mohammedragabmohammedborik · February 26, 2018 09:22 · Jan 15, 2015 · Jan 15, 2015 · Jan 15, 2015
diff --git a/README.md b/README.md
@@ -40,4 +40,4 @@ Example:
         mRecyclerView.setAdapter(mSectionedAdapter);
 ```
 
-You can customize the section layout, changing the layout `section.xm`l and changing the code in the `SectionedGridRecyclerViewAdapter.SectionViewHolder` class and `SectionedGridRecyclerViewAdapter#onBindViewHolder` method.
+You can customize the section layout, changing the layout `section.xml` and changing the code in the `SectionedGridRecyclerViewAdapter.SectionViewHolder` class and `SectionedGridRecyclerViewAdapter#onBindViewHolder` method.
diff --git a/README.md b/README.md
@@ -2,7 +2,7 @@ You can use this class to realize a simple sectioned grid `RecyclerView.Adapter`
 
 ![Screen](http://3.bp.blogspot.com/-8cl5IxT3X7c/VLhOC8EWUiI/AAAAAAAAkMs/2V9K-EoPThc/s400/sectionedGridRecycler.png)  
 
-The `RecyclerView` have to use a `GridLayoutManager`.
+The `RecyclerView` has to use a `GridLayoutManager`.
 
 This is a porting of the class `SimpleSectionedListAdapter` provided by [Google](https://github.com/google/iosched/blob/master/android/src/main/java/com/google/samples/apps/iosched/ui/SimpleSectionedListAdapter.java)
 

diff --git a/README.md b/README.md
@@ -0,0 +1,43 @@
+You can use this class to realize a simple sectioned grid `RecyclerView.Adapter` without changing your code.
+
+![Screen](http://3.bp.blogspot.com/-8cl5IxT3X7c/VLhOC8EWUiI/AAAAAAAAkMs/2V9K-EoPThc/s400/sectionedGridRecycler.png)  
+
+The `RecyclerView` have to use a `GridLayoutManager`.
+
+This is a porting of the class `SimpleSectionedListAdapter` provided by [Google](https://github.com/google/iosched/blob/master/android/src/main/java/com/google/samples/apps/iosched/ui/SimpleSectionedListAdapter.java)
+
+If you are looking for a sectioned list `RecyclerView.Adapter` you can take a look [here](https://gist.github.com/gabrielemariotti/4c189fb1124df4556058)
+
+
+Example:
+```java
+         //Your RecyclerView
+        mRecyclerView = (RecyclerView) getActivity().findViewById(R.id.list);
+        mRecyclerView.setHasFixedSize(true);
+        mRecyclerView.setLayoutManager(new GridLayoutManager(getActivity(),4));
+
+        //Your RecyclerView.Adapter
+        mAdapter = new SimpleAdapter(getActivity());
+
+        //This is the code to provide a sectioned grid
+        List<SectionedGridRecyclerViewAdapter.Section> sections =
+                new ArrayList<SectionedGridRecyclerViewAdapter.Section>();
+
+        //Sections
+        sections.add(new SectionedGridRecyclerViewAdapter.Section(0,"Section 1"));
+        sections.add(new SectionedGridRecyclerViewAdapter.Section(5,"Section 2"));
+        sections.add(new SectionedGridRecyclerViewAdapter.Section(12,"Section 3"));
+        sections.add(new SectionedGridRecyclerViewAdapter.Section(14,"Section 4"));
+        sections.add(new SectionedGridRecyclerViewAdapter.Section(20,"Section 5"));
+
+        //Add your adapter to the sectionAdapter
+        SectionedGridRecyclerViewAdapter.Section[] dummy = new SectionedGridRecyclerViewAdapter.Section[sections.size()];
+        SectionedGridRecyclerViewAdapter mSectionedAdapter = new
+                SectionedGridRecyclerViewAdapter(getActivity(),R.layout.section,R.id.section_text,mRecyclerView,mAdapter);
+        mSectionedAdapter.setSections(sections.toArray(dummy));
+
+        //Apply this adapter to the RecyclerView
+        mRecyclerView.setAdapter(mSectionedAdapter);
+```
+
+You can customize the section layout, changing the layout `section.xm`l and changing the code in the `SectionedGridRecyclerViewAdapter.SectionViewHolder` class and `SectionedGridRecyclerViewAdapter#onBindViewHolder` method.
diff --git a/SectionedGridRecyclerViewAdapter.java b/SectionedGridRecyclerViewAdapter.java
@@ -0,0 +1,183 @@
+/**
+ * @author Gabriele Mariotti ([email protected])
+ */
+public class SectionedGridRecyclerViewAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
+
+    private final Context mContext;
+    private static final int SECTION_TYPE = 0;
+
+    private boolean mValid = true;
+    private int mSectionResourceId;
+    private int mTextResourceId;
+    private LayoutInflater mLayoutInflater;
+    private RecyclerView.Adapter mBaseAdapter;
+    private SparseArray<Section> mSections = new SparseArray<Section>();
+    private RecyclerView mRecyclerView;
+
+
+    public SectionedGridRecyclerViewAdapter(Context context, int sectionResourceId, int textResourceId,RecyclerView recyclerView,
+                                            RecyclerView.Adapter baseAdapter) {
+
+        mLayoutInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
+        mSectionResourceId = sectionResourceId;
+        mTextResourceId = textResourceId;
+        mBaseAdapter = baseAdapter;
+        mContext = context;
+        mRecyclerView = recyclerView;
+
+        mBaseAdapter.registerAdapterDataObserver(new RecyclerView.AdapterDataObserver() {
+            @Override
+            public void onChanged() {
+                mValid = mBaseAdapter.getItemCount()>0;
+                notifyDataSetChanged();
+            }
+
+            @Override
+            public void onItemRangeChanged(int positionStart, int itemCount) {
+                mValid = mBaseAdapter.getItemCount()>0;
+                notifyItemRangeChanged(positionStart, itemCount);
+            }
+
+            @Override
+            public void onItemRangeInserted(int positionStart, int itemCount) {
+                mValid = mBaseAdapter.getItemCount()>0;
+                notifyItemRangeInserted(positionStart, itemCount);
+            }
+
+            @Override
+            public void onItemRangeRemoved(int positionStart, int itemCount) {
+                mValid = mBaseAdapter.getItemCount()>0;
+                notifyItemRangeRemoved(positionStart, itemCount);
+            }
+        });
+
+        final GridLayoutManager layoutManager = (GridLayoutManager)(mRecyclerView.getLayoutManager());
+        layoutManager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
+            @Override
+            public int getSpanSize(int position) {
+                return (isSectionHeaderPosition(position))? layoutManager.getSpanCount() : 1 ;
+            }
+        });
+    }
+
+
+    public static class SectionViewHolder extends RecyclerView.ViewHolder {
+
+        public TextView title;
+
+        public SectionViewHolder(View view,int mTextResourceid) {
+            super(view);
+            title = (TextView) view.findViewById(mTextResourceid);
+        }
+    }
+
+    @Override
+    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int typeView) {
+        if (typeView == SECTION_TYPE) {
+            final View view = LayoutInflater.from(mContext).inflate(mSectionResourceId, parent, false);
+            return new SectionViewHolder(view,mTextResourceId);
+        }else{
+            return mBaseAdapter.onCreateViewHolder(parent, typeView -1);
+        }
+    }
+
+    @Override
+    public void onBindViewHolder(RecyclerView.ViewHolder sectionViewHolder, int position) {
+        if (isSectionHeaderPosition(position)) {
+            ((SectionViewHolder)sectionViewHolder).title.setText(mSections.get(position).title);
+        }else{
+            mBaseAdapter.onBindViewHolder(sectionViewHolder,sectionedPositionToPosition(position));
+        }
+
+    }
+
+    @Override
+    public int getItemViewType(int position) {
+        return isSectionHeaderPosition(position)
+                ? SECTION_TYPE
+                : mBaseAdapter.getItemViewType(sectionedPositionToPosition(position)) +1 ;
+    }
+
+
+    public static class Section {
+        int firstPosition;
+        int sectionedPosition;
+        CharSequence title;
+
+        public Section(int firstPosition, CharSequence title) {
+            this.firstPosition = firstPosition;
+            this.title = title;
+        }
+
+        public CharSequence getTitle() {
+            return title;
+        }
+    }
+
+
+    public void setSections(Section[] sections) {
+        mSections.clear();
+
+        Arrays.sort(sections, new Comparator<Section>() {
+            @Override
+            public int compare(Section o, Section o1) {
+                return (o.firstPosition == o1.firstPosition)
+                        ? 0
+                        : ((o.firstPosition < o1.firstPosition) ? -1 : 1);
+            }
+        });
+
+        int offset = 0; // offset positions for the headers we're adding
+        for (Section section : sections) {
+            section.sectionedPosition = section.firstPosition + offset;
+            mSections.append(section.sectionedPosition, section);
+            ++offset;
+        }
+
+        notifyDataSetChanged();
+    }
+
+    public int positionToSectionedPosition(int position) {
+        int offset = 0;
+        for (int i = 0; i < mSections.size(); i++) {
+            if (mSections.valueAt(i).firstPosition > position) {
+                break;
+            }
+            ++offset;
+        }
+        return position + offset;
+    }
+
+    public int sectionedPositionToPosition(int sectionedPosition) {
+        if (isSectionHeaderPosition(sectionedPosition)) {
+            return RecyclerView.NO_POSITION;
+        }
+
+        int offset = 0;
+        for (int i = 0; i < mSections.size(); i++) {
+            if (mSections.valueAt(i).sectionedPosition > sectionedPosition) {
+                break;
+            }
+            --offset;
+        }
+        return sectionedPosition + offset;
+    }
+
+    public boolean isSectionHeaderPosition(int position) {
+        return mSections.get(position) != null;
+    }
+
+
+    @Override
+    public long getItemId(int position) {
+        return isSectionHeaderPosition(position)
+                ? Integer.MAX_VALUE - mSections.indexOfKey(position)
+                : mBaseAdapter.getItemId(sectionedPositionToPosition(position));
+    }
+
+    @Override
+    public int getItemCount() {
+        return (mValid ? mBaseAdapter.getItemCount() + mSections.size() : 0);
+    }
+
+}
diff --git a/SimpleAdapter.java b/SimpleAdapter.java
@@ -0,0 +1,53 @@
+/**
+ * @author Gabriele Mariotti ([email protected])
+ */
+public class SimpleAdapter extends RecyclerView.Adapter<SimpleAdapter.SimpleViewHolder> {
+    private static final int COUNT = 100;
+
+    private final Context mContext;
+    private final List<Integer> mItems;
+    private int mCurrentItemId = 0;
+
+    public static class SimpleViewHolder extends RecyclerView.ViewHolder {
+        public final TextView title;
+
+        public SimpleViewHolder(View view) {
+            super(view);
+            title = (TextView) view.findViewById(R.id.title);
+        }
+    }
+
+    public SimpleAdapter(Context context) {
+        mContext = context;
+        mItems = new ArrayList<Integer>(COUNT);
+        for (int i = 0; i < COUNT; i++) {
+            addItem(i);
+        }
+    }
+
+    public SimpleViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
+        final View view = LayoutInflater.from(mContext).inflate(R.layout.item, parent, false);
+        return new SimpleViewHolder(view);
+    }
+
+    @Override
+    public void onBindViewHolder(SimpleViewHolder holder, final int position) {
+        holder.title.setText(mItems.get(position).toString());
+    }
+
+    public void addItem(int position) {
+        final int id = mCurrentItemId++;
+        mItems.add(position, id);
+        notifyItemInserted(position);
+    }
+
+    public void removeItem(int position) {
+        mItems.remove(position);
+        notifyItemRemoved(position);
+    }
+
+    @Override
+    public int getItemCount() {
+        return mItems.size();
+    }
+}
diff --git a/item.xml b/item.xml
@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<TextView xmlns:android="http://schemas.android.com/apk/res/android"
+          android:id="@+id/title"
+          android:layout_width="match_parent"
+          android:layout_height="130dp"
+          android:gravity="center"
+          android:layout_margin="4dp"
+          android:textColor="#999999"
+          android:textStyle="bold"
+          android:textSize="22sp"
+          android:background="@drawable/item_background"/>
diff --git a/section.xml b/section.xml
@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="utf-8"?>
+
+<TextView xmlns:android="http://schemas.android.com/apk/res/android"
+          android:layout_width="match_parent"
+          android:layout_height="48dp"
+          android:gravity="center_vertical"
+          android:paddingLeft="16dp"
+          android:singleLine="true"
+          android:textAllCaps="true"
+          android:background="#90CAF9"
+          android:textSize="16sp"
+          android:id="@+id/section_text"
+          android:textStyle="bold" />