Add UVC support

This CL adds support for UVC GadgetFunction. UVC can be enabled/disabled
by setting the `ro.usb.uvc.enabled` property, and this CL makes sure
that the Settings app honors the property when showing USB functions to
the user.

Bug: 242344221
Test: Manually tested that the 'USB Webcam' option is present when the
      property is set, and removed when property is unset.
Change-Id: I5d1ff0a43d3c0c722bc9e03132a581da5c61bd76

res/values/strings.xml

@@ -8710,6 +8710,10 @@
          select what the USB connection for this device should be used for. This choice
          is for transferring photos via PTP. -->
     <string name="usb_use_photo_transfers">PTP</string>
+    <!-- Title of one of the choices in a dialog (with title defined in usb_use) that lets the user
+         select what the USB connection for this device should be used for. This choice
+         is for using the device as a Webcam. -->
+    <string name="usb_use_uvc_webcam">Webcam</string>
     <!-- Title of one of the choices in a dialog (with title defined in usb_use) that lets the user
          select what the USB connection for this device should be used for. This choice
          is for transcoding the files that are transferred via MTP. -->
@@ -8775,6 +8779,8 @@
     <string name="usb_summary_photo_transfers">PTP</string>
     <!-- Settings item summary for USB preference when set to entering MIDI mode [CHAR LIMIT=NONE] -->
     <string name="usb_summary_MIDI">MIDI</string>
+    <!-- Settings item summary for USB preference when set to entering UVC mode [CHAR LIMIT=NONE] -->
+    <string name="usb_summary_UVC">Webcam</string>
     <!-- Settings item summary for USB preference when set to transferring files via MTP
           and powering other device [CHAR LIMIT=NONE] -->
     <string name="usb_summary_file_transfers_power">File transfer and supplying power</string>
@@ -8787,6 +8793,9 @@
     <!-- Settings item summary for USB preference when set to entering MIDI mode
          and powering other device [CHAR LIMIT=NONE] -->
     <string name="usb_summary_MIDI_power">MIDI and supplying power</string>
+    <!-- Settings item summary for USB preference when set to entering UVC mode
+         and powering other device [CHAR LIMIT=NONE] -->
+    <string name="usb_summary_UVC_power">Webcam and supplying power</string>
 
     <!-- Settings item title for background check prefs [CHAR LIMIT=35] -->
     <string name="background_check_pref">Background check</string>

src/com/android/settings/connecteddevice/usb/ConnectedUsbDeviceUpdater.java

@@ -129,6 +129,8 @@ public class ConnectedUsbDeviceUpdater {
                     return R.string.usb_summary_photo_transfers;
                 } else if (functions == UsbManager.FUNCTION_MIDI) {
                     return R.string.usb_summary_MIDI;
+                } else if (functions == UsbManager.FUNCTION_UVC) {
+                    return R.string.usb_summary_UVC;
                 } else {
                     return R.string.usb_summary_charging_only;
                 }
@@ -141,6 +143,8 @@ public class ConnectedUsbDeviceUpdater {
                     return R.string.usb_summary_photo_transfers_power;
                 } else if (functions == UsbManager.FUNCTION_MIDI) {
                     return R.string.usb_summary_MIDI_power;
+                } else if (functions == UsbManager.FUNCTION_UVC) {
+                    return R.string.usb_summary_UVC_power;
                 } else {
                     return R.string.usb_summary_power_only;
                 }

src/com/android/settings/connecteddevice/usb/UsbBackend.java

@@ -53,6 +53,7 @@ public class UsbBackend {
     private final boolean mTetheringRestrictedBySystem;
     private final boolean mMidiSupported;
     private final boolean mTetheringSupported;
+    private final boolean mUVCEnabled;
     private final boolean mIsAdminUser;
 
     private UsbManager mUsbManager;
@@ -74,12 +75,12 @@ public class UsbBackend {
         mFileTransferRestrictedBySystem = isUsbFileTransferRestrictedBySystem(userManager);
         mTetheringRestricted = isUsbTetheringRestricted(userManager);
         mTetheringRestrictedBySystem = isUsbTetheringRestrictedBySystem(userManager);
+        mUVCEnabled = isUvcEnabled();
         mIsAdminUser = userManager.isAdminUser();
 
         mMidiSupported = context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_MIDI);
         final TetheringManager tm = context.getSystemService(TetheringManager.class);
         mTetheringSupported = tm.isTetheringSupported();
-
         updatePorts();
     }
 
@@ -200,6 +201,10 @@ public class UsbBackend {
                 UserManager.DISALLOW_CONFIG_TETHERING, UserHandle.of(UserHandle.myUserId()));
     }
 
+    private static boolean isUvcEnabled() {
+        return UsbManager.isUvcSupportEnabled();
+    }
+
     private boolean areFunctionDisallowed(long functions) {
         return (mFileTransferRestricted && ((functions & UsbManager.FUNCTION_MTP) != 0
                 || (functions & UsbManager.FUNCTION_PTP) != 0))
@@ -209,7 +214,8 @@ public class UsbBackend {
     private boolean areFunctionsDisallowedBySystem(long functions) {
         return (mFileTransferRestrictedBySystem && ((functions & UsbManager.FUNCTION_MTP) != 0
                 || (functions & UsbManager.FUNCTION_PTP) != 0))
-                || (mTetheringRestrictedBySystem && ((functions & UsbManager.FUNCTION_RNDIS) != 0));
+                || (mTetheringRestrictedBySystem && ((functions & UsbManager.FUNCTION_RNDIS) != 0))
+                || (!mUVCEnabled && ((functions & UsbManager.FUNCTION_UVC) != 0));
     }
 
     @VisibleForTesting

src/com/android/settings/connecteddevice/usb/UsbConnectionBroadcastReceiver.java

@@ -87,6 +87,9 @@ public class UsbConnectionBroadcastReceiver extends BroadcastReceiver implements
             if (intent.getExtras().getBoolean(UsbManager.USB_FUNCTION_NCM)) {
                 functions |= UsbManager.FUNCTION_NCM;
             }
+            if (intent.getExtras().getBoolean(UsbManager.USB_FUNCTION_UVC)) {
+                functions |= UsbManager.FUNCTION_UVC;
+            }
             mFunctions = functions;
             mDataRole = mUsbBackend.getDataRole();
             mPowerRole = mUsbBackend.getPowerRole();

src/com/android/settings/connecteddevice/usb/UsbDetailsFunctionsController.java

@@ -52,6 +52,7 @@ public class UsbDetailsFunctionsController extends UsbDetailsController
         FUNCTIONS_MAP.put(UsbManager.FUNCTION_RNDIS, R.string.usb_use_tethering);
         FUNCTIONS_MAP.put(UsbManager.FUNCTION_MIDI, R.string.usb_use_MIDI);
         FUNCTIONS_MAP.put(UsbManager.FUNCTION_PTP, R.string.usb_use_photo_transfers);
+        FUNCTIONS_MAP.put(UsbManager.FUNCTION_UVC, R.string.usb_use_uvc_webcam);
         FUNCTIONS_MAP.put(UsbManager.FUNCTION_NONE, R.string.usb_use_charging_only);
     }