package com.thoughtbot.expandablerecyclerview;
import android.app.Activity;
import android.os.Bundle;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.RecyclerView.ViewHolder;
import android.view.ViewGroup;
import com.thoughtbot.expandablerecyclerview.listeners.ExpandCollapseListener;
import com.thoughtbot.expandablerecyclerview.listeners.GroupExpandCollapseListener;
import com.thoughtbot.expandablerecyclerview.listeners.OnGroupClickListener;
import com.thoughtbot.expandablerecyclerview.models.ExpandableGroup;
import com.thoughtbot.expandablerecyclerview.models.ExpandableList;
import com.thoughtbot.expandablerecyclerview.models.ExpandableListPosition;
import com.thoughtbot.expandablerecyclerview.viewholders.ChildViewHolder;
import com.thoughtbot.expandablerecyclerview.viewholders.GroupViewHolder;
import java.util.List;
public abstract class ExpandableRecyclerViewAdapter<GVH extends GroupViewHolder, CVH extends ChildViewHolder>
extends RecyclerView.Adapter implements ExpandCollapseListener, OnGroupClickListener {
private static final String EXPAND_STATE_MAP = "expandable_recyclerview_adapter_expand_state_map";
protected ExpandableList expandableList;
private ExpandCollapseController expandCollapseController;
private OnGroupClickListener groupClickListener;
private GroupExpandCollapseListener expandCollapseListener;
public ExpandableRecyclerViewAdapter(List<? extends ExpandableGroup> groups) {
this.expandableList = new ExpandableList(groups);
this.expandCollapseController = new ExpandCollapseController(expandableList, this);
}
/**
* Implementation of Adapter.onCreateViewHolder(ViewGroup, int)
* that determines if the list item is a group or a child and calls through
* to the appropriate implementation of either {@link #onCreateGroupViewHolder(ViewGroup, int)}
* or {@link #onCreateChildViewHolder(ViewGroup, int)}}.
*
* @param parent The {@link ViewGroup} into which the new {@link android.view.View}
* will be added after it is bound to an adapter position.
* @param viewType The view type of the new {@code android.view.View}.
* @return Either a new {@link GroupViewHolder} or a new {@link ChildViewHolder}
* that holds a {@code android.view.View} of the given view type.
*/
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
switch (viewType) {
case ExpandableListPosition.GROUP:
GVH gvh = onCreateGroupViewHolder(parent, viewType);
gvh.setOnGroupClickListener(this);
return gvh;
case ExpandableListPosition.CHILD:
CVH cvh = onCreateChildViewHolder(parent, viewType);
return cvh;
default:
throw new IllegalArgumentException("viewType is not valid");
}
}
/**
* Implementation of Adapter.onBindViewHolder(RecyclerView.ViewHolder, int)
* that determines if the list item is a group or a child and calls through
* to the appropriate implementation of either {@link #onBindGroupViewHolder(GroupViewHolder,
* int,
* ExpandableGroup)}
* or {@link #onBindChildViewHolder(ChildViewHolder, int, ExpandableGroup, int)}.
*
* @param holder Either the GroupViewHolder or the ChildViewHolder to bind data to
* @param position The flat position (or index in the list of {@link
* ExpandableList#getVisibleItemCount()} in the list at which to bind
*/
@Override
public void onBindViewHolder(ViewHolder holder, int position) {
ExpandableListPosition listPos = expandableList.getUnflattenedPosition(position);
ExpandableGroup group = expandableList.getExpandableGroup(listPos);
switch (listPos.type) {
case ExpandableListPosition.GROUP:
onBindGroupViewHolder((GVH) holder, position, group);
if (isGroupExpanded(group)) {
((GVH) holder).expand();
} else {
((GVH) holder).collapse();
}
break;
case ExpandableListPosition.CHILD:
onBindChildViewHolder((CVH) holder, position, group, listPos.childPos);
break;
}
}
/**
* @return the number of group and child objects currently expanded
* @see ExpandableList#getVisibleItemCount()
*/
@Override
public int getItemCount() {
return expandableList.getVisibleItemCount();
}
/**
* Gets the view type of the item at the given position.
*
* @param position The flat position in the list to get the view type of
* @return {@value ExpandableListPosition#CHILD} or {@value ExpandableListPosition#GROUP}
* @throws RuntimeException if the item at the given position in the list is not found
*/
@Override
public int getItemViewType(int position) {
return expandableList.getUnflattenedPosition(position).type;
}
/**
* Called when a group is expanded
*
* @param positionStart the flat position of the first child in the {@link ExpandableGroup}
* @param itemCount the total number of children in the {@link ExpandableGroup}
*/
@Override
public void onGroupExpanded(int positionStart, int itemCount) {
//update header
int headerPosition = positionStart - 1;
notifyItemChanged(headerPosition);
// only insert if there items to insert
if (itemCount > 0) {
notifyItemRangeInserted(positionStart, itemCount);
if (expandCollapseListener != null) {
int groupIndex = expandableList.getUnflattenedPosition(positionStart).groupPos;
expandCollapseListener.onGroupExpanded(getGroups().get(groupIndex));
}
}
}
/**
* Called when a group is collapsed
*
* @param positionStart the flat position of the first child in the {@link ExpandableGroup}
* @param itemCount the total number of children in the {@link ExpandableGroup}
*/
@Override
public void onGroupCollapsed(int positionStart, int itemCount) {
//update header
int headerPosition = positionStart - 1;
notifyItemChanged(headerPosition);
// only remote if there items to remove
if (itemCount > 0) {
notifyItemRangeRemoved(positionStart, itemCount);
if (expandCollapseListener != null) {
//minus one to return the position of the header, not first child
int groupIndex = expandableList.getUnflattenedPosition(positionStart - 1).groupPos;
expandCollapseListener.onGroupCollapsed(getGroups().get(groupIndex));
}
}
}
/**
* Triggered by a click on a {@link GroupViewHolder}
*
* @param flatPos the flat position of the {@link GroupViewHolder} that was clicked
* @return false if click expanded group, true if click collapsed group
*/
@Override
public boolean onGroupClick(int flatPos) {
if (groupClickListener != null) {
groupClickListener.onGroupClick(flatPos);
}
return expandCollapseController.toggleGroup(flatPos);
}
/**
* @param flatPos The flat list position of the group
* @return true if the group is expanded, *after* the toggle, false if the group is now collapsed
*/
public boolean toggleGroup(int flatPos) {
return expandCollapseController.toggleGroup(flatPos);
}
/**
* @param group the {@link ExpandableGroup} being toggled
* @return true if the group is expanded, *after* the toggle, false if the group is now collapsed
*/
public boolean toggleGroup(ExpandableGroup group) {
return expandCollapseController.toggleGroup(group);
}
/**
* @param flatPos the flattened position of an item in the list
* @return true if {@code group} is expanded, false if it is collapsed
*/
public boolean isGroupExpanded(int flatPos) {
return expandCollapseController.isGroupExpanded(flatPos);
}
/**
* @param group the {@link ExpandableGroup} being checked for its collapsed state
* @return true if {@code group} is expanded, false if it is collapsed
*/
public boolean isGroupExpanded(ExpandableGroup group) {
return expandCollapseController.isGroupExpanded(group);
}
/**
* Stores the expanded state map across state loss.
* <p>
* Should be called from whatever {@link Activity} that hosts the RecyclerView that {@link
* ExpandableRecyclerViewAdapter} is attached to.
* <p>
* This will make sure to add the expanded state map as an extra to the
* instance state bundle to be used in {@link #onRestoreInstanceState(Bundle)}.
*
* @param savedInstanceState The {@code Bundle} into which to store the
* expanded state map
*/
public void onSaveInstanceState(Bundle savedInstanceState) {
savedInstanceState.putBooleanArray(EXPAND_STATE_MAP, expandableList.expandedGroupIndexes);
}
/**
* Fetches the expandable state map from the saved instance state {@link Bundle}
* and restores the expanded states of all of the list items.
* <p>
* Should be called from {@link Activity#onRestoreInstanceState(Bundle)} in
* the {@link Activity} that hosts the RecyclerView that this
* {@link ExpandableRecyclerViewAdapter} is attached to.
* <p>
*
* @param savedInstanceState The {@code Bundle} from which the expanded
* state map is loaded
*/
public void onRestoreInstanceState(Bundle savedInstanceState) {
if (savedInstanceState == null || !savedInstanceState.containsKey(EXPAND_STATE_MAP)) {
return;
}
expandableList.expandedGroupIndexes = savedInstanceState.getBooleanArray(EXPAND_STATE_MAP);
notifyDataSetChanged();
}
public void setOnGroupClickListener(OnGroupClickListener listener) {
groupClickListener = listener;
}
public void setOnGroupExpandCollapseListener(GroupExpandCollapseListener listener) {
expandCollapseListener = listener;
}
/**
* The full list of {@link ExpandableGroup} backing this RecyclerView
*
* @return the list of {@link ExpandableGroup} that this object was instantiated with
*/
public List<? extends ExpandableGroup> getGroups() {
return expandableList.groups;
}
/**
* Called from {@link #onCreateViewHolder(ViewGroup, int)} when the list item created is a group
*
* @param viewType an int returned by {@link ExpandableRecyclerViewAdapter#getItemViewType(int)}
* @param parent the {@link ViewGroup} in the list for which a {@link GVH} is being created
* @return A {@link GVH} corresponding to the group list item with the {@code ViewGroup} parent
*/
public abstract GVH onCreateGroupViewHolder(ViewGroup parent, int viewType);
/**
* Called from {@link #onCreateViewHolder(ViewGroup, int)} when the list item created is a child
*
* @param viewType an int returned by {@link ExpandableRecyclerViewAdapter#getItemViewType(int)}
* @param parent the {@link ViewGroup} in the list for which a {@link CVH} is being created
* @return A {@link CVH} corresponding to child list item with the {@code ViewGroup} parent
*/
public abstract CVH onCreateChildViewHolder(ViewGroup parent, int viewType);
/**
* Called from onBindViewHolder(RecyclerView.ViewHolder, int) when the list item
* bound to is a child.
* <p>
* Bind data to the {@link CVH} here.
*
* @param holder The {@code CVH} to bind data to
* @param flatPosition the flat position (raw index) in the list at which to bind the child
* @param group The {@link ExpandableGroup} that the the child list item belongs to
* @param childIndex the index of this child within it's {@link ExpandableGroup}
*/
public abstract void onBindChildViewHolder(CVH holder, int flatPosition, ExpandableGroup group,
int childIndex);
/**
* Called from onBindViewHolder(RecyclerView.ViewHolder, int) when the list item bound to is a
* group
* <p>
* Bind data to the {@link GVH} here.
*
* @param holder The {@code GVH} to bind data to
* @param flatPosition the flat position (raw index) in the list at which to bind the group
* @param group The {@link ExpandableGroup} to be used to bind data to this {@link GVH}
*/
public abstract void onBindGroupViewHolder(GVH holder, int flatPosition, ExpandableGroup group);
}
