How do I enable/disable Cut/Copy/Paste menu and toolbar items in a generic way?

Question

I have a windows forms application with controls like textbox, combobox, datagridview etc. These controls allow a user to use the clipboad, i.e. cut/copy and paste text. It is also possible to delete text (which is not related to the clipboard).

My application has a menubar with an Edit item containing Cut/Copy/Paste/Delete items, and a toolbar with these items as well. How can I enable/disable these items properly depending in the state of the control having the focus?

I am looking for a generic way, i.e. I look for an implementation I do once, and can reuse for the future independent of the controls my application will use.

Answer 1

Create an array for each enable/disable group. Add the controls to the array (of course it has to be of the correct type such as Object or Any, etc. depends on the programming language you are using). Then to enable, disable just loop through the array and invoke the enable/disable method or function for each control. Again, depending on the language you may need to cast back.

Answer 2

There is no generic interface or set of methods for getting cut/copy/paste information from a windows forms control.

I suggest your best approach would be to create a wrapper class for each type of control. Then when you want to update the menu state you get the current control with focus and create the appropriate wrapper for it. Then you ask that wrapper for the state information you need. That way you only need to create a wrapper implementation for each type of control you use. Bit of a pain to start with but other time you only need to add the new controls you come across.

Clipboard information is much easier as you can ask the Clipboard singleton if it has data inside and what type it is. Then again you still need to ask the target control if it can accept that type of information so there is still extra work needs doing.