MATLAB Creating Graphical User Interfaces

else

errordlg('Input must be a valid directory','Input Argument Error!')

return

end

else

errordlg('Unrecognized input argument','Input Argument Error!');

return;

end

end

If nargin==3, then the only input arguments to lbox2_OpeningFcn are hObject,

eventdata, and handles. Therefore, the user did not specify a path when they called

lbox2, so the list box shows the contents of the current folder. If nargin>4, then the

varargin input argument contains two additional items (suggesting that the user did

specify a path). Thus, subsequent if statements check to see whether the path is valid.

listbox1_callback

The callback function listbox1_callback executes when the user clicks a list box item.

This statement, near the beginning of the function, returns true whenever the user

double-clicks an item in the list box:

if strcmp(get(handles.figure1,'SelectionType'),'open')

If that condition is true, then listbox1_callback determines which list box item the

user selected:

index_selected = get(handles.listbox1,'Value');

file_list = get(handles.listbox1,'String');

filename = file_list{index_selected};

The rest of the code in this callback function determines how to open the selected item

based on whether the item is a folder, FIG file, or another type of file:

if handles.is_dir(handles.sorted_index(index_selected))

cd (filename)

load_listbox(pwd,handles)

else

[path,name,ext] = fileparts(filename);

switch ext

case '.fig'

guide (filename)

otherwise

try

8 Examples of GUIDE UIs