/**
* 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}.
*
* @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();
}
@Override
boolean performItemClick(RecyclerView parent, View view, int position, long id) {
final Adapter adapter = mRecyclerView.getAdapter();
boolean checkedStateChanged = false;
if (mChoiceMode == ChoiceMode.MULTIPLE) {
boolean checked = !mCheckedStates.get(position, false);
mCheckedStates.put(position, checked);
if (mCheckedIdStates != null && adapter.hasStableIds()) {
if (checked) {
mCheckedIdStates.put(adapter.getItemId(position), position);
} else {
mCheckedIdStates.delete(adapter.getItemId(position));
}
}
if (checked) {
mCheckedCount++;
} else {
mCheckedCount--;
}
checkedStateChanged = true;
} else if (mChoiceMode == ChoiceMode.SINGLE) {
boolean checked = !mCheckedStates.get(position, false);
if (checked) {
mCheckedStates.clear();
mCheckedStates.put(position, true);
if (mCheckedIdStates != null && adapter.hasStableIds()) {
mCheckedIdStates.clear();
mCheckedIdStates.put(adapter.getItemId(position), position);
}
mCheckedCount = 1;
} else if (mCheckedStates.size() == 0 || !mCheckedStates.valueAt(0)) {
mCheckedCount = 0;
}
checkedStateChanged = true;
}
if (checkedStateChanged) {
updateOnScreenCheckedViews();
}
return false;
}
public void onAdapterDataChanged() {
final Adapter adapter = mRecyclerView.getAdapter();
if (mChoiceMode == ChoiceMode.NONE || adapter == null || !adapter.hasStableIds()) {
return;
}
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);
}
}
}