Android/app/src/main/java/com/moiseum/wolnelektury/components/recycler/RecyclerAdapter.java

   1 package com.moiseum.wolnelektury.components.recycler;
   2
   3 import android.content.Context;
   4 import android.support.v7.widget.RecyclerView;
   5 import android.view.LayoutInflater;
   6 import android.view.View;
   7 import android.view.ViewGroup;
   8
   9 import com.moiseum.wolnelektury.connection.models.CategoryModel;
  10
  11 import java.util.Collections;
  12 import java.util.List;
  13
  14 /**
  15  * @author golonkos
  16  */
  17
  18 public abstract class RecyclerAdapter<T, VH extends ViewHolder> extends RecyclerView.Adapter<VH> {
  19
  20         /**
  21          * On click listener.
  22          */
  23         public interface OnItemClickListener<T> {
  24                 /**
  25                  * @param item clicked item
  26                  * @param view clicked view
  27                  */
  28                 void onItemClicked(T item, View view, int position);
  29         }
  30
  31         public enum Selection {
  32                 NONE, SINGLE
  33         }
  34
  35         private static final int NO_POSITION = -1;
  36
  37         private LayoutInflater layoutInflater;
  38         private OnItemClickListener<T> onItemClickListener;
  39
  40         private List<T> items = Collections.emptyList();
  41
  42         private T selectedItem;
  43         private int selectedItemPosition = NO_POSITION;
  44
  45         private Selection selection = Selection.NONE;
  46
  47         private View.OnClickListener onClickListener = new View.OnClickListener() {
  48                 @Override
  49                 public void onClick(View v) {
  50                         int position = (int) v.getTag();
  51                         T item = getItem(position);
  52                         onItemClicked(v, item, position);
  53                 }
  54         };
  55
  56         public RecyclerAdapter(Context context, Selection selection) {
  57                 layoutInflater = LayoutInflater.from(context);
  58                 this.selection = selection;
  59         }
  60
  61         protected void onItemClicked(View view, T item, int position) {
  62                 selectItemAndNotify(item, position);
  63                 if (onItemClickListener != null) {
  64                         onItemClickListener.onItemClicked(item, view, position);
  65                 }
  66         }
  67
  68         @Override
  69         public void onBindViewHolder(VH viewHolder, final int position) {
  70                 viewHolder.itemView.setTag(position);
  71                 viewHolder.itemView.setOnClickListener(onClickListener);
  72                 T item = getItem(position);
  73                 viewHolder.itemView.setSelected(isSelected(getItem(position)));
  74                 viewHolder.bind(item, isSelected(item));
  75         }
  76
  77         @Override
  78         public int getItemCount() {
  79                 return items.size();
  80         }
  81
  82
  83         /**
  84          * @param onItemClickListener item click listener
  85          */
  86         public void setOnItemClickListener(OnItemClickListener<T> onItemClickListener) {
  87                 this.onItemClickListener = onItemClickListener;
  88         }
  89
  90
  91         public OnItemClickListener<T> getOnItemClickListener() {
  92                 return onItemClickListener;
  93         }
  94
  95         public List<T> getItems() {
  96                 return items;
  97         }
  98
  99         /**
 100          * @param items new items
 101          */
 102         public void setItems(List<T> items) {
 103                 this.items = items;
 104                 notifyDataSetChanged();
 105         }
 106
 107         public void addItems(List<T> items) {
 108                 this.items.addAll(items);
 109                 notifyDataSetChanged();
 110         }
 111
 112         /**
 113          * @param position position of element to remove
 114          * @return removed item or null if element not found
 115          */
 116         public T removeItem(int position) {
 117                 if (position >= 0 && position < items.size()) {
 118                         T item = items.remove(position);
 119                         notifyItemRemoved(position);
 120                         notifyItemRangeChanged(position, items.size());
 121                         return item;
 122                 }
 123                 return null;
 124         }
 125
 126         public void clear() {
 127                 this.items.clear();
 128                 notifyDataSetChanged();
 129         }
 130
 131         protected void addItem(int position, T item) {
 132                 items.add(position, item);
 133         }
 134
 135         protected View inflate(int layoutResId, ViewGroup parent) {
 136                 return layoutInflater.inflate(layoutResId, parent, false);
 137         }
 138
 139         /**
 140          * @param position position of element
 141          * @return item from specific position
 142          */
 143         public T getItem(int position) {
 144                 return this.items.get(position);
 145         }
 146
 147         protected abstract String getItemId(T item);
 148
 149         private boolean isSelected(T item) {
 150                 return selectedItem != null && getItemId(selectedItem).contains(getItemId(item));
 151         }
 152
 153         public void selectItem(T item) {
 154                 int position = NO_POSITION;
 155                 for (int i = 0; i < items.size(); i++) {
 156                         if (getItemId(item).equals(getItemId(items.get(i)))) {
 157                                 position = i;
 158                                 break;
 159                         }
 160                 }
 161                 selectItemAndNotify(item, position);
 162         }
 163
 164         private void selectItemAndNotify(T item, int position) {
 165                 int selectedPositionToNotify = selectedItemPosition;
 166                 setSelectedItem(item, position);
 167
 168                 if (selectedPositionToNotify != NO_POSITION) {
 169                         notifyItemChanged(selectedPositionToNotify);
 170                 }
 171                 notifyItemChanged(position);
 172         }
 173
 174         private void setSelectedItem(T item, int position) {
 175                 switch (selection) {
 176                         case SINGLE:
 177                                 selectedItem = item;
 178                                 selectedItemPosition = position;
 179                                 break;
 180                         case NONE:
 181                                 break;
 182                 }
 183         }
 184
 185
 186 }
 187