Use uieditfiel​d.ValueCha​ngedFcn to change uieditfield.value by same amount

I have a gui that contains a uieditfield component. The editfield changes the orientation of a detector by the uieditfield.Value amount. Many times I wish to change the field by increments of 1. For example, I enter a value, say 1 into the edit field box. The next time I want to move the detector by the same amount. When I type in 1 to the uieditfield box, the detector does not move, however, if I type in 1.1 then the detector moves. I believe that this behavior is connected to the uieditfield method ValueChangedFcn. I am using uieditfield.ValueChangedFcn as a callback to move the detector. My question is:

How can I change the orientation of my detector by using constant increments? Should I use a different ui component to get the behavior I need? Is the problem actually in using uieditfield.ValueChangedFcn?

Answer 1

[John Williams]

I found the solution. I needed to set the uieditfield.Value to a different number after I had used the value to change the orientation of my detector. I chose zero as I am unlikely to edit the field with a new value of zero.

Answer 2

[Voss]

It sounds like what's going on is that the ValueChangedFcn does not execute when the uieditfield's Value does not change. So you need a way to update the detector orientation when the detector orientation increment is not changing.

You may consider putting an additional component in your UI, say a uibutton whose ButtonPushedFcn increments the orientation of the detector by the amount given in the uieditfield's Value.

[John Williams]

At the moment, I am using the Tab key to act as the event to call the ValueChangedFcn. My gui is so crowded that there is no more room for extra buttons. I suppose I could always set uieditfield.Value to zero after collecting the new value. Would that work?

[Voss]

I think setting uieditfield.Value to zero after getting the new value would work.

But you may want to rethink your code's structure a little bit, because you need a function to update the detector orientation, say updateDetectorOrientation(), that is not tied only to the uieditfield's ValueChangedFcn. I mean, updateDetectorOrientation() can be called from the uieditfield's ValueChangedFcn, but it also needs to be called any time the detector orientation needs to update for any reason.

[John Williams]

I would love to change my code's structure but I don't really know how to make it better. I am new to Matlab and new to GUI programming but old to programming. In fact, I am a scientist and not really a computer programmer at all. As such, I have never really understood the structure behind GUI programming. I have no reference to see how to do it more effectively.

As of right now, I am calling the updateDetectorOrientation function in three different places, one when I set up the GUI, one when I rotate clockwise and one when I rotate counterclockwise; none of these are callbacks. In the rotate clockwise and counterclockwise functions updateDetectorOrientation is called by the callback function. The whole program is working but my feeling is that it is on the brink of a crash(i.e. anytime someone does something different from what I expected). Do you have a source for properly programming gui programs? Something related to Matlab? I find that the Matlab help stuff is not very useful. Thanks for your insights.