+++ /dev/null
-/*******************************************************************************
- * Copyright (c) 2000, 2003 IBM Corporation and others.
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the Common Public License v1.0
- * which accompanies this distribution, and is available at
- * http://www.eclipse.org/legal/cpl-v10.html
- *
- * Contributors:
- * IBM Corporation - initial API and implementation
- *******************************************************************************/
-package net.sourceforge.phpdt.internal.ui.dnd;
-
-import org.eclipse.swt.dnd.DND;
-import org.eclipse.swt.dnd.DropTargetEvent;
-import org.eclipse.swt.dnd.DropTargetListener;
-import org.eclipse.swt.graphics.Point;
-import org.eclipse.swt.graphics.Rectangle;
-import org.eclipse.swt.widgets.Item;
-import org.eclipse.swt.widgets.TableItem;
-import org.eclipse.swt.widgets.TreeItem;
-
-import org.eclipse.jface.util.Assert;
-import org.eclipse.jface.viewers.StructuredViewer;
-
-/**
- * A drag and drop adapter to be used together with structured viewers.
- * The adapater delegates the <code>dragEnter</code>, <code>dragOperationChanged
- * </code>, <code>dragOver</code> and <code>dropAccept</code> method to the
- * <code>validateDrop</code> method. Furthermore it adds location feedback.
- */
-public class JdtViewerDropAdapter implements DropTargetListener {
-
- /**
- * Constant describing the position of the mouse cursor relative
- * to the target object. This means the mouse is positioned
- * slightly before the target.
- */
- protected static final int LOCATION_BEFORE= 1;
-
- /**
- * Constant describing the position of the mouse cursor relative
- * to the target object. This means the mouse is positioned
- * slightly after the target.
- */
- protected static final int LOCATION_AFTER= 2;
-
- /**
- * Constant describing the position of the mouse cursor relative
- * to the target object. This means the mouse is positioned
- * directly on the target.
- */
- protected static final int LOCATION_ON= 3;
-
- /**
- * Constant describing the position of the mouse cursor relative
- * to the target object. This means the mouse is not positioned
- * over or near any valid target.
- */
- protected static final int LOCATION_NONE= 4;
-
- /**
- * The threshold used to determine if the mouse is before or after
- * an item.
- */
- private static final int LOCATION_EPSILON= 5;
-
- /**
- * Style to enable location feedback.
- */
- public static final int INSERTION_FEEDBACK= 1 << 1;
-
- private StructuredViewer fViewer;
- private int fFeedback;
- private boolean fShowInsertionFeedback;
- private int fRequestedOperation;
- private int fLastOperation;
- protected int fLocation;
- protected Object fTarget;
-
- public JdtViewerDropAdapter(StructuredViewer viewer, int feedback) {
- fViewer= viewer;
- Assert.isNotNull(fViewer);
- fFeedback= feedback;
- fLastOperation= -1;
- }
-
- /**
- * Controls whether the drop adapter shows insertion feedback or not.
- *
- * @param showInsertionFeedback <code>true</code> if the drop adapter is supposed
- * to show insertion feedback. Otherwise <code>false</code>
- */
- public void showInsertionFeedback(boolean showInsertionFeedback) {
- fShowInsertionFeedback= showInsertionFeedback;
- }
-
- /**
- * Returns the viewer this adapter is working on.
- */
- protected StructuredViewer getViewer() {
- return fViewer;
- }
-
- //---- Hooks to override -----------------------------------------------------
-
- /**
- * The actual drop has occurred. Calls <code>drop(Object target, DropTargetEvent event)
- * </code>.
- * @see DropTargetListener#drop(org.eclipse.swt.dnd.DropTargetEvent)
- */
- public void drop(DropTargetEvent event) {
- drop(fTarget, event);
- }
-
- /**
- * The actual drop has occurred.
- * @param target the drop target in form of a domain element.
- * @param event the drop traget event
- */
- public void drop(Object target, DropTargetEvent event) {
- }
-
- /**
- * Checks if the drop is valid. The method calls <code>validateDrop
- * (Object target, DropTargetEvent event). Implementors can alter the
- * <code>currentDataType</code> field and the <code>detail</code> field
- * to give feedback about drop acceptence.
- */
- public void validateDrop(DropTargetEvent event) {
- validateDrop(fTarget, event, fRequestedOperation);
- }
-
- /**
- * Checks if the drop on the current target is valid. The method
- * can alter the <code>currentDataType</code> field and the <code>
- * detail</code> field to give feedback about drop acceptence.
- * @param target the drop target in form of a domain element.
- * @param event the drop traget event
- * @param operation the operation requested by the user.
- */
- public void validateDrop(Object target, DropTargetEvent event, int operation) {
- }
-
- public void dragEnter(DropTargetEvent event) {
- dragOperationChanged(event);
- }
-
- public void dragLeave(DropTargetEvent event) {
- fTarget= null;
- fLocation= LOCATION_NONE;
- }
-
- public void dragOperationChanged(DropTargetEvent event) {
- fRequestedOperation= event.detail;
- fTarget= computeTarget(event);
- fLocation= computeLocation(event);
- validateDrop(event);
- fLastOperation= event.detail;
- computeFeedback(event);
- }
-
- public void dragOver(DropTargetEvent event) {
- Object oldTarget= fTarget;
- fTarget= computeTarget(event);
-
- //set the location feedback
- int oldLocation= fLocation;
- fLocation= computeLocation(event);
- if (oldLocation != fLocation || oldTarget != fTarget || fLastOperation != event.detail) {
- validateDrop(event);
- fLastOperation= event.detail;
- } else {
- event.detail= fLastOperation;
- }
- computeFeedback(event);
- }
-
- public void dropAccept(DropTargetEvent event) {
- fTarget= computeTarget(event);
- validateDrop(event);
- fLastOperation= event.detail;
- }
-
- /**
- * Returns the data held by <code>event.item</code>. Inside a viewer
- * this corresponds to the items data model element.
- */
- protected Object computeTarget(DropTargetEvent event) {
- return event.item == null ? null : event.item.getData();
- }
-
- /**
- * Returns the position of the given coordinates relative to the given target.
- * The position is determined to be before, after, or on the item, based on
- * some threshold value. The return value is one of the LOCATION_* constants
- * defined in this class.
- */
- final protected int computeLocation(DropTargetEvent event) {
- if (!(event.item instanceof Item))
- return LOCATION_NONE;
-
- Item item= (Item) event.item;
- Point coordinates= fViewer.getControl().toControl(new Point(event.x, event.y));
- Rectangle bounds= getBounds(item);
- if (bounds == null) {
- return LOCATION_NONE;
- }
- if ((coordinates.y - bounds.y) < LOCATION_EPSILON) {
- return LOCATION_BEFORE;
- }
- if ((bounds.y + bounds.height - coordinates.y) < LOCATION_EPSILON) {
- return LOCATION_AFTER;
- }
- return LOCATION_ON;
- }
-
- /**
- * Returns the bounds of the given item, or <code>null</code> if it is not a
- * valid type of item.
- */
- private Rectangle getBounds(Item item) {
- if (item instanceof TreeItem)
- return ((TreeItem) item).getBounds();
-
- if (item instanceof TableItem)
- return ((TableItem) item).getBounds(0);
-
- return null;
- }
-
- /**
- * Sets the drag under feedback corresponding to the value of <code>fLocation</code>
- * and the <code>INSERTION_FEEDBACK</code> style bit.
- */
- protected void computeFeedback(DropTargetEvent event) {
- if (!fShowInsertionFeedback && fLocation != LOCATION_NONE) {
- event.feedback= DND.FEEDBACK_SELECT;
- } else {
- if (fLocation == LOCATION_BEFORE) {
- event.feedback= DND.FEEDBACK_INSERT_BEFORE;
- } else if (fLocation == LOCATION_AFTER) {
- event.feedback= DND.FEEDBACK_INSERT_AFTER;
- }
- }
- event.feedback|= fFeedback;
- }
-
- /**
- * Sets the drop operation to </code>DROP_NODE<code>.
- */
- protected void clearDropOperation(DropTargetEvent event) {
- event.detail= DND.DROP_NONE;
- }
-
- /**
- * Returns the requested drop operation.
- */
- protected int getRequestedOperation() {
- return fRequestedOperation;
- }
-}
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