| /******************************************************************************* |
| * Copyright (c) 2005, 2007 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.debug.internal.ui.viewers.model.provisional; |
| |
| import org.eclipse.jface.viewers.ISelection; |
| |
| /** |
| * Resolves selection conflicts within a model. When |
| * a selection exists in a viewer, and a client asks |
| * to set another selection, the selection policy for |
| * that model is asked to determine whether the new |
| * selection should override the previous selection. |
| * When a selection is from a different model, the |
| * original selection is maintained if its model selection |
| * policy specifies the selection to be 'sticky'. |
| * <p> |
| * A selection policy is obtained by querying for the selection |
| * policy factory for a given element. The selection policy factory |
| * will then be asked to create a model selection policy adapter. |
| * The adapter represents selections from an instance of a model. |
| * </p> |
| * |
| * @see IModelSelectionPolicyFactory |
| * @since 3.2 |
| */ |
| public interface IModelSelectionPolicy { |
| |
| /** |
| * Returns whether the given selection is contained in |
| * this model. |
| * |
| * @param selection |
| * @param context |
| * @return |
| */ |
| public boolean contains(ISelection selection, IPresentationContext context); |
| |
| /** |
| * Returns whether the candidate selection overrides the |
| * existing selection. The policy is only asked about selections |
| * that it contains. |
| * |
| * @param existing |
| * @param candidate |
| * @param context |
| * @return |
| */ |
| public boolean overrides(ISelection existing, ISelection candidate, IPresentationContext context); |
| |
| /** |
| * Returns whether the given selection should be maintained in the |
| * face of a selection attempt from a different model. |
| * |
| * @param selection |
| * @param context |
| * @return |
| */ |
| public boolean isSticky(ISelection selection, IPresentationContext context); |
| |
| /** |
| * Replaces an invalid selection. |
| * <p> |
| * This method is called if a model change picked up by a viewer |
| * results in an invalid selection. For instance if an element contained in |
| * the selection has been removed from the viewer, the selection policy associated |
| * with the invalid selection is free to specify a new selection. The default |
| * selection policy returns the <code>newSelection</code> as is (with missing |
| * elements removed). Model selection policies may implement a different strategy |
| * for picking a new selection when the old selection becomes invalid. |
| * </p> |
| * |
| * @param invalidSelection |
| * the selection before the viewer was updated |
| * @param newSelection |
| * the selection after the update, or <code>null</code> if none |
| * @return new selection or <code>null</code> if none |
| */ |
| public ISelection replaceInvalidSelection(ISelection invalidSelection, ISelection newSelection); |
| } |