add UiModeManager.ENABLE_CAR_MODE_NO_WAKE_LOCK flag for enableCarMode

- When this flag is set, system no longer keeps the display on while in car mode.

bug: 15472822
Change-Id: I277368be5227eaf96213684598f278c39e4c34db

3 files changed, 23 insertions, 7 deletions

diff --git a/api/current.txt b/api/current.txt
index a3a99c76a4b6..32c22bde1dba 100644
--- a/api/current.txt
+++ b/api/current.txt
@@ -5219,6 +5219,7 @@ package android.app {
     field public static java.lang.String ACTION_EXIT_DESK_MODE;
     field public static final int DISABLE_CAR_MODE_GO_HOME = 1; // 0x1
     field public static final int ENABLE_CAR_MODE_GO_CAR_HOME = 1; // 0x1
+    field public static final int ENABLE_CAR_MODE_NO_WAKE_LOCK = 2; // 0x2
     field public static final int MODE_NIGHT_AUTO = 0; // 0x0
     field public static final int MODE_NIGHT_NO = 1; // 0x1
     field public static final int MODE_NIGHT_YES = 2; // 0x2
diff --git a/core/java/android/app/UiModeManager.java b/core/java/android/app/UiModeManager.java
index c6731c9df423..f79eb04af0f2 100644
--- a/core/java/android/app/UiModeManager.java
+++ b/core/java/android/app/UiModeManager.java
@@ -123,7 +123,18 @@ public class UiModeManager {
      * will switch to the car home activity even if we are already in car mode.
      */
     public static final int ENABLE_CAR_MODE_GO_CAR_HOME = 0x0001;
-    
+
+    /**
+     * Flag for use with {@link #enableCarMode(int)}: do not hold full wake lock
+     * while in car mode. By default, when this flag is not set, the system may hold
+     * a full wake lock to keep the screen turned on while in car mode.
+     * Setting this flag disables such behavior and the screen may be turned off if
+     * there is no other user activity and no other full wake lock held.
+     * Setting this flag can be relevant for a car dock application that does not require the
+     * screen kept on.
+     */
+    public static final int ENABLE_CAR_MODE_NO_WAKE_LOCK = 0x0002;
+
     /**
      * Force device into car mode, like it had been placed in the car dock.
      * This will cause the device to switch to the car home UI as part of
diff --git a/services/core/java/com/android/server/UiModeManagerService.java b/services/core/java/com/android/server/UiModeManagerService.java
index f59edc7f83e3..4c6b772ee8ab 100644
--- a/services/core/java/com/android/server/UiModeManagerService.java
+++ b/services/core/java/com/android/server/UiModeManagerService.java
@@ -73,6 +73,7 @@ final class UiModeManagerService extends SystemService {
     private boolean mTelevision;
     private boolean mWatch;
     private boolean mComputedNightMode;
+    private int mCarModeEnableFlags;
 
     int mCurUiMode = 0;
     private int mSetUiMode = 0;
@@ -193,7 +194,7 @@ final class UiModeManagerService extends SystemService {
             final long ident = Binder.clearCallingIdentity();
             try {
                 synchronized (mLock) {
-                    setCarModeLocked(true);
+                    setCarModeLocked(true, flags);
                     if (mSystemReady) {
                         updateLocked(flags, 0);
                     }
@@ -208,7 +209,7 @@ final class UiModeManagerService extends SystemService {
             final long ident = Binder.clearCallingIdentity();
             try {
                 synchronized (mLock) {
-                    setCarModeLocked(false);
+                    setCarModeLocked(false, 0);
                     if (mSystemReady) {
                         updateLocked(0, flags);
                     }
@@ -285,7 +286,8 @@ final class UiModeManagerService extends SystemService {
                     pw.print(" mLastBroadcastState="); pw.println(mLastBroadcastState);
             pw.print("  mNightMode="); pw.print(mNightMode);
                     pw.print(" mCarModeEnabled="); pw.print(mCarModeEnabled);
-                    pw.print(" mComputedNightMode="); pw.println(mComputedNightMode);
+                    pw.print(" mComputedNightMode="); pw.print(mComputedNightMode);
+                    pw.print(" mCarModeEnableFlags="); pw.println(mCarModeEnableFlags);
             pw.print("  mCurUiMode=0x"); pw.print(Integer.toHexString(mCurUiMode));
                     pw.print(" mSetUiMode=0x"); pw.println(Integer.toHexString(mSetUiMode));
             pw.print("  mHoldingConfiguration="); pw.print(mHoldingConfiguration);
@@ -311,17 +313,18 @@ final class UiModeManagerService extends SystemService {
         return mCarModeEnabled || mDockState != Intent.EXTRA_DOCK_STATE_UNDOCKED;
     }
 
-    void setCarModeLocked(boolean enabled) {
+    void setCarModeLocked(boolean enabled, int flags) {
         if (mCarModeEnabled != enabled) {
             mCarModeEnabled = enabled;
         }
+        mCarModeEnableFlags = flags;
     }
 
     private void updateDockState(int newState) {
         synchronized (mLock) {
             if (newState != mDockState) {
                 mDockState = newState;
-                setCarModeLocked(mDockState == Intent.EXTRA_DOCK_STATE_CAR);
+                setCarModeLocked(mDockState == Intent.EXTRA_DOCK_STATE_CAR, 0);
                 if (mSystemReady) {
                     updateLocked(UiModeManager.ENABLE_CAR_MODE_GO_CAR_HOME, 0);
                 }
@@ -475,7 +478,8 @@ final class UiModeManagerService extends SystemService {
 
         // keep screen on when charging and in car mode
         boolean keepScreenOn = mCharging &&
-                ((mCarModeEnabled && mCarModeKeepsScreenOn) ||
+                ((mCarModeEnabled && mCarModeKeepsScreenOn &&
+                  (mCarModeEnableFlags & UiModeManager.ENABLE_CAR_MODE_NO_WAKE_LOCK) == 0) ||
                  (mCurUiMode == Configuration.UI_MODE_TYPE_DESK && mDeskModeKeepsScreenOn));
         if (keepScreenOn != mWakeLock.isHeld()) {
             if (keepScreenOn) {