1 package com.android.datetimepicker; 2 3 import android.app.Service; 4 import android.content.Context; 5 import android.database.ContentObserver; 6 import android.net.Uri; 7 import android.os.SystemClock; 8 import android.os.Vibrator; 9 import android.provider.Settings; 10 11 /** 12 * A simple utility class to handle haptic feedback. 13 */ 14 public class HapticFeedbackController { 15 private static final int VIBRATE_DELAY_MS = 125; 16 private static final int VIBRATE_LENGTH_MS = 5; 17 18 private static boolean checkGlobalSetting(Context context) { 19 return Settings.System.getInt(context.getContentResolver(), 20 Settings.System.HAPTIC_FEEDBACK_ENABLED, 0) == 1; 21 } 22 23 private final Context mContext; 24 private final ContentObserver mContentObserver; 25 26 private Vibrator mVibrator; 27 private boolean mIsGloballyEnabled; 28 private long mLastVibrate; 29 30 public HapticFeedbackController(Context context) { 31 mContext = context; 32 mContentObserver = new ContentObserver(null) { 33 @Override 34 public void onChange(boolean selfChange) { 35 mIsGloballyEnabled = checkGlobalSetting(mContext); 36 } 37 }; 38 } 39 40 /** 41 * Call to setup the controller. 42 */ 43 public void start() { 44 mVibrator = (Vibrator) mContext.getSystemService(Service.VIBRATOR_SERVICE); 45 46 // Setup a listener for changes in haptic feedback settings 47 mIsGloballyEnabled = checkGlobalSetting(mContext); 48 Uri uri = Settings.System.getUriFor(Settings.System.HAPTIC_FEEDBACK_ENABLED); 49 mContext.getContentResolver().registerContentObserver(uri, false, mContentObserver); 50 } 51 52 /** 53 * Call this when you don't need the controller anymore. 54 */ 55 public void stop() { 56 mVibrator = null; 57 mContext.getContentResolver().unregisterContentObserver(mContentObserver); 58 } 59 60 /** 61 * Try to vibrate. To prevent this becoming a single continuous vibration, nothing will 62 * happen if we have vibrated very recently. 63 */ 64 public void tryVibrate() { 65 if (mVibrator != null && mIsGloballyEnabled) { 66 long now = SystemClock.uptimeMillis(); 67 // We want to try to vibrate each individual tick discretely. 68 if (now - mLastVibrate >= VIBRATE_DELAY_MS) { 69 mVibrator.vibrate(VIBRATE_LENGTH_MS); 70 mLastVibrate = now; 71 } 72 } 73 } 74 } 75
