Add support for git variables in launchers

This adds git_dir, git_work_tree, git_repo_relative_path and
git_branch. They all work on the selected or named resource, i.e.
${git_branch} would return the current branch in the (first)
selected project. ${git_branch:org.eclipse.jgit/.project} would
return the current branch of the main JGit repository in the
workspace.

The code to pick the selected resource is stolen from Chris
Aniszczyk's commit on a similar topic.

Change-Id: Idad98f57440eb3b083ffd1be0f382bdac33963e3
Signed-off-by: Robin Rosenberg <robin.rosenberg@dewire.com>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

3 files changed, 208 insertions, 0 deletions

diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/UIText.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/UIText.java
index 34e1ccf9fe..9c0d19d211 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/UIText.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/UIText.java
@@ -3740,6 +3740,15 @@ public class UIText extends NLS {
 	public static String GitActionContributor_Pull;
 
 	/** */
+	public static String GitVariableResolver_InternalError;
+
+	/** */
+	public static String GitVariableResolver_NoSelectedResource;
+
+	/** */
+	public static String GitVariableResolver_VariableReferencesNonExistentResource;
+
+	/** */
 	public static String DecoratableResourceHelper_noHead;
 
 	/** */
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/uitext.properties b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/uitext.properties
index 8f3afc4227..aad6db9505 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/uitext.properties
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/uitext.properties
@@ -1294,6 +1294,9 @@ SwitchToMenu_OtherMenuLabel=&Other...
 GitActionContributor_ExpandAll=Expand All
 GitActionContributor_Push=Push
 GitActionContributor_Pull=Pull
+GitVariableResolver_InternalError=Internal error
+GitVariableResolver_NoSelectedResource=No selected resource
+GitVariableResolver_VariableReferencesNonExistentResource=Variable references non-existent resource : {0}
 
 OpenWorkingFileAction_text=&Open
 OpenWorkingFileAction_tooltip=Open working file
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/variables/GitVariableResolver.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/variables/GitVariableResolver.java
new file mode 100644
index 0000000000..1e4bcfbf69
--- /dev/null
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/variables/GitVariableResolver.java
@@ -0,0 +1,196 @@
+/*******************************************************************************
+ * Copyright (C) 2011, Robin Rosenberg
+ * Copyright (C) 2011, 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.variables;
+
+import java.io.IOException;
+import java.util.Iterator;
+
+import org.eclipse.core.resources.IResource;
+import org.eclipse.core.resources.ResourcesPlugin;
+import org.eclipse.core.runtime.CoreException;
+import org.eclipse.core.runtime.IStatus;
+import org.eclipse.core.runtime.Platform;
+import org.eclipse.core.runtime.Status;
+import org.eclipse.core.variables.IDynamicVariable;
+import org.eclipse.core.variables.IDynamicVariableResolver;
+import org.eclipse.egit.core.project.RepositoryMapping;
+import org.eclipse.egit.ui.Activator;
+import org.eclipse.egit.ui.UIText;
+import org.eclipse.jface.viewers.ISelection;
+import org.eclipse.jface.viewers.ISelectionProvider;
+import org.eclipse.jface.viewers.IStructuredSelection;
+import org.eclipse.osgi.util.NLS;
+import org.eclipse.swt.widgets.Display;
+import org.eclipse.ui.IEditorPart;
+import org.eclipse.ui.IWorkbench;
+import org.eclipse.ui.IWorkbenchPage;
+import org.eclipse.ui.IWorkbenchPart;
+import org.eclipse.ui.IWorkbenchPartSite;
+import org.eclipse.ui.IWorkbenchWindow;
+import org.eclipse.ui.PlatformUI;
+
+/**
+ * Resolves Git related information so launchers can use them
+ */
+public class GitVariableResolver implements IDynamicVariableResolver {
+
+	private static final String GIT_REPO_RELATIVE_PATH = "git_repo_relative_path"; //$NON-NLS-1$
+	private static final String GIT_DIR = "git_dir"; //$NON-NLS-1$
+	private static final String GIT_WORK_TREE = "git_work_tree"; //$NON-NLS-1$
+	private static final String GIT_BRANCH = "git_branch"; //$NON-NLS-1$
+
+	public String resolveValue(IDynamicVariable variable, String argument)
+			throws CoreException {
+		if (variable.getName().equals(GIT_DIR))
+			return getGitDir(argument);
+		if (variable.getName().equals(GIT_REPO_RELATIVE_PATH))
+			return getGitRepoRelativePath(argument);
+		if (variable.getName().equals(GIT_WORK_TREE))
+			return getGitWorkTree(argument);
+		if (variable.getName().equals(GIT_BRANCH))
+			return getGitBranch(argument);
+		throw new CoreException(new Status(IStatus.ERROR, Activator
+				.getPluginId(), UIText.GitVariableResolver_InternalError));
+	}
+
+	private String getGitRepoRelativePath(String argument) throws CoreException {
+		IResource res = getResource(argument);
+		if (res == null)
+			return ""; //$NON-NLS-1$
+		RepositoryMapping mapping = RepositoryMapping.getMapping(res);
+		if (mapping != null) {
+			String repoRelativePath = mapping.getRepoRelativePath(res);
+			if (repoRelativePath.equals("")) //$NON-NLS-1$
+				return "."; //$NON-NLS-1$
+			else
+				return repoRelativePath;
+		}
+		return ""; //$NON-NLS-1$
+	}
+
+	private String getGitDir(String argument) throws CoreException {
+		IResource res = getResource(argument);
+		if (res == null)
+			return ""; //$NON-NLS-1$
+		RepositoryMapping mapping = RepositoryMapping.getMapping(res);
+		if (mapping != null)
+			return mapping.getRepository().getDirectory().getAbsolutePath();
+		else
+			return ""; //$NON-NLS-1$
+	}
+
+	private String getGitWorkTree(String argument) throws CoreException {
+		IResource res = getResource(argument);
+		if (res == null)
+			return ""; //$NON-NLS-1$
+		RepositoryMapping mapping = RepositoryMapping.getMapping(res);
+		if (mapping != null)
+			return mapping.getWorkTree().getAbsolutePath();
+		else
+			return ""; //$NON-NLS-1$
+	}
+
+	private String getGitBranch(String argument) throws CoreException {
+		IResource res = getResource(argument);
+		if (res == null)
+			return ""; //$NON-NLS-1$
+		RepositoryMapping mapping = RepositoryMapping.getMapping(res);
+		if (mapping != null)
+			try {
+				return mapping.getRepository().getBranch();
+			} catch (IOException e) {
+				throw new CoreException(new Status(IStatus.ERROR, Activator.getPluginId(), e.getMessage()));
+			}
+		else
+			return ""; //$NON-NLS-1$
+	}
+
+	/**
+	 * Returns the currently selected  or specified resource
+	 * @param argument named resource or null for selected
+	 *
+	 * @return the currently selected <code>IResource</code>, or <code>null</code> if none.
+	 * @throws CoreException
+	 */
+	private IResource getResource(String argument) throws CoreException {
+		IResource res;
+		if (argument == null) {
+			res = getResource();
+			if (res == null)
+				throw new CoreException(new Status(IStatus.ERROR, Activator
+						.getPluginId(), UIText.GitVariableResolver_NoSelectedResource));
+		} else {
+			res = ResourcesPlugin.getWorkspace().getRoot().findMember(argument);
+			if (res == null || !res.exists()) {
+				throw new CoreException(
+						new Status(
+								IStatus.ERROR,
+								Activator.getPluginId(),
+								NLS.bind(
+										UIText.GitVariableResolver_VariableReferencesNonExistentResource,
+										argument)));
+			}
+		}
+		return res;
+	}
+
+	private IResource getResource() {
+		Display display = PlatformUI.getWorkbench().getDisplay();
+		if(display.getThread().equals(Thread.currentThread()))
+			return getSelectedResource();
+		else {
+			final IResource[] resource = new IResource[1];
+			display.syncExec(new Runnable() {
+				public void run() {
+					resource[0] = getSelectedResource();
+				}
+			});
+			return resource[0];
+		}
+	}
+
+	private IResource getSelectedResource() {
+		IResource resource = null;
+		IWorkbench workbench = PlatformUI.getWorkbench();
+		IWorkbenchWindow window = null;
+		if (workbench != null)
+			window = workbench.getActiveWorkbenchWindow();
+		if(window != null) {
+			IWorkbenchPage page  = window.getActivePage();
+			if(page != null) {
+				IWorkbenchPart part = page.getActivePart();
+				if(part instanceof IEditorPart) {
+					IEditorPart epart = (IEditorPart) part;
+					resource = (IResource) epart.getEditorInput().getAdapter(IResource.class);
+				}
+				else if(part != null) {
+					IWorkbenchPartSite site = part.getSite();
+					if(site != null) {
+						ISelectionProvider provider = site.getSelectionProvider();
+						if(provider != null) {
+							ISelection selection = provider.getSelection();
+							if(selection instanceof IStructuredSelection) {
+								IStructuredSelection ss = (IStructuredSelection) selection;
+								if(!ss.isEmpty()) {
+									Iterator iterator = ss.iterator();
+									while (iterator.hasNext() && resource == null) {
+										Object next = iterator.next();
+										resource = (IResource) Platform.getAdapterManager().getAdapter(next, IResource.class);
+									}
+								}
+							}
+						}
+					}
+				}
+			}
+		}
+		return resource;
+	}
+}