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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 browserWindow attribute exposes the context window. On getting, the browserWindow attribute returns a BrowserWindow object representing the context window.

This attribute is named browserWindow and not window to avoid confusion with the global window object.


readonly BrowserWindow browserWindow


The following example creates a button on the browser toolbar. When the button is clicked, the current tab's parent window is detected. If the window is not private, a new private window is opened with the URL of the current tab.

// 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",
  onclick: function() {
    // Get the currently selected tab
    var thisTab = opera.extension.tabs.getSelected();
    // Get the tab's browser window
    var thisWin = thisTab.browserWindow;
    // If the window is not private, open a new private window with the tab's URL
    if (thisWin.private === false) {
      opera.extension.windows.create([{url: thisTab.url}], {private: true});

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