java - 不能从最终的 GestureDetectorCompat 继承

Question

我有一些类可以为回收站 View 启用项目点击。他们都工作得很好。现在我已经将它们复制到一个新项目中，我得到了问题:

cannot inherit from final 'android.support.v4.GestureDetectorCompat'

现在我的类(class)可能出了什么问题？

ClickItemTouchListener.java

package com.stack.overflow.helperClasses;

import android.content.Context;
import android.os.Build;
import android.support.v4.view.GestureDetectorCompat;
import android.support.v4.view.MotionEventCompat;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.RecyclerView.OnItemTouchListener;
import android.view.GestureDetector.SimpleOnGestureListener;
import android.view.MotionEvent;
import android.view.View;

abstract class ClickItemTouchListener implements OnItemTouchListener {
    private static final String LOGTAG = "ClickItemTouchListener";

    private final GestureDetectorCompat mGestureDetector;

    ClickItemTouchListener(RecyclerView hostView) {
        mGestureDetector = new ItemClickGestureDetector(hostView.getContext(),
                new ItemClickGestureListener(hostView));
    }

    private boolean isAttachedToWindow(RecyclerView hostView) {
        if (Build.VERSION.SDK_INT >= 19) {
            return hostView.isAttachedToWindow();
        } else {
            return (hostView.getHandler() != null);
        }
    }

    private boolean hasAdapter(RecyclerView hostView) {
        return (hostView.getAdapter() != null);
    }

    @Override
    public boolean onInterceptTouchEvent(RecyclerView recyclerView, MotionEvent event) {
        if (!isAttachedToWindow(recyclerView) || !hasAdapter(recyclerView)) {
            return false;
        }

        mGestureDetector.onTouchEvent(event);
        return false;
    }

    @Override
    public void onTouchEvent(RecyclerView recyclerView, MotionEvent event) {
        // We can silently track tap and and long presses by silently
        // intercepting touch events in the host RecyclerView.
    }

    abstract boolean performItemClick(RecyclerView parent, View view, int position, long id);
    abstract boolean performItemLongClick(RecyclerView parent, View view, int position, long id);

    private class ItemClickGestureDetector extends GestureDetectorCompat {
        private final ItemClickGestureListener mGestureListener;

        public ItemClickGestureDetector(Context context, ItemClickGestureListener listener) {
            super(context, listener);
            mGestureListener = listener;
        }

        @Override
        public boolean onTouchEvent(MotionEvent event) {
            final boolean handled = super.onTouchEvent(event);

            final int action = event.getAction() & MotionEventCompat.ACTION_MASK;
            if (action == MotionEvent.ACTION_UP) {
                mGestureListener.dispatchSingleTapUpIfNeeded(event);
            }

            return handled;
        }
    }

    private class ItemClickGestureListener extends SimpleOnGestureListener {
        private final RecyclerView mHostView;
        private View mTargetChild;

        public ItemClickGestureListener(RecyclerView hostView) {
            mHostView = hostView;
        }

        public void dispatchSingleTapUpIfNeeded(MotionEvent event) {
            // When the long press hook is called but the long press listener
            // returns false, the target child will be left around to be
            // handled later. In this case, we should still treat the gesture
            // as potential item click.
            if (mTargetChild != null) {
                onSingleTapUp(event);
            }
        }

        @Override
        public boolean onDown(MotionEvent event) {
            final int x = (int) event.getX();
            final int y = (int) event.getY();

            mTargetChild = mHostView.findChildViewUnder(x, y);
            return (mTargetChild != null);
        }

        @Override
        public void onShowPress(MotionEvent event) {
            if (mTargetChild != null) {
                mTargetChild.setPressed(true);
            }
        }

        @Override
        public boolean onSingleTapUp(MotionEvent event) {
            boolean handled = false;

            if (mTargetChild != null) {
                mTargetChild.setPressed(false);

                final int position = mHostView.getChildPosition(mTargetChild);
                final long id = mHostView.getAdapter().getItemId(position);
                handled = performItemClick(mHostView, mTargetChild, position, id);

                mTargetChild = null;
            }

            return handled;
        }

        @Override
        public boolean onScroll(MotionEvent event, MotionEvent event2, float v, float v2) {
            if (mTargetChild != null) {
                mTargetChild.setPressed(false);
                mTargetChild = null;

                return true;
            }

            return false;
        }

        @Override
        public void onLongPress(MotionEvent event) {
            if (mTargetChild == null) {
                return;
            }

            final int position = mHostView.getChildPosition(mTargetChild);
            final long id = mHostView.getAdapter().getItemId(position);
            final boolean handled = performItemLongClick(mHostView, mTargetChild, position, id);

            if (handled) {
                mTargetChild.setPressed(false);
                mTargetChild = null;
            }
        }
    }
}

ItemClickSupport.java

package com.stack.overflow.helperClasses;

import android.support.v7.widget.RecyclerView;
import android.view.HapticFeedbackConstants;
import android.view.SoundEffectConstants;
import android.view.View;

import com.mego.smscloud.R;

public class ItemClickSupport {
    /**
     * Interface definition for a callback to be invoked when an item in the
     * RecyclerView has been clicked.
     */
    public interface OnItemClickListener {
        /**
         * Callback method to be invoked when an item in the RecyclerView
         * has been clicked.
         *
         * @param parent The RecyclerView where the click happened.
         * @param view The view within the RecyclerView that was clicked
         * @param position The position of the view in the adapter.
         * @param id The row id of the item that was clicked.
         */
        void onItemClick(RecyclerView parent, View view, int position, long id);
    }

    /**
     * Interface definition for a callback to be invoked when an item in the
     * RecyclerView has been clicked and held.
     */
    public interface OnItemLongClickListener {
        /**
         * Callback method to be invoked when an item in the RecyclerView
         * has been clicked and held.
         *
         * @param parent The RecyclerView where the click happened
         * @param view The view within the RecyclerView that was clicked
         * @param position The position of the view in the list
         * @param id The row id of the item that was clicked
         *
         * @return true if the callback consumed the long click, false otherwise
         */
        boolean onItemLongClick(RecyclerView parent, View view, int position, long id);
    }

    private final RecyclerView mRecyclerView;
    private final TouchListener mTouchListener;

    private OnItemClickListener mItemClickListener;
    private OnItemLongClickListener mItemLongClickListener;

    private ItemClickSupport(RecyclerView recyclerView) {
        mRecyclerView = recyclerView;

        mTouchListener = new TouchListener(recyclerView);
        recyclerView.addOnItemTouchListener(mTouchListener);
    }

    /**
     * Register a callback to be invoked when an item in the
     * RecyclerView has been clicked.
     *
     * @param listener The callback that will be invoked.
     */
    public void setOnItemClickListener(OnItemClickListener listener) {
        mItemClickListener = listener;
    }

    /**
     * Register a callback to be invoked when an item in the
     * RecyclerView has been clicked and held.
     *
     * @param listener The callback that will be invoked.
     */
    public void setOnItemLongClickListener(OnItemLongClickListener listener) {
        if (!mRecyclerView.isLongClickable()) {
            mRecyclerView.setLongClickable(true);
        }

        mItemLongClickListener = listener;
    }

    public static ItemClickSupport addTo(RecyclerView recyclerView) {
        ItemClickSupport itemClickSupport = from(recyclerView);
        if (itemClickSupport == null) {
            itemClickSupport = new ItemClickSupport(recyclerView);
            recyclerView.setTag(R.id.recyclerview_item_click_support, itemClickSupport);
        } else {
            // TODO: Log warning
        }

        return itemClickSupport;
    }

    public static void removeFrom(RecyclerView recyclerView) {
        final ItemClickSupport itemClickSupport = from(recyclerView);
        if (itemClickSupport == null) {
            // TODO: Log warning
            return;
        }

        recyclerView.removeOnItemTouchListener(itemClickSupport.mTouchListener);
        recyclerView.setTag(R.id.recyclerview_item_click_support, null);
    }

    public static ItemClickSupport from(RecyclerView recyclerView) {
        if (recyclerView == null) {
            return null;
        }

        return (ItemClickSupport) recyclerView.getTag(R.id.recyclerview_item_click_support);
    }

    private class TouchListener extends ClickItemTouchListener {
        TouchListener(RecyclerView recyclerView) {
            super(recyclerView);
        }

        @Override
        boolean performItemClick(RecyclerView parent, View view, int position, long id) {
            if (mItemClickListener != null) {
                view.playSoundEffect(SoundEffectConstants.CLICK);
                mItemClickListener.onItemClick(parent, view, position, id);
                return true;
            }

            return false;
        }

        @Override
        boolean performItemLongClick(RecyclerView parent, View view, int position, long id) {
            if (mItemLongClickListener != null) {
                view.performHapticFeedback(HapticFeedbackConstants.LONG_PRESS);
                return mItemLongClickListener.onItemLongClick(parent, view, position, id);
            }

            return false;
        }


        @Override
        public void onRequestDisallowInterceptTouchEvent(boolean b) {

        }
    }
}

ids.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <item name="recyclerview_item_click_support" type="id"/>
    <item name="recyclerview_item_selection_support" type="id"/>

</resources>

Answer 1

改变自

GestureDetectorCompat

到

GestureDetector