Java tutorial
/******************************************************************************* * Copyright (C) 2008, Marek Zawirski <marek.zawirski@gmail.com> * Copyright (C) 2010, Chris Aniszczyk <caniszczyk@gmail.com> * * 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 *******************************************************************************/ package org.eclipse.egit.ui.internal.components; import java.io.IOException; import org.eclipse.egit.ui.Activator; import org.eclipse.egit.ui.UIText; import org.eclipse.jface.fieldassist.IContentProposal; import org.eclipse.jgit.lib.Constants; import org.eclipse.jgit.lib.ObjectId; import org.eclipse.jgit.lib.ObjectLoader; import org.eclipse.jgit.lib.ObjectReader; import org.eclipse.jgit.lib.PersonIdent; import org.eclipse.jgit.lib.Ref; import org.eclipse.jgit.lib.Repository; import org.eclipse.jgit.revwalk.RevCommit; import org.eclipse.jgit.revwalk.RevTag; import org.eclipse.jgit.revwalk.RevWalk; import org.eclipse.osgi.util.NLS; /** * Content proposal class for refs names, specifically Ref objects - name with * optionally associated object id. This class can be used for Eclipse field * assist as content proposal. * <p> * Content of this proposal is simply a ref name, but description and labels * tries to be smarter - showing easier to read label for user (stripping * prefixes) and information about pointed object if it exists locally. */ public class RefContentProposal implements IContentProposal { private static final String PREFIXES[] = new String[] { Constants.R_HEADS, Constants.R_REMOTES, Constants.R_TAGS }; private final static String branchPF = " [" //$NON-NLS-1$ + UIText.RefContentProposal_branch + "]"; //$NON-NLS-1$ private final static String trackingBranchPF = " [" //$NON-NLS-1$ + UIText.RefContentProposal_trackingBranch + "]"; //$NON-NLS-1$ private final static String tagPF = " [" //$NON-NLS-1$ + UIText.RefContentProposal_tag + "]"; //$NON-NLS-1$ private static final String PREFIXES_DESCRIPTIONS[] = new String[] { branchPF, trackingBranchPF, tagPF }; private static void appendObjectSummary(final StringBuilder sb, final String type, final PersonIdent author, final String message) { sb.append(type); sb.append(" "); //$NON-NLS-1$ sb.append(UIText.RefContentProposal_by); sb.append(" "); //$NON-NLS-1$ sb.append(author.getName()); sb.append("\n"); //$NON-NLS-1$ sb.append(author.getWhen()); sb.append("\n\n"); //$NON-NLS-1$ final int newLine = message.indexOf('\n'); final int last = (newLine != -1 ? newLine : message.length()); sb.append(message.substring(0, last)); } private final Repository db; private final String refName; private final ObjectId objectId; /** * Create content proposal for specified ref. * * @param repo * repository for accessing information about objects. Could be a * local repository even for remote objects. * @param ref * ref being a content proposal. May have null or locally * non-existent object id. */ public RefContentProposal(final Repository repo, final Ref ref) { this(repo, ref.getName(), ref.getObjectId()); } /** * Create content proposal for specified ref name and object id. * * @param repo * repository for accessing information about objects. Could be a * local repository even for remote objects. * @param refName * ref name being a content proposal. * @param objectId * object being pointed by this ref name. May be null or locally * non-existent object. */ public RefContentProposal(final Repository repo, final String refName, final ObjectId objectId) { this.db = repo; this.refName = refName; this.objectId = objectId; } public String getContent() { return refName; } public int getCursorPosition() { return refName.length(); } public String getDescription() { if (objectId == null) return null; ObjectReader reader = db.newObjectReader(); try { final ObjectLoader loader = reader.open(objectId); final StringBuilder sb = new StringBuilder(); sb.append(refName); sb.append('\n'); sb.append(reader.abbreviate(objectId).name()); sb.append(" - "); //$NON-NLS-1$ switch (loader.getType()) { case Constants.OBJ_COMMIT: RevCommit c = new RevWalk(db).parseCommit(objectId); appendObjectSummary(sb, UIText.RefContentProposal_commit, c.getAuthorIdent(), c.getFullMessage()); break; case Constants.OBJ_TAG: RevWalk walk = new RevWalk(db); RevTag t = walk.parseTag(objectId); appendObjectSummary(sb, UIText.RefContentProposal_tag, t.getTaggerIdent(), t.getFullMessage()); break; case Constants.OBJ_TREE: sb.append(UIText.RefContentProposal_tree); break; case Constants.OBJ_BLOB: sb.append(UIText.RefContentProposal_blob); break; default: sb.append(UIText.RefContentProposal_unknownObject); } return sb.toString(); } catch (IOException e) { Activator.logError(NLS.bind(UIText.RefContentProposal_errorReadingObject, objectId), e); return null; } finally { reader.release(); } } public String getLabel() { for (int i = 0; i < PREFIXES.length; i++) if (refName.startsWith(PREFIXES[i])) return refName.substring(PREFIXES[i].length()) + PREFIXES_DESCRIPTIONS[i]; return refName; } }