dag: Allow passing command-line arguments to git-dag

Signed-off-by: David Aguilar <davvid@gmail.com>

cola/app.py

@@ -139,6 +139,14 @@ def parse_args(context):
                       dest='git',
                       metavar='PATH',
                       default='')
+
+    if context == 'git-dag':
+        parser.add_option('-c', '--count',
+                          help='Number of commits to display.',
+                          dest='count',
+                          type='int',
+                          default=1000)
+
     return parser.parse_args()
 
 
@@ -228,7 +236,7 @@ def main(context):
         view = MainView(model)
         ctl = MainController(model, view)
     elif context == 'git-dag':
-        ctl = git_dag(model, app.activeWindow())
+        ctl = git_dag(model, app.activeWindow(), opts=opts, args=args)
         view = ctl.view
 
     # Install UI wrappers for command objects

cola/dag/__init__.py

@@ -14,9 +14,11 @@
 from cola.dag.controller import DAGController
 
 
-def git_dag(model, parent):
+def git_dag(model, parent, opts=None, args=None):
     """Return a pre-populated git DAG widget."""
     dag = DAG(model.currentbranch, 1000)
+    dag.set_options(opts, args)
+
     view = DAGView(model, dag, parent=parent)
     ctl = DAGController(dag, view)
     view.show()

cola/dag/model.py

@@ -1,3 +1,5 @@
+import subprocess
+
 import cola
 from cola import core
 from cola import git
@@ -47,18 +49,38 @@ def new(cls, sha1=None, log_entry=None):
 class DAG(Observable):
     ref_updated = 'ref_updated'
     count_updated = 'count_updated'
+
     def __init__(self, ref, count):
         Observable.__init__(self)
         self.ref = ref
         self.count = count
+        self.overrides = {}
 
     def set_ref(self, ref):
+        changed = ref != self.ref
         self.ref = ref
         self.notify_message_observers(self.ref_updated)
+        return changed
 
     def set_count(self, count):
+        changed = count != self.count
         self.count = count
         self.notify_message_observers(self.count_updated)
+        return changed
+
+    def set_options(self, opts, args):
+        if opts is not None:
+            if self.set_count(opts.count):
+                self.overrides['count'] = opts.count
+
+        if args is not None:
+            ref = subprocess.list2cmdline([core.decode(a) for a in args])
+            if self.set_ref(ref):
+                self.overrides['ref'] = ref
+
+    def overridden(self, opt):
+        return opt in self.overrides
+
 
 class Commit(object):
     root_generation = 0

cola/dag/view.py

@@ -338,8 +338,12 @@ def apply_state(self, state):
             count = state['count']
         except KeyError:
             return
-        self.dag.set_ref(ref)
-        self.dag.set_count(count)
+
+        if not self.dag.overridden('ref'):
+            self.dag.set_ref(ref)
+
+        if not self.dag.overridden('count'):
+            self.dag.set_count(count)
 
     def _model_updated(self):
         self.emit(SIGNAL('model_updated'))