packages/SystemUI/res/layout/navigation_bar.xml

<?xml version="1.0" encoding="utf-8"?>
<!--
**
** Copyright 2011, 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.NavigationBarView
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:systemui="http://schemas.android.com/apk/res-auto"
    android:layout_height="match_parent"
    android:layout_width="match_parent"
    android:background="@drawable/system_bar_background"
    >

    <FrameLayout android:id="@+id/rot0"
        android:layout_height="match_parent"
        android:layout_width="match_parent"
        >

        <LinearLayout
            android:layout_height="match_parent"
            android:layout_width="match_parent"
            android:orientation="horizontal"
            android:clipChildren="false"
            android:clipToPadding="false"
            android:id="@+id/nav_buttons"
            android:animateLayoutChanges="true"
            >

            <!-- navigation controls -->
            <View
                android:layout_width="@dimen/navigation_side_padding"
                android:layout_height="match_parent"
                android:layout_weight="0"
                android:visibility="invisible"
                />
            <com.android.systemui.statusbar.policy.KeyButtonView android:id="@+id/back"
                android:layout_width="@dimen/navigation_key_width"
                android:layout_height="match_parent"
                android:src="@drawable/ic_sysbar_back"
                systemui:keyCode="4"
                android:layout_weight="0"
                android:scaleType="center"
                android:contentDescription="@string/accessibility_back"
                />
            <View
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_weight="1"
                android:visibility="invisible"
                />
            <com.android.systemui.statusbar.policy.KeyButtonView android:id="@+id/home"
                android:layout_width="@dimen/navigation_key_width"
                android:layout_height="match_parent"
                android:src="@drawable/ic_sysbar_home"
                systemui:keyCode="3"
                systemui:keyRepeat="false"
                android:layout_weight="0"
                android:scaleType="center"
                android:contentDescription="@string/accessibility_home"
                />
            <View
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_weight="1"
                android:visibility="invisible"
                />
            <com.android.systemui.statusbar.policy.KeyButtonView android:id="@+id/recent_apps"
                android:layout_width="@dimen/navigation_key_width"
                android:layout_height="match_parent"
                android:src="@drawable/ic_sysbar_recent"
                android:layout_weight="0"
                android:scaleType="center"
                android:contentDescription="@string/accessibility_recent"
                />
            <FrameLayout
                android:layout_width="@dimen/navigation_side_padding"
                android:layout_height="match_parent"
                android:layout_weight="0" >
                <com.android.systemui.statusbar.policy.KeyButtonView
                    android:id="@+id/menu"
                    android:layout_width="@dimen/navigation_extra_key_width"
                    android:layout_height="match_parent"
                    android:contentDescription="@string/accessibility_menu"
                    android:src="@drawable/ic_sysbar_menu"
                    android:visibility="invisible"
                    android:scaleType="centerInside"
                    android:layout_gravity="end"
                    systemui:keyCode="82" />

                <com.android.systemui.statusbar.policy.KeyButtonView
                    android:id="@+id/ime_switcher"
                    android:layout_width="@dimen/navigation_extra_key_width"
                    android:layout_height="match_parent"
                    android:contentDescription="@string/accessibility_ime_switch_button"
                    android:scaleType="centerInside"
                    android:src="@drawable/ic_ime_switcher_default"
                    android:visibility="invisible"
                    android:layout_gravity="end" />
            </FrameLayout>

        </LinearLayout>

        <!-- lights out layout to match exactly -->
        <LinearLayout
            android:layout_height="match_parent"
            android:layout_width="match_parent"
            android:orientation="horizontal"
            android:id="@+id/lights_out"
            android:visibility="gone"
            >
            <ImageView
                android:layout_width="@dimen/navigation_key_width"
                android:layout_height="match_parent"
                android:layout_marginStart="@dimen/navigation_side_padding"
                android:src="@drawable/ic_sysbar_lights_out_dot_small"
                android:scaleType="center"
                android:layout_weight="0"
                android:contentDescription="@string/accessibility_back"
                />
            <View
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_weight="1"
                android:visibility="invisible"
                />
            <ImageView
                android:layout_width="@dimen/navigation_key_width"
                android:layout_height="match_parent"
                android:src="@drawable/ic_sysbar_lights_out_dot_large"
                android:scaleType="center"
                android:layout_weight="0"
                android:contentDescription="@string/accessibility_home"
                />
            <View
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_weight="1"
                android:visibility="invisible"
                />
            <ImageView
                android:layout_width="@dimen/navigation_key_width"
                android:layout_marginEnd="@dimen/navigation_side_padding"
                android:layout_height="match_parent"
                android:src="@drawable/ic_sysbar_lights_out_dot_small"
                android:scaleType="center"
                android:layout_weight="0"
                android:contentDescription="@string/accessibility_recent"
                />
        </LinearLayout>

        <com.android.systemui.statusbar.policy.DeadZone
            android:id="@+id/deadzone"
            android:layout_height="match_parent"
            android:layout_width="match_parent"
            systemui:minSize="@dimen/navigation_bar_deadzone_size"
            systemui:maxSize="@dimen/navigation_bar_deadzone_size_max"
            systemui:holdTime="@integer/navigation_bar_deadzone_hold"
            systemui:decayTime="@integer/navigation_bar_deadzone_decay"
            systemui:orientation="horizontal"
            android:layout_gravity="top"
            />
    </FrameLayout>

    <FrameLayout android:id="@+id/rot90"
        android:layout_height="match_parent"
        android:layout_width="match_parent"
        android:visibility="gone"
        android:paddingTop="0dp"
        >

        <LinearLayout
            android:layout_height="match_parent"
            android:layout_width="match_parent"
            android:orientation="vertical"
            android:clipChildren="false"
            android:clipToPadding="false"
            android:id="@+id/nav_buttons"
            android:animateLayoutChanges="true"
            >

            <!-- navigation controls -->
            <FrameLayout
                android:layout_weight="0"
                android:layout_width="match_parent"
                android:layout_height="@dimen/navigation_side_padding" >
                <com.android.systemui.statusbar.policy.KeyButtonView
                    android:id="@+id/ime_switcher"
                    android:layout_width="match_parent"
                    android:layout_height="@dimen/navigation_extra_key_width"
                    android:contentDescription="@string/accessibility_ime_switch_button"
                    android:scaleType="centerInside"
                    android:src="@drawable/ic_ime_switcher_default"
                    android:layout_gravity="top"
                    android:visibility="invisible" />

                <com.android.systemui.statusbar.policy.KeyButtonView
                    android:id="@+id/menu"
                    android:layout_width="match_parent"
                    android:layout_height="40dp"
                    android:contentDescription="@string/accessibility_menu"
                    android:src="@drawable/ic_sysbar_menu"
                    android:scaleType="centerInside"
                    android:layout_gravity="top"
                    android:visibility="invisible"
                    systemui:keyCode="82" />
            </FrameLayout>

            <com.android.systemui.statusbar.policy.KeyButtonView android:id="@+id/recent_apps"
                android:layout_height="@dimen/navigation_key_width"
                android:layout_width="match_parent"
                android:src="@drawable/ic_sysbar_recent"
                android:scaleType="center"
                android:layout_weight="0"
                android:contentDescription="@string/accessibility_recent"
                />
            <View
                android:layout_height="match_parent"
                android:layout_width="match_parent"
                android:layout_weight="1"
                android:visibility="invisible"
                />
            <com.android.systemui.statusbar.policy.KeyButtonView android:id="@+id/home"
                android:layout_height="@dimen/navigation_key_width"
                android:layout_width="match_parent"
                android:src="@drawable/ic_sysbar_home"
                android:scaleType="center"
                systemui:keyCode="3"
                systemui:keyRepeat="false"
                android:layout_weight="0"
                android:contentDescription="@string/accessibility_home"
                />
            <View
                android:layout_height="match_parent"
                android:layout_width="match_parent"
                android:layout_weight="1"
                android:visibility="invisible"
                />
            <com.android.systemui.statusbar.policy.KeyButtonView android:id="@+id/back"
                android:layout_height="@dimen/navigation_key_width"
                android:layout_width="match_parent"
                android:src="@drawable/ic_sysbar_back"
                android:scaleType="center"
                systemui:keyCode="4"
                android:layout_weight="0"
                android:contentDescription="@string/accessibility_back"
                />
            <View
                android:layout_height="@dimen/navigation_side_padding"
                android:layout_width="match_parent"
                android:layout_weight="0"
                android:visibility="invisible"
                />
        </LinearLayout>

        <!-- lights out layout to match exactly -->
        <LinearLayout
            android:layout_height="match_parent"
            android:layout_width="match_parent"
            android:orientation="vertical"
            android:id="@+id/lights_out"
            android:visibility="gone"
            >
            <ImageView
                android:layout_height="@dimen/navigation_key_width"
                android:layout_marginTop="@dimen/navigation_side_padding"
                android:layout_width="match_parent"
                android:src="@drawable/ic_sysbar_lights_out_dot_small"
                android:scaleType="center"
                android:layout_weight="0"
                android:contentDescription="@string/accessibility_recent"
                />
            <View
                android:layout_height="match_parent"
                android:layout_width="match_parent"
                android:layout_weight="1"
                android:visibility="invisible"
                />
            <ImageView
                android:layout_height="@dimen/navigation_key_width"
                android:layout_width="match_parent"
                android:src="@drawable/ic_sysbar_lights_out_dot_large"
                android:scaleType="center"
                android:layout_weight="0"
                android:contentDescription="@string/accessibility_home"
                />
            <View
                android:layout_height="match_parent"
                android:layout_width="match_parent"
                android:layout_weight="1"
                android:visibility="invisible"
                />
            <ImageView
                android:layout_height="@dimen/navigation_key_width"
                android:layout_marginBottom="@dimen/navigation_side_padding"
                android:layout_width="match_parent"
                android:src="@drawable/ic_sysbar_lights_out_dot_small"
                android:scaleType="center"
                android:layout_weight="0"
                android:contentDescription="@string/accessibility_back"
                />
        </LinearLayout>

        <com.android.systemui.statusbar.policy.DeadZone
            android:id="@+id/deadzone"
            android:layout_height="match_parent"
            android:layout_width="match_parent"
            systemui:minSize="@dimen/navigation_bar_deadzone_size"
            systemui:maxSize="@dimen/navigation_bar_deadzone_size_max"
            systemui:holdTime="@integer/navigation_bar_deadzone_hold"
            systemui:decayTime="@integer/navigation_bar_deadzone_decay"
            systemui:orientation="vertical"
            android:layout_gravity="top"
            />
    </FrameLayout>

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