title: enable context menu for specific cell or item in uitable or uilistbox in matlab
body: <p>I created a uitable (new version using appdesigner) in MATLAB and wanted to support right clicking on cells and showing a cell specific context menu. Much to my surprise there seemed to be no way to support this.</p>
  <p>The context menu only seems to trigger with right click on the uitable, but there is no way of knowing which cell was selected (I think, maybe not?). I created a workaround where I left clicked to select a cell, and during that selection I right clicked using a Java Mouse robot to trigger the context menu. This is super ugly but sort of works. Except, if you need to bring up the menu twice on the same cell. Apparently the cell selected callback only fires once for the cell, until a new cell is selected. I tried literally putting two tables in the same spot and upon selecting one toggling to the other, but the memory of cell selection is table specific, so this only worked for two clicks before both tables had been clicked on the same cell, and toggling visibility back to the first resulted in the cell selection callback not firing (since the cell had not changed) . I tried various approaches to try and deselect the cell (disable/enable, visibility change, data change, etc.), but the cell selection callback never changed.</p>
  <p>I even tried having duplicate columns, where the goal was to hide a column, where normally columns 1 and 2 would be visible (column 3 out of view due to size), and then on clicking on column 2, column 2 would hide itself (0 width) and column 3 (an exact duplicate) would move into its place, thus seeming to the user like multi-clicking was supported. Unfortunately I can't set the column width to 0 -- or rather, setting it to 0 doesn't completely hide the column. Instead there seems to be some minimal width to the column and the whole thing looked awful.</p>
  <p>I wanted to do something similar with a listbox (right click support), but again I couldn't figure out how to identify where I was right clicking. I eventually settled on left clicking on a listbox and using the mouse robot approach to right click to bring up the context menu. Unlike the uitable, it was fairly easy to clear the selection on the listbox (set <code>listbox.Value = {}</code>). However, I strongly dislike the left click instead of right click approach and I'd rather have multiple columns.</p>
  <p>Any suggestions would be much appreciated!!!</p>