Add SectionAdapterListUpdateCallback. Update example 8 with example o…

…f usage.

app/src/main/java/io/github/luizgrp/sectionedrecyclerviewadapter/demo/example8/Example8Fragment.java

@@ -5,13 +5,18 @@
 import android.view.View;
 import android.view.ViewGroup;
 
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
 import java.util.Random;
 
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.fragment.app.Fragment;
+import androidx.recyclerview.widget.DiffUtil;
 import androidx.recyclerview.widget.GridLayoutManager;
 import androidx.recyclerview.widget.RecyclerView;
+import io.github.luizgrp.sectionedrecyclerviewadapter.SectionAdapterListUpdateCallback;
 import io.github.luizgrp.sectionedrecyclerviewadapter.Section;
 import io.github.luizgrp.sectionedrecyclerviewadapter.SectionAdapter;
 import io.github.luizgrp.sectionedrecyclerviewadapter.SectionedRecyclerViewAdapter;
@@ -108,6 +113,21 @@ public void onHeaderClearButtonClicked(@NonNull final NameSection section) {
         }
     }
 
+    @Override
+    public void onHeaderShuffleButtonClicked(@NonNull final NameSection section) {
+        final SectionAdapterListUpdateCallback adapterListUpdateCallback = new SectionAdapterListUpdateCallback(sectionedAdapter.getAdapterForSection(section));
+        final List<Person> oldList = section.getList();
+        final List<Person> newList = new ArrayList<>(oldList);
+        Collections.shuffle(newList);
+
+        final DiffUtil.DiffResult diffResult = DiffUtil.calculateDiff(new PersonListDiffCallback(oldList, newList));
+
+        section.clear();
+        section.addAll(newList);
+
+        diffResult.dispatchUpdatesTo(adapterListUpdateCallback);
+    }
+
     @Override
     public void onHeaderRemoveButtonClicked(@NonNull final NameSection section) {
         final int sectionItemsTotal = section.getSectionItemsTotal();

app/src/main/java/io/github/luizgrp/sectionedrecyclerviewadapter/demo/example8/HeaderViewHolder.java

@@ -13,6 +13,7 @@ class HeaderViewHolder extends RecyclerView.ViewHolder {
     final TextView tvTitle;
     final Button btnAdd;
     final Button btnClear;
+    final Button btnShuffle;
     final Button btnRemove;
     final Button btnStateLoaded;
     final Button btnStateLoading;
@@ -25,6 +26,7 @@ class HeaderViewHolder extends RecyclerView.ViewHolder {
         tvTitle = view.findViewById(R.id.tvTitle);
         btnAdd = view.findViewById(R.id.btnAdd);
         btnClear = view.findViewById(R.id.btnClear);
+        btnShuffle = view.findViewById(R.id.btnShuffle);
         btnRemove = view.findViewById(R.id.btnRemove);
         btnStateLoaded = view.findViewById(R.id.btnStateLoaded);
         btnStateLoading = view.findViewById(R.id.btnStateLoading);

app/src/main/java/io/github/luizgrp/sectionedrecyclerviewadapter/demo/example8/NameSection.java

@@ -72,12 +72,17 @@ public void onBindHeaderViewHolder(RecyclerView.ViewHolder holder) {
 
         headerHolder.btnClear.setOnClickListener(v -> clickListener.onHeaderClearButtonClicked(this));
 
+        headerHolder.btnShuffle.setOnClickListener(v -> clickListener.onHeaderShuffleButtonClicked(this));
+
         headerHolder.btnRemove.setOnClickListener(view ->
                 clickListener.onHeaderRemoveButtonClicked(this));
 
         headerHolder.btnStateLoaded.setOnClickListener(v -> clickListener.onHeaderLoadedButtonClicked(this));
+
         headerHolder.btnStateLoading.setOnClickListener(v -> clickListener.onHeaderLoadingButtonClicked(this));
+
         headerHolder.btnStateFailed.setOnClickListener(v -> clickListener.onHeaderFailedButtonClicked(this));
+
         headerHolder.btnStateEmpty.setOnClickListener(v -> clickListener.onHeaderEmptyButtonClicked(this));
     }
 
@@ -96,10 +101,18 @@ public RecyclerView.ViewHolder getEmptyViewHolder(final View view) {
         return new EmptyViewHolder(view);
     }
 
+    @NonNull List<Person> getList() {
+        return list;
+    }
+
     void add(final int position, @NonNull final Person person) {
         list.add(position, person);
     }
 
+    void addAll(@NonNull final List<Person> newList) {
+        list.addAll(newList);
+    }
+
     void remove(final int position) {
         list.remove(position);
     }
@@ -116,6 +129,8 @@ interface ClickListener {
 
         void onHeaderClearButtonClicked(@NonNull final NameSection section);
 
+        void onHeaderShuffleButtonClicked(@NonNull final NameSection section);
+
         void onHeaderRemoveButtonClicked(@NonNull final NameSection section);
 
         void onHeaderLoadedButtonClicked(@NonNull final NameSection section);

app/src/main/java/io/github/luizgrp/sectionedrecyclerviewadapter/demo/example8/PersonListDiffCallback.java

@@ -0,0 +1,36 @@
+package io.github.luizgrp.sectionedrecyclerviewadapter.demo.example8;
+
+import java.util.List;
+
+import androidx.recyclerview.widget.DiffUtil;
+
+public class PersonListDiffCallback extends DiffUtil.Callback {
+
+    private final List<Person> oldList;
+    private final List<Person> newList;
+
+    PersonListDiffCallback(final List<Person> oldList, final List<Person> newList) {
+        this.oldList = oldList;
+        this.newList = newList;
+    }
+
+    @Override
+    public int getOldListSize() {
+        return oldList != null ? oldList.size() : 0;
+    }
+
+    @Override
+    public int getNewListSize() {
+        return newList != null ? newList.size() : 0;
+    }
+
+    @Override
+    public boolean areItemsTheSame(final int oldItemPosition, final int newItemPosition) {
+        return newList.get(newItemPosition).id.equals(oldList.get(oldItemPosition).id);
+    }
+
+    @Override
+    public boolean areContentsTheSame(final int oldItemPosition, final int newItemPosition) {
+        return newList.get(newItemPosition).equals(oldList.get(oldItemPosition));
+    }
+}

app/src/main/res/layout/section_ex8_header.xml

@@ -50,6 +50,20 @@
             android:textColor="@color/white"
             android:textStyle="bold" />
 
+        <Button
+            android:id="@+id/btnShuffle"
+            style="?android:attr/buttonBarButtonStyle"
+            android:layout_width="wrap_content"
+            android:layout_height="30dp"
+            android:layout_marginStart="15dp"
+            android:layout_marginLeft="15dp"
+            android:background="@drawable/selector_btn"
+            android:paddingLeft="10dp"
+            android:paddingRight="10dp"
+            android:text="@string/shuffle"
+            android:textColor="@color/white"
+            android:textStyle="bold" />
+
         <Button
             android:id="@+id/btnRemove"
             style="?android:attr/buttonBarButtonStyle"

app/src/main/res/values/strings.xml

@@ -36,11 +36,12 @@
     <string name="more">MORE</string>
     <string name="see_more">See more..</string>
     <string name="failed_load">Failed to load, tap to try again.</string>
-    <string name="empty_list">This list is empty.</string>
+    <string name="empty_list">This section is empty.</string>
 
     <string name="add">ADD</string>
     <string name="clear">CLEAR</string>
     <string name="remove">REMOVE</string>
+    <string name="shuffle">SHUFFLE</string>
     <string name="loaded">LOADED</string>
     <string name="loading">LOADING</string>
     <string name="failed">FAILED</string>

library/src/main/java/io/github/luizgrp/sectionedrecyclerviewadapter/SectionAdapterListUpdateCallback.java

@@ -0,0 +1,40 @@
+package io.github.luizgrp.sectionedrecyclerviewadapter;
+
+import androidx.annotation.Nullable;
+import androidx.recyclerview.widget.DiffUtil;
+import androidx.recyclerview.widget.ListUpdateCallback;
+
+/**
+ * ListUpdateCallback that dispatches update events to the given {@link SectionAdapter}.
+ *
+ * @see DiffUtil.DiffResult#dispatchUpdatesTo(ListUpdateCallback)
+ */
+public class SectionAdapterListUpdateCallback implements ListUpdateCallback {
+
+    @SuppressWarnings("PMD.BeanMembersShouldSerialize")
+    private final SectionAdapter sectionAdapter;
+
+    public SectionAdapterListUpdateCallback(final SectionAdapter sectionAdapter) {
+        this.sectionAdapter = sectionAdapter;
+    }
+
+    @Override
+    public void onInserted(final int position, final int count) {
+        sectionAdapter.notifyItemRangeInserted(position, count);
+    }
+
+    @Override
+    public void onRemoved(final int position, final int count) {
+        sectionAdapter.notifyItemRangeRemoved(position, count);
+    }
+
+    @Override
+    public void onMoved(final int fromPosition, final int toPosition) {
+        sectionAdapter.notifyItemMoved(fromPosition, toPosition);
+    }
+
+    @Override
+    public void onChanged(final int position, final int count, @Nullable final Object payload) {
+        sectionAdapter.notifyItemRangeChanged(position, count, payload);
+    }
+}

library/src/test/java/io/github/luizgrp/sectionedrecyclerviewadapter/SectionAdapterListUpdateCallbackTest.java

@@ -0,0 +1,76 @@
+package io.github.luizgrp.sectionedrecyclerviewadapter;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+import static org.mockito.Mockito.verify;
+
+public class SectionAdapterListUpdateCallbackTest {
+
+    @Mock
+    private SectionAdapter sectionAdapter;
+
+    private SectionAdapterListUpdateCallback sectionAdapterListUpdateCallback;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+
+        sectionAdapterListUpdateCallback = new SectionAdapterListUpdateCallback(sectionAdapter);
+    }
+
+    @Test
+    public void givenSectionAdapter_whenOnInserted_thenNotifyItemRangeInsertedIsCalled() {
+        // Given
+        final int position = 3;
+        final int count = 9;
+
+        // When
+        sectionAdapterListUpdateCallback.onInserted(position, count);
+
+        // Then
+        verify(sectionAdapter).notifyItemRangeInserted(position, count);
+    }
+
+    @Test
+    public void givenSectionAdapter_whenOnRemoved_thenNotifyItemRangeRemovedIsCalled() {
+        // Given
+        final int position = 3;
+        final int count = 9;
+
+        // When
+        sectionAdapterListUpdateCallback.onRemoved(position, count);
+
+        // Then
+        verify(sectionAdapter).notifyItemRangeRemoved(position, count);
+    }
+
+    @Test
+    public void givenSectionAdapter_whenOnMoved_thenNotifyItemMovedIsCalled() {
+        // Given
+        final int fromPosition = 3;
+        final int toPosition = 9;
+
+        // When
+        sectionAdapterListUpdateCallback.onMoved(fromPosition, toPosition);
+
+        // Then
+        verify(sectionAdapter).notifyItemMoved(fromPosition, toPosition);
+    }
+
+    @Test
+    public void givenSectionAdapter_whenOnChanged_thenNotifyItemRangeChangedIsCalled() {
+        // Given
+        final int position = 3;
+        final int count = 9;
+        final Object payload = new Object();
+
+        // When
+        sectionAdapterListUpdateCallback.onChanged(position, count, payload);
+
+        // Then
+        verify(sectionAdapter).notifyItemRangeChanged(position, count, payload);
+    }
+}