Thread changes

Use the dependency information of the most recent revisions to
create a threaded view of changes.

Also, use a more efficient query to collect the children of a
change in the change view.

Change-Id: I1cbef9fe7c4f1822b8541e5b4d0e7d2fe2e180a9

examples/reference-gertty.yaml

@@ -142,6 +142,10 @@ commentlinks:
 # of the default side-by-side:
 # diff-view: unified
 
+# Dependent changes are displayed as "threads" in the change list by
+# default.  To disable this behavior, uncomment the following line:
+# thread-changes: false
+
 # Uncomment the following lines to Hide comments by default that match
 # certain criteria.  You can toggle their display with 't'.  Currently
 # the only supported criterion is "author".

gertty/config.py

@@ -110,6 +110,7 @@ class ConfigSchema(object):
                            'change-list-query': str,
                            'diff-view': str,
                            'hide-comments': self.hide_comments,
+                           'thread-changes': bool,
                            })
         return schema
 
@@ -200,6 +201,8 @@ class Config(object):
         for h in self.config.get('hide-comments', []):
             self.hide_comments.append(re.compile(h['author']))
 
+        self.thread_changes = self.config.get('thread-changes', True)
+
     def getServer(self, name=None):
         for server in self.config['servers']:
             if name is None or name == server['name']:

gertty/db.py

@@ -606,8 +606,10 @@ class DatabaseSession(object):
             return None
 
     def getRevisionsByParent(self, parent):
+        if isinstance(parent, basestring):
+            parent = (parent,)
         try:
-            return self.session().query(Revision).filter_by(parent=parent).all()
+            return self.session().query(Revision).filter(Revision.parent.in_(parent)).all()
         except sqlalchemy.orm.exc.NoResultFound:
             return []
 

gertty/view/change.py

@@ -745,11 +745,10 @@ class ChangeView(urwid.WidgetWrap):
 
         # Handle needed-by
         children = {}
-        for revision in change.revisions:
+        children.update((r.change.key, r.change.subject)
-            children.update((r.change.key, r.change.subject)
+                        for r in session.getRevisionsByParent([revision.commit for revision in change.revisions])
-                            for r in session.getRevisionsByParent(revision.commit)
+                        if (r.change.status != 'MERGED' and
-                            if (r.change.status != 'MERGED' and
+                            r == r.change.revisions[-1]))
-                                r == r.change.revisions[-1]))
         self._updateDependenciesWidget(children,
                                        self.needed_by, self.needed_by_rows,
                                        header='Needed by:')

gertty/view/change_list.py

@@ -23,6 +23,29 @@ from gertty import sync
 from gertty.view import change as view_change
 import gertty.view
 
+
+class ThreadStack(object):
+    def __init__(self):
+        self.stack = []
+
+    def push(self, change, children):
+        self.stack.append([change, children])
+
+    def pop(self):
+        change = None
+        while self.stack:
+            if self.stack[-1][1]:
+                # handle children at the tip
+                return self.stack[-1][1].pop(0)
+            else:
+                # current tip has no children, walk up
+                self.stack.pop()
+                continue
+        return None
+
+    def countChildren(self):
+        return [len(x[1]) for x in self.stack]
+
 class ChangeRow(urwid.Button):
     change_focus_map = {None: 'focused',
                         'unreviewed-change': 'focused-unreviewed-change',
@@ -60,7 +83,11 @@ class ChangeRow(urwid.Button):
         else:
             style = 'unreviewed-change'
         self.row_style.set_attr_map({None: style})
-        self.subject.set_text(change.subject)
+        if hasattr(change, '_subject'):
+            subject = change._subject
+        else:
+            subject = change.subject
+        self.subject.set_text(subject)
         self.number.set_text(str(change.number))
         self.project.set_text(change.project.name.split('/')[-1])
         self.owner.set_text(change.owner_name)
@@ -176,6 +203,15 @@ class ChangeListView(urwid.WidgetWrap):
                 change_list = reversed(lst)
             else:
                 change_list = lst
+            if self.app.config.thread_changes:
+                change_list = self._threadChanges(change_list)
+            new_rows = []
+            if len(self.listbox.body):
+                focus_pos = self.listbox.focus_position
+                focus_row = self.listbox.body[focus_pos]
+            else:
+                focus_pos = 0
+                focus_row = None
             for change in change_list:
                 row = self.change_rows.get(change.key)
                 if not row:
@@ -187,14 +223,78 @@ class ChangeListView(urwid.WidgetWrap):
                 else:
                     row.update(change, self.categories)
                     unseen_keys.remove(change.key)
+                new_rows.append(row)
                 i += 1
+            self.listbox.body[:] = new_rows
+            if focus_row in self.listbox.body:
+                pos = self.listbox.body.index(focus_row)
+            else:
+                pos = min(focus_pos, len(self.listbox.body)-1)
+            self.listbox.body.set_focus(pos)
             if lst:
                 self.header.update(self.categories)
         for key in unseen_keys:
             row = self.change_rows[key]
-            self.listbox.body.remove(row)
             del self.change_rows[key]
 
+    def _threadChanges(self, changes):
+        ret = []
+        stack = ThreadStack()
+        children = {}
+        commits = {}
+        orphans = changes[:]
+        for change in changes:
+            for revision in change.revisions:
+                commits[revision.commit] = change
+        for change in changes:
+            revision = change.revisions[-1]
+            parent = commits.get(revision.parent, None)
+            if parent:
+                if parent.revisions[-1].commit != revision.parent:
+                    # Our parent is an outdated revision.  This could
+                    # cause a cycle, so skip.  This change will not
+                    # appear in the thread, but will still appear in
+                    # the list.  TODO: use color to indicate it
+                    # depends on an outdated change.
+                    continue
+                if change in orphans:
+                    orphans.remove(change)
+                v = children.get(parent, [])
+                v.append(change)
+                children[parent] = v
+        if orphans:
+            change = orphans.pop(0)
+        else:
+            change = None
+        while change:
+            prefix = ''
+            stack_children = stack.countChildren()
+            for i, nchildren in enumerate(stack_children):
+                if nchildren:
+                    if i+1 == len(stack_children):
+                        prefix += u'\u251c'
+                    else:
+                        prefix += u'\u2502'
+                else:
+                    if i+1 == len(stack_children):
+                        prefix += u'\u2514'
+                    else:
+                        prefix += u' '
+                if i+1 == len(stack_children):
+                    prefix += u'\u2500'
+                else:
+                    prefix += u' '
+            subject = '%s%s' % (prefix, change.subject)
+            change._subject = subject
+            ret.append(change)
+            if change in children:
+                stack.push(change, children[change])
+            change = stack.pop()
+            if (not change) and orphans:
+                change = orphans.pop(0)
+        assert len(ret) == len(changes)
+        return ret
+
     def clearChangeList(self):
         for key, value in self.change_rows.iteritems():
             self.listbox.body.remove(value)