messageDisplayAction

The messageDisplayAction API was added in Thunderbird 71, and was uplifted to Thunderbird 68.3 ESR. It is similar to Firefox’s browserAction API and can be combined with the messageDisplay API to determine the currently displayed message.

Use a messageDisplayAction to put an icons in the mail window toolbar. In addition to its icon, a messageDisplayAction can also have a tooltip, a badge, and a popup.

Manifest file properties

[message_display_action]
(object)
[browser_style]
(boolean)
[default_area]
(string)
Currently unused.
[default_icon]
(string)
[default_popup]
(string)
[default_title]
(string)
[theme_icons]
(array of ThemeIcons)
Specifies icons to use for dark and light themes

Note

A manifest entry named message_display_action is required to use messageDisplayAction.

Functions

setTitle(details)

Sets the title of the messageDisplayAction. This shows up in the tooltip.

Parameters
details
(object)
title
(string or null)
The string the messageDisplayAction should display when moused over.

getTitle(details)

Gets the title of the messageDisplayAction.

Parameters
details
Return type (Promise)
string

setIcon(details)

Sets the icon for the messageDisplayAction. 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)
[imageData]
(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]
(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}’

setPopup(details)

Sets the html document to be opened as a popup when the user clicks on the messageDisplayAction’s icon.

Parameters
details
(object)
popup
(string or null)
The html file to show in a popup. If set to the empty string (‘’), no popup is shown.

getPopup(details)

Gets the html document set as the popup for this messageDisplayAction.

Parameters
details
Return type (Promise)
string

setBadgeText(details)

Sets the badge text for the messageDisplayAction. The badge is displayed on top of the icon.

Parameters
details
(object)
text
(string or null)
Any number of characters can be passed, but only about four can fit in the space.

getBadgeText(details)

Gets the badge text of the messageDisplayAction. If no tab nor window is specified is specified, the global badge text is returned.

Parameters
details
Return type (Promise)
string

setBadgeBackgroundColor(details)

Sets the background color for the badge.

Parameters
details
(object)
color
(string or ColorArray or null)
An array of four integers in the range [0,255] that make up the RGBA color of the badge. For example, opaque red is [255, 0, 0, 255]. Can also be a string with a CSS value, with opaque red being #FF0000 or #F00.

getBadgeBackgroundColor(details)

Gets the background color of the messageDisplayAction.

Parameters
details
Return type (Promise)

enable([tabId])

Enables the messageDisplayAction for a tab. By default, messageDisplayActions are enabled.

Parameters
[tabId]
(integer)
The id of the tab for which you want to modify the messageDisplayAction.

disable([tabId])

Disables the messageDisplayAction for a tab.

Parameters
[tabId]
(integer)
The id of the tab for which you want to modify the messageDisplayAction.

isEnabled(details)

Checks whether the messageDisplayAction is enabled.

Parameters
details

openPopup()

Opens the extension popup window in the active window.

Events

onClicked(tabId)

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

Parameters for event listeners
tabId
(integer)

Types

ColorArray

An array of four integers in the range [0,255] that make up the RGBA color. For example, opaque red is [255, 0, 0, 255].

array of integer

Details

Specifies to which tab or window the value should be set, or from which one it should be retrieved. If no tab nor window is specified, the global value is set or retrieved.

object
[tabId]
(integer)
When setting a value, it will be specific to the specified tab, and will automatically reset when the tab navigates. When getting, specifies the tab to get the value from; if there is no tab-specific value, the window one will be inherited.
[windowId]
(integer)
When setting a value, it will be specific to the specified window. When getting, specifies the window to get the value from; if there is no window-specific value, the global one will be inherited.

ImageDataType

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

External Types

The following types are not defined by this API, but by the underlying Mozilla WebExtension code base. They are included here, because there is no other public documentation available.

ThemeIcons

Define a set of icons for themes depending on whether Thunderbird detects that the theme uses dark or light text. All provided URLs must be relative to the manifest.json file.

object
dark
(string)
A URL pointing to an icon. This icon displays when a theme using dark text is active (such as the Light theme, and the Default theme if no default_icon is specified).
light
(string)
A URL pointing to an icon. This icon displays when a theme using light text is active (such as the Dark theme).
size
(integer)
The size of the two icons in pixels, for example 16 or 32.