KeyguardClockSwitch 定义在KeyguardStatusView中,

  mClockView = findViewById(R.id.keyguard_clock_container);

KeyguardClockSwitch的父类为：

Class Name: LinearLayout
Class Name: KeyguardStatusView
Class Name: NotificationPanelView
Class Name: NotificationShadeWindowView

layout的包含关系为： keyguard_status_view.xml -> status_bar_expanded.xml -> super_notification_shade.xml

而 super_notification_shade.xml 是在 SuperStatusBarViewFactory的

keyguard_status_view.xml

<?xml version="1.0" encoding="utf-8"?>
<!--
**
** Copyright 2009, 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.
*/
-->

<!-- This is a view that shows general status information in Keyguard. -->
<com.android.keyguard.KeyguardStatusView
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:androidprv="http://schemas.android.com/apk/res-auto"
    android:id="@+id/keyguard_status_view"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:gravity="center_horizontal|top">
    <LinearLayout
        android:id="@+id/status_view_container"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:clipChildren="false"
        android:clipToPadding="false"
        android:orientation="vertical">
        <TextView
            android:id="@+id/logout"
            android:layout_height="@dimen/logout_button_layout_height"
            android:layout_width="wrap_content"
            android:layout_gravity="center_horizontal"
            android:layout_centerHorizontal="true"
            android:layout_marginBottom="@dimen/logout_button_margin_bottom"
            android:gravity="center"
            android:paddingLeft="@dimen/logout_button_padding_horizontal"
            android:paddingRight="@dimen/logout_button_padding_horizontal"
            android:background="@drawable/logout_button_background"
            android:fontFamily="@*android:string/config_bodyFontFamilyMedium"
            android:textAllCaps="true"
            android:textColor="?android:attr/textColorPrimary"
            android:textSize="13sp"
            android:text="@*android:string/global_action_logout" />

        <include
            layout="@layout/keyguard_clock_switch"
            android:id="@+id/keyguard_clock_container"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" />

        <TextView
            android:id="@+id/owner_info"
            android:layout_marginLeft="16dp"
            android:layout_marginRight="16dp"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="@dimen/date_owner_info_margin"
            android:layout_gravity="center_horizontal"
            android:layout_centerHorizontal="true"
            android:textColor="?attr/wallpaperTextColorSecondary"
            android:textSize="@dimen/widget_label_font_size"
            android:letterSpacing="0.05"
            android:ellipsize="marquee"
            android:singleLine="true" />
        <com.android.systemui.statusbar.phone.NotificationIconContainer
            android:id="@+id/clock_notification_icon_container"
            android:layout_width="match_parent"
            android:layout_height="@dimen/notification_shelf_height"
            android:layout_marginTop="@dimen/widget_vertical_padding"
            android:visibility="invisible"
        />
    </LinearLayout>
</com.android.keyguard.KeyguardStatusView>

status_bar_expanded.xml

<?xml version="1.0" encoding="utf-8"?>
<!--
**
** Copyright 2006, 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.
*/
-->


<com.android.systemui.statusbar.phone.NotificationPanelView
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:systemui="http://schemas.android.com/apk/res-auto"
    android:id="@+id/notification_panel"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@android:color/transparent">
    <FrameLayout
        android:id="@+id/big_clock_container"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:visibility="gone" />

    <include
        layout="@layout/keyguard_status_view"
        android:visibility="gone" />

    <com.android.systemui.statusbar.phone.NotificationsQuickSettingsContainer
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_gravity="@integer/notification_panel_layout_gravity"
        android:id="@+id/notification_container_parent"
        android:clipToPadding="false"
        android:clipChildren="false">

        <include layout="@layout/dock_info_overlay" />

        <FrameLayout
            android:id="@+id/qs_frame"
            android:layout="@layout/qs_panel"
            android:layout_width="@dimen/qs_panel_width"
            android:layout_height="match_parent"
            android:layout_gravity="@integer/notification_panel_layout_gravity"
            android:clipToPadding="false"
            android:clipChildren="false"
            systemui:viewType="com.android.systemui.plugins.qs.QS" />

        <com.android.systemui.statusbar.notification.stack.NotificationStackScrollLayout
            android:id="@+id/notification_stack_scroller"
            android:layout_marginTop="@dimen/notification_panel_margin_top"
            android:layout_width="@dimen/notification_panel_width"
            android:layout_height="match_parent"
            android:layout_gravity="@integer/notification_panel_layout_gravity"
            android:layout_marginBottom="@dimen/close_handle_underlap" />

        <include layout="@layout/ambient_indication"
            android:id="@+id/ambient_indication_container" />

        <include layout="@layout/photo_preview_overlay" />

        <ViewStub
            android:id="@+id/keyguard_user_switcher"
            android:layout="@layout/keyguard_user_switcher"
            android:layout_height="match_parent"
            android:layout_width="match_parent" />

        <include
            layout="@layout/keyguard_status_bar"
            android:visibility="invisible" />

        <Button
            android:id="@+id/report_rejected_touch"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="@dimen/status_bar_header_height_keyguard"
            android:text="@string/report_rejected_touch"
            android:visibility="gone" />

    </com.android.systemui.statusbar.phone.NotificationsQuickSettingsContainer>

    <include
        layout="@layout/keyguard_bottom_area"
        android:visibility="gone" />

    <com.android.systemui.statusbar.AlphaOptimizedView
        android:id="@+id/qs_navbar_scrim"
        android:layout_height="96dp"
        android:layout_width="match_parent"
        android:layout_gravity="bottom"
        android:visibility="invisible"
        android:background="@drawable/qs_navbar_scrim" />

    <include layout="@layout/status_bar_expanded_plugin_frame"/>
</com.android.systemui.statusbar.phone.NotificationPanelView>

super_notification_shade.xml

<?xml version="1.0" encoding="utf-8"?>
<!--
**
** Copyright 2020, The Android Open Source Project
** super_notification_shade.xml
** 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.
*/
-->

<!-- This is the notification shade window. -->
<com.android.systemui.statusbar.phone.NotificationShadeWindowView
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:sysui="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true">

    <com.android.systemui.statusbar.BackDropView
            android:id="@+id/backdrop"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:visibility="gone"
            sysui:ignoreRightInset="true"
            >
        <ImageView android:id="@+id/backdrop_back"
                   android:layout_width="match_parent"
                   android:scaleType="centerCrop"
                   android:layout_height="match_parent" />
        <ImageView android:id="@+id/backdrop_front"
                   android:layout_width="match_parent"
                   android:layout_height="match_parent"
                   android:scaleType="centerCrop"
                   android:visibility="invisible" />
    </com.android.systemui.statusbar.BackDropView>

    <com.android.systemui.statusbar.ScrimView
        android:id="@+id/scrim_behind"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:importantForAccessibility="no"
        sysui:ignoreRightInset="true"
        />

    <include layout="@layout/status_bar_expanded"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:visibility="invisible" />

    <include layout="@layout/brightness_mirror" />

    <com.android.systemui.statusbar.ScrimView
        android:id="@+id/scrim_in_front"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:importantForAccessibility="no"
        sysui:ignoreRightInset="true"
    />

    <LinearLayout
        android:id="@+id/lock_icon_container"
        android:orientation="vertical"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="@dimen/status_bar_height"
        android:layout_gravity="top|center_horizontal">
        <com.android.systemui.statusbar.phone.LockIcon
            android:id="@+id/lock_icon"
            android:layout_width="@dimen/keyguard_lock_width"
            android:layout_height="@dimen/keyguard_lock_height"
            android:layout_gravity="center_horizontal"
            android:layout_marginTop="@dimen/keyguard_lock_padding"
            android:contentDescription="@string/accessibility_unlock_button"
            android:src="@*android:drawable/ic_lock"
            android:scaleType="center" />
        <com.android.keyguard.KeyguardMessageArea
            android:id="@+id/keyguard_message_area"
            style="@style/Keyguard.TextView"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="@dimen/keyguard_lock_padding"
            android:gravity="center"
            android:singleLine="true"
            android:ellipsize="marquee"
            android:focusable="true" />
    </LinearLayout>
</com.android.systemui.statusbar.phone.NotificationShadeWindowView>