MATLAB: How to pass Buttondwn function output parameter

Question

Dear All,

How can I pass an output parameter for buttondownfcn?

set(handles.b,'ButtonDownFcn', {@displayMontage, handles});
function curwell = displayMontage(src, evt, handles)
curwell = get(gco,'position');
handles = updateVisCircleColor(curwell(1), curwell(2), 'red', handles);

I want to pass "curwell" back to the initial function call. How can this be done?

Thanks,

Mathew

Answer 1

If by "initial function call" you mean the call

set(handles.b,'ButtonDownFcn', {@displayMontage, handles});

that configured the callback, then the answer is that you cannot do that: that function is probably no longer running, and MATLAB does not keep track of which function or which line of code configured a particular property.

However, you could do something like,

   set(handles.b, 'ButtonDownFcn', {@displayMontage, handles}, 'UserData', []);
   waitfor(handles.b, 'UserData')
   curwell = get(handles.b, 'UserData');
function displayMontage(src, evt, handles)
  curwell = get(gco,'position');
  handles = updateVisCircleColor(curwell(1), curwell(2), 'red', handles);
  set(src, 'UserData', curwell);