lock_icon_container LockIconContainer的显示

LockIconContainer 是直接在super_notification_shade.xml 里面的：

lock_icon_container

<?xml version="1.0" encoding="utf-8"?>
<!-- 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>

控制显示与否：

会基于StatusBarState的状态来更新 updateLockIcon

状态有：

    /**
     * The status bar is in the "normal" shade mode.
     */
    public static final int SHADE = 0;

    /**
     * Status bar is currently the Keyguard.
     */
    public static final int KEYGUARD = 1;

    /**
     * Status bar is in the special mode, where it is fully interactive but still locked. So
     * dismissing the shade will still show the bouncer.
     */
    public static final int SHADE_LOCKED = 2;

    /**
     * Status bar is locked and shows the full screen user switcher.
     */
    public static final int FULLSCREEN_USER_SWITCHER = 3;