New behaviour: Jump to latest

When GoBackThere command is called, but no position was saved in the
current view (buffer/file), it will try to jump to the latest used
position (used either by SaveBackThere or GoBackThere command) if
at least one position was saved in the current session.

This is, in a way, made in response to feature-request #5.

Signed-off-by: Iulius Curt <iulius.curt@gmail.com>

BackThere.py

@@ -9,6 +9,7 @@
 #       Jumps to the latest saved position
 
 
+# TODO: This class is mostly futile and should be replaced
 class BackThereMemory:
     """ Utility class to remember position """
     def __init__(self):
@@ -25,36 +26,69 @@ def get(self):
 
 # One memory bank for each buffer
 bt_memory = {}
+# Keep track of the latest saved position: (position, view)
+bt_latest = None
 
 
 class SaveBackThereCommand(sublime_plugin.TextCommand):
     """ Puts the current location of the cursor in memory """
     def run(self, edit):
+        global bt_memory
+        global bt_latest
+
         buff_id = self.view.buffer_id()
         sels = self.view.sel()
 
         if not buff_id in bt_memory:
             # First time in current buffer
             bt_memory[buff_id] = BackThereMemory()
         bt_memory[buff_id].put(sels[0].begin())
+        bt_latest = (sels[0].begin(), self.view)
 
 
 class GoBackThereCommand(sublime_plugin.TextCommand):
     """ Moves the cursor to the position in memory """
     def run(self, edit):
+        global bt_memory
+        global bt_latest
+
         buff_id = self.view.buffer_id()
+        switch_needed = False
         if buff_id in bt_memory and bt_memory[buff_id].valid:
             saved_region = sublime.Region(bt_memory[buff_id].get())
-
-            # Check if the saved position is still inside the buffer limits
-            buff_end = self.view.size()
-            if saved_region.begin() > buff_end:
-                saved_region = sublime.Region(buff_end, buff_end)
-
-            # Move the cursor _back there_
-            self.view.sel().clear()
-            self.view.sel().add(saved_region)
-
-            # Center the new cursor position in the viewport
-            # (only if cursor is out of viewport)
-            self.view.show(saved_region)
+            current_view = self.view
+            # Update the latest
+            bt_latest = (bt_memory[buff_id].get(), current_view)
+        elif bt_latest:
+            # This is the case where no position is saved in the current view,
+            # but there exists at least one position saved in some other view,
+            # so, that one will be used
+            saved_region = sublime.Region(bt_latest[0])
+            current_view = bt_latest[1]
+            switch_needed = True
+        else:
+            return
+
+        # Check if the saved position is still inside the buffer limits
+        buff_end = current_view.size()
+        if saved_region.begin() > buff_end:
+            saved_region = sublime.Region(buff_end, buff_end)
+
+        # Move the cursor _back there_
+        current_view.sel().clear()
+        current_view.sel().add(saved_region)
+
+        # Center the new cursor position in the viewport
+        # (only if cursor is out of viewport)
+        current_view.show(saved_region)
+
+        # If it's the case, it will call switch_back_window to jump to the
+        # wanted view
+        if switch_needed:
+            self.view.window().run_command('switch_back_window')
+
+
+class SwitchBackWindowCommand(sublime_plugin.WindowCommand):
+    """ Switches the view to where the last position was saved """
+    def run(self):
+        self.window.focus_view(bt_latest[1])