SoftKeyboard.java

/*
 * Copyright (C) 2008-2009 Google Inc.
 *
 * 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.example.android.softkeyboard;

import android.content.Context;
import android.inputmethodservice.InputMethodService;
import android.inputmethodservice.Keyboard;
import android.inputmethodservice.KeyboardView;
import android.text.method.MetaKeyKeyListener;
import android.view.KeyCharacterMap;
import android.view.KeyEvent;
import android.view.View;
import android.view.WindowManager;
import android.view.inputmethod.CompletionInfo;
import android.view.inputmethod.EditorInfo;
import android.view.inputmethod.InputConnection;

import java.util.ArrayList;
import java.util.List;

/**
 * Example of writing an input method for a soft keyboard.  This code is
 * focused on simplicity over completeness, so it should in no way be considered
 * to be a complete soft keyboard implementation.  Its purpose is to provide
 * a basic example for how you would get started writing an input method, to
 * be fleshed out as appropriate.
 */
public class SoftKeyboard extends InputMethodService implements KeyboardView.OnKeyboardActionListener {
    static final boolean DEBUG = false;

    private KeyboardView mInputView;
    private CandidateView mCandidateView;
    private CompletionInfo[] mCompletions;

    private StringBuilder mComposing = new StringBuilder();
    private boolean mPredictionOn;
    private boolean mCompletionOn;
    private int mLastDisplayWidth;
    private boolean mCapsLock;
    private long mLastShiftTime;
    private long mMetaState;

    private Keyboard mSymbolsKeyboard;
    private Keyboard mSymbolsShiftedKeyboard;
    private Keyboard mQwertyKeyboard;

    private String mWordSeparators;

    private void makeKeyboards() {
        // Configuration change is coming after the keyboard gets recreated. So don't rely on that.
        // If keyboards have already been made, check if we have a screen width change and
        // create the keyboard layouts again at the correct orientation
        if (mQwertyKeyboard != null) {
            WindowManager wm = (WindowManager)getSystemService(Context.WINDOW_SERVICE);
            int displayWidth = wm.getDefaultDisplay().getWidth();
            if (displayWidth == mLastDisplayWidth) {
                return;
            }
            mLastDisplayWidth = displayWidth;
        }
        mQwertyKeyboard = new LatinKeyboard(this, R.xml.qwerty);
        mSymbolsKeyboard = new LatinKeyboard(this, R.xml.symbols);
        mSymbolsShiftedKeyboard = new LatinKeyboard(this, R.xml.symbols_shift);
    }

    @Override
    public void onCreate() {
        super.onCreate();
        makeKeyboards();
        mWordSeparators = getResources().getString(R.string.word_separators);
    }

    @Override
    public View onCreateInputView() {
        makeKeyboards();
        mInputView = (KeyboardView)getLayoutInflater().inflate(R.layout.input, null);
        mInputView.setOnKeyboardActionListener(this);
        mInputView.setKeyboard(mQwertyKeyboard);
        return mInputView;
    }

    @Override
    public View onCreateCandidatesView() {
        mCandidateView = new CandidateView(this);
        mCandidateView.setService(this);
        return mCandidateView;
    }

    @Override
    public void onStartInputView(EditorInfo attribute, boolean restarting) {
        mComposing.setLength(0);
        updateCandidates();

        if (!restarting) {
            // Clear shift states.
            mMetaState = 0;
        }

        mPredictionOn = false;
        mCompletionOn = false;
        mCompletions = null;
        Keyboard keyboard;
        switch (attribute.inputType & EditorInfo.TYPE_MASK_CLASS) {
            case EditorInfo.TYPE_CLASS_NUMBER:
            case EditorInfo.TYPE_CLASS_DATETIME:
                keyboard = mSymbolsKeyboard;
                break;
            case EditorInfo.TYPE_CLASS_PHONE:
                keyboard = mSymbolsKeyboard;
                break;
            default:
                keyboard = mQwertyKeyboard;
                mPredictionOn = true;
                // Make sure that passwords are not displayed in candidate view
                int variation = attribute.inputType & EditorInfo.TYPE_MASK_VARIATION;
                if (variation == EditorInfo.TYPE_TEXT_VARIATION_PASSWORD) {
                    mPredictionOn = false;
                }
                if (variation == EditorInfo.TYPE_TEXT_VARIATION_EMAIL_ADDRESS || variation == EditorInfo.TYPE_TEXT_VARIATION_URI) {
                    mPredictionOn = false;
                }
                if ((attribute.inputType & EditorInfo.TYPE_TEXT_FLAG_AUTO_COMPLETE) != 0) {
                    mPredictionOn = false;
                    mCompletionOn = isFullscreenMode();
                }
                updateShiftKeyState(attribute);
                break;
        }

        if (mInputView != null) {
            mInputView.setKeyboard(keyboard);
            mInputView.closing();
        }

        mComposing.setLength(0);
        setSuggestions(null, false, false);
    }

    @Override
    public void onFinishInput() {
        super.onFinishInput();
        mComposing.setLength(0);
        updateCandidates();
        if (mInputView != null) {
            mInputView.closing();
        }
    }

    @Override
    public void onUpdateSelection(int oldSelStart, int oldSelEnd, int newSelStart, int newSelEnd, int candidatesStart, int candidatesEnd) {
        // If the current selection in the text view changes, we should
        // clear whatever candidate text we have.
        if (mComposing.length() > 0 && (newSelStart != candidatesEnd || newSelEnd != candidatesEnd)) {
            mComposing.setLength(0);
            updateCandidates();
            InputConnection ic = getCurrentInputConnection();
            if (ic != null) {
                ic.finishComposingText();
            }
        }
    }

    @Override
    public void onDisplayCompletions(CompletionInfo[] completions) {
        if (mCompletionOn) {
            mCompletions = completions;
            if (completions == null) {
                setSuggestions(null, false, false);
                return;
            }

            List<String> stringList = new ArrayList<String>();
            for (int i = 0; i < (completions != null ? completions.length : 0); i++) {
                CompletionInfo ci = completions[i];
                if (ci != null) {
                    stringList.add(ci.getText().toString());
                }
            }
            setSuggestions(stringList, true, true);
        }
    }

    private boolean translateKeyDown(int keyCode, KeyEvent event) {
        mMetaState = MetaKeyKeyListener.handleKeyDown(mMetaState, keyCode, event);
        int c = event.getUnicodeChar(MetaKeyKeyListener.getMetaState(mMetaState));
        mMetaState = MetaKeyKeyListener.adjustMetaAfterKeypress(mMetaState);
        InputConnection ic = getCurrentInputConnection();
        if (c == 0 || ic == null) {
            return false;
        }

        boolean dead = false;
        if ((c & KeyCharacterMap.COMBINING_ACCENT) != 0) {
            dead = true;
            c = c & KeyCharacterMap.COMBINING_ACCENT_MASK;
        }

        if (mComposing.length() > 0) {
            char accent = mComposing.charAt(mComposing.length() - 1);
            int composed = KeyEvent.getDeadChar(accent, c);
            if (composed != 0) {
                c = composed;
                mComposing.setLength(mComposing.length() - 1);
            }
        }

        onKey(c, null);

        return true;
    }

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        switch (keyCode) {
            case KeyEvent.KEYCODE_BACK:
                if (event.getRepeatCount() == 0 && mInputView != null) {
                    if (mInputView.handleBack()) {
                        return true;
                    }
                }
                break;
            case KeyEvent.KEYCODE_DEL:
                if (mComposing.length() > 0) {
                    onKey(Keyboard.KEYCODE_DELETE, null);
                    return true;
                }
                break;
            default:
                if (mPredictionOn && translateKeyDown(keyCode, event)) {
                    return true;
                }
        }
        return super.onKeyDown(keyCode, event);
    }

    @Override
    public boolean onKeyUp(int keyCode, KeyEvent event) {
        switch (keyCode) {
            case KeyEvent.KEYCODE_DPAD_DOWN:
            case KeyEvent.KEYCODE_DPAD_UP:
            case KeyEvent.KEYCODE_DPAD_LEFT:
            case KeyEvent.KEYCODE_DPAD_RIGHT:
                // Enable shift key and DPAD to do selections
                if (mInputView != null && mInputView.isShown() && mInputView.isShifted()) {
                    event = new KeyEvent(event.getDownTime(), event.getEventTime(), event.getAction(), event.getKeyCode(), event.getRepeatCount(), KeyEvent.META_SHIFT_LEFT_ON | KeyEvent.META_SHIFT_ON);
                    getCurrentInputConnection().sendKeyEvent(event);
                    return true;
                }
                break;
            default:
                if (mPredictionOn) {
                    mMetaState = MetaKeyKeyListener.handleKeyUp(mMetaState, keyCode, event);
                }
        }
        return super.onKeyUp(keyCode, event);
    }

    private void commitTyped(InputConnection inputConnection) {
        if (mComposing.length() > 0) {
            inputConnection.commitText(mComposing, mComposing.length());
            mComposing.setLength(0);
            updateCandidates();
        }
    }

    public void updateShiftKeyState(EditorInfo attr) {
        if (attr != null && mInputView != null && mQwertyKeyboard == mInputView.getKeyboard()) {
            int caps = getCurrentInputConnection().getCursorCapsMode(attr.inputType);
            mInputView.setShifted(mCapsLock || caps != 0);
        }
    }

    private boolean isAlphabet(int code) {
        if (Character.isLetter(code)) {
            return true;
        }
        else {
            return false;
        }
    }

    private void keyDownUp(int keyEventCode) {
        getCurrentInputConnection().sendKeyEvent(new KeyEvent(KeyEvent.ACTION_DOWN, keyEventCode));
        getCurrentInputConnection().sendKeyEvent(new KeyEvent(KeyEvent.ACTION_UP, keyEventCode));
    }

    private void sendKey(int keyCode) {
        switch (keyCode) {
            case '\n':
                keyDownUp(KeyEvent.KEYCODE_ENTER);
                break;
            default:
                if (keyCode >= '0' && keyCode <= '9') {
                    keyDownUp(keyCode - '0' + KeyEvent.KEYCODE_0);
                }
                else {
                    getCurrentInputConnection().commitText(String.valueOf((char)keyCode), 1);
                }
                break;
        }
    }

    // Implementation of KeyboardViewListener
    public void onKey(int primaryCode, int[] keyCodes) {
        if (isWordSeparator(primaryCode)) {
            // Handle separator
            if (mComposing.length() > 0) {
                commitTyped(getCurrentInputConnection());
            }
            sendKey(primaryCode);
            updateShiftKeyState(getCurrentInputEditorInfo());
        }
        else if (primaryCode == Keyboard.KEYCODE_DELETE) {
            handleBackspace();
        }
        else if (primaryCode == Keyboard.KEYCODE_SHIFT) {
            handleShift();
        }
        else if (primaryCode == Keyboard.KEYCODE_CANCEL) {
            handleClose();
            return;
        }
        else if (primaryCode == LatinKeyboardView.KEYCODE_OPTIONS) {
            // Show a menu or somethin'
        }
        else if (primaryCode == Keyboard.KEYCODE_MODE_CHANGE && mInputView != null) {
            Keyboard current = mInputView.getKeyboard();
            if (current == mSymbolsKeyboard || current == mSymbolsShiftedKeyboard) {
                current = mQwertyKeyboard;
            }
            else {
                current = mSymbolsKeyboard;
            }
            mInputView.setKeyboard(current);
            if (current == mSymbolsKeyboard) {
                current.setShifted(false);
            }
        }
        else {
            handleCharacter(primaryCode, keyCodes);
        }
    }

    /**
     * Update the list of available candidates from the current composing
     * text.  This will need to be filled in by however you are determining
     * candidates.
     */
    private void updateCandidates() {
        if (!mCompletionOn) {
            if (mComposing.length() > 0) {
                ArrayList<String> list = new ArrayList<String>();
                list.add(mComposing.toString());
                setSuggestions(list, true, true);
            }
            else {
                setSuggestions(null, false, false);
            }
        }
    }

    public void setSuggestions(List<String> suggestions, boolean completions, boolean typedWordValid) {
        mCandidateView.setSuggestions(suggestions, completions, typedWordValid);
        if (suggestions != null && suggestions.size() > 0) {
            setCandidatesViewShown(true);
        }
        else if (isFullscreenMode()) {
            setCandidatesViewShown(true);
        }
        else {
            setCandidatesViewShown(false);
        }
    }

    private void handleBackspace() {
        final int length = mComposing.length();
        if (length > 1) {
            mComposing.delete(length - 1, length);
            getCurrentInputConnection().setComposingText(mComposing, mComposing.length());
            updateCandidates();
        }
        else if (length > 0) {
            mComposing.setLength(0);
            getCurrentInputConnection().commitText("", 0);
            updateCandidates();
        }
        else {
            //getCurrentInputConnection().deleteSurroundingText(1, 0);
            keyDownUp(KeyEvent.KEYCODE_DEL);
        }
        updateShiftKeyState(getCurrentInputEditorInfo());
    }

    private void handleShift() {
        if (mInputView == null) {
            return;
        }

        Keyboard currentKeyboard = mInputView.getKeyboard();
        if (mQwertyKeyboard == currentKeyboard) {
            // Alphabet keyboard
            checkToggleCapsLock();
            mInputView.setShifted(mCapsLock || !mInputView.isShifted());
        }
        else if (currentKeyboard == mSymbolsKeyboard) {
            mSymbolsKeyboard.setShifted(true);
            mInputView.setKeyboard(mSymbolsShiftedKeyboard);
            mSymbolsShiftedKeyboard.setShifted(true);
        }
        else if (currentKeyboard == mSymbolsShiftedKeyboard) {
            mSymbolsShiftedKeyboard.setShifted(false);
            mInputView.setKeyboard(mSymbolsKeyboard);
            mSymbolsKeyboard.setShifted(false);
        }
    }

    private void handleCharacter(int primaryCode, int[] keyCodes) {
        if (isInputViewShown()) {
            if (mInputView.isShifted()) {
                primaryCode = Character.toUpperCase(primaryCode);
            }
        }
        if (isAlphabet(primaryCode) && mPredictionOn) {
            mComposing.append((char)primaryCode);
            getCurrentInputConnection().setComposingText(mComposing, mComposing.length());
            updateShiftKeyState(getCurrentInputEditorInfo());
            updateCandidates();
        }
        else {
            getCurrentInputConnection().commitText(String.valueOf((char)primaryCode), 0);
        }
    }

    private void handleClose() {
        commitTyped(getCurrentInputConnection());
        dismissSoftInput(0);
        mInputView.closing();
    }

    private void checkToggleCapsLock() {
        long now = System.currentTimeMillis();
        if (mLastShiftTime + 800 > now) {
            mCapsLock = !mCapsLock;
            mLastShiftTime = 0;
        }
        else {
            mLastShiftTime = now;
        }
    }

    protected String getWordSeparators() {
        return mWordSeparators;
    }

    public boolean isWordSeparator(int code) {
        String separators = getWordSeparators();
        return separators.contains(String.valueOf((char)code));
    }

    public void pickDefaultCandidate() {
        pickSuggestionManually(0);
    }

    public void pickSuggestionManually(int index) {
        if (mCompletionOn && mCompletions != null && index >= 0 && index < mCompletions.length) {
            CompletionInfo ci = mCompletions[index];
            getCurrentInputConnection().commitCompletion(ci);
            if (mCandidateView != null) {
                mCandidateView.clear();
            }
            updateShiftKeyState(getCurrentInputEditorInfo());
        }
        else if (mComposing.length() > 0) {
            // If we were generating candidate suggestions for the current
            // text, we would commit one of them here.  But for this sample,
            // we will just commit the current text.
            commitTyped(getCurrentInputConnection());
        }
    }

    public void swipeRight() {
        if (mCompletionOn) {
            pickDefaultCandidate();
        }
    }

    public void swipeLeft() {
        handleBackspace();
    }

    public void swipeDown() {
        handleClose();
    }

    public void swipeUp() {
        // ?
    }

    public void onPress(int primaryCode) {
    }

    public void onRelease(int primaryCode) {
    }
}