Add layout for RadioButtonWithDescription to allow programmatic uses

RadioButtonWithDescription & friends don't support adding via code.
This change wraps up the view properly to allow for inflation and adds
a layout to host the buttons and proxy checked events between the
custom code and the standard callbacks.

Bug: 1015218
Change-Id: Ic4bc5e1d01ee982a4513f9c9b202c40646b8739f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1869024
Commit-Queue: Brandon Wylie <wylieb@chromium.org>
Reviewed-by: Theresa  <twellington@chromium.org>
Reviewed-by: Ender <ender@google.com>
Reviewed-by: Patrick Noland <pnoland@chromium.org>
Cr-Commit-Position: refs/heads/master@{#711479}

chrome/android/java/res/layout/radio_button_group_theme_preference.xml

@@ -10,35 +10,41 @@
     android:layout_height="wrap_content"
     android:orientation="vertical"
     android:focusable="false">
-
-    <org.chromium.chrome.browser.ui.widget.RadioButtonWithDescription
-        android:id="@+id/system_default"
+    <org.chromium.chrome.browser.ui.widget.RadioButtonWithDescriptionLayout
+        android:id="@+id/radio_button_layout"
         android:layout_width="match_parent"
-        android:layout_height="wrap_content"
-        android:background="?attr/selectableItemBackground"
-        app:titleText="@string/themes_system_default_title"
-        app:descriptionText="@string/themes_system_default_summary" />
+        android:layout_height="match_parent">
 
-    <!-- override default padding top and bottom -->
-    <org.chromium.chrome.browser.ui.widget.RadioButtonWithDescription
-        android:id="@+id/light"
-        android:layout_width="match_parent"
-        android:layout_height="wrap_content"
-        android:minHeight="@dimen/min_touch_target_size"
-        android:paddingTop="8dp"
-        android:paddingBottom="8dp"
-        android:background="?attr/selectableItemBackground"
-        app:titleText="@string/light_mode" />
+      <org.chromium.chrome.browser.ui.widget.RadioButtonWithDescription
+          android:id="@+id/system_default"
+          android:layout_width="match_parent"
+          android:layout_height="wrap_content"
+          android:background="?attr/selectableItemBackground"
+          app:titleText="@string/themes_system_default_title"
+          app:descriptionText="@string/themes_system_default_summary" />
 
-    <org.chromium.chrome.browser.ui.widget.RadioButtonWithDescription
-        android:id="@+id/dark"
-        android:layout_width="match_parent"
-        android:layout_height="wrap_content"
-        android:minHeight="@dimen/min_touch_target_size"
-        android:paddingTop="8dp"
-        android:paddingBottom="8dp"
-        android:background="?attr/selectableItemBackground"
-        app:titleText="@string/dark_mode" />
+      <!-- override default padding top and bottom -->
+      <org.chromium.chrome.browser.ui.widget.RadioButtonWithDescription
+          android:id="@+id/light"
+          android:layout_width="match_parent"
+          android:layout_height="wrap_content"
+          android:minHeight="@dimen/min_touch_target_size"
+          android:paddingTop="8dp"
+          android:paddingBottom="8dp"
+          android:background="?attr/selectableItemBackground"
+          app:titleText="@string/light_mode" />
+
+      <org.chromium.chrome.browser.ui.widget.RadioButtonWithDescription
+          android:id="@+id/dark"
+          android:layout_width="match_parent"
+          android:layout_height="wrap_content"
+          android:minHeight="@dimen/min_touch_target_size"
+          android:paddingTop="8dp"
+          android:paddingBottom="8dp"
+          android:background="?attr/selectableItemBackground"
+          app:titleText="@string/dark_mode" />
+
+    </org.chromium.chrome.browser.ui.widget.RadioButtonWithDescriptionLayout>
 
     <!-- Make the row clickable -->
     <LinearLayout

chrome/android/java/res/layout/tri_state_site_settings_preference.xml

@@ -13,27 +13,35 @@
     android:focusable="false"
     android:orientation="vertical">
 
-    <org.chromium.chrome.browser.ui.widget.RadioButtonWithDescription
-        android:id="@+id/allowed"
+    <org.chromium.chrome.browser.ui.widget.RadioButtonWithDescriptionLayout
+        android:id="@+id/radio_button_layout"
         android:layout_width="match_parent"
-        android:layout_height="wrap_content"
-        android:paddingStart="?android:attr/listPreferredItemPaddingStart"
-        android:background="?android:attr/selectableItemBackground"
-        app:titleText="@string/website_settings_category_allowed" />
+        android:layout_height="match_parent">
 
-    <org.chromium.chrome.browser.ui.widget.RadioButtonWithDescription
-        android:id="@+id/ask"
-        android:layout_width="match_parent"
-        android:layout_height="wrap_content"
-        android:paddingStart="?android:attr/listPreferredItemPaddingStart"
-        android:background="?android:attr/selectableItemBackground"
-        app:titleText="@string/website_settings_category_ask" />
 
-    <org.chromium.chrome.browser.ui.widget.RadioButtonWithDescription
-        android:id="@+id/blocked"
-        android:layout_width="match_parent"
-        android:layout_height="wrap_content"
-        android:paddingStart="?android:attr/listPreferredItemPaddingStart"
-        android:background="?android:attr/selectableItemBackground"
-        app:titleText="@string/website_settings_category_blocked" />
+        <org.chromium.chrome.browser.ui.widget.RadioButtonWithDescription
+            android:id="@+id/allowed"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:paddingStart="?android:attr/listPreferredItemPaddingStart"
+            android:background="?android:attr/selectableItemBackground"
+            app:titleText="@string/website_settings_category_allowed" />
+
+        <org.chromium.chrome.browser.ui.widget.RadioButtonWithDescription
+            android:id="@+id/ask"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:paddingStart="?android:attr/listPreferredItemPaddingStart"
+            android:background="?android:attr/selectableItemBackground"
+            app:titleText="@string/website_settings_category_ask" />
+
+        <org.chromium.chrome.browser.ui.widget.RadioButtonWithDescription
+            android:id="@+id/blocked"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:paddingStart="?android:attr/listPreferredItemPaddingStart"
+            android:background="?android:attr/selectableItemBackground"
+            app:titleText="@string/website_settings_category_blocked" />
+
+    </org.chromium.chrome.browser.ui.widget.RadioButtonWithDescriptionLayout>
 </LinearLayout>

chrome/android/java/src/org/chromium/chrome/browser/preferences/themes/RadioButtonGroupThemePreference.java

@@ -11,6 +11,7 @@ import android.util.AttributeSet;
 import android.view.View;
 import android.widget.CheckBox;
 import android.widget.LinearLayout;
+import android.widget.RadioGroup;
 
 import org.chromium.base.BuildInfo;
 import org.chromium.base.VisibleForTesting;
@@ -28,13 +29,14 @@ import java.util.Collections;
  * Light, and Dark.
  */
 public class RadioButtonGroupThemePreference
-        extends Preference implements RadioButtonWithDescription.OnCheckedChangeListener {
+        extends Preference implements RadioGroup.OnCheckedChangeListener {
     private @ThemeSetting int mSetting;
     private ArrayList<RadioButtonWithDescription> mButtons;
     private boolean mDarkenWebsitesEnabled;
     private CheckBox mCheckBox;
     private LinearLayout mLayoutContainer;
     private LinearLayout mCheckboxContainer;
+    private RadioGroup mRadioGroup;
 
     public RadioButtonGroupThemePreference(Context context, AttributeSet attrs) {
         super(context, attrs);
@@ -61,6 +63,9 @@ public class RadioButtonGroupThemePreference
         mCheckBox = (CheckBox) holder.findViewById(R.id.darken_websites);
         mLayoutContainer = (LinearLayout) holder.itemView;
 
+        mRadioGroup = (RadioGroup) holder.findViewById(R.id.radio_button_layout);
+        mRadioGroup.setOnCheckedChangeListener(this);
+
         mCheckboxContainer.setOnClickListener(x -> {
             mCheckBox.setChecked(!mCheckBox.isChecked());
             callChangeListener(mSetting);
@@ -81,11 +86,6 @@ public class RadioButtonGroupThemePreference
         mButtons.set(
                 ThemeSetting.DARK, (RadioButtonWithDescription) holder.findViewById(R.id.dark));
 
-        for (int i = 0; i < ThemeSetting.NUM_ENTRIES; i++) {
-            mButtons.get(i).setRadioButtonGroup(mButtons);
-            mButtons.get(i).setOnCheckedChangeListener(this);
-        }
-
         mButtons.get(mSetting).setChecked(true);
         positionCheckbox();
     }
@@ -107,7 +107,7 @@ public class RadioButtonGroupThemePreference
     }
 
     @Override
-    public void onCheckedChanged() {
+    public void onCheckedChanged(RadioGroup group, int checkedId) {
         for (int i = 0; i < ThemeSetting.NUM_ENTRIES; i++) {
             if (mButtons.get(i).isChecked()) {
                 mSetting = i;

chrome/android/java/src/org/chromium/chrome/browser/preferences/website/TriStateSiteSettingsPreference.java

@@ -8,23 +8,22 @@ import android.content.Context;
 import android.support.v7.preference.Preference;
 import android.support.v7.preference.PreferenceViewHolder;
 import android.util.AttributeSet;
+import android.widget.RadioGroup;
 
 import org.chromium.chrome.R;
 import org.chromium.chrome.browser.ui.widget.RadioButtonWithDescription;
 
-import java.util.Arrays;
-import java.util.List;
-
 /**
  * A 3-state Allowed/Ask/Blocked radio group Preference used for SiteSettings.
  */
 public class TriStateSiteSettingsPreference
-        extends Preference implements RadioButtonWithDescription.OnCheckedChangeListener {
+        extends Preference implements RadioGroup.OnCheckedChangeListener {
     private @ContentSettingValues int mSetting = ContentSettingValues.DEFAULT;
     private int[] mDescriptionIds;
     private RadioButtonWithDescription mAllowed;
     private RadioButtonWithDescription mAsk;
     private RadioButtonWithDescription mBlocked;
+    private RadioGroup mRadioGroup;
 
     public TriStateSiteSettingsPreference(Context context, AttributeSet attrs) {
         super(context, attrs);
@@ -57,7 +56,7 @@ public class TriStateSiteSettingsPreference
     }
 
     @Override
-    public void onCheckedChanged() {
+    public void onCheckedChanged(RadioGroup group, int checkedId) {
         if (mAllowed.isChecked()) {
             mSetting = ContentSettingValues.ALLOW;
         } else if (mAsk.isChecked()) {
@@ -76,6 +75,8 @@ public class TriStateSiteSettingsPreference
         mAllowed = (RadioButtonWithDescription) holder.findViewById(R.id.allowed);
         mAsk = (RadioButtonWithDescription) holder.findViewById(R.id.ask);
         mBlocked = (RadioButtonWithDescription) holder.findViewById(R.id.blocked);
+        mRadioGroup = (RadioGroup) holder.findViewById(R.id.radio_button_layout);
+        mRadioGroup.setOnCheckedChangeListener(this);
 
         if (mDescriptionIds != null) {
             mAllowed.setDescriptionText(getContext().getText(mDescriptionIds[0]));
@@ -83,12 +84,6 @@ public class TriStateSiteSettingsPreference
             mBlocked.setDescriptionText(getContext().getText(mDescriptionIds[2]));
         }
 
-        List<RadioButtonWithDescription> radioGroup = Arrays.asList(mAllowed, mAsk, mBlocked);
-        for (RadioButtonWithDescription option : radioGroup) {
-            option.setRadioButtonGroup(radioGroup);
-            option.setOnCheckedChangeListener(this);
-        }
-
         RadioButtonWithDescription radioButton = findRadioButton(mSetting);
         if (radioButton != null) radioButton.setChecked(true);
     }

chrome/browser/ui/android/widget/BUILD.gn

@@ -25,6 +25,7 @@ android_library("java") {
     "java/src/org/chromium/chrome/browser/ui/widget/MoreProgressButton.java",
     "java/src/org/chromium/chrome/browser/ui/widget/RadioButtonLayout.java",
     "java/src/org/chromium/chrome/browser/ui/widget/RadioButtonWithDescription.java",
+    "java/src/org/chromium/chrome/browser/ui/widget/RadioButtonWithDescriptionLayout.java",
     "java/src/org/chromium/chrome/browser/ui/widget/RoundedCornerImageView.java",
     "java/src/org/chromium/chrome/browser/ui/widget/RoundedIconGenerator.java",
     "java/src/org/chromium/chrome/browser/ui/widget/TintedDrawable.java",
@@ -157,6 +158,7 @@ android_library("ui_widget_java_tests") {
     "java/src/org/chromium/chrome/browser/ui/widget/DualControlLayoutTest.java",
     "java/src/org/chromium/chrome/browser/ui/widget/PromoDialogTest.java",
     "java/src/org/chromium/chrome/browser/ui/widget/RadioButtonLayoutTest.java",
+    "java/src/org/chromium/chrome/browser/ui/widget/RadioButtonWithDescriptionLayoutTest.java",
     "java/src/org/chromium/chrome/browser/ui/widget/RoundedIconGeneratorTest.java",
     "java/src/org/chromium/chrome/browser/ui/widget/highlight/ViewHighlighterTest.java",
     "java/src/org/chromium/chrome/browser/ui/widget/MoreProgressButtonTest.java",

chrome/browser/ui/android/widget/java/res/layout/radio_button_with_description.xml

@@ -4,7 +4,8 @@
      found in the LICENSE file. -->
 
 <!-- RadioButtonWithDescription extends RelativeLayout -->
-<merge xmlns:android="http://schemas.android.com/apk/res/android">
+<merge
+    xmlns:android="http://schemas.android.com/apk/res/android">
 
     <RadioButton
         android:id="@+id/radio_button"

chrome/browser/ui/android/widget/java/res/values/dimens.xml

@@ -12,6 +12,9 @@
     <!-- DualControlLayout dimensions -->
     <dimen name="dual_control_margin_between_items">8dp</dimen>
 
+    <!-- RadioButton(WithDescription)Layout dimensions -->
+    <dimen name="default_vertical_margin_between_items">8dp</dimen>
+
     <!-- RadioButtonWithDescription dimensions -->
     <dimen name="radio_button_with_description_lateral_padding">16dp</dimen>
     <dimen name="radio_button_with_description_vertical_padding">10dp</dimen>

chrome/browser/ui/android/widget/java/src/org/chromium/chrome/browser/ui/widget/RadioButtonLayout.java

@@ -36,7 +36,7 @@ public final class RadioButtonLayout extends RadioGroup {
     public RadioButtonLayout(Context context, AttributeSet attrs) {
         super(context, attrs);
         mMarginBetweenRows = context.getResources().getDimensionPixelSize(
-                R.dimen.dual_control_margin_between_items);
+                R.dimen.default_vertical_margin_between_items);
     }
 
     /**

chrome/browser/ui/android/widget/java/src/org/chromium/chrome/browser/ui/widget/RadioButtonWithDescription.java

@@ -27,12 +27,18 @@ public class RadioButtonWithDescription extends RelativeLayout implements OnClic
     /**
      * Interface to listen to radio button changes.
      */
-    public interface OnCheckedChangeListener { abstract void onCheckedChanged(); }
+    interface ButtonCheckedStateChangedListener {
+        /**
+         * Invoked when a {@link RadioButtonWithDescription} is selected.
+         * @param checkedRadioButton The radio button that was selected.
+         */
+        void onButtonCheckedStateChanged(RadioButtonWithDescription checkedRadioButton);
+    }
 
     private RadioButton mRadioButton;
     private TextView mTitle;
     private TextView mDescription;
-    private OnCheckedChangeListener mOnCheckedChangeListener;
+    private ButtonCheckedStateChangedListener mButtonCheckedStateChangedListener;
 
     private List<RadioButtonWithDescription> mGroup;
 
@@ -100,8 +106,8 @@ public class RadioButtonWithDescription extends RelativeLayout implements OnClic
 
         setChecked(true);
 
-        if (mOnCheckedChangeListener != null) {
-            mOnCheckedChangeListener.onCheckedChanged();
+        if (mButtonCheckedStateChangedListener != null) {
+            mButtonCheckedStateChangedListener.onButtonCheckedStateChanged(this);
         }
     }
 
@@ -112,6 +118,13 @@ public class RadioButtonWithDescription extends RelativeLayout implements OnClic
         mTitle.setText(text);
     }
 
+    /**
+     * @return The text shown in the title section.
+     */
+    public CharSequence getTitleText() {
+        return mTitle.getText();
+    }
+
     /**
      * Sets the text shown in the description section.
      */
@@ -127,6 +140,13 @@ public class RadioButtonWithDescription extends RelativeLayout implements OnClic
         }
     }
 
+    /**
+     * @return The text shown in the description section.
+     */
+    public CharSequence getDescriptionText() {
+        return mDescription.getText();
+    }
+
     /**
      * Returns true if checked.
      */
@@ -145,8 +165,8 @@ public class RadioButtonWithDescription extends RelativeLayout implements OnClic
         if (checked) requestFocus();
     }
 
-    public void setOnCheckedChangeListener(OnCheckedChangeListener listener) {
-        mOnCheckedChangeListener = listener;
+    public void setOnCheckedChangeListener(ButtonCheckedStateChangedListener listener) {
+        mButtonCheckedStateChangedListener = listener;
     }
 
     /**

chrome/browser/ui/android/widget/java/src/org/chromium/chrome/browser/ui/widget/RadioButtonWithDescriptionLayout.java

+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.chrome.browser.ui.widget;
+
+import android.content.Context;
+import android.util.AttributeSet;
+import android.view.View;
+import android.widget.RadioGroup;
+
+import androidx.annotation.Nullable;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Manages a group of exclusive RadioButtonWithDescriptions, automatically inserting a margin in
+ * between the rows to prevent them from squishing together.
+ *
+ * -------------------------------------------------
+ * | O | MESSAGE #1                                |
+ *        description_1                            |
+ * | O | MESSAGE #N                                |
+ *        description_n                            |
+ * -------------------------------------------------
+ */
+public final class RadioButtonWithDescriptionLayout
+        extends RadioGroup implements RadioButtonWithDescription.ButtonCheckedStateChangedListener {
+    /** Encapsulates information required to build a layout. */
+    public static class Option {
+        private final CharSequence mTitle;
+        private final CharSequence mDescription;
+        private final Object mTag;
+
+        /**
+         * @param title The title for this option. This will be displayed as the main text for the
+         *              checkbox.
+         * @param description The description for this option. This will be displayed as the subtext
+         *                    under the main text for the checkbox.
+         * @param tag The tag for this option. This can be used to identify the checkbox in event
+         *            listeners.
+         */
+        public Option(CharSequence title, CharSequence description, @Nullable Object tag) {
+            mTitle = title;
+            mDescription = description;
+            mTag = tag;
+        }
+
+        public CharSequence getTitle() {
+            return mTitle;
+        }
+
+        public CharSequence getDescription() {
+            return mDescription;
+        }
+
+        public Object getTag() {
+            return mTag;
+        }
+    }
+
+    private final int mMarginBetweenRows;
+    private final List<RadioButtonWithDescription> mRadioButtonsWithDescriptions;
+    private OnCheckedChangeListener mOnCheckedChangeListener;
+
+    public RadioButtonWithDescriptionLayout(Context context) {
+        this(context, null);
+    }
+
+    public RadioButtonWithDescriptionLayout(Context context, AttributeSet attrs) {
+        super(context, attrs);
+        mMarginBetweenRows = context.getResources().getDimensionPixelSize(
+                R.dimen.default_vertical_margin_between_items);
+
+        mRadioButtonsWithDescriptions = new ArrayList<>();
+    }
+
+    @Override
+    protected void onFinishInflate() {
+        super.onFinishInflate();
+
+        int childCount = getChildCount();
+        for (int i = 0; i < childCount; i++) {
+            RadioButtonWithDescription b = (RadioButtonWithDescription) getChildAt(i);
+            setupButton(b);
+        }
+
+        updateMargins();
+    }
+
+    /**
+     * @see RadioGroup.OnCheckedChangeListener
+     */
+    @Override
+    public void setOnCheckedChangeListener(OnCheckedChangeListener onCheckedChangeListener) {
+        mOnCheckedChangeListener = onCheckedChangeListener;
+    }
+
+    /**
+     * @see RadioButtonWithDescription.ButtonCheckedStateChangedListener
+     */
+    @Override
+    public void onButtonCheckedStateChanged(RadioButtonWithDescription checkedRadioButton) {
+        mOnCheckedChangeListener.onCheckedChanged(this, checkedRadioButton.getId());
+    }
+
+    /**
+     * Given a set of {@link Option} creates a set of {@link RadioButtonWithDescription}. When lists
+     * are built this way, there are two options for getting the checkbox you want in an event
+     * listener callback.
+     * 1. Set a tag on the Option and use that with {@link View#findViewWithTag).
+     * 2. Use the id passed through to {@link RadioGroup.OnCheckedChangeListener#onCheckedChanged}.
+     *    with {@link View#findViewById}.
+     *
+     * @param options List of options to add to this group.
+     */
+    public void addOptions(List<Option> options) {
+        for (Option option : options) {
+            RadioButtonWithDescription b = new RadioButtonWithDescription(getContext(), null);
+            b.setTitleText(option.getTitle());
+            b.setDescriptionText(option.getDescription());
+            b.setTag(option.getTag());
+
+            setupButton(b);
+
+            addView(b, new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT));
+        }
+
+        updateMargins();
+    }
+
+    /** Sets margins between each of the radio buttons. */
+    private void updateMargins() {
+        int childCount = getChildCount();
+        for (int i = 0; i < childCount - 1; i++) {
+            View child = getChildAt(i);
+            MarginLayoutParams params = (MarginLayoutParams) child.getLayoutParams();
+            params.bottomMargin = mMarginBetweenRows;
+        }
+        // LayoutParam changes only take effect after the next layout pass.
+        requestLayout();
+    }
+
+    private void setupButton(RadioButtonWithDescription radioButton) {
+        radioButton.setOnCheckedChangeListener(this);
+        // Give the button a unique id to allow for calling onCheckedChanged (see
+        // #onCheckedChanged).
+        if (radioButton.getId() == NO_ID) radioButton.setId(generateViewId());
+        radioButton.setRadioButtonGroup(mRadioButtonsWithDescriptions);
+        mRadioButtonsWithDescriptions.add(radioButton);
+    }
+
+    /**
+     * Marks a RadioButton child as being checked.
+     *
+     * @param childIndex Index of the child to select.
+     */
+    void selectChildAtIndexForTesting(int childIndex) {
+        int childCount = getChildCount();
+        for (int i = 0; i < childCount; i++) {
+            RadioButtonWithDescription b = (RadioButtonWithDescription) getChildAt(i);
+            b.setChecked(i == childIndex);
+        }
+    }
+}

chrome/browser/ui/android/widget/java/src/org/chromium/chrome/browser/ui/widget/RadioButtonWithDescriptionLayoutTest.java

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.chrome.browser.ui.widget;
+
+import android.content.Context;
+import android.support.test.InstrumentationRegistry;
+import android.support.test.annotation.UiThreadTest;
+import android.support.test.filters.SmallTest;
+import android.support.test.rule.UiThreadTestRule;
+import android.view.View;
+import android.view.ViewGroup.MarginLayoutParams;
+
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import org.chromium.chrome.test.ChromeJUnit4ClassRunner;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Tests for {@link RadioButtonLayout}.
+ */
+@RunWith(ChromeJUnit4ClassRunner.class)
+public class RadioButtonWithDescriptionLayoutTest {
+    private static final String NON_ZERO_MARGIN_ASSERT_MESSAGE =
+            "First N-1 items should have a non-zero margin";
+    private static final String ZERO_MARGIN_ASSERT_MESSAGE =
+            "The last item should have a zero margin";
+    private static final String TITLE_MATCH_ASSERT_MESSAGE =
+            "Title set through addOptions should match the view's title.";
+    private static final String DESCRIPTION_MATCH_ASSERT_MESSAGE =
+            "Description set through addOptions should match the view's description.";
+    private static final String TAG_MATCH_ASSERT_MESSAGE =
+            "Tag set through addOptions should match the view's tag.";
+
+    @Rule
+    public UiThreadTestRule mRule = new UiThreadTestRule();
+
+    private Context mContext;
+
+    @Before
+    public void setUp() {
+        mContext = InstrumentationRegistry.getTargetContext();
+    }
+
+    @Test
+    @SmallTest
+    @UiThreadTest
+    public void testMargins() {
+        RadioButtonWithDescriptionLayout layout = new RadioButtonWithDescriptionLayout(mContext);
+
+        // Add one set of options.
+        List<RadioButtonWithDescriptionLayout.Option> options = new ArrayList<>();
+        options.add(new RadioButtonWithDescriptionLayout.Option("a", "a_desc", "a_tag"));
+        options.add(new RadioButtonWithDescriptionLayout.Option("b", "b_desc", "b_tag"));
+        options.add(new RadioButtonWithDescriptionLayout.Option("c", "c_desc", "c_tag"));
+        layout.addOptions(options);
+        Assert.assertEquals(3, layout.getChildCount());
+
+        // Test the margins.
+        for (int i = 0; i < layout.getChildCount(); i++) {
+            View child = layout.getChildAt(i);
+            MarginLayoutParams params = (MarginLayoutParams) child.getLayoutParams();
+
+            if (i < layout.getChildCount() - 1) {
+                Assert.assertNotEquals(NON_ZERO_MARGIN_ASSERT_MESSAGE, 0, params.bottomMargin);
+            } else {
+                Assert.assertEquals(ZERO_MARGIN_ASSERT_MESSAGE, 0, params.bottomMargin);
+            }
+        }
+
+        // Add more options.
+        List<RadioButtonWithDescriptionLayout.Option> moreOptions = new ArrayList<>();
+        moreOptions.add(new RadioButtonWithDescriptionLayout.Option("d", "d_desc", null));
+        moreOptions.add(new RadioButtonWithDescriptionLayout.Option("e", "e_desc", null));
+        moreOptions.add(new RadioButtonWithDescriptionLayout.Option("f", "f_desc", null));
+        layout.addOptions(moreOptions);
+        Assert.assertEquals(6, layout.getChildCount());
+
+        // Test the margins.
+        for (int i = 0; i < layout.getChildCount(); i++) {
+            View child = layout.getChildAt(i);
+            MarginLayoutParams params = (MarginLayoutParams) child.getLayoutParams();
+
+            if (i < layout.getChildCount() - 1) {
+                Assert.assertNotEquals(NON_ZERO_MARGIN_ASSERT_MESSAGE, 0, params.bottomMargin);
+            } else {
+                Assert.assertEquals(ZERO_MARGIN_ASSERT_MESSAGE, 0, params.bottomMargin);
+            }
+        }
+    }
+
+    @Test
+    @SmallTest
+    @UiThreadTest
+    public void testAddOptions() {
+        RadioButtonWithDescriptionLayout layout = new RadioButtonWithDescriptionLayout(mContext);
+
+        // Add one set of options.
+        List<RadioButtonWithDescriptionLayout.Option> options = new ArrayList<>();
+        options.add(new RadioButtonWithDescriptionLayout.Option("a", "a_desc", "a_tag"));
+        options.add(new RadioButtonWithDescriptionLayout.Option("b", "b_desc", "b_tag"));
+        options.add(new RadioButtonWithDescriptionLayout.Option("c", "c_desc", "c_tag"));
+        layout.addOptions(options);
+        Assert.assertEquals(3, layout.getChildCount());
+
+        for (int i = 0; i < layout.getChildCount(); i++) {
+            RadioButtonWithDescription b = (RadioButtonWithDescription) layout.getChildAt(i);
+            Assert.assertEquals(
+                    TITLE_MATCH_ASSERT_MESSAGE, options.get(i).getTitle(), b.getTitleText());
+            Assert.assertEquals(DESCRIPTION_MATCH_ASSERT_MESSAGE, options.get(i).getDescription(),
+                    b.getDescriptionText());
+            Assert.assertEquals(TAG_MATCH_ASSERT_MESSAGE, options.get(i).getTag(), b.getTag());
+        }
+
+        // Add even more options, but without tags.
+        List<RadioButtonWithDescriptionLayout.Option> moreOptions = new ArrayList<>();
+        moreOptions.add(new RadioButtonWithDescriptionLayout.Option("d", "d_desc", null));
+        moreOptions.add(new RadioButtonWithDescriptionLayout.Option("e", "e_desc", null));
+        moreOptions.add(new RadioButtonWithDescriptionLayout.Option("f", "f_desc", null));
+        layout.addOptions(moreOptions);
+        Assert.assertEquals(6, layout.getChildCount());
+        for (int i = 0; i < 3; i++) {
+            RadioButtonWithDescription b = (RadioButtonWithDescription) layout.getChildAt(i);
+            Assert.assertEquals(
+                    TITLE_MATCH_ASSERT_MESSAGE, options.get(i).getTitle(), b.getTitleText());
+            Assert.assertEquals(DESCRIPTION_MATCH_ASSERT_MESSAGE, options.get(i).getDescription(),
+                    b.getDescriptionText());
+            Assert.assertEquals(TAG_MATCH_ASSERT_MESSAGE, options.get(i).getTag(), b.getTag());
+        }
+        for (int i = 3; i < 6; i++) {
+            RadioButtonWithDescription b = (RadioButtonWithDescription) layout.getChildAt(i);
+            Assert.assertEquals(TITLE_MATCH_ASSERT_MESSAGE, moreOptions.get(i - 3).getTitle(),
+                    b.getTitleText());
+            Assert.assertEquals(DESCRIPTION_MATCH_ASSERT_MESSAGE,
+                    moreOptions.get(i - 3).getDescription(), b.getDescriptionText());
+            Assert.assertEquals(
+                    TAG_MATCH_ASSERT_MESSAGE, moreOptions.get(i - 3).getTag(), b.getTag());
+        }
+    }
+
+    @Test
+    @SmallTest
+    @UiThreadTest
+    public void testSelection() {
+        final RadioButtonWithDescriptionLayout layout =
+                new RadioButtonWithDescriptionLayout(mContext);
+
+        // Add one set of options.
+        List<RadioButtonWithDescriptionLayout.Option> options = new ArrayList<>();
+        options.add(new RadioButtonWithDescriptionLayout.Option("a", "a_desc", null));
+        options.add(new RadioButtonWithDescriptionLayout.Option("b", "b_desc", null));
+        options.add(new RadioButtonWithDescriptionLayout.Option("c", "c_desc", null));
+        layout.addOptions(options);
+        Assert.assertEquals(3, layout.getChildCount());
+
+        // Nothing should be selected by default.
+        for (int i = 0; i < layout.getChildCount(); i++) {
+            RadioButtonWithDescription child = (RadioButtonWithDescription) layout.getChildAt(i);
+            Assert.assertFalse(child.isChecked());
+        }
+
+        // Select the second one.
+        layout.selectChildAtIndexForTesting(1);
+        for (int i = 0; i < layout.getChildCount(); i++) {
+            RadioButtonWithDescription child = (RadioButtonWithDescription) layout.getChildAt(i);
+            Assert.assertEquals(i == 1, child.isChecked());
+        }
+
+        // Add even more options.
+        List<RadioButtonWithDescriptionLayout.Option> moreOptions = new ArrayList<>();
+        moreOptions.add(new RadioButtonWithDescriptionLayout.Option("d", "d_desc", null));
+        moreOptions.add(new RadioButtonWithDescriptionLayout.Option("e", "e_desc", null));
+        moreOptions.add(new RadioButtonWithDescriptionLayout.Option("f", "f_desc", null));
+        layout.addOptions(moreOptions);
+        Assert.assertEquals(6, layout.getChildCount());
+
+        // Second child should still be checked.
+        for (int i = 0; i < layout.getChildCount(); i++) {
+            RadioButtonWithDescription child = (RadioButtonWithDescription) layout.getChildAt(i);
+            Assert.assertEquals(i == 1, child.isChecked());
+        }
+    }
+}