In 2020a Mathworks added this semi-useful class
matlab.ui.internal.JavaMigrationTools
Which contains static methods to call javacomponent, actxcontrol or to get an object’s JavaFrame or JavaContainer while suppressing the associated warning.

@Yair – I noticed it get back to the previous state after some time or as soon as I put my cursor on the toolbar.

@Yair – I tried youר solution but it set the jpanel to the size of the matlab container and I want the jpanel to fit the jscrollpane.
I found a way to force the jpanel to fit to the jscrollpane :

jpanel.setSize(jscrollpane.getSize)
 

but it only last for some time and then get back automatically to the previous state. Do you know why?

@Melec – you could try to use normalized units in the container handle that is returned as the second output arg by javacomponent

I am trying to add a JTable (which has a number of rows that can change) into a Matlab interface. To do so I put the JTable into a JScrollPane which I draw in my interface through the javacomponent function. The problem is that I can’t find a way to get the right size to assign in the javacomponent function.

I tried to use the preferrable size of the jtable or the preferrable size of the jscrolpane but it is never perfect. Either the table doesn’t fit the all jscrollpane and there is a small band below the table or the jscrollpane is too small.

Then I tried to put the jscrollpane into a JPanel which fixed the table to fit the jscrollpane size. But then the panel is bigger than the table which is OK but its margins change according to the number of rows.

Does it exist a clean way to get the right size to apply in the javacomponent function?

The version that I uploaded to FEX yesterday included panel, uipanel, tab and uitab as newly acceptable parents.

@Yair – the ‘regexprep’ function returns ‘panel’ string for the ‘uipanel’ class. so when I write ‘panel’ I actually mean ‘uipanel’.
But I agree it should be tested for all possible use cases that was added since April-2007 release.

I’ll try doing so and update, so ‘uicomponent’ source in Mathworks can be updated/expanded for new versions of matlab.

Thanks

…and I would also add 'tab' and 'uitab' to this list, by the way…

@Amir – when uicomponent was first created 8 years ago (April 2007), I do not think that panels were accepted as javacomponent parents, so the code was probably correct for the Matlab release at that time. I’m not sure when exactly panels were added as legitimate javacomponent parents, but since that release your fix is good, except that it should also test for 'uipanel' (HG1), not just for 'panel' (HG2).

I’ve looked deeper inside “uicomponent” function and I think I found a bug which related to the “hiding” problem.
Inside “uicomponent” there is a function named “getParent” which suppose to check if parent is valid (figure / uipanel) and return the parent handle.
but the following lines in the end of the function overwrites the actual parent that was found, so parent is always the main figure so the javacomponent isn’t auto hiding with tabs i.e.

 
        position = position + [parentPosition(1:2),0,0];  % pixel position relative to figure
        parent = ancestor(parent,'figure');

I think the problem in line 470:

 
elseif ~any(strcmpi(regexprep(class(hParent),'.*\.',''),{'figure','uicontainer','uiflowcontainer','uigridcontainer'}))

should be:

 
elseif ~any(strcmpi(regexprep(class(hParent),'.*\.',''),{'figure','uicontainer','uiflowcontainer','uigridcontainer','panel'}))

what do you think?