com.tag.MouseDragAndDrop.java Source code

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Here is the source code for com.tag.MouseDragAndDrop.java

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/**
 * Copyright 2011 Taggart Spilman
 * 
 * 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.tag;

import java.awt.Component;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;

import org.apache.commons.lang3.Validate;

public abstract class MouseDragAndDrop implements MouseListener, MouseMotionListener {

    private Component component;
    private MouseEvent startEvent;
    private MouseEvent dragEvent;

    public MouseDragAndDrop(Component component) {
        Validate.notNull(component, "component must not be null");
        this.component = component;
    }

    public Component getComponent() {
        return component;
    }

    public MouseEvent getStartEvent() {
        return startEvent;
    }

    public abstract void selected(MouseEvent e);

    public abstract void dragged(MouseEvent e);

    public abstract void dropped(MouseEvent press, MouseEvent release);

    @Override
    public final void mouseDragged(MouseEvent e) {
        prepare(e);
        if (e.isConsumed())
            return;

        if (dragEvent == null)
            selected(startEvent);

        dragEvent = e;
        dragged(e);
    }

    protected void prepare(MouseEvent e) {
        int mod = e.getModifiers();
        if ((mod & MouseEvent.BUTTON1_MASK) == 0)
            e.consume();
    }

    @Override
    public final void mouseMoved(MouseEvent e) {
    }

    @Override
    public final void mouseClicked(MouseEvent e) {
    }

    @Override
    public final void mousePressed(MouseEvent e) {
        prepare(e);
        if (e.isConsumed())
            return;

        startEvent = e;
    }

    @Override
    public final void mouseReleased(MouseEvent e) {
        if (dragEvent != null)
            dropped(startEvent, e);

        startEvent = null;
        dragEvent = null;
    }

    @Override
    public final void mouseEntered(MouseEvent e) {
    }

    @Override
    public final void mouseExited(MouseEvent e) {
    }

    public void install() {
        component.addMouseListener(this);
        component.addMouseMotionListener(this);
    }

    public void uninstall() {
        component.removeMouseListener(this);
        component.removeMouseMotionListener(this);
    }

}