Add UIElement descriptions

gitg/commit/gitg-commit.vala

@@ -110,6 +110,11 @@ namespace GitgCommit
 			owned get { return _("Commit"); }
 		}
 
+		public string description
+		{
+			owned get { return _("Create new commits and manage the staging area"); }
+		}
+
 		public string? icon
 		{
 			owned get { return "document-save-symbolic"; }

gitg/gitg-ui-elements.vala

@@ -180,7 +180,7 @@ public class UIElements<T> : Object
 
 		d_stack.add_with_properties(e.widget,
 		                            "name", e.id,
-		                            "title", e.display_name,
+		                            "title", e.description,
 		                            "icon-name", e.icon,
 		                            "position", insert_position);
 	}

gitg/history/gitg-history.vala

@@ -164,6 +164,11 @@ namespace GitgHistory
 			owned get { return _("History"); }
 		}
 
+		public string description
+		{
+			owned get { return _("Examine the history of the repository"); }
+		}
+
 		public string? icon
 		{
 			owned get { return "view-list-symbolic"; }

libgitg-ext/gitg-ext-ui-element.vala

@@ -50,6 +50,14 @@ public interface UIElement : Object
 	 */
 	public abstract string display_name { owned get; }
 
+	/**
+	 * The description of the ui element.
+	 *
+	 * This should result in a string which can
+	 * be displayed in the gitg UI to describe the element.
+	 */
+	public abstract string description { owned get; }
+
 	/**
 	 * The ui element icon.
 	 *

plugins/diff/gitg-diff.vala

@@ -71,6 +71,11 @@ namespace GitgDiff
 			owned get { return _("Diff"); }
 		}
 
+		public string description
+		{
+			owned get { return _("Show the changes introduced by the selected commit"); }
+		}
+
 		public string? icon
 		{
 			owned get { return "diff-symbolic"; }

plugins/files/gitg-files.vala

@@ -63,6 +63,11 @@ namespace GitgFiles
 			owned get { return _("Files"); }
 		}
 
+		public string description
+		{
+			owned get { return _("Show the files in the tree of the selected commit"); }
+		}
+
 		public string? icon
 		{
 			owned get { return "system-file-manager-symbolic"; }