Use WindowManagerProxy.getRotation to determine if rotation has changed

- Follow-up of http://ag/19559863 as Config diff on windowConfiguration does not work on 3P Launcher, so diff WindowManagerProxy.getRotation instead
- Also centralized Configuration diff logic into StatefulActivity

Bug: 240730723
Test: manual on 90/180 degree rotation in Launcher, RecentsActivity and 3P Launcher
Change-Id: Ib368ed5d749841a6873a03e2644608ff68885922

src/com/android/launcher3/statemanager/StatefulActivity.java

@@ -15,10 +15,14 @@
  */
 package com.android.launcher3.statemanager;
 
+import static android.content.pm.ActivityInfo.CONFIG_ORIENTATION;
+import static android.content.pm.ActivityInfo.CONFIG_SCREEN_SIZE;
+
 import static com.android.launcher3.LauncherState.FLAG_CLOSE_POPUPS;
 import static com.android.launcher3.LauncherState.FLAG_NON_INTERACTIVE;
 
 import android.content.res.Configuration;
+import android.os.Bundle;
 import android.os.Handler;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -31,6 +35,7 @@ import com.android.launcher3.LauncherRootView;
 import com.android.launcher3.Utilities;
 import com.android.launcher3.statemanager.StateManager.AtomicAnimationFactory;
 import com.android.launcher3.statemanager.StateManager.StateHandler;
+import com.android.launcher3.util.window.WindowManagerProxy;
 import com.android.launcher3.views.BaseDragLayer;
 
 import java.util.List;
@@ -48,6 +53,17 @@ public abstract class StatefulActivity<STATE_TYPE extends BaseState<STATE_TYPE>>
 
     private LauncherRootView mRootView;
 
+    protected Configuration mOldConfig;
+    private int mOldRotation;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+
+        mOldConfig = new Configuration(getResources().getConfiguration());
+        mOldRotation = WindowManagerProxy.INSTANCE.get(this).getRotation(this);
+    }
+
     /**
      * Create handlers to control the property changes for this activity
      */
@@ -198,5 +214,21 @@ public abstract class StatefulActivity<STATE_TYPE extends BaseState<STATE_TYPE>>
      * Handles configuration change when system calls {@link #onConfigurationChanged}, or on other
      * situations that configuration might change.
      */
-    public void handleConfigurationChanged(Configuration newConfig) {}
+    public void handleConfigurationChanged(Configuration newConfig) {
+        int diff = newConfig.diff(mOldConfig);
+        int rotation = WindowManagerProxy.INSTANCE.get(this).getRotation(this);
+        if ((diff & (CONFIG_ORIENTATION | CONFIG_SCREEN_SIZE)) != 0
+                || rotation != mOldRotation) {
+            onHandleConfigurationChanged();
+        }
+
+        mOldConfig.setTo(newConfig);
+        mOldRotation = rotation;
+    }
+
+    /**
+     * Logic for when device configuration changes (rotation, screen size change, multi-window,
+     * etc.)
+     */
+    protected abstract void onHandleConfigurationChanged();
 }