1 /*
2  * Copyright (C) 2007-2008 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License"); you may not
5  * use this file except in compliance with the License. You may obtain a copy of
6  * the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
12  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13  * License for the specific language governing permissions and limitations under
14  * the License.
15  */
16 
17 package android.view.inputmethod;
18 
19 import android.annotation.NonNull;
20 import android.annotation.Nullable;
21 import android.annotation.SdkConstant;
22 import android.annotation.SdkConstant.SdkConstantType;
23 import android.inputmethodservice.InputMethodService;
24 import android.os.IBinder;
25 import android.os.ResultReceiver;
26 
27 /**
28  * The InputMethod interface represents an input method which can generate key
29  * events and text, such as digital, email addresses, CJK characters, other
30  * language characters, and etc., while handling various input events, and send
31  * the text back to the application that requests text input.  See
32  * {@link InputMethodManager} for more general information about the
33  * architecture.
34  *
35  * <p>Applications will not normally use this interface themselves, instead
36  * relying on the standard interaction provided by
37  * {@link android.widget.TextView} and {@link android.widget.EditText}.
38  *
39  * <p>Those implementing input methods should normally do so by deriving from
40  * {@link InputMethodService} or one of its subclasses.  When implementing
41  * an input method, the service component containing it must also supply
42  * a {@link #SERVICE_META_DATA} meta-data field, referencing an XML resource
43  * providing details about the input method.  All input methods also must
44  * require that clients hold the
45  * {@link android.Manifest.permission#BIND_INPUT_METHOD} in order to interact
46  * with the service; if this is not required, the system will not use that
47  * input method, because it can not trust that it is not compromised.
48  *
49  * <p>The InputMethod interface is actually split into two parts: the interface
50  * here is the top-level interface to the input method, providing all
51  * access to it, which only the system can access (due to the BIND_INPUT_METHOD
52  * permission requirement).  In addition its method
53  * {@link #createSession(android.view.inputmethod.InputMethod.SessionCallback)}
54  * can be called to instantate a secondary {@link InputMethodSession} interface
55  * which is what clients use to communicate with the input method.
56  */
57 public interface InputMethod {
58     /**
59      * This is the interface name that a service implementing an input
60      * method should say that it supports -- that is, this is the action it
61      * uses for its intent filter.
62      * To be supported, the service must also require the
63      * {@link android.Manifest.permission#BIND_INPUT_METHOD} permission so
64      * that other applications can not abuse it.
65      */
66     @SdkConstant(SdkConstantType.SERVICE_ACTION)
67     public static final String SERVICE_INTERFACE = "android.view.InputMethod";
68 
69     /**
70      * Name under which an InputMethod service component publishes information
71      * about itself.  This meta-data must reference an XML resource containing
72      * an
73      * <code>&lt;{@link android.R.styleable#InputMethod input-method}&gt;</code>
74      * tag.
75      */
76     public static final String SERVICE_META_DATA = "android.view.im";
77 
78     public interface SessionCallback {
sessionCreated(InputMethodSession session)79         public void sessionCreated(InputMethodSession session);
80     }
81 
82     /**
83      * Called first thing after an input method is created, this supplies a
84      * unique token for the session it has with the system service.  It is
85      * needed to identify itself with the service to validate its operations.
86      * This token <strong>must not</strong> be passed to applications, since
87      * it grants special priviledges that should not be given to applications.
88      *
89      * <p>Note: to protect yourself from malicious clients, you should only
90      * accept the first token given to you.  Any after that may come from the
91      * client.
92      */
attachToken(IBinder token)93     public void attachToken(IBinder token);
94 
95     /**
96      * Bind a new application environment in to the input method, so that it
97      * can later start and stop input processing.
98      * Typically this method is called when this input method is enabled in an
99      * application for the first time.
100      *
101      * @param binding Information about the application window that is binding
102      * to the input method.
103      *
104      * @see InputBinding
105      * @see #unbindInput()
106      */
bindInput(InputBinding binding)107     public void bindInput(InputBinding binding);
108 
109     /**
110      * Unbind an application environment, called when the information previously
111      * set by {@link #bindInput} is no longer valid for this input method.
112      *
113      * <p>
114      * Typically this method is called when the application changes to be
115      * non-foreground.
116      */
unbindInput()117     public void unbindInput();
118 
119     /**
120      * This method is called when the application starts to receive text and it
121      * is ready for this input method to process received events and send result
122      * text back to the application.
123      *
124      * @param inputConnection Optional specific input connection for
125      * communicating with the text box; if null, you should use the generic
126      * bound input connection.
127      * @param info Information about the text box (typically, an EditText)
128      *        that requests input.
129      *
130      * @see EditorInfo
131      */
startInput(InputConnection inputConnection, EditorInfo info)132     public void startInput(InputConnection inputConnection, EditorInfo info);
133 
134     /**
135      * This method is called when the state of this input method needs to be
136      * reset.
137      *
138      * <p>
139      * Typically, this method is called when the input focus is moved from one
140      * text box to another.
141      *
142      * @param inputConnection Optional specific input connection for
143      * communicating with the text box; if null, you should use the generic
144      * bound input connection.
145      * @param attribute The attribute of the text box (typically, a EditText)
146      *        that requests input.
147      *
148      * @see EditorInfo
149      */
restartInput(InputConnection inputConnection, EditorInfo attribute)150     public void restartInput(InputConnection inputConnection, EditorInfo attribute);
151 
152     /**
153      * This method is called when {@code {@link #startInput(InputConnection, EditorInfo)} or
154      * {@code {@link #restartInput(InputConnection, EditorInfo)} needs to be dispatched.
155      *
156      * <p>Note: This method is hidden because the {@code startInputToken} that this method is
157      * dealing with is one of internal details, which should not be exposed to the IME developers.
158      * If you override this method, you are responsible for not breaking existing IMEs that expect
159      * {@link #startInput(InputConnection, EditorInfo)} to be still called back.</p>
160      *
161      * @param inputConnection optional specific input connection for communicating with the text
162      *                        box; if {@code null}, you should use the generic bound input
163      *                        connection
164      * @param editorInfo information about the text box (typically, an EditText) that requests input
165      * @param restarting {@code false} if this corresponds to
166      *                   {@link #startInput(InputConnection, EditorInfo)}. Otherwise this
167      *                   corresponds to {@link #restartInput(InputConnection, EditorInfo)}.
168      * @param startInputToken a token that identifies a logical session that starts with this method
169      *                        call. Some internal IPCs such as {@link
170      *                        InputMethodManager#setImeWindowStatus(IBinder, IBinder, int, int)}
171      *                        require this token to work, and you have to keep the token alive until
172      *                        the next {@link #startInput(InputConnection, EditorInfo, IBinder)} as
173      *                        long as your implementation of {@link InputMethod} relies on such
174      *                        IPCs
175      * @see #startInput(InputConnection, EditorInfo)
176      * @see #restartInput(InputConnection, EditorInfo)
177      * @see EditorInfo
178      * @hide
179      */
dispatchStartInputWithToken(@ullable InputConnection inputConnection, @NonNull EditorInfo editorInfo, boolean restarting, @NonNull IBinder startInputToken)180     default void dispatchStartInputWithToken(@Nullable InputConnection inputConnection,
181             @NonNull EditorInfo editorInfo, boolean restarting,
182             @NonNull IBinder startInputToken) {
183         if (restarting) {
184             restartInput(inputConnection, editorInfo);
185         } else {
186             startInput(inputConnection, editorInfo);
187         }
188     }
189 
190     /**
191      * Create a new {@link InputMethodSession} that can be handed to client
192      * applications for interacting with the input method.  You can later
193      * use {@link #revokeSession(InputMethodSession)} to destroy the session
194      * so that it can no longer be used by any clients.
195      *
196      * @param callback Interface that is called with the newly created session.
197      */
createSession(SessionCallback callback)198     public void createSession(SessionCallback callback);
199 
200     /**
201      * Control whether a particular input method session is active.
202      *
203      * @param session The {@link InputMethodSession} previously provided through
204      * SessionCallback.sessionCreated() that is to be changed.
205      */
setSessionEnabled(InputMethodSession session, boolean enabled)206     public void setSessionEnabled(InputMethodSession session, boolean enabled);
207 
208     /**
209      * Disable and destroy a session that was previously created with
210      * {@link #createSession(android.view.inputmethod.InputMethod.SessionCallback)}.
211      * After this call, the given session interface is no longer active and
212      * calls on it will fail.
213      *
214      * @param session The {@link InputMethodSession} previously provided through
215      * SessionCallback.sessionCreated() that is to be revoked.
216      */
revokeSession(InputMethodSession session)217     public void revokeSession(InputMethodSession session);
218 
219     /**
220      * Flag for {@link #showSoftInput}: this show has been explicitly
221      * requested by the user.  If not set, the system has decided it may be
222      * a good idea to show the input method based on a navigation operation
223      * in the UI.
224      */
225     public static final int SHOW_EXPLICIT = 0x00001;
226 
227     /**
228      * Flag for {@link #showSoftInput}: this show has been forced to
229      * happen by the user.  If set, the input method should remain visible
230      * until deliberated dismissed by the user in its UI.
231      */
232     public static final int SHOW_FORCED = 0x00002;
233 
234     /**
235      * Request that any soft input part of the input method be shown to the user.
236      *
237      * @param flags Provides additional information about the show request.
238      * Currently may be 0 or have the bit {@link #SHOW_EXPLICIT} set.
239      * @param resultReceiver The client requesting the show may wish to
240      * be told the impact of their request, which should be supplied here.
241      * The result code should be
242      * {@link InputMethodManager#RESULT_UNCHANGED_SHOWN InputMethodManager.RESULT_UNCHANGED_SHOWN},
243      * {@link InputMethodManager#RESULT_UNCHANGED_HIDDEN InputMethodManager.RESULT_UNCHANGED_HIDDEN},
244      * {@link InputMethodManager#RESULT_SHOWN InputMethodManager.RESULT_SHOWN}, or
245      * {@link InputMethodManager#RESULT_HIDDEN InputMethodManager.RESULT_HIDDEN}.
246      */
showSoftInput(int flags, ResultReceiver resultReceiver)247     public void showSoftInput(int flags, ResultReceiver resultReceiver);
248 
249     /**
250      * Request that any soft input part of the input method be hidden from the user.
251      * @param flags Provides additional information about the show request.
252      * Currently always 0.
253      * @param resultReceiver The client requesting the show may wish to
254      * be told the impact of their request, which should be supplied here.
255      * The result code should be
256      * {@link InputMethodManager#RESULT_UNCHANGED_SHOWN InputMethodManager.RESULT_UNCHANGED_SHOWN},
257      * {@link InputMethodManager#RESULT_UNCHANGED_HIDDEN InputMethodManager.RESULT_UNCHANGED_HIDDEN},
258      * {@link InputMethodManager#RESULT_SHOWN InputMethodManager.RESULT_SHOWN}, or
259      * {@link InputMethodManager#RESULT_HIDDEN InputMethodManager.RESULT_HIDDEN}.
260      */
hideSoftInput(int flags, ResultReceiver resultReceiver)261     public void hideSoftInput(int flags, ResultReceiver resultReceiver);
262 
263     /**
264      * Notify that the input method subtype is being changed in the same input method.
265      * @param subtype New subtype of the notified input method
266      */
changeInputMethodSubtype(InputMethodSubtype subtype)267     public void changeInputMethodSubtype(InputMethodSubtype subtype);
268 }
269