Invalidate ribbon control in Excel 2013 for multiple workbooks - vb.net

Question

I have a customized ribbon where I added a tab containing a toggle button. This toggle button has a getPressed attribute which is linked to a callback function returning the pressed state of the toggle button. The purpose of the toggle button is to display/hide a custom task pane. This works fine.
However, my issue is that in Excel 2013, if I have two or more workbooks open, when I invalidate the toggle button, only the one of the active workbook is updated. I also want to update the pressed state of the toggle buttons on the other workbooks as the custom task pane is either visible or invisible in all workbooks.
Anyone knows how to do invalidate a control in the ribbon of all workbooks in Excel 2013?
I am using vb.net and excel-dna.
The toggle button is defined like that:
<toggleButton id="toggleButtonInputData" size="large" onAction="rxToggleButton_onAction" getPressed="rxToggleButton_getPressed" getImage="rxButton_GetImage" getLabel="rxbutton_GetLabel" getEnabled="rxGenericControl_GetEnabled" visible="true"/>
The callback function is:
Function rxToggleButton_GetPressed(ctl As CustomUI.IRibbonControl) As Object
Select Case ctl.Id
Case "toggleButtonInputData"
Return CTP_InputData.IsToggleButtonPressed
End Select
End Function
To invalidate the toggle button I use :
Public Sub CTP_InputData_VisibleStateChange() Handles CTP_InputData.VisibleStateChange
XLRibbon.myRibbon.InvalidateControl("toggleButtonInputData")
End Sub

Answer 1

The Invalidation is only processed for the active workbook's ribbon. But when you then switch to another workbook, the callbacks will fire again and will now be applied to the ribbon of the new workbook.
There's a bug and some quirks in Excel 2013 related to this switching:
If you click on the title bar or the ribbon of the workbook you want to activate, everything works as expected. But if you click on a cell in the workbook you're activating, you get two callbacks - the first is applied to the deactivating workbook's ribbon, and the second is applied to the activating workbook's ribbon. The problem is that you cannot distinguish (in your callback) whether you are getting called for the deactivating book. (Using COM events doesn't help either, both callbacks happen after all the COM Workbook- and Window- (De)Activate events have fired.
Apart from this quirky behaviour, one clear bug in Excel 2013 is that the IRibbonControl.Context is not set to the correct window - in both of the callbacks it reflects the activating window, though the first callback will be applied to the deactivating window.
Here's a detailed discussion on the issue: https://social.msdn.microsoft.com/Forums/windowsserver/en-US/a3dade87-1df7-46ec-8876-437194d7553e/how-to-reference-the-correct-workbook-from-a-control-in-a-ribbon-callback?forum=exceldev
In summary, you don't have good control over the state of deactivated ribbons. But if you are only worried about the active ribbon, Invalidate works fine, but you must expect the callback only upon activation.