chrome.input.ime

Description:	Use the `chrome.input.ime` API to implement a custom IME for Chrome OS. This allows your extension to handle keystrokes, set the composition, and manage the candidate window.
Availability:	Since Chrome 35.
Permissions:	"input"

Manifest

You must declare the "input" permission in the extension manifest to use the input.ime API. For example:

      {
        "name": "My extension",
        ...
        "permissions": [
          "input"
        ],
        ...
      }

Examples

The following code creates an IME that converts typed letters to upper case.

      var context_id = -1;
      
      chrome.input.ime.onFocus.addListener(function(context) {
        context_id = context.contextID;
      });
      
      chrome.input.ime.onKeyEvent.addListener(
        function(engineID, keyData) {
          if (keyData.type == "keydown" && keyData.key.match(/^[a-z]$/)) {
            chrome.input.ime.commitText({"contextID": context_id,
                                         "text": keyData.key.toUpperCase()});
            return true;
          } else {
            return false;
          }
        });

For an example of using this API, see the basic input.ime sample. For other examples and for help in viewing the source code, see Samples.

Summary

Types
KeyboardEventType
KeyboardEvent
InputContextType
AutoCapitalizeType
InputContext
MenuItemStyle
MenuItem
UnderlineStyle
WindowPosition
ScreenType
MouseButton
AssistiveWindowType
AssistiveWindowProperties
AssistiveWindowButton
Methods
setComposition − `chrome.input.ime.setComposition(object parameters, function callback)`
clearComposition − `chrome.input.ime.clearComposition(object parameters, function callback)`
commitText − `chrome.input.ime.commitText(object parameters, function callback)`
sendKeyEvents − `chrome.input.ime.sendKeyEvents(object parameters, function callback)`
hideInputView − `chrome.input.ime.hideInputView()`
setCandidateWindowProperties − `chrome.input.ime.setCandidateWindowProperties(object parameters, function callback)`
setCandidates − `chrome.input.ime.setCandidates(object parameters, function callback)`
setCursorPosition − `chrome.input.ime.setCursorPosition(object parameters, function callback)`
setAssistiveWindowProperties − `chrome.input.ime.setAssistiveWindowProperties(object parameters, function callback)`
setAssistiveWindowButtonHighlighted − `chrome.input.ime.setAssistiveWindowButtonHighlighted(object parameters, function callback)`
setMenuItems − `chrome.input.ime.setMenuItems(object parameters, function callback)`
updateMenuItems − `chrome.input.ime.updateMenuItems(object parameters, function callback)`
deleteSurroundingText − `chrome.input.ime.deleteSurroundingText(object parameters, function callback)`
keyEventHandled − `chrome.input.ime.keyEventHandled(string requestId, boolean response)`
Events
onActivate
onDeactivated
onFocus
onBlur
onInputContextUpdate
onKeyEvent
onCandidateClicked
onMenuItemActivated
onSurroundingTextChanged
onReset
onAssistiveWindowButtonClicked

Types

KeyboardEventType

Enum
`"keyup"`, or `"keydown"`

KeyboardEvent

See http://www.w3.org/TR/DOM-Level-3-Events/#events-KeyboardEvent

properties
KeyboardEventType	type	One of keyup or keydown.
string	(optional) requestId	(Deprecated) The ID of the request. Use the `requestId` param from the `onKeyEvent` event instead.
string	(optional) extensionId	The extension ID of the sender of this keyevent.
string	key	Value of the key being pressed
string	code	Value of the physical key being pressed. The value is not affected by current keyboard layout or modifier state.
integer	(optional) keyCode	Since Chrome 37. The deprecated HTML keyCode, which is system- and implementation-dependent numerical code signifying the unmodified identifier associated with the key pressed.
boolean	(optional) altKey	Whether or not the ALT key is pressed.
boolean	(optional) altgrKey	Since Chrome 79. Whether or not the ALTGR key is pressed.
boolean	(optional) ctrlKey	Whether or not the CTRL key is pressed.
boolean	(optional) shiftKey	Whether or not the SHIFT key is pressed.
boolean	(optional) capsLock	Whether or not the CAPS_LOCK is enabled.

InputContextType

Type of value this text field edits, (Text, Number, URL, etc)

Enum
`"text"`, `"search"`, `"tel"`, `"url"`, `"email"`, `"number"`, `"password"`, or `"null"`

AutoCapitalizeType

The auto-capitalize type of the text field.

Enum
`"characters"`, `"words"`, or `"sentences"`

InputContext

Describes an input Context

properties
integer	contextID	This is used to specify targets of text field operations. This ID becomes invalid as soon as onBlur is called.
InputContextType	type	Type of value this text field edits, (Text, Number, URL, etc)
boolean	autoCorrect	Since Chrome 40. Whether the text field wants auto-correct.
boolean	autoComplete	Since Chrome 40. Whether the text field wants auto-complete.
AutoCapitalizeType	autoCapitalize	Since Chrome 69. The auto-capitalize type of the text field.
boolean	spellCheck	Since Chrome 40. Whether the text field wants spell-check.
boolean	shouldDoLearning	Since Chrome 68. Whether text entered into the text field should be used to improve typing suggestions for the user.

MenuItemStyle

The type of menu item. Radio buttons between separators are considered grouped.

Enum
`"check"`, `"radio"`, or `"separator"`

MenuItem

A menu item used by an input method to interact with the user from the language menu.

properties
string	id	String that will be passed to callbacks referencing this MenuItem.
string	(optional) label	Text displayed in the menu for this item.
MenuItemStyle	(optional) style	The type of menu item.
boolean	(optional) visible	Indicates this item is visible.
boolean	(optional) checked	Indicates this item should be drawn with a check.
boolean	(optional) enabled	Indicates this item is enabled.

UnderlineStyle

The type of the underline to modify this segment.

Enum
`"underline"`, `"doubleUnderline"`, or `"noUnderline"`

WindowPosition

Where to display the candidate window. If set to 'cursor', the window follows the cursor. If set to 'composition', the window is locked to the beginning of the composition.

Enum
`"cursor"`, or `"composition"`

ScreenType

The screen type under which the IME is activated.

Enum
`"normal"`, `"login"`, `"lock"`, or `"secondary-login"`

MouseButton

Which mouse buttons was clicked.

Enum
`"left"`, `"middle"`, or `"right"`

AssistiveWindowType

Type of assistive window.

Enum
`"undo"`

AssistiveWindowProperties

Since Chrome 85. Warning: this is the current Dev channel. Learn more.

Properties of the assistive window.

properties
AssistiveWindowType	type
boolean	visible	Sets true to show AssistiveWindow, sets false to hide.
string	(optional) announceString	Strings for ChromeVox to announce.

AssistiveWindowButton

ID of buttons in assistive window.

Enum
`"undo"`, or `"addToDictionary"`

Methods

setComposition


              chrome.input.ime.setComposition(object parameters, function callback)

Set the current composition. If this extension does not own the active IME, this fails.

Parameters

object

parameters

integer

contextID

ID of the context where the composition text will be set

string

text

Text to set

integer

(optional) selectionStart

Position in the text that the selection starts at.

integer

(optional) selectionEnd

Position in the text that the selection ends at.

integer

cursor

Position in the text of the cursor.

array of object

(optional) segments

List of segments and their associated types.

Properties of each object

integer	start	Index of the character to start this segment at
integer	end	Index of the character to end this segment after.
UnderlineStyle	style	The type of the underline to modify this segment.

function

(optional) callback

Called when the operation completes with a boolean indicating if the text was accepted or not. On failure, runtime.lastError is set.

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

function(boolean success) {...};

boolean

success

clearComposition


              chrome.input.ime.clearComposition(object parameters, function callback)

Clear the current composition. If this extension does not own the active IME, this fails.

Parameters

object

parameters

integer

contextID

ID of the context where the composition will be cleared

function

(optional) callback

Called when the operation completes with a boolean indicating if the text was accepted or not. On failure, runtime.lastError is set.

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

function(boolean success) {...};

boolean

success

commitText


              chrome.input.ime.commitText(object parameters, function callback)

Commits the provided text to the current input.

Parameters

object

parameters

integer	contextID	ID of the context where the text will be committed
string	text	The text to commit

function

(optional) callback

Called when the operation completes with a boolean indicating if the text was accepted or not. On failure, runtime.lastError is set.

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

function(boolean success) {...};

boolean

success

sendKeyEvents


              chrome.input.ime.sendKeyEvents(object parameters, function callback)

Sends the key events. This function is expected to be used by virtual keyboards. When key(s) on a virtual keyboard is pressed by a user, this function is used to propagate that event to the system.

Parameters

object

parameters

integer	contextID	ID of the context where the key events will be sent, or zero to send key events to non-input field.
array of KeyboardEvent	keyData	Data on the key event.

function

(optional) callback

Called when the operation completes.

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

function() {...};

hideInputView


              chrome.input.ime.hideInputView()

Hides the input view window, which is popped up automatically by system. If the input view window is already hidden, this function will do nothing.

setCandidateWindowProperties


              chrome.input.ime.setCandidateWindowProperties(object parameters, function callback)

Sets the properties of the candidate window. This fails if the extension doesn't own the active IME

Parameters

object

parameters

string

engineID

ID of the engine to set properties on.

object

properties

boolean	(optional) visible	True to show the Candidate window, false to hide it.
boolean	(optional) cursorVisible	True to show the cursor, false to hide it.
boolean	(optional) vertical	True if the candidate window should be rendered vertical, false to make it horizontal.
integer	(optional) pageSize	The number of candidates to display per page.
string	(optional) auxiliaryText	Text that is shown at the bottom of the candidate window.
boolean	(optional) auxiliaryTextVisible	True to display the auxiliary text, false to hide it.
integer	(optional) totalCandidates	Since Chrome 84. The total number of candidates for the candidate window.
integer	(optional) currentCandidateIndex	Since Chrome 84. The index of the current chosen candidate out of total candidates.
WindowPosition	(optional) windowPosition	Where to display the candidate window.

function

(optional) callback

Called when the operation completes.

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

function(boolean success) {...};

boolean

success

setCandidates


              chrome.input.ime.setCandidates(object parameters, function callback)

Sets the current candidate list. This fails if this extension doesn't own the active IME

Parameters

object

parameters

integer

contextID

ID of the context that owns the candidate window.

array of object

candidates

List of candidates to show in the candidate window

Properties of each object

string

candidate

The candidate

integer

The candidate's id

integer

(optional) parentId

The id to add these candidates under

string

(optional) label

Short string displayed to next to the candidate, often the shortcut key or index

string

(optional) annotation

Additional text describing the candidate

object

(optional) usage

The usage or detail description of word.

string	title	The title string of details description.
string	body	The body string of detail description.

function

(optional) callback

Called when the operation completes.

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

function(boolean success) {...};

boolean

success

setCursorPosition


              chrome.input.ime.setCursorPosition(object parameters, function callback)

Set the position of the cursor in the candidate window. This is a no-op if this extension does not own the active IME.

Parameters

object

parameters

integer	contextID	ID of the context that owns the candidate window.
integer	candidateID	ID of the candidate to select.

function

(optional) callback

Called when the operation completes

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

function(boolean success) {...};

boolean

success

setAssistiveWindowProperties


              chrome.input.ime.setAssistiveWindowProperties(object parameters, function callback)

Since Chrome 85. Warning: this is the current Dev channel. Learn more.

Shows/Hides an assistive window with the given properties.

Parameters

object

parameters

integer	contextID	ID of the context owning the assistive window.
AssistiveWindowProperties	properties	Properties of the assistive window.

function

(optional) callback

Called when the operation completes.

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

function(boolean success) {...};

boolean

success

setAssistiveWindowButtonHighlighted


              chrome.input.ime.setAssistiveWindowButtonHighlighted(object parameters, function callback)

Not fully implemented. You must build Chromium from source to try this API. Learn more.

Highlights/Unhighlights a button in an assistive window.

Parameters

object

parameters

integer	contextID	ID of the context owning the assistive window.
AssistiveWindowButton	buttonID	The ID of the button
AssistiveWindowType	windowType	The window type the button belongs to.
string	(optional) announceString	The text for the screenreader to announce.
boolean	highlighted	Whether the button should be highlighted.

function

(optional) callback

Called when the operation completes. On failure, runtime.lastError is set.

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

function() {...};

setMenuItems


              chrome.input.ime.setMenuItems(object parameters, function callback)

Adds the provided menu items to the language menu when this IME is active.

Parameters

object

parameters

string	engineID	ID of the engine to use
array of MenuItem	items	MenuItems to add. They will be added in the order they exist in the array.

function

(optional) callback

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

function() {...};

updateMenuItems


              chrome.input.ime.updateMenuItems(object parameters, function callback)

Updates the state of the MenuItems specified

Parameters

object

parameters

string	engineID	ID of the engine to use
array of MenuItem	items	Array of MenuItems to update

function

(optional) callback

Called when the operation completes

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

function() {...};

deleteSurroundingText


              chrome.input.ime.deleteSurroundingText(object parameters, function callback)

Deletes the text around the caret.

Parameters

object

parameters

string	engineID	ID of the engine receiving the event.
integer	contextID	ID of the context where the surrounding text will be deleted.
integer	offset	The offset from the caret position where deletion will start. This value can be negative.
integer	length	The number of characters to be deleted

function

(optional) callback

Called when the operation completes.

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

function() {...};

keyEventHandled


              chrome.input.ime.keyEventHandled(string requestId, boolean response)

Indicates that the key event received by onKeyEvent is handled. This should only be called if the onKeyEvent listener is asynchronous.

Parameters
string	requestId	Request id of the event that was handled. This should come from keyEvent.requestId
boolean	response	True if the keystroke was handled, false if not

Events

onActivate

This event is sent when an IME is activated. It signals that the IME will be receiving onKeyPress events.

addListener


                    chrome.input.ime.onActivate.addListener(function callback)

Parameters

function

callback


                    chrome.input.ime.onKeyEvent.addListener(function callback)

Parameters

function

callback

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

function(string engineID, KeyboardEvent keyData, string requestId) {...};

string

engineID

ID of the engine receiving the event

KeyboardEvent

keyData

Data on the key event

string

requestId

Since Chrome 79.

ID of the request. If the event listener returns undefined, then keyEventHandled must be called later with this requestId.

onCandidateClicked

This event is sent if this extension owns the active IME.

addListener


                    chrome.input.ime.onCandidateClicked.addListener(function callback)

Parameters

function

callback

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

function(string engineID, integer candidateID, MouseButton button) {...};

string	engineID	ID of the engine receiving the event
integer	candidateID	ID of the candidate that was clicked.
MouseButton	button	Which mouse buttons was clicked.

onMenuItemActivated

Called when the user selects a menu item

addListener


                    chrome.input.ime.onMenuItemActivated.addListener(function callback)

Parameters

function

callback

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

function(string engineID, string name) {...};

string	engineID	ID of the engine receiving the event
string	name	Name of the MenuItem which was activated

onSurroundingTextChanged

Called when the editable string around caret is changed or when the caret position is moved. The text length is limited to 100 characters for each back and forth direction.

addListener


                    chrome.input.ime.onSurroundingTextChanged.addListener(function callback)

Parameters

function

callback

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

function(string engineID, object surroundingInfo) {...};

string

engineID

ID of the engine receiving the event

object

surroundingInfo

The surrounding information.

string	text	The text around the cursor. This is only a subset of all text in the input field.
integer	focus	The ending position of the selection. This value indicates caret position if there is no selection.
integer	anchor	The beginning position of the selection. This value indicates caret position if there is no selection.
integer	offset	Since Chrome 46. The offset position of `text`. Since `text` only includes a subset of text around the cursor, offset indicates the absolute position of the first character of `text`.

onReset

This event is sent when chrome terminates ongoing text input session.

addListener


                    chrome.input.ime.onReset.addListener(function callback)

Parameters

function

callback

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

function(string engineID) {...};

string

engineID

ID of the engine receiving the event

onAssistiveWindowButtonClicked

Since Chrome 85. Warning: this is the current Dev channel. Learn more.

This event is sent when a button in an assistive window is clicked.

addListener


                    chrome.input.ime.onAssistiveWindowButtonClicked.addListener(function callback)

Parameters

function

callback

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

function(object details) {...};

object

details

AssistiveWindowButton	buttonID	The ID of the button clicked.
AssistiveWindowType	windowType	The type of the assistive window.