Support predictive back from all apps to home

bug: b/238475505
Test: manual

Change-Id: Ibf4f7f41a26b044a538e2cd566d2297ed88f1b99
diff --git a/src/com/android/launcher3/LauncherState.java b/src/com/android/launcher3/LauncherState.java
index 5dddc6f..b9e4c17 100644
--- a/src/com/android/launcher3/LauncherState.java
+++ b/src/com/android/launcher3/LauncherState.java
@@ -34,6 +34,8 @@
 import android.graphics.Color;
 import android.view.animation.Interpolator;
 
+import androidx.annotation.FloatRange;
+
 import com.android.launcher3.statemanager.BaseState;
 import com.android.launcher3.statemanager.StateManager;
 import com.android.launcher3.states.HintState;
@@ -342,6 +344,27 @@
         }
     }
 
+    /**
+     * Find {@link StateManager} and target {@link LauncherState} to handle back progress in
+     * predictive back gesture.
+     */
+    public void onBackProgressed(
+            Launcher launcher, @FloatRange(from = 0.0, to = 1.0) float backProgress) {
+        StateManager<LauncherState> lsm = launcher.getStateManager();
+        LauncherState toState = lsm.getLastState();
+        lsm.onBackProgressed(toState, backProgress);
+    }
+
+    /**
+     * Find {@link StateManager} and target {@link LauncherState} to handle backProgress in
+     * predictive back gesture.
+     */
+    public void onBackCancelled(Launcher launcher) {
+        StateManager<LauncherState> lsm = launcher.getStateManager();
+        LauncherState toState = lsm.getLastState();
+        lsm.onBackCancelled(toState);
+    }
+
     public static abstract class PageAlphaProvider {
 
         public final Interpolator interpolator;