org.smallmind.swing.dragndrop.DropHandler Maven / Gradle / Ivy
/*
* Copyright (c) 2007 through 2024 David Berkman
*
* This file is part of the SmallMind Code Project.
*
* The SmallMind Code Project is free software, you can redistribute
* it and/or modify it under either, at your discretion...
*
* 1) The terms of GNU Affero General Public License as published by the
* Free Software Foundation, either version 3 of the License, or (at
* your option) any later version.
*
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* 2) The terms of the Apache License, Version 2.0.
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* The SmallMind Code Project is distributed in the hope that it will
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* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License or Apache License for more details.
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* ------------------------------------------------------------------
* If you modify this Program, or any covered work, by linking or
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package org.smallmind.swing.dragndrop;
import java.awt.Component;
import java.awt.dnd.DropTarget;
import java.awt.dnd.DropTargetDragEvent;
import java.awt.dnd.DropTargetDropEvent;
import java.awt.dnd.DropTargetEvent;
import java.awt.dnd.DropTargetListener;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;
public abstract class DropHandler implements DropTargetListener {
private static final AtomicBoolean DROP_PERMISSION = new AtomicBoolean(false);
private static final AtomicInteger DROP_ACTIONS = new AtomicInteger(0);
private final DropTarget dropTarget;
private final int actions;
public DropHandler (Component component, int actions) {
this(component, actions, true);
}
public DropHandler (Component component, int actions, boolean active) {
this.actions = actions;
dropTarget = new DropTarget(component, actions, this, active);
}
public static boolean hasDropPermission () {
return DROP_PERMISSION.get();
}
public static int getCurrentDropActions () {
return DROP_ACTIONS.get();
}
public abstract boolean canDrop (DropTargetDragEvent dropTargetDragEvent);
public abstract boolean dropComplete (DropTargetDropEvent dropTargetDropEvent);
public boolean isActive () {
return dropTarget.isActive();
}
public void setActive (boolean active) {
dropTarget.setActive(active);
}
@Override
public void dragEnter (DropTargetDragEvent dropTargetDragEvent) {
DROP_ACTIONS.set(actions);
}
@Override
public void dragOver (DropTargetDragEvent dropTargetDragEvent) {
DROP_PERMISSION.set(canDrop(dropTargetDragEvent));
}
@Override
public void dropActionChanged (DropTargetDragEvent dropTargetDragEvent) {
}
@Override
public void dragExit (DropTargetEvent dropTargetEvent) {
}
@Override
public void drop (DropTargetDropEvent dropTargetDropEvent) {
if ((dropTargetDropEvent.getDropAction() & actions) != 0) {
dropTargetDropEvent.acceptDrop(dropTargetDropEvent.getDropAction());
dropTargetDropEvent.getDropTargetContext().dropComplete(dropComplete(dropTargetDropEvent));
} else {
dropTargetDropEvent.rejectDrop();
}
}
}