Use SettingsLib's MainSwitchBar to replace SwitchBar in Settings.

To log Settings metrics, the MainSwitch extends MainSwitchBar and
replace the SwitchBar in SettingsActivity.

Bug: 175181773
Test: Run robotest and apply the widget in Settings and see the ui

Change-Id: I3add3702e9058ad9192b5172c7cf0e2ccfb55a70

src/com/android/settings/widget/SettingsMainSwitchBar.java

@@ -0,0 +1,129 @@
+/*
+ * 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.widget;
+
+import android.app.settings.SettingsEnums;
+import android.content.Context;
+import android.util.AttributeSet;
+import android.view.View;
+import android.widget.Switch;
+
+import com.android.settings.overlay.FeatureFactory;
+import com.android.settingslib.core.instrumentation.MetricsFeatureProvider;
+import com.android.settingslib.widget.MainSwitchBar;
+
+/**
+ * A {@link MainSwitchBar} with a customized Switch and provides the metrics feature.
+ */
+public class SettingsMainSwitchBar extends MainSwitchBar {
+
+    /**
+     * Called before the checked state of the Switch has changed.
+     */
+    public interface OnBeforeCheckedChangeListener {
+
+        /**
+         * @param switchView The Switch view whose state has changed.
+         * @param isChecked  The new checked state of switchView.
+         */
+        boolean onBeforeCheckedChanged(Switch switchView, boolean isChecked);
+    }
+
+    private final MetricsFeatureProvider mMetricsFeatureProvider;
+    private OnBeforeCheckedChangeListener mOnBeforeListener;
+
+    private Switch mSwitch;
+    private String mMetricsTag;
+
+    public SettingsMainSwitchBar(Context context) {
+        this(context, null);
+    }
+
+    public SettingsMainSwitchBar(Context context, AttributeSet attrs) {
+        this(context, attrs, 0);
+    }
+
+    public SettingsMainSwitchBar(Context context, AttributeSet attrs, int defStyleAttr) {
+        this(context, attrs, defStyleAttr, 0);
+    }
+
+    public SettingsMainSwitchBar(Context context, AttributeSet attrs, int defStyleAttr,
+            int defStyleRes) {
+        super(context, attrs, defStyleAttr, defStyleRes);
+        mMetricsFeatureProvider = FeatureFactory.getFactory(context).getMetricsFeatureProvider();
+
+        mSwitch = (Switch) findViewById(android.R.id.switch_widget);
+
+        addOnSwitchChangeListener((switchView, isChecked) -> logMetrics(isChecked));
+    }
+
+    @Override
+    protected void onRestrictedIconClick() {
+        mMetricsFeatureProvider.action(
+                SettingsEnums.PAGE_UNKNOWN,
+                SettingsEnums.ACTION_SETTINGS_PREFERENCE_CHANGE,
+                SettingsEnums.PAGE_UNKNOWN,
+                mMetricsTag + "/switch_bar|restricted",
+                1);
+    }
+
+    @Override
+    public void setChecked(boolean checked) {
+        if (mOnBeforeListener != null
+                && mOnBeforeListener.onBeforeCheckedChanged(mSwitch, checked)) {
+            return;
+        }
+        super.setChecked(checked);
+    }
+
+    /**
+     * Update the status of switch but doesn't notify the mOnBeforeListener.
+     */
+    public void setCheckedInternal(boolean checked) {
+        super.setChecked(checked);
+    }
+
+    /**
+     * Set the OnBeforeCheckedChangeListener.
+     */
+    public void setOnBeforeCheckedChangeListener(OnBeforeCheckedChangeListener listener) {
+        mOnBeforeListener = listener;
+    }
+
+    /**
+     * Returns if this view is visible.
+     */
+    public boolean isShowing() {
+        return (getVisibility() == View.VISIBLE);
+    }
+
+    /**
+     * Set the metrics tag.
+     */
+    public void setMetricsTag(String tag) {
+        mMetricsTag = tag;
+    }
+
+    private void logMetrics(boolean isChecked) {
+        mMetricsFeatureProvider.action(
+                SettingsEnums.PAGE_UNKNOWN,
+                SettingsEnums.ACTION_SETTINGS_PREFERENCE_CHANGE,
+                SettingsEnums.PAGE_UNKNOWN,
+                mMetricsTag + "/switch_bar",
+                isChecked ? 1 : 0);
+    }
+}