com.github.dm.rf.android.internal.SparseArrayIterator Maven / Gradle / Ivy
/**
* 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.github.dm.rf.android.internal;
import android.annotation.TargetApi;
import android.os.Build.VERSION;
import android.os.Build.VERSION_CODES;
import android.util.SparseArray;
import com.github.dm.rf.android.entry.IntSparseObjectEntry;
import com.github.dm.rf.android.entry.ParcelableIntSparseObjectEntry;
import com.github.dm.rf.android.entry.SparseArrayEntry;
import com.github.dm.rf.android.entry.SparseEntries;
import java.util.NoSuchElementException;
/**
* Implementation of a {@link SparseIterator} of
* {@link SparseArrayEntry} elements.
*
* To let this class implement both the iterator and the entry is a precise design choice in order
* to achieve the highest performance and the lowest memory usage.
* The drawback is that the iterated entries cannot be copied and used outside the
* for use. Fortunately, that is not the common behavior of iteration.
* To work around the just described issue, each entry con generate an immutable copy of itself
* storing only the key and value objects but losing any reference to the backing sparse
* collection.
*
* Created by davide-maestroni on 3/10/14.
*
* @param the entry value type.
*/
class SparseArrayIterator extends AbstractSparseIterator>
implements SparseArrayEntry {
private final SparseArray mSparseArray;
private int mPosition;
private V mValue;
public SparseArrayIterator(final SparseArray array) {
super(array.size());
mSparseArray = array;
}
@Override
@SuppressWarnings("EqualsWhichDoesntCheckParameterClass")
public boolean equals(final Object o) {
return SparseEntries.equal(this, o);
}
@Override
public int hashCode() {
return SparseEntries.hashCode(this);
}
@Override
public String toString() {
return getKey() + "=" + getValue();
}
@Override
public int getIndex() {
return mPosition;
}
@Override
public int getKey() {
return mSparseArray.keyAt(mPosition);
}
@Override
public V getValue() {
return mValue;
}
@Override
public void setValue(final V value) {
mSparseArray.setValueAt(mPosition, value);
mValue = value;
}
@Override
public IntSparseObjectEntry toImmutable() {
return SparseEntries.entry(getKey(), mValue);
}
@Override
public ParcelableIntSparseObjectEntry toParcelable() {
return SparseEntries.parcelableEntry(getKey(), mValue);
}
@Override
protected SparseArrayEntry getElementAt(final int position) {
try {
mValue = mSparseArray.valueAt(position);
} catch (final IndexOutOfBoundsException e) {
throw new NoSuchElementException();
}
mPosition = position;
return this;
}
@Override
@TargetApi(11)
protected void removeElement() {
if (VERSION.SDK_INT >= VERSION_CODES.HONEYCOMB) {
mSparseArray.removeAt(mPosition);
} else {
mSparseArray.remove(getKey());
}
}
}