Create temporary decorations for project nodes

The label decoration of project nodes contains important information,
i.e. the repository name as well as the current branch. This change
introduces a temporary decoration for project nodes that only contains
this textual (label) information and is shown immediately. The final
decoration is shown as soon as a full recursive walk through the whole
project has been performed.

Change-Id: I376b9284b35bfc5960102182753ed90498da0829
Signed-off-by: Philipp Thun <philipp.thun@sap.com>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

3 files changed, 108 insertions, 47 deletions

diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/decorators/DecoratableResourceAdapter.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/decorators/DecoratableResourceAdapter.java
index 5eddaf7b67..05c19ed381 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/decorators/DecoratableResourceAdapter.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/decorators/DecoratableResourceAdapter.java
@@ -36,9 +36,7 @@ import org.eclipse.jgit.errors.MissingObjectException;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.FileMode;
 import org.eclipse.jgit.lib.ObjectId;
-import org.eclipse.jgit.lib.Ref;
 import org.eclipse.jgit.lib.Repository;
-import org.eclipse.jgit.lib.RepositoryState;
 import org.eclipse.jgit.revwalk.RevWalk;
 import org.eclipse.jgit.treewalk.EmptyTreeIterator;
 import org.eclipse.jgit.treewalk.TreeWalk;
@@ -75,16 +73,11 @@ class DecoratableResourceAdapter extends DecoratableResource {
 			mapping = RepositoryMapping.getMapping(resource);
 			repository = mapping.getRepository();
 			headId = repository.resolve(Constants.HEAD);
-
 			store = Activator.getDefault().getPreferenceStore();
-			String repoName = Activator.getDefault().getRepositoryUtil().getRepositoryName(repository);
-			RepositoryState state = repository.getRepositoryState();
-			if (state != RepositoryState.SAFE)
-				repositoryName = repoName + '|' + state.getDescription();
-			else
-				repositoryName = repoName;
 
-			branch = getShortBranch();
+			repositoryName = DecoratableResourceHelper
+					.getRepositoryName(repository);
+			branch = DecoratableResourceHelper.getShortBranch(repository);
 
 			TreeWalk treeWalk = createThreeWayTreeWalk();
 			if (treeWalk == null)
@@ -112,22 +105,6 @@ class DecoratableResourceAdapter extends DecoratableResource {
 		}
 	}
 
-	private String getShortBranch() throws IOException {
-		Ref head = repository.getRef(Constants.HEAD);
-		if (head != null && !head.isSymbolic()) {
-			String refString = Activator.getDefault().getRepositoryUtil()
-					.mapCommitToRef(repository, repository.getFullBranch(),
-							false);
-			if (refString != null) {
-				return repository.getFullBranch().substring(0, 7)
-						+ "... (" + refString + ")"; //$NON-NLS-1$ //$NON-NLS-2$
-			} else
-				return repository.getFullBranch().substring(0, 7) + "..."; //$NON-NLS-1$
-		}
-
-		return repository.getBranch();
-	}
-
 	private void extractResourceProperties(TreeWalk treeWalk) throws IOException {
 		DecoratableResourceHelper.decorateResource(this, treeWalk);
 	}
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/decorators/DecoratableResourceHelper.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/decorators/DecoratableResourceHelper.java
index 9a72f20300..6826a8ddfc 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/decorators/DecoratableResourceHelper.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/decorators/DecoratableResourceHelper.java
@@ -13,11 +13,13 @@ import java.util.ArrayList;
 import java.util.Map;
 import java.util.WeakHashMap;
 
+import org.eclipse.core.resources.IProject;
 import org.eclipse.core.resources.IResource;
 import org.eclipse.egit.core.ContainerTreeIterator;
 import org.eclipse.egit.core.ContainerTreeIterator.ResourceEntry;
 import org.eclipse.egit.core.IteratorService;
 import org.eclipse.egit.core.project.RepositoryMapping;
+import org.eclipse.egit.ui.Activator;
 import org.eclipse.egit.ui.internal.decorators.IDecoratableResource.Staged;
 import org.eclipse.jgit.dircache.DirCache;
 import org.eclipse.jgit.dircache.DirCacheEntry;
@@ -25,7 +27,9 @@ import org.eclipse.jgit.dircache.DirCacheIterator;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.FileMode;
 import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.lib.Ref;
 import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.lib.RepositoryState;
 import org.eclipse.jgit.revwalk.RevWalk;
 import org.eclipse.jgit.treewalk.EmptyTreeIterator;
 import org.eclipse.jgit.treewalk.TreeWalk;
@@ -128,6 +132,29 @@ public class DecoratableResourceHelper {
 		return decoratableResources;
 	}
 
+	/**
+	 * Creates a temporary decoratable resource for the given project
+	 *
+	 * This temporary decoratable resource only contains the name of the
+	 * repository and the current branch.
+	 *
+	 * @param project
+	 *            the project to be decorated
+	 * @return the decoratable resource
+	 * @throws IOException
+	 */
+	static IDecoratableResource createTemporaryDecoratableResource(
+			final IProject project) throws IOException {
+		final DecoratableResource decoratableResource = new DecoratableResource(
+				project);
+		final Repository repository = RepositoryMapping.getMapping(project)
+				.getRepository();
+		decoratableResource.repositoryName = getRepositoryName(repository);
+		decoratableResource.branch = getShortBranch(repository);
+		decoratableResource.tracked = true;
+		return decoratableResource;
+	}
+
 	static DirCache getDirCache(Repository repository) throws IOException {
 		synchronized(repoToDirCache) {
 			DirCache dirCache = repoToDirCache.get(repository);
@@ -233,4 +260,32 @@ public class DecoratableResourceHelper {
 		}
 		return decoratableResource;
 	}
+
+	static String getRepositoryName(Repository repository) {
+		String repoName = Activator.getDefault().getRepositoryUtil()
+				.getRepositoryName(repository);
+		RepositoryState state = repository.getRepositoryState();
+		if (state != RepositoryState.SAFE)
+			return repoName + '|' + state.getDescription();
+		else
+			return repoName;
+	}
+
+	static String getShortBranch(Repository repository) throws IOException {
+		Ref head = repository.getRef(Constants.HEAD);
+		if (head != null && !head.isSymbolic()) {
+			String refString = Activator
+					.getDefault()
+					.getRepositoryUtil()
+					.mapCommitToRef(repository, repository.getFullBranch(),
+							false);
+			if (refString != null) {
+				return repository.getFullBranch().substring(0, 7)
+						+ "... (" + refString + ")"; //$NON-NLS-1$ //$NON-NLS-2$
+			} else
+				return repository.getFullBranch().substring(0, 7) + "..."; //$NON-NLS-1$
+		}
+
+		return repository.getBranch();
+	}
 }
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/decorators/GitLightweightDecorator.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/decorators/GitLightweightDecorator.java
index 38df16a34d..e2e8f3389c 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/decorators/GitLightweightDecorator.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/decorators/GitLightweightDecorator.java
@@ -205,6 +205,8 @@ public class GitLightweightDecorator extends LabelProvider implements
 		if (resource == null)
 			return;
 
+		// Step 1: Perform cheap tests
+
 		// Don't decorate if the workbench is not running
 		if (!PlatformUI.isWorkbenchRunning())
 			return;
@@ -222,34 +224,36 @@ public class GitLightweightDecorator extends LabelProvider implements
 		if (!resource.exists() && !resource.isPhantom())
 			return;
 
+		IDecoratableResource decoratableResource = null;
+		final DecorationHelper helper = new DecorationHelper(
+				activator.getPreferenceStore());
+
+		// Step 2: Read session properties
+
 		try {
 			final Boolean notDecoratable = (Boolean) resource
 					.getSessionProperty(NOT_DECORATABLE_KEY);
 			if (notDecoratable != null && notDecoratable.equals(Boolean.TRUE))
-				// Resource is not decoratable, do not try again
+				// Step 2a: Return - resource is not decoratable
 				return;
 
-			final IDecoratableResource decoratableResource = (IDecoratableResource) resource
+			decoratableResource = (IDecoratableResource) resource
 					.getSessionProperty(DECORATABLE_RESOURCE_KEY);
-			boolean decorated = false;
 			if (decoratableResource != null) {
-				// Use stored decoratable resource (even when it is outdated)
-				final DecorationHelper helper = new DecorationHelper(
-						activator.getPreferenceStore());
-				helper.decorate(decoration, decoratableResource);
-				decorated = true;
-			}
-
-			final Long refreshed = (Long) resource
-					.getSessionProperty(REFRESHED_KEY);
-			if (refreshed != null) {
-				final Long refresh = (Long) resource.getWorkspace().getRoot()
-						.getSessionProperty(REFRESH_KEY);
-				if (refresh == null
-						|| refresh.longValue() <= refreshed.longValue()) {
-					// Stored decoratable resource is up-to-date
-					if (decorated)
+				final Long refreshed = (Long) resource
+						.getSessionProperty(REFRESHED_KEY);
+				if (refreshed != null) {
+					final Long refresh = (Long) resource.getWorkspace()
+							.getRoot().getSessionProperty(REFRESH_KEY);
+					if (refresh == null
+							|| refresh.longValue() <= refreshed.longValue()) {
+						// Condition: Stored decoratable resource exists and is
+						// up-to-date
+						//
+						// Step 2b: Apply stored decoratable resource and return
+						helper.decorate(decoration, decoratableResource);
 						return;
+					}
 				}
 			}
 		} catch (CoreException e) {
@@ -257,6 +261,11 @@ public class GitLightweightDecorator extends LabelProvider implements
 			return;
 		}
 
+		// Condition: Stored decoratable resource either not exists or is
+		// out-dated
+		//
+		// Step 3: Perform more expensive tests
+
 		// Don't decorate ignored resources (e.g. bin folder content)
 		if (Team.isIgnoredHint(resource))
 			return;
@@ -271,8 +280,28 @@ public class GitLightweightDecorator extends LabelProvider implements
 		if (mapping.getRepoRelativePath(resource) == null)
 			return;
 
-		// No (up-to-date) stored decoratable resource is available, thus
-		// decoration request is added to the queue
+		// Step 4: For project nodes only: create temporary decoratable resource
+		if (resource.getType() == IResource.PROJECT) {
+			try {
+				decoratableResource = DecoratableResourceHelper
+						.createTemporaryDecoratableResource(resource
+								.getProject());
+			} catch (IOException e) {
+				handleException(
+						resource,
+						new CoreException(Activator.createErrorStatus(
+								UIText.Decorator_exceptionMessage, e)));
+				return;
+			}
+		}
+
+		// Step 5: Apply out-dated or temporary decoratable resource and
+		// continue
+		if (decoratableResource != null) {
+			helper.decorate(decoration, decoratableResource);
+		}
+
+		// Step 6: Add decoration request to the queue
 		GitDecoratorJob.getJobForRepository(
 				mapping.getGitDirAbsolutePath().toString())
 				.addDecorationRequest(element);