import com.google.gwt.user.client.ui.HTML;

/**
 * 
 * <p>
 * <img class='ai' src='../../../../resources/XSlider.png' />
 * </p>
 */
public class XSlider extends Composite implements DragEventsHandler, HasValueChangeHandlers<Integer> {

    private int _value = 0;
    private FlowPanel _panel = new FlowPanel();
    private HTML _label = new HTML("0%");
    private HTML _slider = new HTML();

    public XSlider() {
        initWidget(_panel);
        setStyleName(XStyle.xslider.name());

        sinkEvents(Event.ONCLICK | Event.ONTOUCHCANCEL | Event.ONTOUCHEND | Event.ONTOUCHMOVE | Event.ONTOUCHSTART);

        _panel.add(_label);
        _panel.add(_slider);

        _label.setStyleName("label");
        _slider.setStyleName("bar");
        _slider.setHTML("<div class=right></div><div class=left></div><div class=thumb></div>");
    }

    public XSlider(int initialValue) {
        this();
        setValue(initialValue);
    }

    @Override
    public void onBrowserEvent(Event e) {
        e.stopPropagation();
        super.onBrowserEvent(e);
    }

    @Override
    public void onLoad() {
        super.onLoad();
        DragController.get().addDragEventsHandler(this);
    }

    @Override
    public void onUnload() {
        DragController.get().removeDragEventsHandler(this);
    }

    @Override
    public void onDragStart(DragEvent e) {
        DragController.get().captureDragEvents(this);
        int value = computeNewValue_(e);
        setValue(value);
    }

    @Override
    public void onDragMove(DragEvent e) {
        e.stopPropagation();
        int value = computeNewValue_(e);
        setValue(value);
    }

    @Override
    public void onDragEnd(DragEvent e) {
        DragController.get().releaseDragCapture(this);
    }

    public void setValue(int value) {
        if (_value != value) {
            _value = value;
            updateSliderPosition_();
            ValueChangeEvent.fire(this, _value);
        }
    }

    public int getValue() {
        return _value;
    }

    @Override
    public HandlerRegistration addValueChangeHandler(ValueChangeHandler<Integer> handler) {
        return this.addHandler(handler, ValueChangeEvent.getType());
    }

    public void setLabelVisible(boolean display) {
        if (display) {
            _label.setVisible(true);
        } else {
            _label.setVisible(false);
        }
    }

    private int computeNewValue_(DragEvent e) {
        Element ele = _slider.getElement();
        int offset = (int) e.X - ele.getAbsoluteLeft();
        int width = ele.getClientWidth();
        int value = offset * 100 / width;
        if (value > 100) {
            value = 100;
        } else if (value < 0) {
            value = 0;
        }
        return value;
    }

    private void updateSliderPosition_() {
        _label.setHTML(_value + "%");
        Element slider = getSliderElement_();
        slider.getStyle().setWidth(_value, Unit.PCT);
    }

    private Element getSliderElement_() {
        return (Element) _slider.getElement().getChild(1);
    }

    @Override
    public void onDragMoveHorizontal(DragEvent e) {
        // Not implemented
    }

    @Override
    public void onDragMoveVertical(DragEvent e) {
        // Not implemented
    }
}