Changed how to use and extend the DragItemAdapter

You should no longer override removeItem, addItem, changeItemPosition
and getPositionForItemId(). This is now done by the super class.
Instead you need to set the item list by calling setItemList() with
a List<T> type.

If you want you can still override the methods if needed.

README.md

@@ -17,7 +17,7 @@ Youtube demo video<br>
     }
 
     dependencies {
-        compile 'com.github.woxthebox:draglistview:1.0.9'
+        compile 'com.github.woxthebox:draglistview:1.1.0'
     }
 
 ## Usage
@@ -96,39 +96,15 @@ List and Grid layouts are used as example in the sample project.
         mBoardView.addColumnList(listAdapter, header, false);
 
 
-  For your adapter, extend DragItemAdapter and implement the methods below.
+  For your adapter, extend DragItemAdapter and call setItemList() with a List<T> type. setItemList() can be called anytime later to change the list.
   You also need to provide a boolean to the super constructor to decide if you want the drag to happen on long press or directly when touching the item.
 
-    private ArrayList<Pair<Long, String>> mItemList;  
-
-    @Override
-    public Object removeItem(int pos) {
-        Object item = mItemList.remove(pos);
-        notifyItemRemoved(pos);
-        return item;
-    }
-
-    @Override
-    public void addItem(int pos, Object item) {
-        mItemList.add(pos, (Pair<Long, String>) item);
-        notifyItemInserted(pos);
-    }
-
-    @Override
-    public int getPositionForItemId(long id) {
-        for (int i = 0; i < mItemList.size(); i++) {
-            if (id == mItemList.get(i).first) {
-                return i;
-            }
-        }
-        return -1;
-    }
-
-    @Override
-    public void changeItemPosition(int fromPos, int toPos) {
-        Pair<Long, String> pair = mItemList.remove(fromPos);
-        mItemList.add(toPos, pair);
-        notifyDataSetChanged();
+    public ItemAdapter(ArrayList<Pair<Long, String>> list, int layoutId, int grabHandleId, boolean dragOnLongPress) {
+        super(dragOnLongPress);
+        mLayoutId = layoutId;
+        mGrabHandleId = grabHandleId;
+        setHasStableIds(true);
+        setItemList(list);
     }
 
   Your ViewHolder should extend DragItemAdapter.ViewHolder and you must supply an id of the view that should respond to a drag.

library/gradle.properties

@@ -1,4 +1,4 @@
-VERSION_NAME=1.0.9
+VERSION_NAME=1.1.0
 VERSION_CODE=10
 GROUP=com.github.woxthebox
 

library/src/main/java/com/woxthebox/draglistview/DragItemAdapter.java

@@ -20,7 +20,9 @@
 import android.view.MotionEvent;
 import android.view.View;
 
-public abstract class DragItemAdapter<VH extends DragItemAdapter.ViewHolder> extends RecyclerView.Adapter<VH> {
+import java.util.List;
+
+public abstract class DragItemAdapter<T, VH extends DragItemAdapter.ViewHolder> extends RecyclerView.Adapter<VH> {
 
     interface DragStartedListener {
         void onDragStarted(View itemView, long itemId);
@@ -30,17 +32,58 @@ interface DragStartedListener {
     private long mDragItemId = -1;
     private boolean mDragOnLongPress;
     private boolean mDragEnabled = true;
+    protected List<T> mItemList;
 
-    public abstract Object removeItem(int pos);
+    public DragItemAdapter(boolean dragOnLongPress) {
+        mDragOnLongPress = dragOnLongPress;
+    }
 
-    public abstract void addItem(int pos, Object item);
+    public void setItemList(List<T> itemList) {
+        mItemList = itemList;
+        notifyDataSetChanged();
+    }
 
-    public abstract int getPositionForItemId(long id);
+    public List<T> getItemList() {
+        return mItemList;
+    }
 
-    public abstract void changeItemPosition(int fromPos, int toPos);
+    public Object removeItem(int pos) {
+        if (mItemList != null && mItemList.size() > pos) {
+            Object item = mItemList.remove(pos);
+            notifyItemRemoved(pos);
+            return item;
+        }
+        return null;
+    }
 
-    public DragItemAdapter(boolean dragOnLongPress) {
-        mDragOnLongPress = dragOnLongPress;
+    public void addItem(int pos, T item) {
+        if (mItemList != null && mItemList.size() > pos) {
+            mItemList.add(pos, item);
+            notifyItemInserted(pos);
+        }
+    }
+
+    public void changeItemPosition(int fromPos, int toPos) {
+        if (mItemList != null && mItemList.size() > fromPos && mItemList.size() > toPos) {
+            T item = mItemList.remove(fromPos);
+            mItemList.add(toPos, item);
+            notifyDataSetChanged();
+        }
+    }
+
+    public int getPositionForItemId(long id) {
+        int count = getItemCount();
+        for (int i = 0; i < count; i++) {
+            if (id == getItemId(i)) {
+                return i;
+            }
+        }
+        return -1;
+    }
+
+    @Override
+    public int getItemCount() {
+        return mItemList == null ? 0 : mItemList.size();
     }
 
     @Override

sample/src/main/java/com/woxthebox/draglistview/sample/ItemAdapter.java

@@ -27,18 +27,17 @@
 
 import java.util.ArrayList;
 
-public class ItemAdapter extends DragItemAdapter<ItemAdapter.ViewHolder> {
+public class ItemAdapter extends DragItemAdapter<Pair<Long, String>, ItemAdapter.ViewHolder> {
 
-    private ArrayList<Pair<Long, String>> mItemList;
     private int mLayoutId;
     private int mGrabHandleId;
 
     public ItemAdapter(ArrayList<Pair<Long, String>> list, int layoutId, int grabHandleId, boolean dragOnLongPress) {
         super(dragOnLongPress);
-        mItemList = list;
         mLayoutId = layoutId;
         mGrabHandleId = grabHandleId;
         setHasStableIds(true);
+        setItemList(list);
     }
 
     @Override
@@ -47,36 +46,6 @@ public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
         return new ViewHolder(view);
     }
 
-    @Override
-    public Object removeItem(int pos) {
-        Object item = mItemList.remove(pos);
-        notifyItemRemoved(pos);
-        return item;
-    }
-
-    @Override
-    public void addItem(int pos, Object item) {
-        mItemList.add(pos, (Pair<Long, String>) item);
-        notifyItemInserted(pos);
-    }
-
-    @Override
-    public void changeItemPosition(int fromPos, int toPos) {
-        Pair<Long, String> pair = mItemList.remove(fromPos);
-        mItemList.add(toPos, pair);
-        notifyDataSetChanged();
-    }
-
-    @Override
-    public int getPositionForItemId(long id) {
-        for (int i = 0; i < mItemList.size(); i++) {
-            if (id == mItemList.get(i).first) {
-                return i;
-            }
-        }
-        return -1;
-    }
-
     @Override
     public void onBindViewHolder(ViewHolder holder, int position) {
         super.onBindViewHolder(holder, position);
@@ -85,17 +54,12 @@ public void onBindViewHolder(ViewHolder holder, int position) {
         holder.itemView.setTag(text);
     }
 
-    @Override
-    public int getItemCount() {
-        return mItemList != null ? mItemList.size() : 0;
-    }
-
     @Override
     public long getItemId(int position) {
         return mItemList.get(position).first;
     }
 
-    public class ViewHolder extends DragItemAdapter.ViewHolder {
+    public class ViewHolder extends DragItemAdapter<Pair<Long, String>, ItemAdapter.ViewHolder>.ViewHolder {
         public TextView mText;
 
         public ViewHolder(final View itemView) {