Syntax: Offer to adjust 'translate_tabs_to_spaces'

Instead of just being obnoxious, we offer to change the setting to
prevent users from making mistakes by accidentally introducing tab
characters.

Updates #308.

plugins/syntaxtest_dev.py

@@ -27,11 +27,6 @@
 )
 
 
-def _show_tab_warning():
- sublime.error_message("Syntax tests do not work properly with tabs as indentation."
- "\n\nYou MUST use spaces!")
-
-
 def get_syntax_test_tokens(view):
  """Parse the first line of the given view into a SyntaxTestHeader.
 
@@ -73,7 +68,8 @@ def __del__(self):
  # or plugin was unloaded.
  # Complain about the former, if we have a test file.
  if self.header and not self.is_applicable(self.view.settings()):
- _show_tab_warning()
+ sublime.error_message("Syntax tests do not work properly with tabs as indentation."
+ "\n\nYou MUST use spaces!")
 
  def on_modified_async(self):
  """If the view has a filename, and that file name starts with
@@ -411,8 +407,11 @@ def on_load(self, view):
  current_syntax = view.settings().get('syntax', None)
  test_syntax = test_header.syntax_file
 
- # resource-relative path specified
- if "/" in test_syntax and current_syntax != test_syntax:
+ if current_syntax != test_syntax:
+ pass
+
+ # resource path specified
+ elif "/" in test_syntax:
  *_, file_name = test_syntax.rpartition("/")
  if test_syntax in sublime.find_resources(file_name):
  view.assign_syntax(test_syntax)
@@ -431,8 +430,14 @@ def on_load(self, view):
  logger.info("Couldn't find a syntax matching %r", test_syntax)
  view.assign_syntax(self.PLAIN_TEXT)
 
- # warn user if they try to do something stupid
+ # offer user to fix settings if they try to do something stupid
  if not view.settings().get('translate_tabs_to_spaces', False):
- _show_tab_warning()
+ if sublime.ok_cancel_dialog(
+ "This view is configured to use tabs for indentation."
+ "Syntax tests do not work properly with tabs.\n"
+ "Do you want to change this view's settings to use spaces?",
+ "Change setting"
+ ):
+ view.settings().set('translate_tabs_to_spaces', True)
 
  on_post_save_async = on_load