Add scrollable KeyboardView

/*

 * Copyright (C) 2013 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.inputmethod.keyboard.internal;

import android.content.Context;

import android.util.AttributeSet;

import android.view.GestureDetector;

import android.view.MotionEvent;

import android.widget.ScrollView;

import android.widget.Scroller;

import com.android.inputmethod.keyboard.Key;

import com.android.inputmethod.keyboard.KeyDetector;

import com.android.inputmethod.keyboard.Keyboard;

import com.android.inputmethod.keyboard.KeyboardView;

import com.android.inputmethod.latin.R;

/**

 * This is an extended {@link KeyboardView} class that hosts a scroll keyboard.

 * Multi-touch unsupported. No {@link PointerTracker}s. No gesture support.

 */

public final class ScrollKeyboardView extends KeyboardView implements

        ScrollViewWithNotifier.ScrollListener, GestureDetector.OnGestureListener {

    private static final boolean PAGINATION = false;

    public interface OnKeyClickListener {

        public void onKeyClick(Key key);

    }

    private static final OnKeyClickListener EMPTY_LISTENER = new OnKeyClickListener() {

        @Override

        public void onKeyClick(final Key key) {}

    };

    private OnKeyClickListener mListener = EMPTY_LISTENER;

    private final KeyDetector mKeyDetector = new KeyDetector(0.0f /*keyHysteresisDistance */);

    private final GestureDetector mGestureDetector;

    private final Scroller mScroller;

    private ScrollViewWithNotifier mScrollView;

    public ScrollKeyboardView(final Context context, final AttributeSet attrs) {

        this(context, attrs, R.attr.keyboardViewStyle);

    }

    public ScrollKeyboardView(final Context context, final AttributeSet attrs, final int defStyle) {

        super(context, attrs, defStyle);

        mGestureDetector = new GestureDetector(context, this);

        mGestureDetector.setIsLongpressEnabled(false /* isLongpressEnabled */);

        mScroller = new Scroller(context);

    }

    public void setScrollView(final ScrollViewWithNotifier scrollView) {

        mScrollView = scrollView;

        scrollView.setScrollListener(this);

    }

    private final Runnable mScrollTask = new Runnable() {

        @Override

        public void run() {

            final Scroller scroller = mScroller;

            final ScrollView scrollView = mScrollView;

            scroller.computeScrollOffset();

            scrollView.scrollTo(0, scroller.getCurrY());

            if (!scroller.isFinished()) {

                scrollView.post(this);

            }

        }

    };

    // {@link ScrollViewWithNotified#ScrollListener} methods.

    @Override

    public void notifyScrollChanged(final int scrollX, final int scrollY, final int oldX,

            final int oldY) {

        if (PAGINATION) {

            mScroller.forceFinished(true /* finished */);

            mScrollView.removeCallbacks(mScrollTask);

            final int currentTop = mScrollView.getScrollY();

            final int pageHeight = getKeyboard().mBaseHeight;

            final int lastPageNo = currentTop / pageHeight;

            final int lastPageTop = lastPageNo * pageHeight;

            final int nextPageNo = lastPageNo + 1;

            final int nextPageTop = Math.min(nextPageNo * pageHeight, getHeight() - pageHeight);

            final int scrollTo = (currentTop - lastPageTop) < (nextPageTop - currentTop)

                    ? lastPageTop : nextPageTop;

            final int deltaY = scrollTo - currentTop;

            mScroller.startScroll(0, currentTop, 0, deltaY, 300);

            mScrollView.post(mScrollTask);

        }

    }

    @Override

    public void notifyOverScrolled(final int scrollX, final int scrollY, final boolean clampedX,

            final boolean clampedY) {

        releaseCurrentKey();

    }

    public void setOnKeyClickListener(final OnKeyClickListener listener) {

        mListener = listener;

    }

    /**

     * {@inheritDoc}

     */

    @Override

    public void setKeyboard(final Keyboard keyboard) {

        super.setKeyboard(keyboard);

        mKeyDetector.setKeyboard(keyboard, 0 /* correctionX */, 0 /* correctionY */);

    }

    /**

     * {@inheritDoc}

     */

    @Override

    public boolean onTouchEvent(final MotionEvent e) {

        if (mGestureDetector.onTouchEvent(e)) {

            return true;

        }

        final Key key = getKey(e);

        if (key != null && key != mCurrentKey) {

            releaseCurrentKey();

        }

        return true;

    }

    // {@link GestureDetector#OnGestureListener} methods.

    private Key mCurrentKey;

    private Key getKey(final MotionEvent e) {

        final int index = e.getActionIndex();

        final int x = (int)e.getX(index);

        final int y = (int)e.getY(index);

        return mKeyDetector.detectHitKey(x, y);

    }

    public void releaseCurrentKey() {

        final Key currentKey = mCurrentKey;

        if (currentKey == null) {

            return;

        }

        currentKey.onReleased();

        invalidateKey(currentKey);

        mCurrentKey = null;

    }

    @Override

    public boolean onDown(final MotionEvent e) {

        final Key key = getKey(e);

        releaseCurrentKey();

        mCurrentKey = key;

        if (key == null) {

            return false;

        }

        // TODO: May call {@link KeyboardActionListener#onPressKey(int,int,boolean)}.

        key.onPressed();

        invalidateKey(key);

        return false;

    }

    @Override

    public void onShowPress(final MotionEvent e) {

        // User feedback is done at {@link #onDown(MotionEvent)}.

    }

    @Override

    public boolean onSingleTapUp(final MotionEvent e) {

        final Key key = getKey(e);

        releaseCurrentKey();

        if (key == null) {

            return false;

        }

        // TODO: May call {@link KeyboardActionListener#onReleaseKey(int,boolean)}.

        key.onReleased();

        invalidateKey(key);

        mListener.onKeyClick(key);

        return true;

    }

    @Override

    public boolean onScroll(final MotionEvent e1, final MotionEvent e2, final float distanceX,

           final float distanceY) {

        releaseCurrentKey();

        return false;

    }

    @Override

    public boolean onFling(final MotionEvent e1, final MotionEvent e2, final float velocityX,

            final float velocityY) {

        releaseCurrentKey();

        return false;

    }

    @Override

    public void onLongPress(final MotionEvent e) {

        // Long press detection of {@link #mGestureDetector} is disabled and not used.

    }

}

/*

 * Copyright (C) 2013 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.inputmethod.keyboard.internal;

import android.content.Context;

import android.util.AttributeSet;

import android.widget.ScrollView;

/**

 * This is an extended {@link ScrollView} that can notify

 * {@link ScrollView#onScrollChanged(int,int,int,int} and

 * {@link ScrollView#onOverScrolled(int,int,int,int)} to a content view.

 */

public class ScrollViewWithNotifier extends ScrollView {

    private ScrollListener mScrollListener = EMPTY_LISTER;

    public interface ScrollListener {

        public void notifyScrollChanged(int scrollX, int scrollY, int oldX, int oldY);

        public void notifyOverScrolled(int scrollX, int scrollY, boolean clampedX,

                boolean clampedY);

    }

    private static final ScrollListener EMPTY_LISTER = new ScrollListener() {

        @Override

        public void notifyScrollChanged(int scrollX, int scrollY, int oldX, int oldY) {}

        @Override

        public void notifyOverScrolled(int scrollX, int scrollY, boolean clampedX,

                boolean clampedY) {}

    };

    public ScrollViewWithNotifier(final Context context, final AttributeSet attrs) {

        super(context, attrs);

    }

    @Override

    protected void onScrollChanged(final int scrollX, final int scrollY, final int oldX,

            final int oldY) {

        super.onScrollChanged(scrollX, scrollY, oldX, oldY);

        mScrollListener.notifyScrollChanged(scrollX, scrollY, oldX, oldY);

    }

    @Override

    protected void onOverScrolled(final int scrollX, final int scrollY, final boolean clampedX,

            final boolean clampedY) {

        super.onOverScrolled(scrollX, scrollY, clampedX, clampedY);

        mScrollListener.notifyOverScrolled(scrollX, scrollY, clampedX, clampedY);

    }

    public void setScrollListener(final ScrollListener listener) {

        mScrollListener = listener;

    }

}