added 'Diff Selections' command

Author: colinta

README.md

@@ -1,7 +1,7 @@
 FileDiffs Plugin for Sublime Text 2
 ===================================
 
-Show diffs between the current file, or selection(s) in the current file, and clipboard, another file, or unsaved changes.
+Show diffs between the current file (or selection(s) in the current file) with the clipboard, another file, or unsaved changes.
 
 
 Installation
@@ -28,6 +28,8 @@ The rest of the commands are not bound by default:
 
 `file_diff_clipboard`: Shows the diff of the current file or selection(s) and the clipboard (the clipboard is considered the "new" file unless `reverse` is True)
 
+`file_diff_selections`: Shows the diff of the first and second selected regions.  The file_diff_menu command checks for exactly two regions selected, otherwise it doesn't display this command.
+
 `file_diff_saved`: Shows the diff of the current file or selection(s) and the saved file.
 
 `file_diff_file`: Shows the diff of the current file or selection(s) and a file that is in the current project.

file_diffs.py

@@ -10,6 +10,7 @@
 
 
 CLIPBOARD = u'Diff file with Clipboard'
+SELECTIONS = u'Diff Selections'
 SAVED = u'Diff file with Saved'
 FILE = u'Diff file with File in Project…'
 TAB = u'Diff file with Open Tab…'
@@ -21,17 +22,19 @@
 class FileDiffMenuCommand(sublime_plugin.TextCommand):
     def run(self, edit):
         menu_items = FILE_DIFFS
-        regions = [region for region in self.view.sel()]
-        for region in regions:
-            if not region.empty():
-                menu_items = [f.replace(u'Diff file', u'Diff selection') for f in FILE_DIFFS]
-                break
+        regions = self.view.sel()
+        if len(regions) == 1 and not regions[0].empty():
+            menu_items = [f.replace(u'Diff file', u'Diff selection') for f in FILE_DIFFS]
+        elif len(regions) == 2:
+            menu_items.insert(1, SELECTIONS)
 
         def on_done(index):
             if index == -1:
                 return
             elif FILE_DIFFS[index] == CLIPBOARD:
                 self.view.run_command('file_diff_clipboard')
+            elif FILE_DIFFS[index] == SELECTIONS:
+                self.view.run_command('file_diff_selections')
             elif FILE_DIFFS[index] == SAVED:
                 self.view.run_command('file_diff_saved')
             elif FILE_DIFFS[index] == FILE:
@@ -104,6 +107,15 @@ def run(self, edit, **kwargs):
         self.show_diff(diff)
 
 
+class FileDiffSelectionsCommand(FileDiffCommand):
+    def run(self, edit, **kwargs):
+        regions = self.view.sel()
+        current = self.view.substr(regions[0])
+        diff = self.view.substr(regions[1])
+        diff = self.run_diff(current, diff)
+        self.show_diff(diff)
+
+
 class FileDiffSavedCommand(FileDiffCommand):
     def run(self, edit, **kwargs):
         content = ''