Demo updating a view without losing focus

Add a FocusArea to the Cards tab to demonstrate how to update a
view properly.

Fixes: 185377477
Test: manual
Change-Id: I66038ef4677ee904246bf1dd16503fca4b27c9c1

2 files changed, 126 insertions, 0 deletions

diff --git a/RotaryPlayground/src/com/android/car/rotaryplayground/CustomButton.java b/RotaryPlayground/src/com/android/car/rotaryplayground/CustomButton.java
new file mode 100644
index 0000000..924908f
--- /dev/null
+++ b/RotaryPlayground/src/com/android/car/rotaryplayground/CustomButton.java
@@ -0,0 +1,65 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.car.rotaryplayground;
+
+import android.content.Context;
+import android.util.AttributeSet;
+import android.widget.Button;
+
+import androidx.annotation.Nullable;
+
+public class CustomButton extends Button {
+
+    private static final int[] STATE_ROTARY_ENABLED = {R.attr.state_rotary_enabled};
+
+    private boolean mRotaryEnabled = true;
+
+    public CustomButton(Context context) {
+        super(context);
+    }
+
+    public CustomButton(Context context, @Nullable AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    public CustomButton(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
+        super(context, attrs, defStyleAttr);
+    }
+
+    public CustomButton(Context context, @Nullable AttributeSet attrs, int defStyleAttr,
+            int defStyleRes) {
+        super(context, attrs, defStyleAttr, defStyleRes);
+    }
+
+    public void setRotaryEnabled(boolean enabled) {
+        mRotaryEnabled = enabled;
+        refreshDrawableState();
+    }
+
+    public boolean isRotaryEnabled() {
+        return mRotaryEnabled;
+    }
+
+    @Override
+    protected int[] onCreateDrawableState(int extraSpace) {
+        final int[] drawableState = super.onCreateDrawableState(extraSpace + 1);
+        if (mRotaryEnabled) {
+            mergeDrawableStates(drawableState, STATE_ROTARY_ENABLED);
+        }
+        return drawableState;
+    }
+}
diff --git a/RotaryPlayground/src/com/android/car/rotaryplayground/RotaryCards.java b/RotaryPlayground/src/com/android/car/rotaryplayground/RotaryCards.java
index 28f34a1..730c7c5 100644
--- a/RotaryPlayground/src/com/android/car/rotaryplayground/RotaryCards.java
+++ b/RotaryPlayground/src/com/android/car/rotaryplayground/RotaryCards.java
@@ -16,13 +16,18 @@
 
 package com.android.car.rotaryplayground;
 
+import android.graphics.drawable.Drawable;
 import android.os.Bundle;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
+import android.widget.Button;
+
 import androidx.annotation.Nullable;
 import androidx.fragment.app.Fragment;
 
+import com.android.car.ui.FocusArea;
+
 /** Fragment to demo a layout with cards that are FocusArea containers. */
 public class RotaryCards extends Fragment {
 
@@ -30,6 +35,62 @@ public class RotaryCards extends Fragment {
     public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container,
             @Nullable Bundle savedInstanceState) {
         View view = inflater.inflate(R.layout.rotary_cards, container, false);
+
+        // This button will be removed and immediately added back after click. So the focus
+        // highlight will jump to another view after rotary click.
+        FocusArea focusArea5 = view.findViewById(R.id.focus_area5);
+        Button button5a = view.findViewById(R.id.button_5a);
+        button5a.setOnClickListener(v -> {
+            int index = focusArea5.indexOfChild(button5a);
+            focusArea5.removeView(button5a);
+            focusArea5.addView(button5a, index);
+        });
+
+        // The background of this button will be changed after click. The focus highlight will stay
+        // on this Button after click.
+        Button button5b = view.findViewById(R.id.button_5b);
+        boolean[] stopped = {false};
+        button5b.setOnClickListener(v -> {
+            stopped[0] = !stopped[0];
+            Drawable drawable = view.getContext().getDrawable(
+                    stopped[0] ? R.drawable.ic_stop : R.drawable.ic_play_arrow);
+            button5b.setBackground(drawable);
+        });
+
+        // This button will be removed and immediately added back after click. It's not focusable
+        // but its container is focusable. The focus highlight will stay on the container after
+        // click.
+        ViewGroup button5cContainer = view.findViewById(R.id.button_5c_container);
+        Button button5c = view.findViewById(R.id.button_5c);
+        button5c.setFocusable(false);
+        button5cContainer.setOnClickListener(v -> {
+            button5cContainer.removeView(button5c);
+            button5cContainer.addView(button5c, 0);
+        });
+
+        // This button will be removed then added back and request focus explicitly after click.
+        // So the focus highlight will jump to another view then jump back after rotary click.
+        Button button5d = view.findViewById(R.id.button_5d);
+        button5d.setOnClickListener(v -> {
+            boolean needRestoreFocus = button5d.isFocused();
+            int index = focusArea5.indexOfChild(button5d);
+            focusArea5.removeView(button5d);
+            focusArea5.addView(button5d, index);
+            if (needRestoreFocus) {
+                button5d.requestFocus();
+            }
+        });
+
+        // This button will be disabled after click. So the focus highlight will jump to another
+        // view after rotary click.
+        Button button5e = view.findViewById(R.id.button_5e);
+        button5e.setOnClickListener(v -> button5e.setEnabled(!button5e.isEnabled()));
+
+        // This button will appear disabled but is not disabled after click. So the focus
+        // highlight will stay after rotary click.
+        CustomButton button5f = view.findViewById(R.id.button_5f);
+        button5f.setOnClickListener(v -> button5f.setRotaryEnabled(!button5f.isRotaryEnabled()));
+
         return view;
     }
 }