if statement asking if an addlistener() event has occured

Is there a way to write an if statement that says something like:

if % addlistener(handles.Edit1, 'String','PostGet',f) occured %do something end

Answer 1

[Sean de Wolski]

I don't really understand why you would want to do this. The purpose of the listener is to fire when something (some event) happens. Why then do you need an if()? When this something happens, the listener will fire and your if() will happen automagically.

[Adam Kaas]

Here's what I discovered would happen after I got the addlistener() to work. Let's say I use the drop down menu and select the 5th option. The 5th option doesn't use all of the parameters available. The ones that it doesn't use I used set(handles.Edit1, 'Enable', 'off'); to gray it out. This is great because out of the 22 different options, a user could see which parameters each one uses. Obviously on Manual, I want all parameters enabled. With my addlistener() in place, if I choose option 5, when I edit the value in an edit box, it will switch to manual however any edit text boxes that were disabled remain disabled. I was going to create an if statement that told the GUI to re-enable all parameters if the popup menu was switched to Manual. Does that make any sense?

[Sean de Wolski]

Just have the same listener enable them all!

addlistener(...,@manualAndEnable)

function manualAndEnable(src,evt)

set(h1,'enable','on');

set(h2,'enable','on');

etc..

[Adam Kaas]

Tried messing around with this for awhile. I'm sure it's a simple fix but I'm not seeing it. I attempted to do what you had suggested and maybe you can tell me what I did wrong Sean. Here's my code:

function ManualAndEnable(~,~)

set(handles.Profile,'Value',1);

set(handles.RelativePower1, 'Enable', 'on');

set(handles.RelativePower2, 'Enable', 'on');

set(handles.RelativePower3, 'Enable', 'on');

set(handles.RelativePower4, 'Enable', 'on');

set(handles.DelayProfileShape1, 'Enable', 'on');

set(handles.DelayProfileShape2, 'Enable', 'on');

set(handles.DelayProfileShape3, 'Enable', 'on');

set(handles.DelayProfileShape4, 'Enable', 'on');

set(handles.DopplerSpread1, 'Enable', 'on');

set(handles.DopplerSpread2, 'Enable', 'on');

set(handles.DopplerSpread3, 'Enable', 'on');

set(handles.DopplerSpread4, 'Enable', 'on');

set(handles.DopplerShift1, 'Enable', 'on');

set(handles.DopplerShift2, 'Enable', 'on');

set(handles.DopplerShift3, 'Enable', 'on');

set(handles.DopplerShift4, 'Enable', 'on');

set(handles.DopplerShiftDelay1, 'Enable', 'on');

set(handles.DopplerShiftDelay2, 'Enable', 'on');

set(handles.DopplerShiftDelay3, 'Enable', 'on');

set(handles.DopplerShiftDelay4, 'Enable', 'on');

set(handles.FilterOrder1, 'Enable', 'on');

set(handles.FilterOrder2, 'Enable', 'on');

set(handles.FilterOrder3, 'Enable', 'on');

set(handles.FilterOrder4, 'Enable', 'on');

set(handles.RelativeDelay2, 'Enable', 'on');

set(handles.RelativeDelay3, 'Enable', 'on');

set(handles.RelativeDelay4, 'Enable', 'on');

set(handles.DelaySpread_us1, 'Enable', 'on');

set(handles.DelaySpread_us2, 'Enable', 'on');

set(handles.DelaySpread_us3, 'Enable', 'on');

set(handles.DelaySpread_us4, 'Enable', 'on');

set(handles.DelayPeak_us1, 'Enable', 'on')

set(handles.DelayPeak_us2, 'Enable', 'on');

set(handles.DelayPeak_us3, 'Enable', 'on');

set(handles.DelayPeak_us4, 'Enable', 'on');

set(handles.EnableButton2, 'Value', 0);

set(handles.EnableButton3, 'Value', 0);

set(handles.EnableButton4, 'Value', 0);

Getting an error for each line that all states:

Undefined variable "handles" or class "handles.Profile".

Error in channel_model_gui>ManualAndEnable (line 193)

set(handles.Profile,'Value',1);

Warning: Error occurred while evaluating listener callback.

> In openfig at 135

In gui_mainfcn>local_openfig at 286

In gui_mainfcn at 234

In channel_model_gui at 42

Undefined variable "handles" or class "handles.Profile".

[Walter Roberson]

The listener you add should be an anonymous function that captures the figure number of the GUI and passes it to the callback. Then in the callback, use guidata() applied to that figure to pull back the handles structure.

handles = guidata(TheFigureNumber);

[Adam Kaas]

So I can't have an addlistener(handles.Edit1,'String','PostGet',@ManualAndEnable);?

I figured doing that it would call this function that is intended to run all of that posted above.

[Walter Roberson]

addlistener(handles.Edit1,'String','PostGet',@(src, evt) ManualAndEnable(src, evt, gcf))

function ManualAndEnable(~,~, GUI_Figure_number)

handles = guidata(GUI_Figure_number)

[Adam Kaas]

Is this what you were saying I should be doing Walter?

addlistener(handles.Edit1,'String','PostGet',@(~,~) ManualAndEnable(handles.Edit1,'String', gcf))

function ManualAndEnable(~,~, GUI_Figure_number)

handles = guidata(GUI_Figure_number)

set(handles.Profile,'Value',1);

set(handles.Edit1, 'Enable', 'on');

This causesthe following errors:

Attempt to reference field of non-structure array.

Error in channel_model_gui>ManualAndEnable (line 104)

set(handles.Profile,'Value',1);

Error in channel_model_gui>@(~,~)ManualAndEnable(handles.RelativePower1,'String',gcf) (line

57)

addlistener(handles.RelativePower1,'String','PostGet',@(~,~)ManualAndEnable(handles.RelativePower1,'String',gcf));

Warning: Error occurred while evaluating listener callback.

[Walter Roberson]

Please put a breakpoint in at the "handles = " and see what value you are getting for GUI_Figure_number, and then what result you get from the guidata() call.

[Adam Kaas]

GUI_Figure_number value is 1, and right after the guidata() call I get a Figure 1 display that is all gray. handles is showing a value of [ ] in my workspace.

[Sean de Wolski]

Skip the whole GUIDATA thing. Instead of passing gcf has the third input, pass handles.

,@(~,~)ManualAndEnable(handles.RelativePower1,'String',handles));

then in ManualAndEnable(src,evt,handles)

etc...

[Adam Kaas]

IT WORKS!! Thanks so much guys!

[Walter Roberson]

Your handles must have been associated with a different figure number I guess.

[Sean de Wolski]

or improperly GUIDATAed (new verb!). That is why I avoid GUIDATA like the plague.

Answer 2

[Walter Roberson]

Have the listener set a variable in an area you can test.

[Adam Kaas]

So could I use an expression such as

addlistener(handles.Edit1, 'String', 'PostGet', n=1);

then test my n variable? I tried it and it doesn't like the expression at all and I can't find any documentation why.