[meld] filediff: Add new set_file() API for setting a single file/pane

[Kai Willadsen <kaiw src gnome org>]

commit f0621a0afbc7fb212d13c77f73b809ebf57843f1
Author: Kai Willadsen <kai willadsen gmail com>
Date:   Tue Nov 21 06:33:09 2017 +1000

    filediff: Add new set_file() API for setting a single file/pane

 meld/filediff.py |   10 ++++++++++
 1 files changed, 10 insertions(+), 0 deletions(-)
---
diff --git a/meld/filediff.py b/meld/filediff.py
index d2e5ae7..dd41813 100644
--- a/meld/filediff.py
+++ b/meld/filediff.py
@@ -1061,6 +1061,16 @@ class FileDiff(melddoc.MeldDoc, gnomeglade.Component):
         for pane, gfile, encoding in files:
             self.load_file_in_pane(pane, gfile, encoding)
 
+    def set_file(
+            self,
+            pane: int,
+            gfile: Gio.File,
+            encoding: GtkSource.Encoding = None):
+        self._disconnect_buffer_handlers()
+        self.undosequence.clear()
+        self.linediffer.clear()
+        self.load_file_in_pane(pane, gfile, encoding)
+
     def load_file_in_pane(
             self,
             pane: int,