alvinalexander.com | career | drupal | java | mac | mysql | perl | scala | uml | unix  

Android example source code file (MultiTapKeyListener.java)

This example Android source code file (MultiTapKeyListener.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, basekeylistener, capitalize, editable, handler, keyevent, multitapkeylistener, object, os, runnable, spannable, spanwatcher, sparsearray, string, timeout, ui, util, utilities, view

The MultiTapKeyListener.java Android example source code

/*
 * Copyright (C) 2006 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 android.text.method;

import android.view.KeyEvent;
import android.view.View;
import android.os.Handler;
import android.os.SystemClock;
import android.text.*;
import android.text.method.TextKeyListener.Capitalize;
import android.util.SparseArray;

/**
 * This is the standard key listener for alphabetic input on 12-key
 * keyboards.  You should generally not need to instantiate this yourself;
 * TextKeyListener will do it for you.
 */
public class MultiTapKeyListener extends BaseKeyListener
        implements SpanWatcher {
    private static MultiTapKeyListener[] sInstance =
        new MultiTapKeyListener[Capitalize.values().length * 2];

    private static final SparseArray<String> sRecs = new SparseArray();

    private Capitalize mCapitalize;
    private boolean mAutoText;

    static {
        sRecs.put(KeyEvent.KEYCODE_1,     ".,1!@#$%^&*:/?'=()");
        sRecs.put(KeyEvent.KEYCODE_2,     "abc2ABC");
        sRecs.put(KeyEvent.KEYCODE_3,     "def3DEF");
        sRecs.put(KeyEvent.KEYCODE_4,     "ghi4GHI");
        sRecs.put(KeyEvent.KEYCODE_5,     "jkl5JKL");
        sRecs.put(KeyEvent.KEYCODE_6,     "mno6MNO");
        sRecs.put(KeyEvent.KEYCODE_7,     "pqrs7PQRS");
        sRecs.put(KeyEvent.KEYCODE_8,     "tuv8TUV");
        sRecs.put(KeyEvent.KEYCODE_9,     "wxyz9WXYZ");
        sRecs.put(KeyEvent.KEYCODE_0,     "0+");
        sRecs.put(KeyEvent.KEYCODE_POUND, " ");
    };

    public MultiTapKeyListener(Capitalize cap,
                               boolean autotext) {
        mCapitalize = cap;
        mAutoText = autotext;
    }

    /**
     * Returns a new or existing instance with the specified capitalization
     * and correction properties.
     */
    public static MultiTapKeyListener getInstance(boolean autotext,
                                                  Capitalize cap) {
        int off = cap.ordinal() * 2 + (autotext ? 1 : 0);

        if (sInstance[off] == null) {
            sInstance[off] = new MultiTapKeyListener(cap, autotext);
        }

        return sInstance[off];
    }

    public int getInputType() {
        return makeTextContentType(mCapitalize, mAutoText);
    }
    
    public boolean onKeyDown(View view, Editable content,
                             int keyCode, KeyEvent event) {
        int selStart, selEnd;
        int pref = 0;

        if (view != null) {
            pref = TextKeyListener.getInstance().getPrefs(view.getContext());
        }

        {
            int a = Selection.getSelectionStart(content);
            int b = Selection.getSelectionEnd(content);

            selStart = Math.min(a, b);
            selEnd = Math.max(a, b);
        }

        int activeStart = content.getSpanStart(TextKeyListener.ACTIVE);
        int activeEnd = content.getSpanEnd(TextKeyListener.ACTIVE);

        // now for the multitap cases...

        // Try to increment the character we were working on before
        // if we have one and it's still the same key.

        int rec = (content.getSpanFlags(TextKeyListener.ACTIVE)
                    & Spannable.SPAN_USER) >>> Spannable.SPAN_USER_SHIFT;

        if (activeStart == selStart && activeEnd == selEnd &&
            selEnd - selStart == 1 &&
            rec >= 0 && rec < sRecs.size()) {
            if (keyCode == KeyEvent.KEYCODE_STAR) {
                char current = content.charAt(selStart);

                if (Character.isLowerCase(current)) {
                    content.replace(selStart, selEnd,
                                    String.valueOf(current).toUpperCase());
                    removeTimeouts(content);
                    Timeout t = new Timeout(content);

                    return true;
                }
                if (Character.isUpperCase(current)) {
                    content.replace(selStart, selEnd,
                                    String.valueOf(current).toLowerCase());
                    removeTimeouts(content);
                    Timeout t = new Timeout(content);

                    return true;
                }
            }

            if (sRecs.indexOfKey(keyCode) == rec) {
                String val = sRecs.valueAt(rec);
                char ch = content.charAt(selStart);
                int ix = val.indexOf(ch);

                if (ix >= 0) {
                    ix = (ix + 1) % (val.length());

                    content.replace(selStart, selEnd, val, ix, ix + 1);
                    removeTimeouts(content);
                    Timeout t = new Timeout(content);

                    return true;
                }
            }

            // Is this key one we know about at all?  If so, acknowledge
            // that the selection is our fault but the key has changed
            // or the text no longer matches, so move the selection over
            // so that it inserts instead of replaces.

            rec = sRecs.indexOfKey(keyCode);

            if (rec >= 0) {
                Selection.setSelection(content, selEnd, selEnd);
                selStart = selEnd;
            }
        } else {
            rec = sRecs.indexOfKey(keyCode);
        }

        if (rec >= 0) {
            // We have a valid key.  Replace the selection or insertion point
            // with the first character for that key, and remember what
            // record it came from for next time.

            String val = sRecs.valueAt(rec);

            int off = 0;
            if ((pref & TextKeyListener.AUTO_CAP) != 0 &&
                TextKeyListener.shouldCap(mCapitalize, content, selStart)) {
                for (int i = 0; i < val.length(); i++) {
                    if (Character.isUpperCase(val.charAt(i))) {
                        off = i;
                        break;
                    }
                }
            }

            if (selStart != selEnd) {
                Selection.setSelection(content, selEnd);
            }

            content.setSpan(OLD_SEL_START, selStart, selStart,
                            Spannable.SPAN_MARK_MARK);

            content.replace(selStart, selEnd, val, off, off + 1);

            int oldStart = content.getSpanStart(OLD_SEL_START);
            selEnd = Selection.getSelectionEnd(content);

            if (selEnd != oldStart) {
                Selection.setSelection(content, oldStart, selEnd);

                content.setSpan(TextKeyListener.LAST_TYPED, 
                                oldStart, selEnd,
                                Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);

                content.setSpan(TextKeyListener.ACTIVE,
                            oldStart, selEnd,
                            Spannable.SPAN_EXCLUSIVE_EXCLUSIVE |
                            (rec << Spannable.SPAN_USER_SHIFT));

            }

            removeTimeouts(content);
            Timeout t = new Timeout(content);

            // Set up the callback so we can remove the timeout if the
            // cursor moves.

            if (content.getSpanStart(this) < 0) {
                KeyListener[] methods = content.getSpans(0, content.length(),
                                                    KeyListener.class);
                for (Object method : methods) {
                    content.removeSpan(method);
                }
                content.setSpan(this, 0, content.length(),
                                Spannable.SPAN_INCLUSIVE_INCLUSIVE);
            }

            return true;
        }

        return super.onKeyDown(view, content, keyCode, event);
    }

    public void onSpanChanged(Spannable buf,
                              Object what, int s, int e, int start, int stop) {
        if (what == Selection.SELECTION_END) {
            buf.removeSpan(TextKeyListener.ACTIVE);
            removeTimeouts(buf);
        }
    }

    private static void removeTimeouts(Spannable buf) {
        Timeout[] timeout = buf.getSpans(0, buf.length(), Timeout.class);

        for (int i = 0; i < timeout.length; i++) {
            Timeout t = timeout[i];

            t.removeCallbacks(t);
            t.mBuffer = null;
            buf.removeSpan(t);
        }
    }

    private class Timeout
    extends Handler
    implements Runnable
    {
        public Timeout(Editable buffer) {
            mBuffer = buffer;
            mBuffer.setSpan(Timeout.this, 0, mBuffer.length(),
                            Spannable.SPAN_INCLUSIVE_INCLUSIVE);

            postAtTime(this, SystemClock.uptimeMillis() + 2000);
        }

        public void run() {
            Spannable buf = mBuffer;

            if (buf != null) {
                int st = Selection.getSelectionStart(buf);
                int en = Selection.getSelectionEnd(buf);

                int start = buf.getSpanStart(TextKeyListener.ACTIVE);
                int end = buf.getSpanEnd(TextKeyListener.ACTIVE);

                if (st == start && en == end) {
                    Selection.setSelection(buf, Selection.getSelectionEnd(buf));
                }

                buf.removeSpan(Timeout.this);
            }
        }

        private Editable mBuffer;
    }

    public void onSpanAdded(Spannable s, Object what, int start, int end) { }
    public void onSpanRemoved(Spannable s, Object what, int start, int end) { }
}

Other Android examples (source code examples)

Here is a short list of links related to this Android MultiTapKeyListener.java source code file:

... this post is sponsored by my books ...

#1 New Release!

FP Best Seller

 

new blog posts

 

Copyright 1998-2021 Alvin Alexander, alvinalexander.com
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.