Android 指纹

指纹图标的显示隐藏

指纹的显示由UdfpsController控制，

UdfpsOverlayController通过FingerprintManager 绑定了FingerprintService

final UdfpsOverlayController mUdfpsOverlayController = new UdfpsOverlayController();
mFingerprintManager.setUdfpsOverlayController(mUdfpsOverlayController);

oneway interface IUdfpsOverlayController {
    // Shows the overlay  for the given sensor with a reason from BiometricOverlayConstants.
    void showUdfpsOverlay(long requestId, int sensorId, int reason, IUdfpsOverlayControllerCallback callback);

    // Hides the overlay.
    void hideUdfpsOverlay(int sensorId);

    // Check acquiredInfo for the acquired type (BiometricFingerprintConstants#FingerprintAcquired).
    // Check BiometricFingerprintConstants#shouldTurnOffHbm for whether the acquiredInfo
    // should turn off HBM.
    void onAcquired(int sensorId, int acquiredInfo);

    // Notifies of enrollment progress changes.
    void onEnrollmentProgress(int sensorId, int remaining);

    // Notifies when a non-terminal error occurs (e.g. user moved their finger too fast).
    void onEnrollmentHelp(int sensorId);

    // Shows debug messages on the UDFPS overlay.
    void setDebugMessage(int sensorId, String message);
}

showUdfpsOverlay 显示指纹图标，hideUdfpsOverlay 隐藏指纹图标

调用指纹

通过FingerprintManager的authenticate方法可以调用起指纹

fingerprintManagerCompat.authenticate(null, 0 /* flags */, cancellationSignal, callback, null /* handler */);

指纹的授权结果，主要通过AuthenticationCallback进行回调反馈

public static abstract class AuthenticationCallback {
    /**
* Called when an unrecoverable error has been encountered and the operation is complete.
* No further callbacks will be made on this object.
*  @param  errMsgId An integer identifying the error message
*  @param  errString A human-readable error string that can be shown in UI
*/
public void onAuthenticationError(int errMsgId, CharSequence errString) { }

    /**
* Called when a recoverable error has been encountered during authentication. The help
* string is provided to give the user guidance for what went wrong, such as
* "Sensor dirty, please clean it."
*  @param  helpMsgId An integer identifying the error message
*  @param  helpString A human-readable string that can be shown in UI
*/
public void onAuthenticationHelp(int helpMsgId, CharSequence helpString) { }

    /**
* Called when a fingerprint is recognized.
*  @param  result An object containing authentication-related data
*/
public void onAuthenticationSucceeded(AuthenticationResult result) { }

    /**
* Called when a fingerprint is valid but not recognized.
*/
public void onAuthenticationFailed() { }
}