Add 'Recent Conversations' to the conversation page

Test: atest
Bug: 171191376
Change-Id: Id7208312dff0cc022c2f16b3872fae1a9dc09ed7

src/com/android/settings/notification/app/RecentConversationPreference.java

@@ -0,0 +1,80 @@
+/*
+ * Copyright (C) 2020 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.settings.notification.app;
+
+import android.content.Context;
+import android.view.View;
+
+import androidx.preference.PreferenceViewHolder;
+
+import com.android.settings.R;
+import com.android.settingslib.TwoTargetPreference;
+
+import com.google.common.annotations.VisibleForTesting;
+
+public class RecentConversationPreference extends TwoTargetPreference {
+
+    private OnClearClickListener mOnClearClickListener;
+
+    private View mClearView;
+
+    public interface OnClearClickListener {
+        void onClear();
+    }
+
+    public RecentConversationPreference(Context context) {
+        super(context);
+    }
+
+    public void setOnClearClickListener(
+            OnClearClickListener onClearClickListener) {
+        mOnClearClickListener = onClearClickListener;
+    }
+
+    @VisibleForTesting
+    View getClearView() {
+        return mClearView;
+    }
+
+    @Override
+    protected int getSecondTargetResId() {
+        return R.layout.preference_widget_clear;
+    }
+
+    @VisibleForTesting
+    int getClearId() {
+        return R.id.clear_button;
+    }
+
+    @VisibleForTesting
+    boolean hasClearListener() {
+        return mOnClearClickListener != null;
+    }
+
+    @Override
+    public void onBindViewHolder(PreferenceViewHolder view) {
+        super.onBindViewHolder(view);
+        final View widgetFrame = view.findViewById(android.R.id.widget_frame);
+        widgetFrame.setVisibility(mOnClearClickListener != null ? View.VISIBLE : View.GONE);
+        mClearView = view.findViewById(getClearId());
+        mClearView.setOnClickListener(v -> {
+            if (mOnClearClickListener != null) {
+                mOnClearClickListener.onClear();
+            }
+        });
+    }
+
+}