OnGadget

Enable the specified gadget.

This command enables the specified gadget. When a gadget is enabled, these things happen:

• its imagery is displayed normally (not ghosted)
  
  
• the GFLG_DISABLED flag is cleared
  
  
• the gadget can thereafter be selected by the user
  
  

The window parameter must point to the window which contains the gadget, or which contains the requester that contains the gadget The requester parameter must only be valid if the gadget has the GTYP_REQGADGET flag set, a requirement for all requester gadgets.

NOTE:

it's never safe to tinker with the gadget list yourself. Don't

supply some gadget that Intuition hasn't already processed in the usual way.

NOTE:

for compatibility reasons, this function will refresh all

gadgets in a requester, and all gadgets from gadget to the end of the gadget list if gadget is in a window.

If you want to improve on this behavior, you may perform the equivalent operation yourself: remove a gadget or gadgets, change the state of their GFLG_DISABLED flag, replace the gadgets using AddGList(), and selectively call RefreshGList().

Gadget

pointer to the gadget that you want disabled

Window

pointer to a window structure containing the gadget or containing the requester which contains the gadget

Requester

pointer to a requester (may by NULL if this isn't a requester gadget (i.e. GTYP_REQGADGET is not set)).

Traditional gadgets are rendered very simply. This can result in incomplete clearing away of the ghosting pattern when OnGadget() is used. For example, a button whose imagery consists of an IntuiText inside a rectangular Border doesn't have the button interior cleared by OnGadget(). This is because OnGadget() clears the GFLG_DISABLED flag then redraws the gadget. Redrawing this gadget consists of redrawing the border and text. Nothing redraws the field.

The solution to this type of problem is to either use a gadget whose imagery is a struct Image that covers the whole select area, or to manually remove the gadget, erase the gadget's select area (say using EraseRect()), then clear the GFLG_DISABLED flag, add the gadget back to the window, and refresh it.

OffGadget()