[meld] dirdiff: Add an emblem indicator for the current marked path

[Kai Willadsen <kaiw src gnome org>]

commit 036c7ac027fe3ddb4898037ddfe4211ed23b1376
Author: Kai Willadsen <kai willadsen gmail com>
Date:   Sat Mar 12 09:28:10 2022 +1000

    dirdiff: Add an emblem indicator for the current marked path
    
    This is deliberately choosing to override the "newest" marker for two
    reasons:
     - if you're manually marking something for comparison like this, you
       probably don't actually care about whether this one or the other side
       is newest, since you're basically indicating that the file you're
       comparing to on the other side isn't the correct one; and
     - adding a new tree store column (or a third emblem location) just to
       store mark information seems like massive overkill.

 meld/dirdiff.py | 26 +++++++++++++++++++++-----
 1 file changed, 21 insertions(+), 5 deletions(-)
---
diff --git a/meld/dirdiff.py b/meld/dirdiff.py
index 2e024431..5e8de5a2 100644
--- a/meld/dirdiff.py
+++ b/meld/dirdiff.py
@@ -248,6 +248,7 @@ def _files_same(files, regexes, comparison_args):
 
 
 EMBLEM_NEW = "emblem-new"
+EMBLEM_SELECTED = "emblem-default-symbolic"
 EMBLEM_SYMLINK = "emblem-symbolic-link"
 
 COL_EMBLEM, COL_EMBLEM_SECONDARY, COL_SIZE, COL_TIME, COL_PERMS, COL_END = (
@@ -821,6 +822,7 @@ class DirDiff(Gtk.VBox, tree.TreeviewCommon, MeldDoc):
         locations = [os.path.abspath(l) if l else '' for l in locations]
 
         self.current_path = None
+        self.marked = None
         self.model.clear()
         for m in self.msgarea_mgr:
             m.clear()
@@ -1464,10 +1466,14 @@ class DirDiff(Gtk.VBox, tree.TreeviewCommon, MeldDoc):
         if selected is None:
             return
 
-        self.marked = {
-            'mark': self.model.get_iter(selected[0]),
-            'pane': pane
-        }
+        old_it = self.marked['mark'] if self.marked else None
+        it = self.model.get_iter(selected[0])
+
+        self.marked = {'mark': it, 'pane': pane}
+
+        self._update_item_state(it)
+        if old_it:
+            self._update_item_state(old_it)
 
     def action_diff_marked(self, *args):
         pane = self._get_focused_pane()
@@ -1706,7 +1712,17 @@ class DirDiff(Gtk.VBox, tree.TreeviewCommon, MeldDoc):
             if stats[j]:
                 self.model.set_path_state(
                     it, j, state, isdir[j], display_text=name_overrides[j])
-                emblem = EMBLEM_NEW if j in newest else None
+
+                if (
+                    self.marked and
+                    self.marked["pane"] == j and
+                    self.model.get_string_from_iter(self.marked["mark"]) ==
+                    self.model.get_string_from_iter(it)
+                ):
+                    emblem = EMBLEM_SELECTED
+                else:
+                    emblem = EMBLEM_NEW if j in newest else None
+
                 link_emblem = EMBLEM_SYMLINK if j in symlinks else None
                 self.model.unsafe_set(it, j, {
                     COL_EMBLEM: emblem,