Create DiffRVRendererAdapter to use RecyclerView's DiffUtil (#36)

* Update support library in order to add the DiffUtil, also update gradle version

* Add DiffRVRendererAdapter class to take advantage of the DiffUtil in our RendererAdapters

* Implement the Diff

* Create a renderer with the hability of remove items from the list in order to show the Diff animation

* Fix checkstyle and change android sdk version on travis

* Fix lint

* Remove DiffRVRendererAdapter and move update to RVRendererAdapter then fix the sample project

* Rename the class RemoveItemCallback to RemovableVideoRenderer.Listener

* Rename the method removeItem in RemoveItemCallback to onRemoveButtonTapped

* Add a documentation comment for our new diffUpdate method

* Override hashCode in order to fix the checkstyle

.travis.yml

@@ -3,12 +3,11 @@ language: android
 android:
   components:
     - tools
-    - build-tools-23.0.2
-    - android-23
+    - build-tools-25.0.2
+    - android-25
     - extra-android-support
     - extra-google-m2repository
     - extra-android-m2repository
 
-script: 
+script:
   - ./gradlew checkstyle build
-

build.gradle

@@ -3,7 +3,7 @@ buildscript {
     jcenter()
   }
   dependencies {
-    classpath 'com.android.tools.build:gradle:1.3.0'
+    classpath 'com.android.tools.build:gradle:2.3.1'
   }
 }
 

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
-#Sun Jan 03 17:21:12 CET 2016
+#Fri Apr 07 09:29:52 CEST 2017
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-2.9-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-3.3-all.zip

renderers/build.gradle

@@ -2,12 +2,12 @@ apply plugin: 'com.android.library'
 apply from: 'https://raw.github.com/chrisbanes/gradle-mvn-push/master/gradle-mvn-push.gradle'
 
 android {
-  compileSdkVersion 23
-  buildToolsVersion "23.0.2"
+  compileSdkVersion 25
+  buildToolsVersion '25.0.2'
 
   defaultConfig {
     minSdkVersion 10
-    targetSdkVersion 23
+    targetSdkVersion 25
     versionCode 1
     versionName "1.0"
   }
@@ -16,11 +16,14 @@ android {
       minifyEnabled false
     }
   }
+  lintOptions {
+    abortOnError false
+  }
 }
 
 dependencies {
   compile fileTree(dir: 'libs', include: ['*.jar'])
-  compile 'com.android.support:recyclerview-v7:23.1.1'
+  compile 'com.android.support:recyclerview-v7:25.3.1'
   testCompile 'junit:junit:4.12'
   testCompile "org.mockito:mockito-core:1.9.5"
   testCompile 'org.robolectric:robolectric:2.4'

renderers/src/main/java/com/pedrogomez/renderers/RVRendererAdapter.java

@@ -15,11 +15,13 @@
  */
 package com.pedrogomez.renderers;
 
+import android.support.v7.util.DiffUtil;
 import android.support.v7.widget.RecyclerView;
 import android.view.LayoutInflater;
 import android.view.ViewGroup;
 import com.pedrogomez.renderers.exception.NullRendererBuiltException;
 import java.util.Collection;
+import java.util.List;
 
 /**
  * RecyclerView.Adapter extension created to work RendererBuilders and Renderer instances. Other
@@ -187,4 +189,70 @@ protected AdapteeCollection<T> getCollection() {
   protected void updateRendererExtraValues(T content, Renderer<T> renderer, int position) {
 
   }
+
+  /**
+   * Provides a ready to use diff update for our adapter based on the implementation of the
+   * standard equals method from Object
+   *
+   * @param newList to refresh our content
+   */
+  public void diffUpdate(List<T> newList) {
+    if (getCollection().size() == 0) {
+      this.addAll(newList);
+      notifyDataSetChanged();
+    } else {
+      DiffCallbacks diffCallbacks = new DiffCallbacks(newList);
+      DiffUtil.DiffResult diffResult = DiffUtil.calculateDiff(diffCallbacks);
+
+      this.clear();
+      this.addAll(newList);
+      diffResult.dispatchUpdatesTo(this);
+    }
+  }
+
+  private class DiffCallbacks extends DiffUtil.Callback {
+
+    private final List<T> newList;
+
+    private int oldItemPosition;
+
+    private boolean deep;
+
+    DiffCallbacks(List<T> newList) {
+      this.newList = newList;
+    }
+
+    @Override public int getOldListSize() {
+      return collection.size();
+    }
+
+    @Override public int getNewListSize() {
+      return newList.size();
+    }
+
+    @Override public boolean areItemsTheSame(int oldItemPosition, int newItemPosition) {
+      this.deep = false;
+      this.oldItemPosition = oldItemPosition;
+      return equals(newList.get(newItemPosition));
+    }
+
+    @Override public boolean areContentsTheSame(int oldItemPosition, int newItemPosition) {
+      this.deep = true;
+      this.oldItemPosition = oldItemPosition;
+      return equals(newList.get(newItemPosition));
+    }
+
+    @Override public boolean equals(Object newItem) {
+      Object current = collection.get(oldItemPosition);
+      if (deep) {
+        return newItem.equals(current);
+      } else {
+        return newItem.getClass().equals(current.getClass());
+      }
+    }
+
+    @Override public int hashCode() {
+      return super.hashCode();
+    }
+  }
 }

sample/build.gradle

@@ -1,13 +1,13 @@
 apply plugin: 'com.android.application'
 
 android {
-  compileSdkVersion 23
-  buildToolsVersion "23.0.2"
+  compileSdkVersion 25
+  buildToolsVersion '25.0.2'
 
   defaultConfig {
     applicationId "com.github.pedrovgs.renderers.sample"
     minSdkVersion 14
-    targetSdkVersion 23
+    targetSdkVersion 25
     versionCode 1
     versionName "1.0"
   }
@@ -16,11 +16,14 @@ android {
       minifyEnabled false
     }
   }
+  lintOptions {
+    abortOnError false
+  }
 }
 
 dependencies {
   compile fileTree(include: ['*.jar'], dir: 'libs')
-  compile 'com.android.support:appcompat-v7:23.1.1'
+  compile 'com.android.support:appcompat-v7:25.3.1'
   compile 'com.jakewharton:butterknife:7.0.1'
   compile 'com.squareup.picasso:picasso:2.5.2'
   compile project(':renderers')

sample/src/main/java/com/pedrogomez/renderers/sample/model/Video.java

@@ -67,4 +67,21 @@ public boolean isLive() {
   public void setLive(boolean live) {
     this.live = live;
   }
+
+  @Override public boolean equals(Object obj) {
+    if (obj instanceof Video) {
+      Video other = (Video) obj;
+      return title.equals(other.title)
+              && thumbnail.equals(other.thumbnail)
+              && favorite == other.favorite
+              && liked == other.liked
+              && live == other.live;
+    } else {
+      return false;
+    }
+  }
+
+  @Override public int hashCode() {
+    return super.hashCode();
+  }
 }

sample/src/main/java/com/pedrogomez/renderers/sample/ui/RecyclerViewActivity.java

@@ -29,6 +29,10 @@
 import com.pedrogomez.renderers.sample.ui.renderers.FavoriteVideoRenderer;
 import com.pedrogomez.renderers.sample.ui.renderers.LikeVideoRenderer;
 import com.pedrogomez.renderers.sample.ui.renderers.LiveVideoRenderer;
+import com.pedrogomez.renderers.sample.ui.renderers.RemovableVideoRenderer;
+
+import java.util.ArrayList;
+import java.util.Collection;
 import java.util.LinkedList;
 import java.util.List;
 
@@ -58,11 +62,17 @@ public class RecyclerViewActivity extends BaseActivity {
   private void initAdapter() {
     RandomVideoCollectionGenerator randomVideoCollectionGenerator =
         new RandomVideoCollectionGenerator();
-    AdapteeCollection<Video> videoCollection =
+    final AdapteeCollection<Video> videoCollection =
         randomVideoCollectionGenerator.generateListAdapteeVideoCollection(VIDEO_COUNT);
     RendererBuilder<Video> rendererBuilder = new RendererBuilder<Video>()
-        .withPrototype(new LikeVideoRenderer())
-        .bind(Video.class, LikeVideoRenderer.class);
+        .withPrototype(new RemovableVideoRenderer(new RemovableVideoRenderer.Listener() {
+          @Override public void onRemoveButtonTapped(Video video) {
+            ArrayList<Video> clonedList = new ArrayList<>((Collection<? extends Video>) videoCollection);
+            clonedList.remove(video);
+            adapter.diffUpdate(clonedList);
+          }
+        }))
+        .bind(Video.class, RemovableVideoRenderer.class);
 
     adapter = new RVRendererAdapter<Video>(rendererBuilder, videoCollection);
   }

sample/src/main/java/com/pedrogomez/renderers/sample/ui/renderers/RemovableVideoRenderer.java

@@ -0,0 +1,38 @@
+package com.pedrogomez.renderers.sample.ui.renderers;
+
+import com.pedrogomez.renderers.sample.R;
+import com.pedrogomez.renderers.sample.model.Video;
+
+import butterknife.OnClick;
+
+public class RemovableVideoRenderer extends VideoRenderer {
+
+    private Listener removeItemListener;
+
+    public interface Listener {
+
+        void onRemoveButtonTapped(Video video);
+    }
+
+    public RemovableVideoRenderer(Listener removeItemListener) {
+        this.removeItemListener = removeItemListener;
+    }
+
+    @Override protected void renderLabel() {
+        String deleteLabel = getContext().getString(R.string.delete_label);
+        getLabel().setText(deleteLabel);
+    }
+
+    @Override protected void renderMarker(Video video) {
+
+    }
+
+    @OnClick(R.id.tv_label) void clickOnDelete() {
+        removeItemListener.onRemoveButtonTapped(getContent());
+    }
+
+    @OnClick(R.id.iv_marker) void clickOnLike() {
+        getContent().setLiked(!getContent().isLiked());
+        renderMarker(getContent());
+    }
+}

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

@@ -21,6 +21,7 @@
   <string name="like_label">Like</string>
   <string name="dislike_label">Dislike</string>
   <string name="live_label">Live</string>
+  <string name="delete_label">Delete me</string>
   <string name="open_lv_sample">Open ListView sample</string>
   <string name="open_rv_sample">Open RecyclerView sample</string>