code: def tabActiveMarkupChanged(self, tab):
  		'''
  		Perform all UI state changes that need to be done when the
  		active markup class of the current tab has changed.
  		'''
  		if tab == self.currentTab:
  			markupClass = tab.getActiveMarkupClass()
  			dtMarkdown = (markupClass == markups.MarkdownMarkup)
  			dtMkdOrReST = dtMarkdown or (markupClass == markups.ReStructuredTextMarkup)
  			self.formattingBox.setEnabled(dtMarkdown)
  			self.symbolBox.setEnabled(dtMarkdown)
  			self.actionUnderline.setEnabled(dtMarkdown)
  			self.actionBold.setEnabled(dtMkdOrReST)
  			self.actionItalic.setEnabled(dtMkdOrReSTf tabActiveMarkupChanged(self, tab):
  		'''
  		Perform all UI state changes that need to be done when the
  		active markup class of the current tab has changed.
  		'''
  		if tab == self.currentTab:
  			markupClass = tab.getActiveMarkupClass()
  			dtMarkdown = (markupClass == markups.MarkdownMarkup)
  			dtMkdOrReST = dtMarkdown or (markupClass == markups.ReStructuredTextMarkup)
  			self.formattingBox.setEnabled(dtMarkdown)
  			self.symbolBox.setEnabled(dtMarkdown)
  			self.actionUnderline.setEnabled(dtMarkdown)
  			self.actionBold.setEnabled(dtMkdOrReST)
  			self.actionItalic.setEnabled(dtMkdOrReST)
docs: Perform all UI state changes that need to be done when the
  		active markup class of the current tab has changed.