How do you check what toolbox tab is currently open?

Question

Can you know which tab is currently opened in the blockly toolbox? If so, can anyone show me an example or code snippet?

Answer 1

The toolbox contains a Closure UI Tree.

To get the name of the most recent tab while accessing a minimum set of private members:

var tree = workspace.getToolbox().tree_;  
var selectedItem = tree.getSelectedItem();
if (selectedItem) {
  var itemText = selectedItem.getText();
} else {
  console.log('no item selected');
}

Answer 2

I found the answer by doing trial and error things!

[workspace here].toolbox_.lastCategory_.html_.privateDoNotAccessOrElseSafeHtmlWrappedValue_

stores a string whith the most recent selected tab, and

workspace.toolbox_.lastCategory_.selected_

gives a boolean which lets you know if the last selected tab is currently selected.