Example usage for android.widget Adapter hasStableIds

Introduction

In this page you can find the example usage for android.widget Adapter hasStableIds.

Prototype

boolean hasStableIds();

Source Link

Document

Indicates whether the item ids are stable across changes to the underlying data.

Usage

From source file:co.codecrunch.musicplayerlite.recyclerviewutils.ItemSelectionSupport.java

/**
 * Defines the choice behavior for the List. By default, Lists do not have any choice behavior
 * ({@link ChoiceMode#NONE}). By setting the choiceMode to {@link ChoiceMode#SINGLE}, the
 * List allows up to one item to  be in a chosen state. By setting the choiceMode to
 * {@link ChoiceMode#MULTIPLE}, the list allows any number of items to be chosen.
 *
 * @param choiceMode One of {@link ChoiceMode#NONE}, {@link ChoiceMode#SINGLE}, or
 * {@link ChoiceMode#MULTIPLE}// w ww.  j  ava  2  s .c  o  m
 */
public void setChoiceMode(ChoiceMode choiceMode) {
    if (mChoiceMode == choiceMode) {
        return;
    }

    mChoiceMode = choiceMode;

    if (mChoiceMode != ChoiceMode.NONE) {
        if (mCheckedStates == null) {
            mCheckedStates = new CheckedStates();
        }

        final Adapter adapter = mRecyclerView.getAdapter();
        if (mCheckedIdStates == null && adapter != null && adapter.hasStableIds()) {
            mCheckedIdStates = new CheckedIdStates();
        }
    }
}

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From source file:co.codecrunch.musicplayerlite.recyclerviewutils.ItemSelectionSupport.java

public void onAdapterDataChanged() {
    final Adapter adapter = mRecyclerView.getAdapter();
    if (mChoiceMode == ChoiceMode.NONE || adapter == null || !adapter.hasStableIds()) {
        return;//ww  w  . j  a  v a  2s .  c o  m
    }

    final int itemCount = adapter.getItemCount();

    // Clear out the positional check states, we'll rebuild it below from IDs.
    mCheckedStates.clear();

    for (int checkedIndex = 0; checkedIndex < mCheckedIdStates.size(); checkedIndex++) {
        final long currentId = mCheckedIdStates.keyAt(checkedIndex);
        final int currentPosition = mCheckedIdStates.valueAt(checkedIndex);

        final long newPositionId = adapter.getItemId(currentPosition);
        if (currentId != newPositionId) {
            // Look around to see if the ID is nearby. If not, uncheck it.
            final int start = Math.max(0, currentPosition - CHECK_POSITION_SEARCH_DISTANCE);
            final int end = Math.min(currentPosition + CHECK_POSITION_SEARCH_DISTANCE, itemCount);

            boolean found = false;
            for (int searchPos = start; searchPos < end; searchPos++) {
                final long searchId = adapter.getItemId(searchPos);
                if (currentId == searchId) {
                    found = true;
                    mCheckedStates.put(searchPos, true);
                    mCheckedIdStates.setValueAt(checkedIndex, searchPos);
                    break;
                }
            }

            if (!found) {
                mCheckedIdStates.delete(currentId);
                mCheckedCount--;
                checkedIndex--;
            }
        } else {
            mCheckedStates.put(currentPosition, true);
        }
    }
}

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From source file:co.codecrunch.musicplayerlite.recyclerviewutils.ItemSelectionSupport.java

/**
 * Sets the checked state of the specified position. The is only valid if
 * the choice mode has been set to {@link ChoiceMode#SINGLE} or
 * {@link ChoiceMode#MULTIPLE}.//  ww  w  .j av  a  2  s.c o  m
 *
 * @param position The item whose checked state is to be checked
 * @param checked The new checked state for the item
 */
public void setItemChecked(int position, boolean checked) {
    if (mChoiceMode == ChoiceMode.NONE) {
        return;
    }

    final Adapter adapter = mRecyclerView.getAdapter();

    if (mChoiceMode == ChoiceMode.MULTIPLE) {
        boolean oldValue = mCheckedStates.get(position);
        mCheckedStates.put(position, checked);

        if (mCheckedIdStates != null && adapter.hasStableIds()) {
            if (checked) {
                mCheckedIdStates.put(adapter.getItemId(position), position);
            } else {
                mCheckedIdStates.delete(adapter.getItemId(position));
            }
        }

        if (oldValue != checked) {
            if (checked) {
                mCheckedCount++;
            } else {
                mCheckedCount--;
            }
        }
    } else {
        boolean updateIds = mCheckedIdStates != null && adapter.hasStableIds();

        // Clear all values if we're checking something, or unchecking the currently
        // selected item
        if (checked || isItemChecked(position)) {
            mCheckedStates.clear();

            if (updateIds) {
                mCheckedIdStates.clear();
            }
        }

        // This may end up selecting the checked we just cleared but this way
        // we ensure length of mCheckStates is 1, a fact getCheckedItemPosition relies on
        if (checked) {
            mCheckedStates.put(position, true);

            if (updateIds) {
                mCheckedIdStates.put(adapter.getItemId(position), position);
            }

            mCheckedCount = 1;
        } else if (mCheckedStates.size() == 0 || !mCheckedStates.valueAt(0)) {
            mCheckedCount = 0;
        }
    }

    updateOnScreenCheckedViews();
}

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