content: /*
   * Copyright (C) 2010 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.amnesica.kryptey.inputmethod.keyboard.internal;
  
  import android.util.Log;
  
  import java.util.ArrayList;
  
  public final class PointerTrackerQueue {
    private static final String TAG = PointerTrackerQueue.class.getSimpleName();
    private static final boolean DEBUG = false;
  
    public interface Element {
      boolean isModifier();
  
      boolean isInDraggingFinger();
  
      void onPhantomUpEvent(long eventTime);
  
      void cancelTrackingForAction();
    }
  
    private static final int INITIAL_CAPACITY = 10;
    // Note: {@link #mExpandableArrayOfActivePointers} and {@link #mArraySize} are synchronized by
    // {@link #mExpandableArrayOfActivePointers}
    private final ArrayList<Element> mExpandableArrayOfActivePointers =
        new ArrayList<>(INITIAL_CAPACITY);
    private int mArraySize = 0;
  
    public int size() {
      synchronized (mExpandableArrayOfActivePointers) {
        return mArraySize;
      }
    }
  
    public void add(final Element pointer) {
      synchronized (mExpandableArrayOfActivePointers) {
        if (DEBUG) {
          Log.d(TAG, "add: " + pointer + " " + this);
        }
        final ArrayList<Element> expandableArray = mExpandableArrayOfActivePointers;
        final int arraySize = mArraySize;
        if (arraySize < expandableArray.size()) {
          expandableArray.set(arraySize, pointer);
        } else {
          expandableArray.add(pointer);
        }
        mArraySize = arraySize + 1;
      }
    }
  
    public void remove(final Element pointer) {
      synchronized (mExpandableArrayOfActivePointers) {
        if (DEBUG) {
          Log.d(TAG, "remove: " + pointer + " " + this);
        }
        final ArrayList<Element> expandableArray = mExpandableArrayOfActivePointers;
        final int arraySize = mArraySize;
        int newIndex = 0;
        for (int index = 0; index < arraySize; index++) {
          final Element element = expandableArray.get(index);
          if (element == pointer) {
            if (newIndex != index) {
              Log.w(TAG, "Found duplicated element in remove: " + pointer);
            }
            continue; // Remove this element from the expandableArray.
          }
          if (newIndex != index) {
            // Shift this element toward the beginning of the expandableArray.
            expandableArray.set(newIndex, element);
          }
          newIndex++;
        }
        mArraySize = newIndex;
      }
    }
  
    public void releaseAllPointersOlderThan(final Element pointer, final long eventTime) {
      synchronized (mExpandableArrayOfActivePointers) {
        if (DEBUG) {
          Log.d(TAG, "releaseAllPointerOlderThan: " + pointer + " " + this);
        }
        final ArrayList<Element> expandableArray = mExpandableArrayOfActivePointers;
        final int arraySize = mArraySize;
        int newIndex, index;
        for (newIndex = index = 0; index < arraySize; index++) {
          final Element element = expandableArray.get(index);
          if (element == pointer) {
            break; // Stop releasing elements.
          }
          if (!element.isModifier()) {
            element.onPhantomUpEvent(eventTime);
            continue; // Remove this element from the expandableArray.
          }
          if (newIndex != index) {
            // Shift this element toward the beginning of the expandableArray.
            expandableArray.set(newIndex, element);
          }
          newIndex++;
        }
        // Shift rest of the expandableArray.
        int count = 0;
        for (; index < arraySize; index++) {
          final Element element = expandableArray.get(index);
          if (element == pointer) {
            count++;
            if (count > 1) {
              Log.w(TAG, "Found duplicated element in releaseAllPointersOlderThan: "
                  + pointer);
            }
          }
          if (newIndex != index) {
            // Shift this element toward the beginning of the expandableArray.
            expandableArray.set(newIndex, expandableArray.get(index));
          }
          newIndex++;
        }
        mArraySize = newIndex;
      }
    }
  
    public void releaseAllPointers(final long eventTime) {
      releaseAllPointersExcept(null, eventTime);
    }
  
    public void releaseAllPointersExcept(final Element pointer, final long eventTime) {
      synchronized (mExpandableArrayOfActivePointers) {
        if (DEBUG) {
          if (pointer == null) {
            Log.d(TAG, "releaseAllPointers: " + this);
          } else {
            Log.d(TAG, "releaseAllPointerExcept: " + pointer + " " + this);
          }
        }
        final ArrayList<Element> expandableArray = mExpandableArrayOfActivePointers;
        final int arraySize = mArraySize;
        int newIndex = 0, count = 0;
        for (int index = 0; index < arraySize; index++) {
          final Element element = expandableArray.get(index);
          if (element == pointer) {
            count++;
            if (count > 1) {
              Log.w(TAG, "Found duplicated element in releaseAllPointersExcept: "
                  + pointer);
            }
          } else {
            element.onPhantomUpEvent(eventTime);
            continue; // Remove this element from the expandableArray.
          }
          if (newIndex != index) {
            // Shift this element toward the beginning of the expandableArray.
            expandableArray.set(newIndex, element);
          }
          newIndex++;
        }
        mArraySize = newIndex;
      }
    }
  
    public boolean hasModifierKeyOlderThan(final Element pointer) {
      synchronized (mExpandableArrayOfActivePointers) {
        final ArrayList<Element> expandableArray = mExpandableArrayOfActivePointers;
        final int arraySize = mArraySize;
        for (int index = 0; index < arraySize; index++) {
          final Element element = expandableArray.get(index);
          if (element == pointer) {
            return false; // Stop searching modifier key.
          }
          if (element.isModifier()) {
            return true;
          }
        }
        return false;
      }
    }
  
    public boolean isAnyInDraggingFinger() {
      synchronized (mExpandableArrayOfActivePointers) {
        final ArrayList<Element> expandableArray = mExpandableArrayOfActivePointers;
        final int arraySize = mArraySize;
        for (int index = 0; index < arraySize; index++) {
          final Element element = expandableArray.get(index);
          if (element.isInDraggingFinger()) {
            return true;
          }
        }
        return false;
      }
    }
  
    public void cancelAllPointerTrackers() {
      synchronized (mExpandableArrayOfActivePointers) {
        if (DEBUG) {
          Log.d(TAG, "cancelAllPointerTracker: " + this);
        }
        final ArrayList<Element> expandableArray = mExpandableArrayOfActivePointers;
        final int arraySize = mArraySize;
        for (int index = 0; index < arraySize; index++) {
          final Element element = expandableArray.get(index);
          element.cancelTrackingForAction();
        }
      }
    }
  
    @Override
    public String toString() {
      synchronized (mExpandableArrayOfActivePointers) {
        final StringBuilder sb = new StringBuilder();
        final ArrayList<Element> expandableArray = mExpandableArrayOfActivePointers;
        final int arraySize = mArraySize;
        for (int index = 0; index < arraySize; index++) {
          final Element element = expandableArray.get(index);
          if (sb.length() > 0) {
            sb.append(" ");
          }
          sb.append(element.toString());
        }
        return "[" + sb + "]";
      }
    }
  }
  