Add "repo overview" command.

The overview command shows an overview of each branch in all (or the
specified) projects.  The overview lists any local commits that have
not yet been merged into the project.

The report output is inspired by the report displayed following a
"repo prune" event, with the addition of listing the one-line log
messages for each commit that is not yet merged.

The report can also be filtered to show only active branches; by
default all branches that have commits beyond the upstream HEAD will
be listed.

Change-Id: Ibe67793991ad1aa38de3bc9747de4ba64e5591aa
diff --git a/subcmds/overview.py b/subcmds/overview.py
new file mode 100644
index 0000000..96fa93d
--- /dev/null
+++ b/subcmds/overview.py
@@ -0,0 +1,80 @@
+#
+# Copyright (C) 2012 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from color import Coloring
+from command import PagedCommand
+
+
+class Overview(PagedCommand):
+  common = True
+  helpSummary = "Display overview of unmerged project branches"
+  helpUsage = """
+%prog [--current-branch] [<project>...]
+"""
+  helpDescription = """
+The '%prog' command is used to display an overview of the projects branches,
+and list any local commits that have not yet been merged into the project.
+
+The -b/--current-branch option can be used to restrict the output to only
+branches currently checked out in each project.  By default, all branches
+are displayed.
+"""
+
+  def _Options(self, p):
+    p.add_option('-b', '--current-branch',
+                 dest="current_branch", action="store_true",
+                 help="Consider only checked out branches")
+
+  def Execute(self, opt, args):
+    all = []
+    for project in self.GetProjects(args):
+      br = [project.GetUploadableBranch(x)
+            for x in project.GetBranches().keys()]
+      br = [x for x in br if x]
+      if opt.current_branch:
+        br = [x for x in br if x.name == project.CurrentBranch]
+      all.extend(br)
+
+    if not all:
+      return
+
+    class Report(Coloring):
+      def __init__(self, config):
+        Coloring.__init__(self, config, 'status')
+        self.project = self.printer('header', attr='bold')
+
+    out = Report(all[0].project.config)
+    out.project('Projects Overview')
+    out.nl()
+
+    project = None
+
+    for branch in all:
+      if project != branch.project:
+        project = branch.project
+        out.nl()
+        out.project('project %s/' % project.relpath)
+        out.nl()
+
+      commits = branch.commits
+      date = branch.date
+      print '%s %-33s (%2d commit%s, %s)' % (
+            branch.name == project.CurrentBranch and '*' or ' ',
+            branch.name,
+            len(commits),
+            len(commits) != 1 and 's' or ' ',
+            date)
+      for commit in commits:
+        print '%-35s   - %s' % ('', commit)