Google Chrome Extensions

chrome.pageAction

Use page actions to put icons inside the address bar. Page actions represent actions that can be taken on the current page, but that aren't applicable to all pages. Some examples:

The RSS icon in the following screenshot represents a page action that lets you subscribe to the RSS feed for the current page.

If you want the extension's icon to always be visible, use a browser action instead.

Manifest

Register your page action in the extension manifest like this: 

{
  "name": "My extension",
  ...
  "page_action": {
    "default_icon": {                    // optional
      "19": "images/icon19.png",           // optional
      "38": "images/icon38.png"            // optional
    },
    "default_title": "Google Mail",      // optional; shown in tooltip
    "default_popup": "popup.html"        // optional
  },
  ...
}

If you only provide one of the 19px or 38px icon size, the extension system will scale the icon you provide to the pixel density of the user's display, which can lose detail or make it look fuzzy. The old syntax for registering the default icon is still supported: 

{
  "name": "My extension",
  ...
  "page_action": {
    ...
    "default_icon": "images/icon19.png"  // optional
    // equivalent to "default_icon": { "19": "images/icon19.png" }
  },
  ...
}

Parts of the UI

Like browser actions, page actions can have an icon, a tooltip, and popup; they can't have badges, however. In addition, page actions can appear and disappear. You can find information about icons, tooltips, and popups by reading about the browser action UI.

You make a page action appear and disappear using the show() and hide() methods, respectively. By default, a page action is hidden. When you show it, you specify the tab in which the icon should appear. The icon remains visible until the tab is closed or starts displaying a different URL (because the user clicks a link, for example).

Tips

For the best visual impact, follow these guidelines:

Examples

You can find simple examples of using page actions in the examples/api/pageAction directory. For other examples and for help in viewing the source code, see Samples.

API Reference: chrome.pageAction

Types

ImageDataType

( imagedata )
Pixel data for an image. Must be an ImageData object (for example, from a canvas element).

Methods

show

chrome.pageAction.show(integer tabId)

Shows the page action. The page action is shown whenever the tab is selected.

Parameters

tabId ( integer )
The id of the tab for which you want to modify the page action.

hide

chrome.pageAction.hide(integer tabId)

Hides the page action.

Parameters

tabId ( integer )
The id of the tab for which you want to modify the page action.

setTitle

chrome.pageAction.setTitle(object details)

Sets the title of the page action. This is displayed in a tooltip over the page action.

Parameters

details ( object )
tabId ( integer )
The id of the tab for which you want to modify the page action.
title ( string )
The tooltip string.

getTitle

chrome.pageAction.getTitle(object details)

Gets the title of the browser action.

Parameters

details ( object )
tabId ( integer )
Specify the tab to get the title from.

Callback function

The callback parameter should specify a function that looks like this:

function(string result) {...};
result ( string )

setIcon

chrome.pageAction.setIcon(object details)

Sets the icon for the page action. The icon can be specified either as the path to an image file or as the pixel data from a canvas element, or as dictionary of either one of those. Either the path or the imageData property must be specified.

Parameters

details ( object )
tabId ( integer )
The id of the tab for which you want to modify the page action.
imageData ( optional ImageDataType or object )
Either an ImageData object or a dictionary {size -> ImageData} representing icon to be set. If the icon is specified as a dictionary, the actual image to be used is chosen depending on screen's pixel density. If the number of image pixels that fit into one screen space unit equals scale, then image with size scale * 19 will be selected. Initially only scales 1 and 2 will be supported. At least one image must be specified. Note that 'details.imageData = foo' is equivalent to 'details.imageData = {'19': foo}'
path ( optional string or object )
Either a relative image path or a dictionary {size -> relative image path} pointing to icon to be set. If the icon is specified as a dictionary, the actual image to be used is chosen depending on screen's pixel density. If the number of image pixels that fit into one screen space unit equals scale, then image with size scale * 19 will be selected. Initially only scales 1 and 2 will be supported. At least one image must be specified. Note that 'details.path = foo' is equivalent to 'details.imageData = {'19': foo}'
iconIndex ( optional integer )
Deprecated. This argument is ignored.

Callback function

If you specify the callback parameter, it should specify a function that looks like this:

function() {...};

setPopup

chrome.pageAction.setPopup(object details)

Sets the html document to be opened as a popup when the user clicks on the page action's icon.

Parameters

details ( object )
tabId ( integer )
The id of the tab for which you want to modify the page action.
popup ( string )
The html file to show in a popup. If set to the empty string (''), no popup is shown.

getPopup

chrome.pageAction.getPopup(object details)

Gets the html document set as the popup for this browser action.

Parameters

details ( object )
tabId ( integer )
Specify the tab to get the popup from.

Callback function

The callback parameter should specify a function that looks like this:

function(string result) {...};
result ( string )

Events

onClicked

chrome.pageAction.onClicked.addListener(function(tabs.Tab tab) {...});

Fired when a page action icon is clicked. This event will not fire if the page action has a popup.

Listener Parameters

tab ( tabs.Tab )

Sample Extensions that use chrome.pageAction

  • Page action by content – Shows a page action for HTML pages containing the word 'sandwich'
  • Page action by URL – Shows a page action for urls which have the letter 'g' in them.
  • Mappy – Finds addresses in the web page you're on and pops up a map window.