Android example source code file (InputConnectionWrapper.java)

This example Android source code file (InputConnectionWrapper.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Android by Example" ^TM.

Java - Android tags/keywords

android, bundle, charsequence, extractedtext, got, iinputcontextcallback, input, inputconnectionwrapper, inputcontextcallback, inputmethod, interruptedexception, max_wait_time_millis, os, remoteexception, string, tag, timed, ui, view

The InputConnectionWrapper.java Android example source code

/*
 * Copyright (C) 2008 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.internal.view;

import com.android.internal.view.IInputContext;

import android.os.Bundle;
import android.os.RemoteException;
import android.os.SystemClock;
import android.util.Log;
import android.view.KeyEvent;
import android.view.inputmethod.CompletionInfo;
import android.view.inputmethod.ExtractedText;
import android.view.inputmethod.ExtractedTextRequest;
import android.view.inputmethod.InputConnection;

public class InputConnectionWrapper implements InputConnection {
    private static final int MAX_WAIT_TIME_MILLIS = 2000;
    private final IInputContext mIInputContext;
    
    static class InputContextCallback extends IInputContextCallback.Stub {
        private static final String TAG = "InputConnectionWrapper.ICC";
        public int mSeq;
        public boolean mHaveValue;
        public CharSequence mTextBeforeCursor;
        public CharSequence mTextAfterCursor;
        public ExtractedText mExtractedText;
        public int mCursorCapsMode;
        
        // A 'pool' of one InputContextCallback.  Each ICW request will attempt to gain
        // exclusive access to this object.
        private static InputContextCallback sInstance = new InputContextCallback();
        private static int sSequenceNumber = 1;
        
        /**
         * Returns an InputContextCallback object that is guaranteed not to be in use by
         * any other thread.  The returned object's 'have value' flag is cleared and its expected
         * sequence number is set to a new integer.  We use a sequence number so that replies that
         * occur after a timeout has expired are not interpreted as replies to a later request.
         */
        private static InputContextCallback getInstance() {
            synchronized (InputContextCallback.class) {
                // Return sInstance if it's non-null, otherwise construct a new callback
                InputContextCallback callback;
                if (sInstance != null) {
                    callback = sInstance;
                    sInstance = null;
                    
                    // Reset the callback
                    callback.mHaveValue = false;
                } else {
                    callback = new InputContextCallback();
                }
                
                // Set the sequence number
                callback.mSeq = sSequenceNumber++;
                return callback;
            }
        }
        
        /**
         * Makes the given InputContextCallback available for use in the future.
         */
        private void dispose() {
            synchronized (InputContextCallback.class) {
                // If sInstance is non-null, just let this object be garbage-collected
                if (sInstance == null) {
                    // Allow any objects being held to be gc'ed
                    mTextAfterCursor = null;
                    mTextBeforeCursor = null;
                    mExtractedText = null;
                    sInstance = this;
                }
            }
        }
        
        public void setTextBeforeCursor(CharSequence textBeforeCursor, int seq) {
            synchronized (this) {
                if (seq == mSeq) {
                    mTextBeforeCursor = textBeforeCursor;
                    mHaveValue = true;
                    notifyAll();
                } else {
                    Log.i(TAG, "Got out-of-sequence callback " + seq + " (expected " + mSeq
                            + ") in setTextBeforeCursor, ignoring.");
                }
            }
        }

        public void setTextAfterCursor(CharSequence textAfterCursor, int seq) {
            synchronized (this) {
                if (seq == mSeq) {
                    mTextAfterCursor = textAfterCursor;
                    mHaveValue = true;
                    notifyAll();
                } else {
                    Log.i(TAG, "Got out-of-sequence callback " + seq + " (expected " + mSeq
                            + ") in setTextAfterCursor, ignoring.");
                }
            }
        }

        public void setCursorCapsMode(int capsMode, int seq) {
            synchronized (this) {
                if (seq == mSeq) {
                    mCursorCapsMode = capsMode; 
                    mHaveValue = true;  
                    notifyAll();
                } else {
                    Log.i(TAG, "Got out-of-sequence callback " + seq + " (expected " + mSeq
                            + ") in setCursorCapsMode, ignoring.");
                }
            }
        }

        public void setExtractedText(ExtractedText extractedText, int seq) {
            synchronized (this) {
                if (seq == mSeq) {
                    mExtractedText = extractedText;
                    mHaveValue = true;
                    notifyAll();
                } else {
                    Log.i(TAG, "Got out-of-sequence callback " + seq + " (expected " + mSeq
                            + ") in setExtractedText, ignoring.");
                }
            }
        }
        
        /**
         * Waits for a result for up to {@link #MAX_WAIT_TIME_MILLIS} milliseconds.
         * 
         * <p>The caller must be synchronized on this callback object.
         */
        void waitForResultLocked() {
            long startTime = SystemClock.uptimeMillis();
            long endTime = startTime + MAX_WAIT_TIME_MILLIS;

            while (!mHaveValue) {
                long remainingTime = endTime - SystemClock.uptimeMillis();
                if (remainingTime <= 0) {
                    Log.w(TAG, "Timed out waiting on IInputContextCallback");
                    return;
                }
                try {
                    wait(remainingTime);
                } catch (InterruptedException e) {
                }
            }
        }
    }

    public InputConnectionWrapper(IInputContext inputContext) {
        mIInputContext = inputContext;
    }

    public CharSequence getTextAfterCursor(int length, int flags) {
        CharSequence value = null;
        try {
            InputContextCallback callback = InputContextCallback.getInstance();
            mIInputContext.getTextAfterCursor(length, flags, callback.mSeq, callback);
            synchronized (callback) {
                callback.waitForResultLocked();
                if (callback.mHaveValue) {
                    value = callback.mTextAfterCursor;
                }
            }
            callback.dispose();
        } catch (RemoteException e) {
            return null;
        }
        return value;
    }
    
    public CharSequence getTextBeforeCursor(int length, int flags) {
        CharSequence value = null;
        try {
            InputContextCallback callback = InputContextCallback.getInstance();
            mIInputContext.getTextBeforeCursor(length, flags, callback.mSeq, callback);
            synchronized (callback) {
                callback.waitForResultLocked();
                if (callback.mHaveValue) {
                    value = callback.mTextBeforeCursor;
                }
            }
            callback.dispose();
        } catch (RemoteException e) {
            return null;
        }
        return value;
    }
    
    public int getCursorCapsMode(int reqModes) {
        int value = 0;
        try {
            InputContextCallback callback = InputContextCallback.getInstance();
            mIInputContext.getCursorCapsMode(reqModes, callback.mSeq, callback);
            synchronized (callback) {
                callback.waitForResultLocked();
                if (callback.mHaveValue) {
                    value = callback.mCursorCapsMode;
                }
            }
            callback.dispose();
        } catch (RemoteException e) {
            return 0;
        }
        return value;
    }
    
    public ExtractedText getExtractedText(ExtractedTextRequest request, int flags) {
        ExtractedText value = null;
        try {
            InputContextCallback callback = InputContextCallback.getInstance();
            mIInputContext.getExtractedText(request, flags, callback.mSeq, callback);
            synchronized (callback) {
                callback.waitForResultLocked();
                if (callback.mHaveValue) {
                    value = callback.mExtractedText;
                }
            }
            callback.dispose();
        } catch (RemoteException e) {
            return null;
        }
        return value;
    }
    
    public boolean commitText(CharSequence text, int newCursorPosition) {
        try {
            mIInputContext.commitText(text, newCursorPosition);
            return true;
        } catch (RemoteException e) {
            return false;
        }
    }

    public boolean commitCompletion(CompletionInfo text) {
        try {
            mIInputContext.commitCompletion(text);
            return true;
        } catch (RemoteException e) {
            return false;
        }
    }

    public boolean setSelection(int start, int end) {
        try {
            mIInputContext.setSelection(start, end);
            return true;
        } catch (RemoteException e) {
            return false;
        }
    }
    
    public boolean performEditorAction(int actionCode) {
        try {
            mIInputContext.performEditorAction(actionCode);
            return true;
        } catch (RemoteException e) {
            return false;
        }
    }
    
    public boolean performContextMenuAction(int id) {
        try {
            mIInputContext.performContextMenuAction(id);
            return true;
        } catch (RemoteException e) {
            return false;
        }
    }
    
    public boolean setComposingText(CharSequence text, int newCursorPosition) {
        try {
            mIInputContext.setComposingText(text, newCursorPosition);
            return true;
        } catch (RemoteException e) {
            return false;
        }
    }

    public boolean finishComposingText() {
        try {
            mIInputContext.finishComposingText();
            return true;
        } catch (RemoteException e) {
            return false;
        }
    }

    public boolean beginBatchEdit() {
        try {
            mIInputContext.beginBatchEdit();
            return true;
        } catch (RemoteException e) {
            return false;
        }
    }
    
    public boolean endBatchEdit() {
        try {
            mIInputContext.endBatchEdit();
            return true;
        } catch (RemoteException e) {
            return false;
        }
    }
    
    public boolean sendKeyEvent(KeyEvent event) {
        try {
            mIInputContext.sendKeyEvent(event);
            return true;
        } catch (RemoteException e) {
            return false;
        }
    }

    public boolean clearMetaKeyStates(int states) {
        try {
            mIInputContext.clearMetaKeyStates(states);
            return true;
        } catch (RemoteException e) {
            return false;
        }
    }
    
    public boolean deleteSurroundingText(int leftLength, int rightLength) {
        try {
            mIInputContext.deleteSurroundingText(leftLength, rightLength);
            return true;
        } catch (RemoteException e) {
            return false;
        }
    }

    public boolean reportFullscreenMode(boolean enabled) {
        try {
            mIInputContext.reportFullscreenMode(enabled);
            return true;
        } catch (RemoteException e) {
            return false;
        }
    }

    public boolean performPrivateCommand(String action, Bundle data) {
        try {
            mIInputContext.performPrivateCommand(action, data);
            return true;
        } catch (RemoteException e) {
            return false;
        }
    }
}