Page 149 - Basics of MATLAB and Beyond

Callbacks are fastest when they are implemented as function calls;
do not implement your callbacks as script m-files or as an eval of a
string. The reason is that matlab compiles a function the first time it
is encountered, whereas m-files and evals are interpreted line by line.
The button-style uicontrols (pushbuttons, radiobuttons, and check-
boxes) are used by simply clicking on them with the mouse. Others
need more interaction: you must choose an item from a list (listboxes or
popupmenus) or specify a numeric value (sliders) or type in text (edit
boxes). We discuss briefly the operation of each of these different kinds
of uicontrols.

34.2 UIControls

Edit Boxes
Edit boxes are designed to read in a piece of typed text. The text inside
an Edit box is accessed via the box’s String property:
h = uicontrol(’style’,’edit’,’String’,’Hello’);

You can change it using the set command:
set(h,’string’,’Bye’)
or you can click in the box and change it by typing something else. You
can access what has been typed into an edit box by getting its string
property. After typing qwe into the box you can type:
>> get(h,’string’)
ans =
qwe
Numbers typed into edit boxes remain strings until you convert them to
numbers:
>> x = get(h,’string’)
x =
10.3
>> x+1
ans =
50 49 47 52
>> str2num(x) + 1
ans =
11.3000
Text

Good GUIs have instructive text that indicates the function of a uicon-
trol. These can be placed with the text-style uicontrol. In the following
GUIthe “Name:”, “Address:”, and “Sex:” labels are three separate
uicontrols of Text style.

c 2000 by CRC Press LLC