Fix #7. Add DiffUtil compatibility.

Author: RobbeSneyders

README.md

@@ -51,7 +51,7 @@ Add this library as dependency to your project:
 
 ```groovy
 dependencies {
-        compile 'com.github.RobbeSneyders:Modular2Recycler:v1.0.1'
+        compile 'com.github.RobbeSneyders:Modular2Recycler:v1.0.2'
 }
 ```
 

app/build.gradle

@@ -1,13 +1,13 @@
 apply plugin: 'com.android.application'
 
 android {
-    compileSdkVersion 24
-    buildToolsVersion "24.0.1"
+    compileSdkVersion 25
+    buildToolsVersion "25.0.2"
 
     defaultConfig {
         applicationId "com.cuttingedge.pokeapp"
         minSdkVersion 11
-        targetSdkVersion 24
+        targetSdkVersion 25
         versionCode 1
         versionName "1.0"
     }
@@ -22,8 +22,8 @@ android {
 dependencies {
     compile fileTree(dir: 'libs', include: ['*.jar'])
     testCompile 'junit:junit:4.12'
-    compile 'com.android.support:support-v4:24.1.1'
-    compile 'com.android.support:appcompat-v7:24.1.1'
-    compile 'com.android.support:design:24.1.1'
+    compile 'com.android.support:support-v4:25.1.1'
+    compile 'com.android.support:appcompat-v7:25.1.1'
+    compile 'com.android.support:design:25.1.1'
     compile project(path: ':library')
 }

app/src/main/java/com/cuttingedge/PokeApp/Backpack/BackpackActivity.java

@@ -4,6 +4,7 @@
 import android.os.Bundle;
 import android.support.design.widget.FloatingActionButton;
 import android.support.v4.content.res.ResourcesCompat;
+import android.support.v7.util.DiffUtil;
 import android.support.v7.widget.LinearLayoutManager;
 import android.support.v7.widget.RecyclerView;
 import android.support.v7.widget.RecyclerView.ViewHolder;
@@ -86,9 +87,11 @@ private void toggleAlphabetic() {
             isAlphabetic = true;
         }
 
-        List<ModularItem> list = addHeaders(pokemonList);
-        // swaps the data of the adapter
-        adapter.swap(list);
+        List<ModularItem> newList = addHeaders(pokemonList);
+        List<ModularItem> oldList = adapter.getList();
+        DiffUtil.DiffResult result = DiffUtil.calculateDiff(new DiffCallback(oldList, newList));
+        adapter.swap(newList, false);
+        result.dispatchUpdatesTo(adapter);
     }
 
 

app/src/main/java/com/cuttingedge/PokeApp/Backpack/DiffCallback.java

@@ -0,0 +1,43 @@
+package com.cuttingedge.PokeApp.Backpack;
+
+import android.support.v7.util.DiffUtil;
+
+import com.cuttingedge.adapter2recycler.ModularItem;
+
+import java.util.List;
+
+/**
+ * Created by Robbe Sneyders.
+ *
+ * Class that calculates the difference between two lists.
+ * Demonstrate the use of DiffUtil
+ */
+public class DiffCallback extends DiffUtil.Callback {
+    private List<ModularItem> mOldList;
+    private List<ModularItem> mNewList;
+
+    public DiffCallback(List<ModularItem> oldList, List<ModularItem> newList) {
+        this.mOldList = oldList;
+        this.mNewList = newList;
+    }
+
+    @Override
+    public int getOldListSize() {
+        return mOldList != null ? mOldList.size() : 0;
+    }
+
+    @Override
+    public int getNewListSize() {
+        return mNewList != null ? mNewList.size() : 0;
+    }
+
+    @Override
+    public boolean areItemsTheSame(int oldItemPosition, int newItemPosition) {
+        return mNewList.get(newItemPosition) == mOldList.get(oldItemPosition);
+    }
+
+    @Override
+    public boolean areContentsTheSame(int oldItemPosition, int newItemPosition) {
+        return mNewList.get(newItemPosition).equals(mOldList.get(oldItemPosition));
+    }
+}

library/build.gradle

@@ -1,12 +1,12 @@
 apply plugin: 'com.android.library'
 
 android {
-    compileSdkVersion 24
-    buildToolsVersion "24.0.1"
+    compileSdkVersion 25
+    buildToolsVersion "25.0.2"
 
     defaultConfig {
         minSdkVersion 11
-        targetSdkVersion 24
+        targetSdkVersion 25
         versionCode 1
         versionName "1.0"
     }
@@ -21,7 +21,7 @@ android {
 dependencies {
     compile fileTree(dir: 'libs', include: ['*.jar'])
     testCompile 'junit:junit:4.12'
-    compile 'com.android.support:support-v4:24.1.1'
-    compile 'com.android.support:appcompat-v7:24.1.1'
-    compile 'com.android.support:design:24.1.1'
+    compile 'com.android.support:support-v4:25.1.1'
+    compile 'com.android.support:appcompat-v7:25.1.1'
+    compile 'com.android.support:design:25.1.1'
 }

library/src/main/java/com/cuttingedge/adapter2recycler/Adapter/ModularAdapter.java

@@ -103,17 +103,30 @@ public void removeItems(List<I> items) {
 
     /**
      * Swap whole list at once
+     *
      * @param newList new list
      */
     public void swap(List<I> newList){
+        swap(newList, true);
+    }
+
+    /**
+     * Swap whole list at once
+     *
+     * @param newList new list
+     * @param notify true if method should notify adapter of changes, false otherwise (for example
+     *               when using DiffUtils)
+     */
+    public void swap(List<I> newList, boolean notify){
         if (list != null) {
             list.clear();
             list.addAll(newList);
         }
         else {
             list = newList;
         }
-        notifyDataSetChanged();
+        if (notify)
+            notifyDataSetChanged();
     }