public final class

InputMethodManager

extends Object
java.lang.Object
   ↳ android.view.inputmethod.InputMethodManager

Class Overview

Central system API to the overall input method framework (IMF) architecture, which arbitrates interaction between applications and the current input method. You can retrieve an instance of this interface with Context.getSystemService().

Topics covered here:

  1. Architecture Overview

Architecture Overview

There are three primary parties involved in the input method framework (IMF) architecture:

  • The input method manager as expressed by this class is the central point of the system that manages interaction between all other parts. It is expressed as the client-side API here which exists in each application context and communicates with a global system service that manages the interaction across all processes.
  • An input method (IME) implements a particular interaction model allowing the user to generate text. The system binds to the current input method that is use, causing it to be created and run, and tells it when to hide and show its UI. Only one IME is running at a time.
  • Multiple client applications arbitrate with the input method manager for input focus and control over the state of the IME. Only one such client is ever active (working with the IME) at a time.

Applications

In most cases, applications that are using the standard TextView or its subclasses will have little they need to do to work well with soft input methods. The main things you need to be aware of are:

  • Properly set the inputType if your editable text views, so that the input method will have enough context to help the user in entering text into them.
  • Deal well with losing screen space when the input method is displayed. Ideally an application should handle its window being resized smaller, but it can rely on the system performing panning of the window if needed. You should set the windowSoftInputMode attribute on your activity or the corresponding values on windows you create to help the system determine whether to pan or resize (it will try to determine this automatically but may get it wrong).
  • You can also control the preferred soft input state (open, closed, etc) for your window using the same windowSoftInputMode attribute.

More finer-grained control is available through the APIs here to directly interact with the IMF and its IME -- either showing or hiding the input area, letting the user pick an input method, etc.

For the rare people amongst us writing their own text editors, you will need to implement onCreateInputConnection(EditorInfo) to return a new instance of your own InputConnection interface allowing the IME to interact with your editor.

Input Methods

An input method (IME) is implemented as a Service, typically deriving from InputMethodService. It must provide the core InputMethod interface, though this is normally handled by InputMethodService and implementors will only need to deal with the higher-level API there.

See the InputMethodService class for more information on implementing IMEs.

Security

There are a lot of security issues associated with input methods, since they essentially have freedom to completely drive the UI and monitor everything the user enters. The Android input method framework also allows arbitrary third party IMEs, so care must be taken to restrict their selection and interactions.

Here are some key points about the security architecture behind the IMF:

  • Only the system is allowed to directly access an IME's InputMethod interface, via the BIND_INPUT_METHOD permission. This is enforced in the system by not binding to an input method service that does not require this permission, so the system can guarantee no other untrusted clients are accessing the current input method outside of its control.

  • There may be many client processes of the IMF, but only one may be active at a time. The inactive clients can not interact with key parts of the IMF through the mechanisms described below.

  • Clients of an input method are only given access to its InputMethodSession interface. One instance of this interface is created for each client, and only calls from the session associated with the active client will be processed by the current IME. This is enforced by AbstractInputMethodService for normal IMEs, but must be explicitly handled by an IME that is customizing the raw InputMethodSession implementation.

  • Only the active client's InputConnection will accept operations. The IMF tells each client process whether it is active, and the framework enforces that in inactive processes calls on to the current InputConnection will be ignored. This ensures that the current IME can only deliver events and text edits to the UI that the user sees as being in focus.

  • An IME can never interact with an InputConnection while the screen is off. This is enforced by making all clients inactive while the screen is off, and prevents bad IMEs from driving the UI when the user can not be aware of its behavior.

  • A client application can ask that the system let the user pick a new IME, but can not programmatically switch to one itself. This avoids malicious applications from switching the user to their own IME, which remains running when the user navigates away to another application. An IME, on the other hand, is allowed to programmatically switch the system to another IME, since it already has full control of user input.

  • The user must explicitly enable a new IME in settings before they can switch to it, to confirm with the system that they know about it and want to make it available for use.

Summary

Constants
int HIDE_IMPLICIT_ONLY Flag for hideSoftInputFromWindow(IBinder, int) to indicate that the soft input window should only be hidden if it was not explicitly shown by the user.
int HIDE_NOT_ALWAYS Flag for hideSoftInputFromWindow(IBinder, int) to indicate that the soft input window should normally be hidden, unless it was originally shown with SHOW_FORCED.
int RESULT_HIDDEN Flag for the ResultReceiver result code from showSoftInput(View, int, ResultReceiver) and hideSoftInputFromWindow(IBinder, int, ResultReceiver): the state of the soft input window changed from shown to hidden.
int RESULT_SHOWN Flag for the ResultReceiver result code from showSoftInput(View, int, ResultReceiver) and hideSoftInputFromWindow(IBinder, int, ResultReceiver): the state of the soft input window changed from hidden to shown.
int RESULT_UNCHANGED_HIDDEN Flag for the ResultReceiver result code from showSoftInput(View, int, ResultReceiver) and hideSoftInputFromWindow(IBinder, int, ResultReceiver): the state of the soft input window was unchanged and remains hidden.
int RESULT_UNCHANGED_SHOWN Flag for the ResultReceiver result code from showSoftInput(View, int, ResultReceiver) and hideSoftInputFromWindow(IBinder, int, ResultReceiver): the state of the soft input window was unchanged and remains shown.
int SHOW_FORCED Flag for showSoftInput(View, int) to indicate that the user has forced the input method open (such as by long-pressing menu) so it should not be closed until they explicitly do so.
int SHOW_IMPLICIT Flag for showSoftInput(View, int) to indicate that this is an implicit request to show the input window, not as the result of a direct request by the user.
Public Methods
void displayCompletions(View view, CompletionInfo[] completions)
List<InputMethodInfo> getEnabledInputMethodList()
List<InputMethodInfo> getInputMethodList()
void hideSoftInputFromInputMethod(IBinder token, int flags)
Close/hide the input method's soft input area, so the user no longer sees it or can interact with it.
boolean hideSoftInputFromWindow(IBinder windowToken, int flags, ResultReceiver resultReceiver)
Request to hide the soft input window from the context of the window that is currently accepting input.
boolean hideSoftInputFromWindow(IBinder windowToken, int flags)
Synonym for {@link #hideSoftInputFromWindow(IBinder, int, ResultReceiver) without a result: request to hide the soft input window from the context of the window that is currently accepting input.
void hideStatusIcon(IBinder imeToken)
boolean isAcceptingText()
Return true if the currently served view is accepting full text edits.
boolean isActive()
Return true if any view is currently active in the input method.
boolean isActive(View view)
Return true if the given view is the currently active view for the input method.
boolean isFullscreenMode()
Allows you to discover whether the attached input method is running in fullscreen mode.
boolean isWatchingCursor(View view)
Returns true if the current input method wants to watch the location of the input editor's cursor in its window.
void restartInput(View view)
If the input method is currently connected to the given view, restart it with its new contents.
void sendAppPrivateCommand(View view, String action, Bundle data)
Call InputMethodSession.appPrivateCommand() on the current Input Method.
void setInputMethod(IBinder token, String id)
Force switch to a new input method component.
void showInputMethodPicker()
boolean showSoftInput(View view, int flags)
Synonym for showSoftInput(View, int, ResultReceiver) without a result receiver: explicitly request that the current input method's soft input area be shown to the user, if needed.
boolean showSoftInput(View view, int flags, ResultReceiver resultReceiver)
Explicitly request that the current input method's soft input area be shown to the user, if needed.
void showSoftInputFromInputMethod(IBinder token, int flags)
Show the input method's soft input area, so the user sees the input method window and can interact with it.
void showStatusIcon(IBinder imeToken, String packageName, int iconId)
void toggleSoftInput(int showFlags, int hideFlags)
void toggleSoftInputFromWindow(IBinder windowToken, int showFlags, int hideFlags)
This method toggles the input method window display.
void updateCursor(View view, int left, int top, int right, int bottom)
Report the current cursor location in its window.
void updateExtractedText(View view, int token, ExtractedText text)
void updateSelection(View view, int selStart, int selEnd, int candidatesStart, int candidatesEnd)
Report the current selection range.
[Expand]
Inherited Methods
From class java.lang.Object

Constants

public static final int HIDE_IMPLICIT_ONLY

Flag for hideSoftInputFromWindow(IBinder, int) to indicate that the soft input window should only be hidden if it was not explicitly shown by the user.

Constant Value: 1 (0x00000001)

public static final int HIDE_NOT_ALWAYS

Flag for hideSoftInputFromWindow(IBinder, int) to indicate that the soft input window should normally be hidden, unless it was originally shown with SHOW_FORCED.

Constant Value: 2 (0x00000002)

public static final int RESULT_HIDDEN

Flag for the ResultReceiver result code from showSoftInput(View, int, ResultReceiver) and hideSoftInputFromWindow(IBinder, int, ResultReceiver): the state of the soft input window changed from shown to hidden.

Constant Value: 3 (0x00000003)

public static final int RESULT_SHOWN

Flag for the ResultReceiver result code from showSoftInput(View, int, ResultReceiver) and hideSoftInputFromWindow(IBinder, int, ResultReceiver): the state of the soft input window changed from hidden to shown.

Constant Value: 2 (0x00000002)

public static final int RESULT_UNCHANGED_HIDDEN

Flag for the ResultReceiver result code from showSoftInput(View, int, ResultReceiver) and hideSoftInputFromWindow(IBinder, int, ResultReceiver): the state of the soft input window was unchanged and remains hidden.

Constant Value: 1 (0x00000001)

public static final int RESULT_UNCHANGED_SHOWN

Flag for the ResultReceiver result code from showSoftInput(View, int, ResultReceiver) and hideSoftInputFromWindow(IBinder, int, ResultReceiver): the state of the soft input window was unchanged and remains shown.

Constant Value: 0 (0x00000000)

public static final int SHOW_FORCED

Flag for showSoftInput(View, int) to indicate that the user has forced the input method open (such as by long-pressing menu) so it should not be closed until they explicitly do so.

Constant Value: 2 (0x00000002)

public static final int SHOW_IMPLICIT

Flag for showSoftInput(View, int) to indicate that this is an implicit request to show the input window, not as the result of a direct request by the user. The window may not be shown in this case.

Constant Value: 1 (0x00000001)

Public Methods

public void displayCompletions (View view, CompletionInfo[] completions)

public List<InputMethodInfo> getEnabledInputMethodList ()

public List<InputMethodInfo> getInputMethodList ()

public void hideSoftInputFromInputMethod (IBinder token, int flags)

Close/hide the input method's soft input area, so the user no longer sees it or can interact with it. This can only be called from the currently active input method, as validated by the given token.

Parameters
token Supplies the identifying token given to an input method when it was started, which allows it to perform this operation on itself.
flags Provides additional operating flags. Currently may be 0 or have the HIDE_IMPLICIT_ONLY, HIDE_NOT_ALWAYS bit set.

public boolean hideSoftInputFromWindow (IBinder windowToken, int flags, ResultReceiver resultReceiver)

Request to hide the soft input window from the context of the window that is currently accepting input. This should be called as a result of the user doing some actually than fairly explicitly requests to have the input window hidden.

Parameters
windowToken The token of the window that is making the request, as returned by View.getWindowToken().
flags Provides additional operating flags. Currently may be 0 or have the HIDE_IMPLICIT_ONLY bit set.
resultReceiver If non-null, this will be called by the IME when it has processed your request to tell you what it has done. The result code you receive may be either RESULT_UNCHANGED_SHOWN, RESULT_UNCHANGED_HIDDEN, RESULT_SHOWN, or RESULT_HIDDEN.

public boolean hideSoftInputFromWindow (IBinder windowToken, int flags)

Synonym for {@link #hideSoftInputFromWindow(IBinder, int, ResultReceiver) without a result: request to hide the soft input window from the context of the window that is currently accepting input.

Parameters
windowToken The token of the window that is making the request, as returned by View.getWindowToken().
flags Provides additional operating flags. Currently may be 0 or have the HIDE_IMPLICIT_ONLY bit set.

public void hideStatusIcon (IBinder imeToken)

public boolean isAcceptingText ()

Return true if the currently served view is accepting full text edits. If false, it has no input connection, so can only handle raw key events.

public boolean isActive ()

Return true if any view is currently active in the input method.

public boolean isActive (View view)

Return true if the given view is the currently active view for the input method.

public boolean isFullscreenMode ()

Allows you to discover whether the attached input method is running in fullscreen mode. Return true if it is fullscreen, entirely covering your UI, else returns false.

public boolean isWatchingCursor (View view)

Returns true if the current input method wants to watch the location of the input editor's cursor in its window.

public void restartInput (View view)

If the input method is currently connected to the given view, restart it with its new contents. You should call this when the text within your view changes outside of the normal input method or key input flow, such as when an application calls TextView.setText().

Parameters
view The view whose text has changed.

public void sendAppPrivateCommand (View view, String action, Bundle data)

Call InputMethodSession.appPrivateCommand() on the current Input Method.

Parameters
view Optional View that is sending the command, or null if you want to send the command regardless of the view that is attached to the input method.
action Name of the command to be performed. This must be a scoped name, i.e. prefixed with a package name you own, so that different developers will not create conflicting commands.
data Any data to include with the command.

public void setInputMethod (IBinder token, String id)

Force switch to a new input method component. This can only be called from the currently active input method, as validated by the given token.

Parameters
token Supplies the identifying token given to an input method when it was started, which allows it to perform this operation on itself.
id The unique identifier for the new input method to be switched to.

public void showInputMethodPicker ()

public boolean showSoftInput (View view, int flags)

Synonym for showSoftInput(View, int, ResultReceiver) without a result receiver: explicitly request that the current input method's soft input area be shown to the user, if needed.

Parameters
view The currently focused view, which would like to receive soft keyboard input.
flags Provides additional operating flags. Currently may be 0 or have the SHOW_IMPLICIT bit set.

public boolean showSoftInput (View view, int flags, ResultReceiver resultReceiver)

Explicitly request that the current input method's soft input area be shown to the user, if needed. Call this if the user interacts with your view in such a way that they have expressed they would like to start performing input into it.

Parameters
view The currently focused view, which would like to receive soft keyboard input.
flags Provides additional operating flags. Currently may be 0 or have the SHOW_IMPLICIT bit set.
resultReceiver If non-null, this will be called by the IME when it has processed your request to tell you what it has done. The result code you receive may be either RESULT_UNCHANGED_SHOWN, RESULT_UNCHANGED_HIDDEN, RESULT_SHOWN, or RESULT_HIDDEN.

public void showSoftInputFromInputMethod (IBinder token, int flags)

Show the input method's soft input area, so the user sees the input method window and can interact with it. This can only be called from the currently active input method, as validated by the given token.

Parameters
token Supplies the identifying token given to an input method when it was started, which allows it to perform this operation on itself.
flags Provides additional operating flags. Currently may be 0 or have the SHOW_IMPLICIT or SHOW_FORCED bit set.

public void showStatusIcon (IBinder imeToken, String packageName, int iconId)

public void toggleSoftInput (int showFlags, int hideFlags)

public void toggleSoftInputFromWindow (IBinder windowToken, int showFlags, int hideFlags)

This method toggles the input method window display. If the input window is already displayed, it gets hidden. If not the input window will be displayed.

Parameters
windowToken The token of the window that is making the request, as returned by View.getWindowToken().
showFlags Provides additional operating flags. May be 0 or have the SHOW_IMPLICIT, SHOW_FORCED bit set.
hideFlags Provides additional operating flags. May be 0 or have the HIDE_IMPLICIT_ONLY, HIDE_NOT_ALWAYS bit set.

public void updateCursor (View view, int left, int top, int right, int bottom)

Report the current cursor location in its window.

public void updateExtractedText (View view, int token, ExtractedText text)

public void updateSelection (View view, int selStart, int selEnd, int candidatesStart, int candidatesEnd)

Report the current selection range.