Fix jump in animation for hotseat while re-arranging icons

While re-arranging icons the hotseat remains in scale 1.0f, while the workspace reduces it's scale (as defined by SpringLoadedState.java). Previously, the code to aggregate animations was assuming hotseat and workspace always had the same scale.

MultiScaleProperty.get() was being used to set the starting value of the animation. Previously, it was returning the last aggregated value. However, this value was correct only for the workspace, but not for the hotseat. Returning the current view scale makes it always correct.

Bug: 220271046
Test: Dragged icons from hotseat to workspace, and verified animation didn't jump
Change-Id: Ic01776c1d8e3967624626ed7c44d194a06295790

src/com/android/launcher3/util/MultiScalePropertyFactory.java

@@ -18,6 +18,8 @@ package com.android.launcher3.util;
 
 import android.util.ArrayMap;
 import android.util.FloatProperty;
+import android.util.Log;
+import android.view.View;
 
 import com.android.launcher3.Utilities;
 
@@ -33,8 +35,10 @@ import com.android.launcher3.Utilities;
  *
  * @param <T> Type where to apply the property.
  */
-public abstract class MultiScalePropertyFactory<T> {
+public class MultiScalePropertyFactory<T extends View> {
 
+    private static final boolean DEBUG = false;
+    private static final String TAG = "MultiScaleProperty";
     private final String mName;
     private final ArrayMap<Integer, MultiScaleProperty> mProperties =
             new ArrayMap<Integer, MultiScaleProperty>();
@@ -56,7 +60,6 @@ public abstract class MultiScalePropertyFactory<T> {
                 (k) -> new MultiScaleProperty(index, mName + "_" + index));
     }
 
-
     /**
      * Each [setValue] will be aggregated with the other properties values created by the
      * corresponding factory.
@@ -91,11 +94,22 @@ public abstract class MultiScalePropertyFactory<T> {
             mLastAggregatedValue = Utilities.boundToRange(multValue, minValue, maxValue);
             mValue = newValue;
             apply(obj, mLastAggregatedValue);
+
+            if (DEBUG) {
+                Log.d(TAG, "name=" + mName
+                        + " newValue=" + newValue + " mInx=" + mInx
+                        + " aggregated=" + mLastAggregatedValue + " others= " + mProperties);
+            }
         }
 
         @Override
-        public Float get(T t) {
-            return mLastAggregatedValue;
+        public Float get(T view) {
+            // The scale of the view should match mLastAggregatedValue. Still, if it has been
+            // changed without using this property, it can differ. As this get method is usually
+            // used to set the starting point on an animation, this would result in some jumps
+            // when the view scale is different than the last aggregated value. To stay on the
+            // safe side, let's return the real view scale.
+            return view.getScaleX();
         }
 
         @Override
@@ -104,6 +118,8 @@ public abstract class MultiScalePropertyFactory<T> {
         }
     }
 
-    /** Applies value to object after setValue method is called. */
-    protected abstract void apply(T obj, float value);
+    protected void apply(View view, float value) {
+        view.setScaleX(value);
+        view.setScaleY(value);
+    }
 }