Include canvas in ItemTouchHelper swipe callback

build.gradle

@@ -2,7 +2,7 @@
 buildscript {
 
   ext.KOTLIN_VERSION = "1.1.4-3"
-  ext.ANDROID_PLUGIN_VERSION = "3.0.0-beta4"
+  ext.ANDROID_PLUGIN_VERSION = "3.0.0-beta5"
 
   repositories {
     google()

epoxy-adapter/src/main/java/com/airbnb/epoxy/EpoxyModelTouchCallback.java

@@ -228,11 +228,12 @@ protected void onChildDraw(Canvas c, RecyclerView recyclerView, EpoxyViewHolder
     float clampedProgress = Math.max(-1f, Math.min(1f, swipeProgress));
 
     //noinspection unchecked
-    onSwipeProgressChanged((T) model, itemView, clampedProgress);
+    onSwipeProgressChanged((T) model, itemView, clampedProgress, c);
   }
 
   @Override
-  public void onSwipeProgressChanged(T model, View itemView, float swipeProgress) {
+  public void onSwipeProgressChanged(T model, View itemView, float swipeProgress,
+      Canvas canvas) {
 
   }
 }

epoxy-adapter/src/main/java/com/airbnb/epoxy/EpoxySwipeCallback.java

@@ -1,5 +1,6 @@
 package com.airbnb.epoxy;
 
+import android.graphics.Canvas;
 import android.support.v7.widget.helper.ItemTouchHelper;
 import android.view.View;
 
@@ -30,10 +31,13 @@ public interface EpoxySwipeCallback<T extends EpoxyModel> extends BaseEpoxyTouch
    * @param itemView      The view that is being swiped
    * @param swipeProgress A float from -1 to 1 representing the percentage that the view has been
    *                      swiped relative to its width. This will be positive if the view is being
-   *                      swiped to the right and negative if it is swiped to the left. For example,
-   *                      if the view has been swiped halfway to the right this will be 0.5
+   *                      swiped to the right and negative if it is swiped to the left. For
+   *                      example,
+   * @param canvas        The canvas on which RecyclerView is drawing its children. You can draw to
+   *                      this to support custom swipe animations.
    */
-  void onSwipeProgressChanged(T model, View itemView, float swipeProgress);
+  void onSwipeProgressChanged(T model, View itemView, float swipeProgress,
+      Canvas canvas);
 
   /**
    * Called when the user has released their touch on the view. If the displacement passed the swipe

epoxy-adapter/src/main/java/com/airbnb/epoxy/EpoxyTouchHelper.java

@@ -1,5 +1,6 @@
 package com.airbnb.epoxy;
 
+import android.graphics.Canvas;
 import android.support.v7.widget.RecyclerView;
 import android.support.v7.widget.helper.ItemTouchHelper;
 import android.view.View;
@@ -413,8 +414,9 @@ public void onSwipeStarted(U model, View itemView, int adapterPosition) {
             }
 
             @Override
-            public void onSwipeProgressChanged(U model, View itemView, float swipeProgress) {
-              callbacks.onSwipeProgressChanged(model, itemView, swipeProgress);
+            public void onSwipeProgressChanged(U model, View itemView, float swipeProgress,
+                Canvas canvas) {
+              callbacks.onSwipeProgressChanged(model, itemView, swipeProgress, canvas);
             }
 
             @Override
@@ -448,7 +450,8 @@ public void onSwipeStarted(T model, View itemView, int adapterPosition) {
     }
 
     @Override
-    public void onSwipeProgressChanged(T model, View itemView, float swipeProgress) {
+    public void onSwipeProgressChanged(T model, View itemView, float swipeProgress,
+        Canvas canvas) {
 
     }