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Google Chrome Extensions (Labs)

chrome.devtools.panels

Use the chrome.devtools.panels module to integrate your extension into Developer Tools window UI: create your own panels, access existing panels, and add sidebars.

See DevTools APIs summary for general introduction to using Developer Tools APIs.

Overview

Each extension panel and sidebar is displayed as a separate HTML page. All extension pages displayed in the Developer Tools window have access to all modules in chrome.devtools API, as well as to chrome.extension API. Other extension APIs are not available to the pages within Developer Tools window, but you may invoke them by sending a request to the background page of your extension, similarly to how it's done in the content scripts.

You can use the setOpenResourceHandler() method to install a callback function that handles user requests to open a resource (typically, a click on a resource link in the Developer Tools window). At most one of the installed handlers gets called; users can specify (using the Developer Tools Settings dialog) either the default behavior or an extension to handle resource open requests. If an extension calls setOpenResourceHandler() multiple times, only the last handler is retained.

Examples

The following code adds a panel contained in Panel.html, represented by FontPicker.png on the Developer Tools toolbar and labeled as Font Picker:

chrome.devtools.panels.create("Font Picker",
                              "FontPicker.png",
                              "Panel.html"
                              function(panel) { ... });

The following code adds a sidebar pane contained in Sidebar.html and titled Font Properties to the Elements panel, then sets its height to 8ex: 

chrome.devtools.panels.elements.createSidebarPane("Font Properties",
    function(sidebar) {
      sidebar.setPage("Sidebar.html");
      sidebar.setHeight("8ex");
    });

This screenshot demonstrates the effect the above examples would have on Developer Tools window: Extension icon panel on DevTools toolbar

You can find examples that use this API in Samples.

API reference: chrome.devtools.panels

Properties

elements

chrome.devtools.panels.elements
elements
Elements panel.

Methods

create

chrome.devtools.panels.create(string title, string iconPath, string pagePath, function callback)

Creates an extension panel.

Parameters

title
( string )
Title that is displayed next to the extension icon in the Developer Tools toolbar.
iconPath
( string )
Path of the panel's icon relative to the extension directory.
pagePath
( string )
Path of the panel's HTML page relative to the extension directory.
callback
( optional function )
A function that is called when the panel is created.

Callback function

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

function(ExtensionPanel panel) {...};
panel
An ExtensionPanel object representing the created panel.

setOpenResourceHandler

chrome.devtools.panels.setOpenResourceHandler(function callback)

Specifies the function to be called when the user clicks a resource link in the Developer Tools window. To unset the handler, either call the method with no parameters or pass null as the parameter.

Parameters

callback
( optional function )
A function that is called when the user clicks on a valid resource link in Developer Tools window. Note that if the user clicks an invalid URL or an XHR, this function is not called.

Callback function

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

function(object Resource) {...};
Resource
( object )
A Resource object for the resource that was clicked.

Types

ElementsPanel

( object )
Represents the Elements panel.

Methods of ElementsPanel

createSidebarPane

elementsPanel.createSidebarPane(string title, function callback)

Creates a pane within panel's sidebar.

Parameters

title
( string )
Text that is displayed in sidebar caption.
callback
( optional function )
A callback invoked when the sidebar is created.

Callback function

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

function(ExtensionSidebarPane result) {...};
result
An ExtensionSidebarPane object for created sidebar pane.

Events of ElementsPanel

onSelectionChanged

elementsPanel.onSelectionChanged.addListener(function() {...});

Fired when an object is selected in the panel.

ExtensionPanel

( object )
Represents a panel created by extension.

Methods of ExtensionPanel

createStatusBarButton

Button extensionPanel.createStatusBarButton(string iconPath, string tooltipText, boolean disabled)

Appends a button to the status bar of the panel.

Parameters

iconPath
( string )
Path to the icon of the button. The file should contain a 64x24-pixel image composed of two 32x24 icons. The left icon is used when the button is inactive; the right icon is displayed when the button is pressed.
tooltipText
( string )
Text shown as a tooltip when user hovers the mouse over the button.
disabled
( boolean )
Whether the button is disabled.

Returns

( Button )
Undocumented.

Events of ExtensionPanel

onHidden

extensionPanel.onHidden.addListener(function() {...});

Fired when the user switches away from the panel.

onSearch

extensionPanel.onSearch.addListener(function(string action, string queryString) {...});

Fired upon a search action (start of a new search, search result navigation, or search being canceled).

Listener parameters

action
( string )
Type of search action being performed.
queryString
( optional string )
Query string (only for 'performSearch').

onShown

extensionPanel.onShown.addListener(function(DOMWindow window) {...});

Fired when the user switches to the panel.

Listener parameters

window
( DOMWindow )
The window object of panel's page.

ExtensionSidebarPane

( object )
A sidebar created by the extension.

Methods of ExtensionSidebarPane

setExpression

extensionSidebarPane.setExpression(string expression, string rootTitle, function callback)

Sets an expression that is evaluated within the inspected page. The result is displayed in the sidebar pane.

Parameters

expression
( string )
An expression to be evaluated in context of the inspected page. JavaScript objects and DOM nodes are displayed in an expandable tree similar to the console/watch.
rootTitle
( optional string )
An optional title for the root of the expression tree.
callback
( optional function )
A callback invoked after the sidebar pane is updated with the expression evaluation results.

Callback function

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

function(null) {...};

setHeight

extensionSidebarPane.setHeight(string height)

Sets the height of the sidebar.

Parameters

height
( string )
A CSS-like size specification, such as '100px' or '12ex'.

setObject

extensionSidebarPane.setObject(string jsonObject, string rootTitle, function callback)

Sets a JSON-compliant object to be displayed in the sidebar pane.

Parameters

jsonObject
( string )
An object to be displayed in context of the inspected page. Evaluated in the context of the caller (API client).
rootTitle
( optional string )
An optional title for the root of the expression tree.
callback
( optional function )
A callback invoked after the sidebar is updated with the object.

Callback function

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

function(null) {...};

setPage

extensionSidebarPane.setPage(string path)

Sets an HTML page to be displayed in the sidebar pane.

Parameters

path
( string )
Relative path of an extension page to display within the sidebar.

Events of ExtensionSidebarPane

onHidden

extensionSidebarPane.onHidden.addListener(function() {...});

Fired when the sidebar pane becomes hidden as a result of the user switching away from the panel that hosts the sidebar pane.

onShown

extensionSidebarPane.onShown.addListener(function(DOMWindow window) {...});

Fired when the sidebar pane becomes visible as a result of user switching to the panel that hosts it.

Listener parameters

window
( optional DOMWindow )
The window object of the sidebar page, if one was set with the setPage() method.

Button

( object )
A button created by the extension.

Methods of Button

update

button.update(string iconPath, string tooltipText, boolean disabled)

Updates the attributes of the button. If some of the arguments are omitted or null, the corresponding attributes are not updated.

Parameters

iconPath
( optional string )
Path to the new icon of the button.
tooltipText
( optional string )
Text shown as a tooltip when user hovers the mouse over the button.
disabled
( optional boolean )
Whether the button is disabled.

Events of Button

onClicked

button.onClicked.addListener(function() {...});

Fired when the button is clicked.