[PK Setting] add keyboard review under keyboard selection page

Demo video as attached in bug.
Add new image view for keyboard layout review.
Reuse NewKeyboardLayoutPickerController under
NewKeyboardLayoutPickerFragment when get update for keyboard layout, get
preview image from inputManager and set to the view.

This feature will be guided with keyboard_layout_preview_flag, if the
flag is off, preview image from InputManager will be null.

Bug: 305588594
Test: Verified on device
Change-Id: Ic6f8e469d3cf7114dab6935304706ad42bf83608

res/layout/keyboard_layout_picker.xml

@@ -20,6 +20,13 @@
     android:id="@+id/keyboard_layout_picker_container"
     android:orientation="vertical">
 
+    <ImageView
+        android:id="@+id/keyboard_layout_preview"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:adjustViewBounds="true"
+        android:scaleType="fitCenter"/>
+
     <FrameLayout
         android:id="@+id/keyboard_layout_title"
         android:layout_width="match_parent"

src/com/android/settings/SettingsPreferenceFragment.java

@@ -479,7 +479,10 @@ public abstract class SettingsPreferenceFragment extends InstrumentedPreferenceF
                 mDialogFragment.dismiss();
                 mDialogFragment = null;
             }
-            getListView().clearOnScrollListeners();
+            RecyclerView view = getListView();
+            if (view != null) {
+                view.clearOnScrollListeners();
+            }
         }
         super.onDetach();
     }

src/com/android/settings/inputmethod/NewKeyboardLayoutPickerContent.java

@@ -27,6 +27,20 @@ import com.android.settings.dashboard.DashboardFragment;
 public class NewKeyboardLayoutPickerContent extends DashboardFragment {
 
     private static final String TAG = "KeyboardLayoutPicker";
+    private NewKeyboardLayoutPickerController mNewKeyboardLayoutPickerController;
+    private ControllerUpdateCallback mControllerUpdateCallback;
+
+    public interface ControllerUpdateCallback {
+        /**
+         * Called when mNewKeyBoardLayoutPickerController been initialized.
+         */
+        void onControllerUpdated(NewKeyboardLayoutPickerController
+                newKeyboardLayoutPickerController);
+    }
+
+    public void setControllerUpdateCallback(ControllerUpdateCallback controllerUpdateCallback) {
+        this.mControllerUpdateCallback = controllerUpdateCallback;
+    }
 
     @Override
     public void onAttach(Context context) {
@@ -40,7 +54,11 @@ public class NewKeyboardLayoutPickerContent extends DashboardFragment {
             getActivity().finish();
             return;
         }
-        use(NewKeyboardLayoutPickerController.class).initialize(this);
+        mNewKeyboardLayoutPickerController = use(NewKeyboardLayoutPickerController.class);
+        mNewKeyboardLayoutPickerController.initialize(this);
+        if (mControllerUpdateCallback != null) {
+            mControllerUpdateCallback.onControllerUpdated(mNewKeyboardLayoutPickerController);
+        }
     }
 
     @Override
@@ -56,4 +74,8 @@ public class NewKeyboardLayoutPickerContent extends DashboardFragment {
     protected int getPreferenceScreenResId() {
         return R.xml.new_keyboard_layout_picker_fragment;
     }
+
+    public NewKeyboardLayoutPickerController getController() {
+        return mNewKeyboardLayoutPickerController;
+    }
 }

src/com/android/settings/inputmethod/NewKeyboardLayoutPickerController.java

@@ -59,6 +59,7 @@ public class NewKeyboardLayoutPickerController extends BasePreferenceController
     private String mFinalSelectedLayout;
     private String mLayout;
     private MetricsFeatureProvider mMetricsFeatureProvider;
+    private KeyboardLayoutSelectedCallback mKeyboardLayoutSelectedCallback;
 
     public NewKeyboardLayoutPickerController(Context context, String key) {
         super(context, key);
@@ -100,7 +101,7 @@ public class NewKeyboardLayoutPickerController extends BasePreferenceController
 
     @Override
     public void onStop() {
-        if (!mLayout.equals(mFinalSelectedLayout)) {
+        if (mLayout != null && !mLayout.equals(mFinalSelectedLayout)) {
             String change = "From:" + mLayout + ", to:" + mFinalSelectedLayout;
             mMetricsFeatureProvider.action(
                     mContext, SettingsEnums.ACTION_PK_LAYOUT_CHANGED, change);
@@ -121,6 +122,14 @@ public class NewKeyboardLayoutPickerController extends BasePreferenceController
         return AVAILABLE;
     }
 
+    /**
+     * Registers {@link KeyboardLayoutSelectedCallback} and get updated.
+     */
+    public void registerKeyboardSelectedCallback(KeyboardLayoutSelectedCallback
+            keyboardLayoutSelectedCallback) {
+        this.mKeyboardLayoutSelectedCallback = keyboardLayoutSelectedCallback;
+    }
+
     @Override
     public boolean handlePreferenceTreeClick(Preference preference) {
         if (!(preference instanceof TickButtonPreference)) {
@@ -128,6 +137,9 @@ public class NewKeyboardLayoutPickerController extends BasePreferenceController
         }
 
         final TickButtonPreference pref = (TickButtonPreference) preference;
+        if (mKeyboardLayoutSelectedCallback != null && mPreferenceMap.containsKey(preference)) {
+            mKeyboardLayoutSelectedCallback.onSelected(mPreferenceMap.get(preference));
+        }
         pref.setSelected(true);
         if (mPreviousSelection != null && !mPreviousSelection.equals(preference.getKey())) {
             TickButtonPreference preSelectedPref = mScreen.findPreference(mPreviousSelection);
@@ -166,6 +178,9 @@ public class NewKeyboardLayoutPickerController extends BasePreferenceController
             pref.setTitle(layout.getLabel());
 
             if (mLayout.equals(layout.getLabel())) {
+                if (mKeyboardLayoutSelectedCallback != null) {
+                    mKeyboardLayoutSelectedCallback.onSelected(layout);
+                }
                 pref.setSelected(true);
                 mPreviousSelection = layout.getDescriptor();
             }
@@ -200,4 +215,11 @@ public class NewKeyboardLayoutPickerController extends BasePreferenceController
         }
         return label;
     }
+
+    public interface KeyboardLayoutSelectedCallback {
+        /**
+         * Called when KeyboardLayout been selected.
+         */
+        void onSelected(KeyboardLayout keyboardLayout);
+    }
 }

src/com/android/settings/inputmethod/NewKeyboardLayoutPickerFragment.java

@@ -16,35 +16,75 @@
 
 package com.android.settings.inputmethod;
 
+import static android.view.View.GONE;
+import static android.view.View.VISIBLE;
+
+import android.graphics.drawable.Drawable;
+import android.hardware.input.InputManager;
+import android.hardware.input.KeyboardLayout;
 import android.os.Bundle;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
+import android.widget.ImageView;
 
 import androidx.fragment.app.Fragment;
 
 import com.android.settings.R;
 
+//TODO: b/316243168 - [Physical Keyboard Setting] Refactor NewKeyboardLayoutPickerFragment
 public class NewKeyboardLayoutPickerFragment extends Fragment {
+    private static final int DEFAULT_KEYBOARD_PREVIEW_WIDTH = 1630;
+    private static final int DEFAULT_KEYBOARD_PREVIEW_HEIGHT = 540;
+
+    private ImageView mKeyboardLayoutPreview;
+    private InputManager mInputManager;
+    private final NewKeyboardLayoutPickerController.KeyboardLayoutSelectedCallback
+            mKeyboardLayoutSelectedCallback =
+            new NewKeyboardLayoutPickerController.KeyboardLayoutSelectedCallback() {
+                @Override
+                public void onSelected(KeyboardLayout keyboardLayout) {
+                    if (mInputManager != null && mKeyboardLayoutPreview != null) {
+                        Drawable previewDrawable = mInputManager.getKeyboardLayoutPreview(
+                                keyboardLayout,
+                                DEFAULT_KEYBOARD_PREVIEW_WIDTH, DEFAULT_KEYBOARD_PREVIEW_HEIGHT);
+                        mKeyboardLayoutPreview.setVisibility(
+                                previewDrawable == null ? GONE : VISIBLE);
+                        if (previewDrawable != null) {
+                            mKeyboardLayoutPreview.setImageDrawable(previewDrawable);
+                        }
+                    }
+                }
+            };
+
+    private final NewKeyboardLayoutPickerContent.ControllerUpdateCallback
+            mControllerUpdateCallback =
+                    newKeyboardLayoutPickerController -> {
+                        if (newKeyboardLayoutPickerController != null) {
+                            newKeyboardLayoutPickerController.registerKeyboardSelectedCallback(
+                                    mKeyboardLayoutSelectedCallback);
+                        }
+                    };
 
     @Override
     public View onCreateView(LayoutInflater inflater, ViewGroup container,
             Bundle savedInstanceState) {
-
+        mInputManager = requireContext().getSystemService(InputManager.class);
         ViewGroup fragmentView = (ViewGroup) inflater.inflate(
                 R.layout.keyboard_layout_picker, container, false);
+        mKeyboardLayoutPreview = fragmentView.findViewById(R.id.keyboard_layout_preview);
         getActivity().getSupportFragmentManager()
                 .beginTransaction()
                 .replace(R.id.keyboard_layout_title, new NewKeyboardLayoutPickerTitle())
                 .commit();
 
         NewKeyboardLayoutPickerContent fragment = new NewKeyboardLayoutPickerContent();
+        fragment.setControllerUpdateCallback(mControllerUpdateCallback);
         fragment.setArguments(getArguments());
         getActivity().getSupportFragmentManager()
                 .beginTransaction()
                 .replace(R.id.keyboard_layouts, fragment)
                 .commit();
-
         return fragmentView;
     }
 }