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/SettingsMainSwitchPreference.java

@@ -0,0 +1,217 @@
+/*
+ * 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.settings.widget;
+
+import android.content.Context;
+import android.util.AttributeSet;
+
+import androidx.preference.PreferenceViewHolder;
+import androidx.preference.TwoStatePreference;
+
+import com.android.settings.R;
+import com.android.settings.widget.SettingsMainSwitchBar.OnBeforeCheckedChangeListener;
+import com.android.settingslib.RestrictedLockUtils;
+import com.android.settingslib.widget.OnMainSwitchChangeListener;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * SettingsMainSwitchPreference is a Preference with a customized Switch.
+ * This component is used as the main switch of the page
+ * to enable or disable the prefereces on the page.
+ */
+public class SettingsMainSwitchPreference extends TwoStatePreference {
+    private final List<OnBeforeCheckedChangeListener> mBeforeCheckedChangeListeners =
+            new ArrayList<>();
+    private final List<OnMainSwitchChangeListener> mSwitchChangeListeners = new ArrayList<>();
+
+    private SettingsMainSwitchBar mMainSwitchBar;
+    private String mTitle;
+
+    private RestrictedLockUtils.EnforcedAdmin mEnforcedAdmin;
+
+    public SettingsMainSwitchPreference(Context context) {
+        super(context);
+        init();
+    }
+
+    public SettingsMainSwitchPreference(Context context, AttributeSet attrs) {
+        super(context, attrs);
+        init();
+    }
+
+    public SettingsMainSwitchPreference(Context context, AttributeSet attrs, int defStyleAttr) {
+        super(context, attrs, defStyleAttr);
+        init();
+    }
+
+    public SettingsMainSwitchPreference(Context context, AttributeSet attrs, int defStyleAttr,
+            int defStyleRes) {
+        super(context, attrs, defStyleAttr, defStyleRes);
+        init();
+    }
+
+    @Override
+    public void onBindViewHolder(PreferenceViewHolder holder) {
+        super.onBindViewHolder(holder);
+
+        holder.setDividerAllowedAbove(true);
+        holder.setDividerAllowedBelow(false);
+
+        mMainSwitchBar = (SettingsMainSwitchBar) holder.findViewById(R.id.main_switch_bar);
+        mMainSwitchBar.show();
+        updateStatus(isChecked());
+        registerListenerToSwitchBar();
+    }
+
+    private void init() {
+        setLayoutResource(R.layout.preference_widget_main_switch);
+    }
+
+    /**
+     * Return the SettingsMainSwitchBar
+     */
+    public final SettingsMainSwitchBar getSwitchBar() {
+        return mMainSwitchBar;
+    }
+
+    /**
+     * Set the preference title text
+     */
+    public void setTitle(String text) {
+        mTitle = text;
+        if (mMainSwitchBar != null) {
+            mMainSwitchBar.setTitle(mTitle);
+        }
+    }
+
+    /**
+     * Update the switch status of preference
+     */
+    public void updateStatus(boolean checked) {
+        setChecked(checked);
+        if (mMainSwitchBar != null) {
+            mMainSwitchBar.setChecked(checked);
+            mMainSwitchBar.setTitle(mTitle);
+            mMainSwitchBar.setDisabledByAdmin(mEnforcedAdmin);
+            mMainSwitchBar.show();
+        }
+    }
+
+    /**
+     * Show the MainSwitchBar
+     */
+    public void show() {
+        if (mMainSwitchBar != null) {
+            mMainSwitchBar.show();
+        }
+    }
+
+    /**
+     * Hide the MainSwitchBar
+     */
+    public void hide() {
+        if (mMainSwitchBar != null) {
+            mMainSwitchBar.hide();
+        }
+    }
+
+    /**
+     * Returns if the MainSwitchBar is visible.
+     */
+    public boolean isShowing() {
+        if (mMainSwitchBar != null) {
+            return mMainSwitchBar.isShowing();
+        }
+        return false;
+    }
+
+    /**
+     * Update the status of switch but doesn't notify the mOnBeforeListener.
+     */
+    public void setCheckedInternal(boolean checked) {
+        if (mMainSwitchBar != null) {
+            mMainSwitchBar.setCheckedInternal(checked);
+        }
+    }
+
+    /**
+     * Enable or disable the text and switch.
+     */
+    public void setEnabled(boolean enabled) {
+        if (mMainSwitchBar != null) {
+            mMainSwitchBar.setEnabled(enabled);
+        }
+    }
+
+    /**
+     * Set the OnBeforeCheckedChangeListener.
+     */
+    public void setOnBeforeCheckedChangeListener(OnBeforeCheckedChangeListener listener) {
+        if (mMainSwitchBar == null) {
+            mBeforeCheckedChangeListeners.add(listener);
+        } else {
+            mMainSwitchBar.setOnBeforeCheckedChangeListener(listener);
+        }
+    }
+
+    /**
+     * Adds a listener for switch changes
+     */
+    public void addOnSwitchChangeListener(OnMainSwitchChangeListener listener) {
+        if (mMainSwitchBar == null) {
+            mSwitchChangeListeners.add(listener);
+        } else {
+            mMainSwitchBar.addOnSwitchChangeListener(listener);
+        }
+    }
+
+    /**
+     * Remove a listener for switch changes
+     */
+    public void removeOnSwitchChangeListener(OnMainSwitchChangeListener listener) {
+        if (mMainSwitchBar == null) {
+            mSwitchChangeListeners.remove(listener);
+        } else {
+            mMainSwitchBar.removeOnSwitchChangeListener(listener);
+        }
+    }
+
+    /**
+     * If admin is not null, disables the text and switch but keeps the view clickable.
+     * Otherwise, calls setEnabled which will enables the entire view including
+     * the text and switch.
+     */
+    public void setDisabledByAdmin(RestrictedLockUtils.EnforcedAdmin admin) {
+        mEnforcedAdmin = admin;
+        if (mMainSwitchBar != null) {
+            mMainSwitchBar.setDisabledByAdmin(mEnforcedAdmin);
+        }
+    }
+
+    private void registerListenerToSwitchBar() {
+        for (OnBeforeCheckedChangeListener listener : mBeforeCheckedChangeListeners) {
+            mMainSwitchBar.setOnBeforeCheckedChangeListener(listener);
+        }
+        for (OnMainSwitchChangeListener listener : mSwitchChangeListeners) {
+            mMainSwitchBar.addOnSwitchChangeListener(listener);
+        }
+        mBeforeCheckedChangeListeners.clear();
+        mSwitchChangeListeners.clear();
+    }
+}