bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/navigator/CommonDragAdapter.java - platform/eclipse.platform.ui - Git at Google

 /*******************************************************************************
  * Copyright (c) 2003, 2015 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.ui.navigator;

 import java.util.ArrayList;
 import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Set;

 import org.eclipse.core.runtime.SafeRunner;
 import org.eclipse.jface.util.LocalSelectionTransfer;
 import org.eclipse.jface.viewers.ISelection;
 import org.eclipse.jface.viewers.ISelectionProvider;
 import org.eclipse.jface.viewers.IStructuredSelection;
 import org.eclipse.swt.dnd.DragSource;
 import org.eclipse.swt.dnd.DragSourceAdapter;
 import org.eclipse.swt.dnd.DragSourceEvent;
 import org.eclipse.swt.dnd.Transfer;
 import org.eclipse.swt.widgets.Control;
 import org.eclipse.ui.internal.navigator.NavigatorSafeRunnable;
 import org.eclipse.ui.internal.navigator.Policy;
 import org.eclipse.ui.internal.navigator.dnd.NavigatorPluginDropAction;
 import org.eclipse.ui.part.PluginTransfer;

 /**
  *
  * Provides an implementation of {@link DragSourceAdapter} which uses the
  * extensions provided by the associated {@link INavigatorContentService}.
  *
  * <p>
  * Clients should not need to create an instance of this class unless they are
  * creating their own custom viewer. Otherwise, {@link CommonViewer} configures
  * its drag adapter automatically.
  * </p>
  *
  * @see INavigatorDnDService
  * @see CommonDragAdapterAssistant
  * @see CommonDropAdapter
  * @see CommonDropAdapterAssistant
  * @see CommonViewer
  * @since 3.2
  *
  */
 public final class CommonDragAdapter extends DragSourceAdapter {

 	private final INavigatorContentService contentService;

 	private final ISelectionProvider provider;

 	private CommonDragAdapterAssistant setDataAssistant;

 	private List<CommonDragAdapterAssistant> assistantsToUse;

 	/**
 	 * Create a DragAdapter that drives the configuration of the drag data.
 	 *
 	 * @param aContentService
 	 *            The content service this Drag Adapter is associated with
 	 * @param aProvider
 	 *            The provider that can give the current selection from the
 	 *            appropriate viewer.
 	 */
 	public CommonDragAdapter(INavigatorContentService aContentService,
 			ISelectionProvider aProvider) {
 		super();
 		contentService = aContentService;
 		provider = aProvider;
 		assistantsToUse = new ArrayList<CommonDragAdapterAssistant>();
 	}

 	/**
 	 *
 	 * @return An array of supported Drag Transfer types. The list contains [
 	 *         {@link LocalSelectionTransfer#getTransfer()},
 	 *         {@link PluginTransfer#getInstance()}] in addition to any
 	 *         supported types contributed by the
 	 *         {@link CommonDragAdapterAssistant assistants}.
 	 * @see CommonDragAdapterAssistant
 	 * @see LocalSelectionTransfer
 	 * @see PluginTransfer
 	 */
 	public Transfer[] getSupportedDragTransfers() {
 		CommonDragAdapterAssistant[] assistants = contentService
 				.getDnDService().getCommonDragAssistants();

 		Set<Transfer> supportedTypes = new LinkedHashSet<Transfer>();
 		supportedTypes.add(PluginTransfer.getInstance());
 		supportedTypes.add(LocalSelectionTransfer.getTransfer());
 		Transfer[] transferTypes = null;
 		for (CommonDragAdapterAssistant assistant : assistants) {
 			transferTypes = assistant.getSupportedTransferTypes();
 			for (Transfer transferType : transferTypes) {
 				if (transferType != null) {
 					supportedTypes.add(transferType);
 				}
 			}
 		}

 		Transfer[] transfers = supportedTypes
 				.toArray(new Transfer[supportedTypes.size()]);
 		return transfers;
 	}

 	@Override
 	public void dragStart(final DragSourceEvent event) {
 		if (Policy.DEBUG_DND) {
 			System.out.println("CommonDragAdapter.dragStart (begin): " + event); //$NON-NLS-1$
 		}
 		SafeRunner.run(new NavigatorSafeRunnable() {
 			@Override
 			public void run() throws Exception {
 				DragSource dragSource = (DragSource) event.widget;
 				if (Policy.DEBUG_DND) {
 					System.out.println("CommonDragAdapter.dragStart source: " + dragSource); //$NON-NLS-1$
 				}
 				Control control = dragSource.getControl();
 				if (control == control.getDisplay().getFocusControl()) {
 					ISelection selection = provider.getSelection();
 					assistantsToUse.clear();

 					if (!selection.isEmpty()) {
 						LocalSelectionTransfer.getTransfer().setSelection(selection);

 						boolean doIt = false;
 						INavigatorDnDService dndService = contentService.getDnDService();
 						CommonDragAdapterAssistant[] assistants = dndService
 								.getCommonDragAssistants();
 						if (assistants.length == 0)
 							doIt = true;
 						for (CommonDragAdapterAssistant assistant : assistants) {
 							if (Policy.DEBUG_DND) {
 								System.out
 										.println("CommonDragAdapter.dragStart assistant: " + assistant); //$NON-NLS-1$
 							}
 							event.doit = true;
 							assistant.dragStart(event, (IStructuredSelection) selection);
 							doIt |= event.doit;
 							if (event.doit) {
 								if (Policy.DEBUG_DND) {
 									System.out
 											.println("CommonDragAdapter.dragStart assistant - event.doit == true"); //$NON-NLS-1$
 								}
 								assistantsToUse.add(assistant);
 							}
 						}

 						event.doit = doIt;
 					} else {
 						event.doit = false;
 					}
 				} else {
 					event.doit = false;
 				}
 			}
 		});

 		if (Policy.DEBUG_DND) {
 			System.out.println("CommonDragAdapter.dragStart (end): doit=" + event.doit); //$NON-NLS-1$
 		}
 	}

 	@Override
 	public void dragSetData(final DragSourceEvent event) {

 		final ISelection selection = LocalSelectionTransfer.getTransfer()
 				.getSelection();

 		if (Policy.DEBUG_DND) {
 			System.out
 					.println("CommonDragAdapter.dragSetData: event" + event + " selection=" + selection); //$NON-NLS-1$ //$NON-NLS-2$
 		}

 		if (LocalSelectionTransfer.getTransfer()
 				.isSupportedType(event.dataType)) {
 			event.data = selection;

 			if (Policy.DEBUG_DND) {
 				System.out
 						.println("CommonDragAdapter.dragSetData set LocalSelectionTransfer: " + event.data); //$NON-NLS-1$
 			}
 		} else if (PluginTransfer.getInstance().isSupportedType(event.dataType)) {
 			event.data = NavigatorPluginDropAction
 					.createTransferData(contentService);
 			if (Policy.DEBUG_DND) {
 				System.out
 						.println("CommonDragAdapter.dragSetData set PluginTransfer: " + event.data); //$NON-NLS-1$
 			}
 		} else if (selection instanceof IStructuredSelection) {
 			if (Policy.DEBUG_DND) {
 				System.out
 						.println("CommonDragAdapter.dragSetData looking for assistants"); //$NON-NLS-1$
 			}

 			for (int i = 0, len = assistantsToUse.size(); i < len; i++) {
 				final CommonDragAdapterAssistant assistant = assistantsToUse.get(i);
 				if (Policy.DEBUG_DND) {
 					System.out
 							.println("CommonDragAdapter.dragSetData assistant: " + assistant); //$NON-NLS-1$
 				}

 				Transfer[] supportedTransferTypes = assistant
 						.getSupportedTransferTypes();
 				final boolean[] getOut = new boolean[1];
 				for (Transfer supportedTransferType : supportedTransferTypes) {
 					if (supportedTransferType.isSupportedType(event.dataType)) {
 						SafeRunner.run(new NavigatorSafeRunnable() {
 							@Override
 							public void run() throws Exception {
 								if (Policy.DEBUG_DND) {
 									System.out
 											.println("CommonDragAdapter.dragSetData supported xfer type"); //$NON-NLS-1$
 								}
 								if (assistant.setDragData(event, (IStructuredSelection) selection)) {
 									if (Policy.DEBUG_DND) {
 										System.out
 												.println("CommonDragAdapter.dragSetData set data " + event.data); //$NON-NLS-1$
 									}
 									setDataAssistant = assistant;
 									getOut[0] = true;
 								}
 							}
 						});
 						if (getOut[0])
 							return;
 					}
 				}
 			}

 			if (Policy.DEBUG_DND) {
 				System.out
 						.println("CommonDragAdapter.dragSetData FAILED no assistant handled it"); //$NON-NLS-1$
 			}
 			event.doit = false;

 		} else {
 			if (Policy.DEBUG_DND) {
 				System.out
 						.println("CommonDragAdapter.dragSetData FAILED can't identify transfer type"); //$NON-NLS-1$
 			}
 			event.doit = false;
 		}
 	}

 	@Override
 	public void dragFinished(DragSourceEvent event) {

 		if (Policy.DEBUG_DND) {
 			System.out.println("CommonDragAdapter.dragFinished(): " + event); //$NON-NLS-1$
 		}

 		ISelection selection = LocalSelectionTransfer.getTransfer().getSelection();

 		if (event.doit && selection instanceof IStructuredSelection && setDataAssistant != null)
 			setDataAssistant.dragFinished(event, (IStructuredSelection) selection);

 		setDataAssistant = null;

 		LocalSelectionTransfer.getTransfer().setSelection(null);

 		// TODO Handle clean up if drop target was outside of workbench
 		// if (event.doit != false) {
 		//
 		// }
 	}

 }
	/*******************************************************************************
	* Copyright (c) 2003, 2015 IBM Corporation and others.
	* All rights reserved. This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License v1.0
	* which accompanies this distribution, and is available at
	* http://www.eclipse.org/legal/epl-v10.html
	*
	* Contributors:
	* IBM Corporation - initial API and implementation
	*******************************************************************************/
	package org.eclipse.ui.navigator;

	import java.util.ArrayList;
	import java.util.LinkedHashSet;
	import java.util.List;
	import java.util.Set;

	import org.eclipse.core.runtime.SafeRunner;
	import org.eclipse.jface.util.LocalSelectionTransfer;
	import org.eclipse.jface.viewers.ISelection;
	import org.eclipse.jface.viewers.ISelectionProvider;
	import org.eclipse.jface.viewers.IStructuredSelection;
	import org.eclipse.swt.dnd.DragSource;
	import org.eclipse.swt.dnd.DragSourceAdapter;
	import org.eclipse.swt.dnd.DragSourceEvent;
	import org.eclipse.swt.dnd.Transfer;
	import org.eclipse.swt.widgets.Control;
	import org.eclipse.ui.internal.navigator.NavigatorSafeRunnable;
	import org.eclipse.ui.internal.navigator.Policy;
	import org.eclipse.ui.internal.navigator.dnd.NavigatorPluginDropAction;
	import org.eclipse.ui.part.PluginTransfer;

	/**
	*
	* Provides an implementation of {@link DragSourceAdapter} which uses the
	* extensions provided by the associated {@link INavigatorContentService}.
	*
	* <p>
	* Clients should not need to create an instance of this class unless they are
	* creating their own custom viewer. Otherwise, {@link CommonViewer} configures
	* its drag adapter automatically.
	* </p>
	*
	* @see INavigatorDnDService
	* @see CommonDragAdapterAssistant
	* @see CommonDropAdapter
	* @see CommonDropAdapterAssistant
	* @see CommonViewer
	* @since 3.2
	*
	*/
	public final class CommonDragAdapter extends DragSourceAdapter {

	private final INavigatorContentService contentService;

	private final ISelectionProvider provider;

	private CommonDragAdapterAssistant setDataAssistant;

	private List<CommonDragAdapterAssistant> assistantsToUse;

	/**
	* Create a DragAdapter that drives the configuration of the drag data.
	*
	* @param aContentService
	* The content service this Drag Adapter is associated with
	* @param aProvider
	* The provider that can give the current selection from the
	* appropriate viewer.
	*/
	public CommonDragAdapter(INavigatorContentService aContentService,
	ISelectionProvider aProvider) {
	super();
	contentService = aContentService;
	provider = aProvider;
	assistantsToUse = new ArrayList<CommonDragAdapterAssistant>();
	}

	/**
	*
	* @return An array of supported Drag Transfer types. The list contains [
	* {@link LocalSelectionTransfer#getTransfer()},
	* {@link PluginTransfer#getInstance()}] in addition to any
	* supported types contributed by the
	* {@link CommonDragAdapterAssistant assistants}.
	* @see CommonDragAdapterAssistant
	* @see LocalSelectionTransfer
	* @see PluginTransfer
	*/
	public Transfer[] getSupportedDragTransfers() {
	CommonDragAdapterAssistant[] assistants = contentService
	.getDnDService().getCommonDragAssistants();

	Set<Transfer> supportedTypes = new LinkedHashSet<Transfer>();
	supportedTypes.add(PluginTransfer.getInstance());
	supportedTypes.add(LocalSelectionTransfer.getTransfer());
	Transfer[] transferTypes = null;
	for (CommonDragAdapterAssistant assistant : assistants) {
	transferTypes = assistant.getSupportedTransferTypes();
	for (Transfer transferType : transferTypes) {
	if (transferType != null) {
	supportedTypes.add(transferType);
	}
	}
	}

	Transfer[] transfers = supportedTypes
	.toArray(new Transfer[supportedTypes.size()]);
	return transfers;
	}

	@Override
	public void dragStart(final DragSourceEvent event) {
	if (Policy.DEBUG_DND) {
	System.out.println("CommonDragAdapter.dragStart (begin): " + event); //$NON-NLS-1$
	}
	SafeRunner.run(new NavigatorSafeRunnable() {
	@Override
	public void run() throws Exception {
	DragSource dragSource = (DragSource) event.widget;
	if (Policy.DEBUG_DND) {
	System.out.println("CommonDragAdapter.dragStart source: " + dragSource); //$NON-NLS-1$
	}
	Control control = dragSource.getControl();
	if (control == control.getDisplay().getFocusControl()) {
	ISelection selection = provider.getSelection();
	assistantsToUse.clear();

	if (!selection.isEmpty()) {
	LocalSelectionTransfer.getTransfer().setSelection(selection);

	boolean doIt = false;
	INavigatorDnDService dndService = contentService.getDnDService();
	CommonDragAdapterAssistant[] assistants = dndService
	.getCommonDragAssistants();
	if (assistants.length == 0)
	doIt = true;
	for (CommonDragAdapterAssistant assistant : assistants) {
	if (Policy.DEBUG_DND) {
	System.out
	.println("CommonDragAdapter.dragStart assistant: " + assistant); //$NON-NLS-1$
	}
	event.doit = true;
	assistant.dragStart(event, (IStructuredSelection) selection);
	doIt \|= event.doit;
	if (event.doit) {
	if (Policy.DEBUG_DND) {
	System.out
	.println("CommonDragAdapter.dragStart assistant - event.doit == true"); //$NON-NLS-1$
	}
	assistantsToUse.add(assistant);
	}
	}

	event.doit = doIt;
	} else {
	event.doit = false;
	}
	} else {
	event.doit = false;
	}
	}
	});

	if (Policy.DEBUG_DND) {
	System.out.println("CommonDragAdapter.dragStart (end): doit=" + event.doit); //$NON-NLS-1$
	}
	}

	@Override
	public void dragSetData(final DragSourceEvent event) {

	final ISelection selection = LocalSelectionTransfer.getTransfer()
	.getSelection();

	if (Policy.DEBUG_DND) {
	System.out
	.println("CommonDragAdapter.dragSetData: event" + event + " selection=" + selection); //$NON-NLS-1$ //$NON-NLS-2$
	}

	if (LocalSelectionTransfer.getTransfer()
	.isSupportedType(event.dataType)) {
	event.data = selection;

	if (Policy.DEBUG_DND) {
	System.out
	.println("CommonDragAdapter.dragSetData set LocalSelectionTransfer: " + event.data); //$NON-NLS-1$
	}
	} else if (PluginTransfer.getInstance().isSupportedType(event.dataType)) {
	event.data = NavigatorPluginDropAction
	.createTransferData(contentService);
	if (Policy.DEBUG_DND) {
	System.out
	.println("CommonDragAdapter.dragSetData set PluginTransfer: " + event.data); //$NON-NLS-1$
	}
	} else if (selection instanceof IStructuredSelection) {
	if (Policy.DEBUG_DND) {
	System.out
	.println("CommonDragAdapter.dragSetData looking for assistants"); //$NON-NLS-1$
	}

	for (int i = 0, len = assistantsToUse.size(); i < len; i++) {
	final CommonDragAdapterAssistant assistant = assistantsToUse.get(i);
	if (Policy.DEBUG_DND) {
	System.out
	.println("CommonDragAdapter.dragSetData assistant: " + assistant); //$NON-NLS-1$
	}

	Transfer[] supportedTransferTypes = assistant
	.getSupportedTransferTypes();
	final boolean[] getOut = new boolean[1];
	for (Transfer supportedTransferType : supportedTransferTypes) {
	if (supportedTransferType.isSupportedType(event.dataType)) {
	SafeRunner.run(new NavigatorSafeRunnable() {
	@Override
	public void run() throws Exception {
	if (Policy.DEBUG_DND) {
	System.out
	.println("CommonDragAdapter.dragSetData supported xfer type"); //$NON-NLS-1$
	}
	if (assistant.setDragData(event, (IStructuredSelection) selection)) {
	if (Policy.DEBUG_DND) {
	System.out
	.println("CommonDragAdapter.dragSetData set data " + event.data); //$NON-NLS-1$
	}
	setDataAssistant = assistant;
	getOut[0] = true;
	}
	}
	});
	if (getOut[0])
	return;
	}
	}
	}

	if (Policy.DEBUG_DND) {
	System.out
	.println("CommonDragAdapter.dragSetData FAILED no assistant handled it"); //$NON-NLS-1$
	}
	event.doit = false;

	} else {
	if (Policy.DEBUG_DND) {
	System.out
	.println("CommonDragAdapter.dragSetData FAILED can't identify transfer type"); //$NON-NLS-1$
	}
	event.doit = false;
	}
	}

	@Override
	public void dragFinished(DragSourceEvent event) {

	if (Policy.DEBUG_DND) {
	System.out.println("CommonDragAdapter.dragFinished(): " + event); //$NON-NLS-1$
	}

	ISelection selection = LocalSelectionTransfer.getTransfer().getSelection();

	if (event.doit && selection instanceof IStructuredSelection && setDataAssistant != null)
	setDataAssistant.dragFinished(event, (IStructuredSelection) selection);

	setDataAssistant = null;

	LocalSelectionTransfer.getTransfer().setSelection(null);

	// TODO Handle clean up if drop target was outside of workbench
	// if (event.doit != false) {
	//
	// }
	}

	}