Add haptic feedback to Launcher recent apps scrolling

Add light LOW_TICK effects when the scrolling on RecentsView
snaps to a page, and a stronger TICK effect when the edges
absorb the scroll (by scrolling fast towards one of the edges).

Fix: 182382085
Test: manual
Change-Id: Ifb917ae499f73607707773f9870eb39cd6fe16ef

src/com/android/launcher3/PagedView.java

@@ -479,9 +479,11 @@ public abstract class PagedView<T extends View & PageIndicator> extends ViewGrou
                 if (newPos < mMinScroll && oldPos >= mMinScroll) {
                     mEdgeGlowLeft.onAbsorb((int) mScroller.getCurrVelocity());
                     mScroller.abortAnimation();
+                    onEdgeAbsorbingScroll();
                 } else if (newPos > mMaxScroll && oldPos <= mMaxScroll) {
                     mEdgeGlowRight.onAbsorb((int) mScroller.getCurrVelocity());
                     mScroller.abortAnimation();
+                    onEdgeAbsorbingScroll();
                 }
             }
 
@@ -1332,6 +1334,13 @@ public abstract class PagedView<T extends View & PageIndicator> extends ViewGrou
 
     protected void onNotSnappingToPageInFreeScroll() { }
 
+    /**
+     * Called when the view edges absorb part of the scroll. Subclasses can override this
+     * to provide custom behavior during animation.
+     */
+    protected void onEdgeAbsorbingScroll() {
+    }
+
     protected boolean shouldFlingForVelocity(int velocity) {
         float threshold = mAllowEasyFling ? mEasyFlingThresholdVelocity : mFlingThresholdVelocity;
         return Math.abs(velocity) > threshold;

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

@@ -21,15 +21,19 @@ import static android.provider.Settings.System.HAPTIC_FEEDBACK_ENABLED;
 import static com.android.launcher3.util.Executors.MAIN_EXECUTOR;
 import static com.android.launcher3.util.Executors.UI_HELPER_EXECUTOR;
 
+import android.annotation.SuppressLint;
 import android.annotation.TargetApi;
 import android.content.ContentResolver;
 import android.content.Context;
 import android.database.ContentObserver;
+import android.media.AudioAttributes;
 import android.os.Build;
 import android.os.VibrationEffect;
 import android.os.Vibrator;
 import android.provider.Settings;
 
+import com.android.launcher3.Utilities;
+
 /**
  * Wrapper around {@link Vibrator} to easily perform haptic feedback where necessary.
  */
@@ -39,6 +43,11 @@ public class VibratorWrapper {
     public static final MainThreadInitializedObject<VibratorWrapper> INSTANCE =
             new MainThreadInitializedObject<>(VibratorWrapper::new);
 
+    public static final AudioAttributes VIBRATION_ATTRS = new AudioAttributes.Builder()
+            .setUsage(AudioAttributes.USAGE_ASSISTANCE_SONIFICATION)
+            .setContentType(AudioAttributes.CONTENT_TYPE_SONIFICATION)
+            .build();
+
     public static final VibrationEffect EFFECT_CLICK =
             createPredefined(VibrationEffect.EFFECT_CLICK);
 
@@ -81,4 +90,24 @@ public class VibratorWrapper {
             UI_HELPER_EXECUTOR.execute(() -> mVibrator.vibrate(vibrationEffect));
         }
     }
+
+    /**
+     * Vibrates with a single primitive, if supported, or use a fallback effect instead. This only
+     * vibrates if haptic feedback is available and enabled.
+     */
+    @SuppressLint("NewApi")
+    public void vibrate(int primitiveId, float primitiveScale, VibrationEffect fallbackEffect) {
+        if (mHasVibrator && mIsHapticFeedbackEnabled) {
+            UI_HELPER_EXECUTOR.execute(() -> {
+                if (Utilities.ATLEAST_R && primitiveId >= 0
+                        && mVibrator.areAllPrimitivesSupported(primitiveId)) {
+                    mVibrator.vibrate(VibrationEffect.startComposition()
+                            .addPrimitive(primitiveId, primitiveScale)
+                            .compose(), VIBRATION_ATTRS);
+                } else {
+                    mVibrator.vibrate(fallbackEffect, VIBRATION_ATTRS);
+                }
+            });
+        }
+    }
 }