org.utgenome.gwt.utgb.client.track.TrackRangeSelector.java Source code

Introduction

Here is the source code for org.utgenome.gwt.utgb.client.track.TrackRangeSelector.java

Source

/*--------------------------------------------------------------------------
 *  Copyright 2007 utgenome.org
 *
 *  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.
 *--------------------------------------------------------------------------*/
//--------------------------------------
// UTGB Gallery Project
//
// TrackRangeSelector.java
// Since: Apr 3, 2007
//
// $URL$ 
// $Author$
//--------------------------------------
package org.utgenome.gwt.utgb.client.track;

import org.utgenome.gwt.utgb.client.ui.AbsoluteFocusPanel;
import org.utgenome.gwt.widget.client.Style;

import com.google.gwt.core.client.GWT;
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.user.client.Element;
import com.google.gwt.user.client.Event;
import com.google.gwt.user.client.ui.HTML;
import com.google.gwt.user.client.ui.Widget;

/**
 * {@link TrackRangeSelector} supports range selection on a displayed track. In order to use {@link TrackRangeSelector},
 * your track must implement the {@link RangeSelectable} interface.
 * 
 * @author leo
 * 
 */
public class TrackRangeSelector implements MouseDownHandler, MouseMoveHandler {
    boolean isInRangeSelectMode = false;
    HTML rangeIndicator = new HTML();

    RangeSelectable track;
    AbsoluteFocusPanel trackPanel;
    int x1 = -1;
    int x2 = -1;
    int windowWidth = 800;

    public TrackRangeSelector(RangeSelectable track) {
        this.track = track;
        this.trackPanel = track.getAbsoluteFocusPanel();

        Style.fontSize(rangeIndicator, 8);
        Style.border(rangeIndicator, 1, "solid", "#66CCFF");
        Style.margin(rangeIndicator, 0);
        Style.padding(rangeIndicator, 0);
        Style.zIndex(rangeIndicator, 2000);
        //rangeIndicator.setStyleName("track-range");
        rangeIndicator.setHeight("10px");

        trackPanel.addMouseMoveHandler(this);
        trackPanel.addMouseDownHandler(this);

    }

    public void setWindowWidth(int windowWidth) {
        this.windowWidth = windowWidth;
    }

    /**
     * An event handler when a mouse down event is reported from a child widget of the trackPanel.
     * 
     * @param x
     * @param y
     */
    public void onMouseDownFromChild(Widget sender, int x, int y) {
        //      int xOnWindow = x - trackPanel.getFocusPanel().getAbsoluteLeft();
        //      if (xOnWindow < 0)
        //         xOnWindow = 0;
        //      onMouseDown(trackPanel.getFocusPanel(), xOnWindow, y);
        onMouseDown(trackPanel.getFocusPanel().getElement(),
                x + sender.getAbsoluteLeft() - trackPanel.getAbsoluteLeft(), y);
    }

    public void onMouseDownFromChild(MouseDownEvent e) {
        onMouseDown(trackPanel.getFocusPanel().getElement(), e.getScreenX() - trackPanel.getAbsoluteLeft(),
                e.getY());

    }

    public void onMouseDown(MouseDownEvent e) {
        onMouseDown((Element) e.getRelativeElement().cast(), e.getX(), e.getY());
    }

    public void onMouseDown(Element element, int x, int y) {

        if (!isInRangeSelectMode) {
            GWT.log("range start: x1= " + x, null);
            Event.setCapture(element);
            x1 = x;
            rangeIndicator.setWidth("1px");
            trackPanel.add(rangeIndicator, x1, 0);
        } else {
            Event.releaseCapture(element);
            x2 = (x < windowWidth) ? x : windowWidth;
            GWT.log("range   end: x2= " + x2, null);
            trackPanel.remove(rangeIndicator);
            if (x1 >= 0 && x2 >= 0)
                track.onRangeSelect(x1, x2);
        }

        isInRangeSelectMode = !isInRangeSelectMode;
    }

    public void onMouseMove(MouseMoveEvent e) {
        if (!isInRangeSelectMode)
            return;

        int x = e.getX();
        int width = x - x1;
        if (width <= 0) {
            rangeIndicator.removeFromParent();
            trackPanel.add(rangeIndicator, x, 0);
            width = -width;
        }
        if (width >= windowWidth)
            width = windowWidth;
        rangeIndicator.setWidth(width + "px");
    }

}