Code completion and navigation for selection values

[trinhanhngoc]

• [ ] Python binary expressions
• [ ] Python assignments
• [ ] Search domains
• [ ] Record values
• [ ] Test assertEqual, assertNotEqual
• [ ] fields.Field(states="...")
• [ ] fields.Selection(ondelete="...")
• [ ] fields.Selection(default="...")
• [ ] fields.Selection(selection_add="...")
• XML attributes
  • [ ] states="..."
  • [ ] statusbar_visible="..."