Support accessibility shorcut secondary action (1/n)

Create a new preference that could let users enable accessibility
shortcut and choose which shortcut type they prefer to use.

This CL only contains preference layout and functions interfaces.
Functions implementation will be added in next CL.

Bug: 142530063
Test: Maunal, make RunSettingsRoboTests
Change-Id: I69e832638547cd3f38da2192f22c7e219bbcc018

src/com/android/settings/accessibility/ShortcutPreference.java

@@ -0,0 +1,108 @@
+/*
+ * Copyright (C) 2019 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.accessibility;
+
+import android.content.Context;
+import android.util.AttributeSet;
+import android.view.View;
+import android.widget.CheckBox;
+
+import androidx.annotation.Nullable;
+import androidx.preference.Preference;
+import androidx.preference.PreferenceViewHolder;
+
+import com.android.settings.R;
+
+/**
+ * Preference that can enable accessibility shortcut and let users choose which shortcut type they
+ * prefer to use.
+ */
+public class ShortcutPreference extends Preference {
+
+    private View.OnClickListener mCheckBoxListener;
+    private View.OnClickListener mSettingButtonListener;
+
+    private boolean mChecked = false;
+
+    ShortcutPreference(Context context, AttributeSet attrs) {
+        super(context, attrs);
+
+        setLayoutResource(R.layout.accessibility_shortcut_secondary_action);
+    }
+
+    @Override
+    public void onBindViewHolder(PreferenceViewHolder holder) {
+        super.onBindViewHolder(holder);
+        holder.itemView.setClickable(false);
+
+        final CheckBox checkBox = holder.itemView.findViewById(R.id.checkbox);
+        checkBox.setOnClickListener(mCheckBoxListener);
+        checkBox.setChecked(mChecked);
+        final View settingButton = holder.itemView.findViewById(R.id.settings_button);
+        settingButton.setOnClickListener(mSettingButtonListener);
+    }
+
+    /**
+     * Set the shortcut checkbox according to checked value.
+     *
+     * @param checked the state value of shortcut checkbox.
+     */
+    public void setChecked(boolean checked) {
+        if (checked != mChecked) {
+            mChecked = checked;
+            notifyChanged();
+        }
+    }
+
+    /**
+     * Set the given onClickListener to the SettingButtonListener.
+     *
+     * @param listener the given onClickListener.
+     */
+    public void setSettingButtonListener(@Nullable View.OnClickListener listener) {
+        mSettingButtonListener = listener;
+        notifyChanged();
+    }
+
+    /**
+     * Returns the callback to be invoked when the setting button is clicked.
+     *
+     * @return The callback to be invoked
+     */
+    public View.OnClickListener getSettingButtonListener() {
+        return mSettingButtonListener;
+    }
+
+    /**
+     * Set the given onClickListener to the CheckBoxListener.
+     *
+     * @param listener the given onClickListener.
+     */
+    public void setCheckBoxListener(@Nullable View.OnClickListener listener) {
+        mCheckBoxListener = listener;
+        notifyChanged();
+    }
+
+    /**
+     * Returns the callback to be invoked when the checkbox is clicked.
+     *
+     * @return The callback to be invoked
+     */
+    public View.OnClickListener getCheckBoxListener() {
+        return mCheckBoxListener;
+    }
+}