winontop | Python library for keeping your applications always on top

I created a plotter using three popup menus: one for X-variable, one for Y, and one for a figure name. When a figure name (number) is selected, its callback function grabs strings from X and Y popup menus, search these from a loaded dataset, and plots them on a selected figure.

What I want to do is multiple-selection on a popup menu. I researched quite a bit and learned that popup menu doesn't have that capability in the regular documented way.

The reason why I don't want to and almost can't use list box is that my GUI has many panels from top to bottom; each containing the three popup menus mentioned above. Each panel represents one dataset. This means if I select and load ten .MAT files, a GUI will be created with 10 panels from top to bottom. Each dataset can have as many as 100 or more variables. The height of the list box (showing, say, only ten variables) and some margins above and below X (times) 10 will create a gigantic GUI that will be basically unusable.

I came across some java scripting discussion that might work by using JcomboBox with some stern warnings, but I didn't actually find the code of it.

Is there a way?

Imagine in the snapshot below that the drop-down list from the Y-axis popup menu was actually a list box and all panels also have the same height list box. It'll be very hard to use this tool efficiently. What I want to do is to select one X-variable, TIME for example (which is the way with popup menu), and be able to select multiple Y-variables. Then, when I select a figure, the plotter will plot those Y-variables against the selected X-variable. I can do this iteratively. Somebody in our group requested this capability and I am scoping its possibility.

I incorporated @excaza idea and I'm having a hard time to figure out how to retain the selected y variable names while I select a figure for them to be plotted. See the image below.

This is definitely going in the right direction. My problem is now where I can retain the selected index information. The function below is the callback function of the "Y-axis" pushbutton. I was thinking about storing the selected y-variable names to its Tag property, but I'm not sure if that's good idea. I certainly don't want to create a global variable, either. Any idea?