Best way to Start using App Designer?

Jumping in with both feet, I have tried to create an app to run some simple code that manipulates vectors in the complex plane. I have reviewed the existing help and tutorials on the subject but it isn't entirely clear how to start the process. My intuition led me to think that you'd launch App Designer from the code you were working on, and then create the GUI to interface with the code. From what I have seen so far, it is the other way around....you create the GUI first on a blank slate, THEN you have to insert the "functional" code that you want the GUI to control. Any comments on my observations? Feel free to give advice!

[M G]

Thank you for your reply, it is a very good start. I am still left wondering, how the App is linked to the original code. You mentioned callbacks to the code. But, how does the app that you are working on know where the code is? Does the name of the App have to be the same as the name of the code file (but different file extension), and do they have to be stored in the same Folder? I know, these are basic questions but I am entirely new to MatLab, so apologies in advance...

[Ameer Hamza]

In the App Designer, there is Design View and then there is Code View. All the code resides in Code view tab.

[M G]

And, since there is no code when starting a new App, one has to shuffle back and forth between the code you want to create the App for, and App Designer....cutting and pasting as you go?

[Ameer Hamza]

You can first add all the components you want to the app canvas, and then code the way you want the components to interact with each other.

Answer 1

[Ameer Hamza]

"From what I have seen so far, it is the other way around"

Your observation is correct. In-App designer, you will first create graphics interface and then write callbacks and functions to respond to different events related to GUI. App designer is designed with the goal to minimize the need for code to create GUI itself, you can just drag and drop GUI elements, app inventor will create that code in the background for you. In this way, the user can focus on the actual features of GUI. It also helps in keeping code organized and minimize chances of errors.

"My intuition led me to think that you'd launch App Designer from the code you were working on, and then create the GUI to interface with the code."

This is not done in App designer since MATLAB already have tools to create GUI and link to your existing code. See GUIDE and Programmatically creating GUI.

To get started with App designer, you we need to have an understanding of these fractures of MATLAB

• OOP in MATLAB.
• Events, listeners, and callbacks.
• Handle classes are part of OOP, but due to their importance, I mentioned it separately.

These resources will help you get started for advanced App designer usage.

[M G]

Thanks for your help with my inquiry. Your pointers were very useful. My comment on App Designer is that, yes, it does make it "easy" to create an App but in fact it does not entirely automate the process of migrating from a running Code, to a GUI App. It does, of course, provide an automated linkage between the GUI objects and the app code, and that is huge. The user then has to create the linkage between the GUI objects and the functional code, and that does have a steep learning curve if you've never done anything of the sort before! MG

[Ameer Hamza]

Yes, I agree. You have to establish the linkage yourself, and that's what makes it more flexible and powerful. It gives you very detailed control over all the UI components and how they interface with each other.