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This documentation relates to Opera's now deprecated .oex Extension API framework for Opera versions <= 12.15 and also provided by our OEX2NEX shim library.

For the latest Opera Extensions API documentation for Opera versions > 12.15 please consult the latest Opera Extensions API documentation online.


The readonly position attribute exposes the current tab position. On getting, the tab position is only returned if the browser tab is open, otherwise NaN is returned.


readonly unsigned long position


The following example creates a button on the browser toolbar. When the button is clicked, the position of the currently selected tab is displayed in the button's badge.

// The background process (e.g. index.html)

// Specify the properties of the button before creating it.
var UIItemProperties = {
  disabled: false,
  title: "Example extension",
  icon: "images/icon_18.png",
  badge: {
    backgroundColor: '#cc0000',
    color: '#ffffff'

// Create the button and add it to the toolbar.
var button = opera.contexts.toolbar.createItem( UIItemProperties );  

button.addEventListener('click', handleClick, false);

function handleClick() {
  // Get the currently selected tab
  var thisTab = opera.extension.tabs.getSelected();
  // Display the tab's position in the button's badge
  button.badge.textContent = thisTab.position;