Subpanel issues?

[mikeporter]

I am embarking on a project that would do well with extensive use of subpanels. What problems (or issues) have you run into. I already found out that you can't change the autoscaling of a graph in a subpanel by right clicking on the graph...

Anything else (important) lurking in the weeds?

Mike...

[JRA]

Here is one thing I've noticed: If you have a graph displayed through a subpanel, the names of the axes may be blacked out. I looked into it and found that this is because it is showing the background of the subpanel. You need to open the VI which is actually being displayed and set the background color of the axis name (with the set color tool) to be the same color as the background of the graph (or whatever color you prefer).

[mikeporter]

You're right, come to think of it I saw that too.

Mike...

[JRA]

I just realized that I had inadvertenly written "background." You want to set the foreground to a particular color. That will make it viewable when it's displayed through a subpanel.

[mikeporter]

I have been playing with this for a few days and have found a few things that are perhaps underdocumented and which might be helpful...

First, subpanels work great! Very cool indeed!

Second, there are a couple concepts that you need to wrap your head around. To begin, even though it looks like you are making calls to the subpanel VI you really aren't--you're just observing it's front panel. This is purely speculation, but I wouldn't be suprised to find out that the technology underlying subpanels is very similar to that which drives the remote frontpanel capability in LV.

This distinction becomes important when you need the VI making the subpanel calls to actually interact with the subpanel VIs (i.e. pass data back and forth, reference one another, etc). The examples that ship with LV show making calls using an Open VI Reference call to get a reference to the target VI. This means that the subpanel doesn't know it's be accessed as a subpanel, as a result the "calling" VI doesn't appear in the subpanel's call chain.

Because the appearance of the subpanel VI's front panel was psychologically stronger that the fact of how the code was connecting to the subpanel VI, I was initially fooled and reported it as a possible bug--after all it sure seemed like I was calling the other VI. But it now seems that this is the proper behavior given the type of reference opened to the subpanel VI. The program making the subpanel calls (if that's even the right term) was connected to the subpanel vi on some level, but it wasn't linked to it in the programming sense, hence its absence from the call chain.

If however, you do a call-by-reference, in that case you are actually linking to the subpanel vi so you can pass data through connector panes and the call chain shows the VI making the subpanel connection. As you would expect with or without a subpanel to provide a view of the front panel.

Hope this helps anyone else working with this functionality. I'll keep ya'll posted if I come across anything else that might be helpful.

Mike...

[Greg_McKaskle2]

> panel. This is purely speculation, but I wouldn't be suprised to find
> out that the technology underlying subpanels is very similar to that
> which drives the remote frontpanel capability in LV.
>
Actually, the subPanel feature is not at all related to the Remote Panel
Viewer. Instead, the better mental model to have is that of dynamically
called popup panels. You load the subVI using VI server, and you have a
choice to open it and run/call it in a popup panel, or in a subPanel.
The VI will run and be left open using rules very similar to the popup
panel, but it doesn't draw into its own window, instead it shares a
rectangle of the owning window/control.

Greg McKskle

[Nyar]

Here are some other issues I stumbled over while working with sub panels:

-Table column headers are not resizeable
-Lab View crashes if you want to scroll a table (table was on a tab btw)

These problems, along with those concerning the graphs (zooming, axis label), forced me to realize my project without sub panels.

[malosh]

I didn't manage to use the 'Run' method on a VI in a subpanel, which led me to abandone some stuff I wanted to do...

[Soroush]

Another subpanel issue, here

Related to using ActiveX controls in subpanels.

[asche]

Hello All,
here are a few things I have noticed.
1. The position of an ActiveX object (a camera view in my case) depends on the size of the subpanel container. I had to adjust the activex container position elements to shift it around. Could it be that its position is related to the entire FP of the sub-vi, or something like that?
2. There are some event issues. I have a table that captures the left mouse button properly, but not the right one. I have my own pop-up menu that works fine stand alone, but does not see the event in a subpanel, but rather displays the lv table right click menu. There is no event structure in the top-vi, and I inserted timers in the concurring event loops of the nested sub-panels.

It makes for a seemingly elegant way to built guis, but when pushed seems exceedingly weak in implementation.