[meld] Fix interactions between new diff tab and chain-switching handling

[Kai Willadsen <kaiw src gnome org>]

commit 219c30b5011bdbbfaf9dfd8ad5925499b3f3ebcc
Author: Kai Willadsen <kai willadsen gmail com>
Date:   Sat Dec 8 05:25:01 2012 +1000

    Fix interactions between new diff tab and chain-switching handling

 meld/meldwindow.py      |   23 +++++++++++++++--------
 meld/new_diff_dialog.py |   10 ++++++----
 2 files changed, 21 insertions(+), 12 deletions(-)
---
diff --git a/meld/meldwindow.py b/meld/meldwindow.py
index 85449f3..dbb2b60 100644
--- a/meld/meldwindow.py
+++ b/meld/meldwindow.py
@@ -570,14 +570,16 @@ class MeldWindow(gnomeglade.Component):
                 page.on_file_changed(filename)
 
     def _append_page(self, page, icon):
-        nbl = notebooklabel.NotebookLabel(icon, "", lambda b: self.try_remove_page(page))
-        self.notebook.append_page( page.widget, nbl)
+        nbl = notebooklabel.NotebookLabel(icon, "",
+                                          lambda b: self.try_remove_page(page))
+        self.notebook.append_page(page.widget, nbl)
 
         # Change focus to the newly created page only if the user is on a
-        # DirDiff or VcView page.  This prevents cycling through X pages
-        # when X diffs are initiated.
+        # DirDiff or VcView page, or if it's a new tab page. This prevents
+        # cycling through X pages when X diffs are initiated.
         if isinstance(self.current_doc(), dirdiff.DirDiff) or \
-           isinstance(self.current_doc(), vcview.VcView):
+           isinstance(self.current_doc(), vcview.VcView) or \
+           isinstance(page, new_diff_dialog.NewDiffTab):
             self.notebook.set_current_page(self.notebook.page_num(page.widget))
 
         if hasattr(page, 'scheduler'):
@@ -589,14 +591,19 @@ class MeldWindow(gnomeglade.Component):
             page.connect("status-changed",
                          lambda obj, arg: self.statusbar.set_doc_status(arg))
 
-        # Allow reordering of tabs
-        self.notebook.set_tab_reorderable(page.widget, True);
+        self.notebook.set_tab_reorderable(page.widget, True)
 
     def append_new_comparison(self):
         doc = new_diff_dialog.NewDiffTab(self)
         self._append_page(doc, "document-new")
         self.on_notebook_label_changed(doc, _("New comparison"), None)
-        doc.connect("diff-created", lambda x: self.try_remove_page(doc))
+
+        def diff_created_cb(doc, newdoc):
+            self.try_remove_page(doc)
+            idx = self.notebook.page_num(newdoc.widget)
+            self.notebook.set_current_page(idx)
+
+        doc.connect("diff-created", diff_created_cb)
         return doc
 
     def append_dirdiff(self, dirs, auto_compare=False):
diff --git a/meld/new_diff_dialog.py b/meld/new_diff_dialog.py
index ab2bd21..4b208be 100644
--- a/meld/new_diff_dialog.py
+++ b/meld/new_diff_dialog.py
@@ -28,7 +28,8 @@ class NewDiffTab(gobject.GObject, gnomeglade.Component):
     __gtype_name__ = "NewDiffTab"
 
     __gsignals__ = {
-        'diff-created': (gobject.SIGNAL_RUN_FIRST, gobject.TYPE_NONE, ()),
+        'diff-created': (gobject.SIGNAL_RUN_FIRST, gobject.TYPE_NONE,
+                         (object,)),
     }
 
     def __init__(self, parentapp):
@@ -93,15 +94,16 @@ class NewDiffTab(gobject.GObject, gnomeglade.Component):
             path = gfile.get_path() if gfile else ""
             compare_paths.append(path)
 
-        self.diff_methods[self.diff_type](compare_paths)
-        self.emit('diff-created')
+        tab = self.diff_methods[self.diff_type](compare_paths)
+        self.emit('diff-created', tab)
 
     def on_button_new_blank_clicked(self, *args):
         # TODO: This doesn't work the way I'd like for DirDiff and VCView.
         # It should do something similar to FileDiff; give a tab with empty
         # file entries and no comparison done.
         compare_paths = [""] * self._get_num_paths()
-        self.diff_methods[self.diff_type](compare_paths)
+        tab = self.diff_methods[self.diff_type](compare_paths)
+        self.emit('diff-created', tab)
 
     def on_container_switch_in_event(self, *args):
         pass