[meld] tree: Add a helper to iterate over rows matching a set of states

[Kai Willadsen <kaiw src gnome org>]

commit 23b5de892bef63e2cff46ec055e8d97024692d39
Author: Kai Willadsen <kai willadsen gmail com>
Date:   Sat Sep 30 08:04:18 2017 +1000

    tree: Add a helper to iterate over rows matching a set of states

 meld/tree.py |   11 +++++++++++
 1 files changed, 11 insertions(+), 0 deletions(-)
---
diff --git a/meld/tree.py b/meld/tree.py
index 06eb590..61bac4d 100644
--- a/meld/tree.py
+++ b/meld/tree.py
@@ -241,3 +241,14 @@ class DiffTreeStore(Gtk.TreeStore):
             if key in text:
                 return False
         return True
+
+    def state_rows(self, states):
+        """Generator of rows in one of the given states
+
+        Tree iterators are returned in depth-first tree order.
+        """
+        root = self.get_iter_first()
+        for it in self.inorder_search_down(root):
+            state = self.get_state(it, 0)
+            if state in states:
+                yield it