1 files changed, 47 insertions, 0 deletions
diff --git a/ranger/core/actions.py b/ranger/core/actions.py
index 1c5459d0..40fd52a3 100644
--- a/ranger/core/actions.py
+++ b/ranger/core/actions.py
@@ -1262,6 +1262,53 @@ class Actions(  # pylint: disable=too-many-instance-attributes,too-many-public-m
             i += 1
         return self.tab_open(i, path)
 
+    def tab_shift(self, offset=0, to=None):  # pylint: disable=invalid-name
+        """Shift the tab left/right
+
+        Shift the current tab to the left or right by either:
+        offset - changes the tab number by offset
+        to - shifts the tab to the specified tab number
+        """
+
+        oldtab_index = self.current_tab
+        if to is None:
+            assert isinstance(offset, int)
+            # enumerated index (1 to 9)
+            newtab_index = oldtab_index + offset
+        else:
+            assert isinstance(to, int)
+            newtab_index = to
+        # shift tabs without enumerating, preserve tab numbers when can
+        if newtab_index != oldtab_index:
+            # the other tabs shift in the opposite direction
+            if (newtab_index - oldtab_index) > 0:
+                direction = -1
+            else:
+                direction = 1
+
+            def tabshiftreorder(source_index):
+                # shift the tabs to make source_index empty
+                if source_index in self.tabs:
+                    target_index = source_index + direction
+                    # make the target_index empty recursively
+                    tabshiftreorder(target_index)
+                    # shift the source to target
+                    source_tab = self.tabs[source_index]
+                    self.tabs[target_index] = source_tab
+                    del self.tabs[source_index]
+
+            # first remove the current tab from the dict
+            oldtab = self.tabs[oldtab_index]
+            del self.tabs[oldtab_index]
+            # make newtab_index empty by shifting
+            tabshiftreorder(newtab_index)
+            self.tabs[newtab_index] = oldtab
+            self.current_tab = newtab_index
+            self.thistab = oldtab
+            self.ui.titlebar.request_redraw()
+            self.signal_emit('tab.layoutchange')
+        return None
+
     def tab_switch(self, path, create_directory=False):
         """Switches to tab of given path, opening a new tab as necessary.