How to assign a default in a GUI?

Dear all,

I am building a GUI and at one button function I want to import a string from a popup menu. However, if the user didn't chose any string from the popup menu then 'gray' should be set as a default. I wrote it like this

colormap_label = handles.colormap_label; % import the color map effect type from the popup menu

if isnan(colormap_label)
    colormap_label = 'gray'
end

this code have an error message "Reference to non-existent field 'colormap_label".

Any one knows how to solve that?

Regards, Meshoo

Answer 1

[Image Analyst]

Load up your popup so that the first item is a space or "gray" or something like that. Then just get the value and assign whatever you want.

popupValue = get(handles.popup1, 'Value');
if popupValue == 1 % first item on the list (blank or gray or default or whatever you put in there)
  colormap_label = 'gray'
elseif popupValue == 2
  colormap_label = 'jet'
elseif popupValue == 3
  colormap_label = 'winter'
end
set(handles.colormap_label, 'String', colormap_label);

[Meshooo]

Thank you very much but I would like to know what was wrong with my code?

[Image Analyst]

You were trying to access a field of handles that doesn't exist. If you wanted a value or string from a popup, you should have used get() like I did.