sidebarAction.setIcon()

Your extension should specify an icon for the sidebar in the sidebar_action manifest key. This is called the "manifest icon".

If you don't specify an icon in the sidebar_action key, you get the browser's default icon. This is called the "default icon".

If you set a new icon using setIcon(), and include the tabId option, then the icon is set only for the given tab. This icon is called the "tab-specific icon".

If you set a new icon using setIcon(), and include the windowId option, then the icon is set only for the given window. This icon is called the "window-specific icon", and will appear in all tabs of that window that do not have a tab-specific icon set.

If you set a new icon using setIcon(), and omit both the tabId and windowId options, then this sets the "global icon". The global icon will then appear in all tabs that do not have a tab-specific icon set and whose window does not have a window-specific icon.

details

object. An object with the following properties:

imageData Optional

sidebarAction.ImageDataType or object. This is either a single ImageData object or a dictionary object.

Use a dictionary object to specify multiple ImageData objects in different sizes, so the icon does not have to be scaled for a device with a different pixel density. If imageData is a dictionary, the value of each property is an ImageData object, and its name is its size, like this:

{
    16: image16,
    32: image32
  }

The browser will choose the image to use depending on the screen's pixel density. See Choosing icon sizes for more information on this.

path Optional

string or object. This is either a relative path to an icon file or it is a dictionary object.

Use a dictionary object to specify multiple icon files in different sizes, so the icon does not have to be scaled for a device with a different pixel density. If path is a dictionary, the value of each property is a relative path, and its name is its size, like this:

{
    16: "path/to/image16.jpg",
    32: "path/to/image32.jpg"
  }

The browser will choose the image to use depending on the screen's pixel density. See Choosing icon sizes for more information on this.

If path is an empty string, the browser will use the default icon.

If path is not empty but does not point to an icon file, then the icon is hidden.

If path is null, and tabId was specified, and the specified tab had a tab-specific icon set: then the tab-specific icon is reset to the global icon (if a global icon is set) or the manifest icon.

if path is null, and tabId was omitted, and there was a global icon set, it will be reset to the manifest icon.

tabId Optional

integer. Sets the icon only for the given tab.

windowId Optional

integer. Sets the icon only for the given window.

• If windowId and tabId are both specified, the function fails and the icon is not set.
• If windowId and tabId are both omitted, the icon is set globally.

A Promise that will be fulfilled with no arguments once the icon has been set.

The code below toggles the sidebar icon for the active tab when the user clicks a browser action:

let on = false;

function toggle(tab) {
  if (on) {
    browser.sidebarAction.setIcon({
      path: "off.svg",
      tabId: tab.id
    });
    on = false;
  } else {
    browser.sidebarAction.setIcon({
      path: "on.svg",
      tabId: tab.id
    });
    on = true;
  }
}

browser.browserAction.onClicked.addListener(toggle);