android.content.ContextWrapper Java Examples

/**
 * 从文件中读取数据
 *
 * @param context
 * @param key
 * @param defValue
 * @return
 */
public static Object getData(Context context, String key, Object defValue) {
    try {
        //利用java反射机制将XML文件自定义存储
        Field field;
        // 获取ContextWrapper对象中的mBase变量。该变量保存了ContextImpl对象
        field = ContextWrapper.class.getDeclaredField("mBase");
        field.setAccessible(true);
        // 获取mBase变量
        Object obj = field.get(context);
        // 获取ContextImpl。mPreferencesDir变量，该变量保存了数据文件的保存路径
        field = obj.getClass().getDeclaredField("mPreferencesDir");
        field.setAccessible(true);
        // 创建自定义路径
        File file = new File(FILE_PATH);
        // 修改mPreferencesDir变量的值
        field.set(obj, file);

        String type = defValue.getClass().getSimpleName();
        SharedPreferences sharedPreferences = context.getSharedPreferences
                (FILE_NAME, Context.MODE_PRIVATE);

        //defValue为为默认值，如果当前获取不到数据就返回它
        if ("Integer".equals(type)) {
            return sharedPreferences.getInt(key, (Integer) defValue);
        } else if ("Boolean".equals(type)) {
            return sharedPreferences.getBoolean(key, (Boolean) defValue);
        } else if ("String".equals(type)) {
            return sharedPreferences.getString(key, (String) defValue);
        } else if ("Float".equals(type)) {
            return sharedPreferences.getFloat(key, (Float) defValue);
        } else if ("Long".equals(type)) {
            return sharedPreferences.getLong(key, (Long) defValue);
        }

        return null;
    } catch (Exception e) {
        return defValue;
    }
}
 

private OfflineMapDownloader(Context context) {
    super();
    this.context = context;

    listeners = new ArrayList<OfflineMapDownloaderListener>();

    mutableOfflineMapDatabases = new ArrayList<OfflineMapDatabase>();
    // Load OfflineMapDatabases from File System
    ContextWrapper cw = new ContextWrapper(context);
    for (String s : cw.databaseList()) {
        if (!s.toLowerCase().contains("partial") && !s.toLowerCase().contains("journal")) {
            // Setup Database Handler
            OfflineDatabaseManager.getOfflineDatabaseManager(context).getOfflineDatabaseHandlerForMapId(s, true);

            // Create the Database Object
            OfflineMapDatabase omd = new OfflineMapDatabase(context, s);
            omd.initializeDatabase();
            mutableOfflineMapDatabases.add(omd);
        }
    }

    this.state = MBXOfflineMapDownloaderState.MBXOfflineMapDownloaderStateAvailable;
}
 

public static ContextWrapper wrap(Context context, Locale newLocale) {

        Resources res = context.getResources();
        Configuration configuration = res.getConfiguration();

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
            configuration.setLocale(newLocale);

            LocaleList localeList = new LocaleList(newLocale);
            LocaleList.setDefault(localeList);
            configuration.setLocales(localeList);

            context = context.createConfigurationContext(configuration);

        } else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
            configuration.setLocale(newLocale);
            context = context.createConfigurationContext(configuration);
        } else {
            configuration.locale = newLocale;
            res.updateConfiguration(configuration, res.getDisplayMetrics());
        }

        return new ContextWrapper(context);
    }
 

public static Context wrapContext(Context context) {
    Resources res = context.getResources();
    Configuration configuration = res.getConfiguration();

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
        configuration.setLocale(getLocale());
        LocaleList localeList = getLocales();
        LocaleList.setDefault(localeList);
        configuration.setLocales(localeList);
        context = context.createConfigurationContext(configuration);

    } else {
        configuration.setLocale(getLocale());
        context = context.createConfigurationContext(configuration);

    }

    return new ContextWrapper(context);
}
 

@Override
public Context getContext() {
  // Return a context wrapper that will allow us to override the behavior of registering
  // the receiver for battery changed events.
  return new ContextWrapper(super.getContext()) {
    @Override
    public Context getApplicationContext() {
      return this;
    }

    @Override
    public Intent registerReceiver(BroadcastReceiver receiver, IntentFilter filter) {
      // For the BatteryIntent, use test values to avoid breaking from emulator changes.
      if (filter.hasAction(Intent.ACTION_BATTERY_CHANGED)) {
        // If we ever call this with a receiver, it will be broken.
        assertNull(receiver);
        return BatteryIntentProvider.getBatteryIntent();
      }
      return getBaseContext().registerReceiver(receiver, filter);
    }
  };
}
 

private Activity getActivity(View view)
{
    Context context = view.getContext();
    while (context instanceof ContextWrapper) {
        if (context instanceof Activity) {
            return (Activity)context;
        }
        context = ((ContextWrapper)context).getBaseContext();
    }

    //alternative method
    View content = view.findViewById(android.R.id.content);
    if(content != null)
        return (Activity) content.getContext();
    else
        return null;
}
 

/**
 * 通过上下问获取activity
 */
private static Activity getActivityFromContext(Context context) {
    if (context != null) {
        if (context instanceof Activity) {
            return (Activity) context;
        } else if (context instanceof ContextWrapper) {
            while (!(context instanceof Activity) && context instanceof ContextWrapper) {
                context = ((ContextWrapper) context).getBaseContext();
            }
            if (context instanceof Activity) {
                return (Activity) context;
            }
        }
    }
    return getCurAc();
}
 

/**
 * android:onClick doesn't handle views with a ContextWrapper context. This method
 * backports new framework functionality to traverse the Context wrappers to find a
 * suitable target.
 */
private void checkOnClickListener(View view, AttributeSet attrs) {
    final Context context = view.getContext();

    if (!(context instanceof ContextWrapper) ||
            (Build.VERSION.SDK_INT >= 15 && !ViewCompat.hasOnClickListeners(view))) {
        // Skip our compat functionality if: the Context isn't a ContextWrapper, or
        // the view doesn't have an OnClickListener (we can only rely on this on API 15+ so
        // always use our compat code on older devices)
        return;
    }

    final TypedArray a = context.obtainStyledAttributes(attrs, sOnClickAttrs);
    final String handlerName = a.getString(0);
    if (handlerName != null) {
        view.setOnClickListener(new DeclaredOnClickListener(view, handlerName));
    }
    a.recycle();
}
 

/**
 * 获取 View context 所属的 Activity
 * @param view {@link View}
 * @return {@link Activity}
 */
public static Activity getActivity(final View view) {
    if (view != null) {
        try {
            Context context = view.getContext();
            while (context instanceof ContextWrapper) {
                if (context instanceof Activity) {
                    return (Activity) context;
                }
                context = ((ContextWrapper) context).getBaseContext();
            }
        } catch (Exception e) {
            LogPrintUtils.eTag(TAG, e, "getActivity");
        }
    }
    return null;
}
 

/**
 * 反射获取ActivityThread中的Instrumentation对象
 * 从而拦截Activity跳转
 */
@Deprecated
private void hookInstrumentation() {
    try {
        Context contextImpl = ((ContextWrapper) mHostContext).getBaseContext();
        Object activityThread = ReflectionUtils.getFieldValue(contextImpl, "mMainThread");
        Field instrumentationF = activityThread.getClass().getDeclaredField("mInstrumentation");
        instrumentationF.setAccessible(true);
        Instrumentation hostInstr = (Instrumentation) instrumentationF.get(activityThread);
        mPluginInstrument = new PluginInstrument(hostInstr, mPluginPackageName);
    } catch (Exception e) {
        ErrorUtil.throwErrorIfNeed(e);
        PluginManager.deliver(mHostContext, false, mPluginPackageName,
                ErrorType.ERROR_PLUGIN_HOOK_INSTRUMENTATION, "hookInstrumentation failed");
    }
}
 

private void initLayout() {
    inflate(getContext(), R.layout.carbon_toolbar, this);
    super.setNavigationIcon(null);
    super.setTitle(null);
    content = findViewById(R.id.carbon_toolbarContent);
    title = findViewById(R.id.carbon_toolbarTitle);
    icon = findViewById(R.id.carbon_toolbarIcon);
    toolStrip = findViewById(R.id.carbon_toolbarMenu);

    icon.setOnClickListener(view -> {
        if (getContext() == null)
            return;
        Context context = getContext();
        while (!(context instanceof Activity))
            context = ((ContextWrapper) context).getBaseContext();
        if (context instanceof UpAwareActivity) {
            ((UpAwareActivity) context).onUpPressed();
        } else {
            ((Activity) context).onBackPressed();
        }
    });
}
 

/**
 * Returns the nearest context in the chain (as defined by ContextWrapper.getBaseContext()) which
 * is an instance of the specified type, or null if one could not be found
 *
 * @param context Initial context
 * @param clazz Class instance to look for
 * @param <T>
 * @return the first context which is an instance of the specified class, or null if none exists
 */
public static @Nullable <T> T findContextOfType(
  @Nullable Context context, Class<? extends T> clazz) {
  while (!(clazz.isInstance(context))) {
    if (context instanceof ContextWrapper) {
      Context baseContext = ((ContextWrapper) context).getBaseContext();
      if (context == baseContext) {
        return null;
      } else {
        context = baseContext;
      }
    } else {
      return null;
    }
  }
  return (T) context;
}
 

public static boolean validateResourceFiles(Context context, KcaDBHelper helper) {
    int count = 0;
    ContextWrapper cw = new ContextWrapper(context);
    File directory = cw.getDir("data", Context.MODE_PRIVATE);
    for (final File entry : directory.listFiles()) {
        try {
            Reader reader = new FileReader(entry);
            new JsonParser().parse(reader);
            count += 1;
        } catch (FileNotFoundException | IllegalStateException | JsonSyntaxException e ) {
            e.printStackTrace();
            if (helper != null) helper.recordErrorLog(ERROR_TYPE_DATALOAD, entry.getName(), "validateResourceFiles", "2", getStringFromException(e));
            setPreferences(context, PREF_DATALOAD_ERROR_FLAG, true);
            return false;
        }
    }
    return count > 0;
}
 

Context getAppContext(final String packageName) {
	final Resources resources = getResources(packageName);
	Context context = null;
	try {
		context = getHostContext().createPackageContext(packageName,
				Context.CONTEXT_IGNORE_SECURITY | Context.CONTEXT_INCLUDE_CODE);
	} catch (PackageManager.NameNotFoundException e) {
		context = getHostContext();
	}
	return new ContextWrapper(context) {
		@Override
		public Resources getResources() {
			return resources;
		}

		@Override
		public String getPackageName() {
			return packageName;
		}
	};
}
 

public static JsonArray getJsonArrayFromStorage(Context context, String name, KcaDBHelper helper) {

        if (getBooleanPreferences(context, PREF_RES_USELOCAL)) {
            return getJsonArrayFromAsset(context, name, helper);
        } else {
            ContextWrapper cw = new ContextWrapper(context);
            File directory = cw.getDir("data", Context.MODE_PRIVATE);
            File jsonFile = new File(directory, name);
            JsonArray data = new JsonArray();
            try {
                Reader reader = new FileReader(jsonFile);
                data = new JsonParser().parse(reader).getAsJsonArray();
                reader.close();
            } catch (IOException | IllegalStateException | JsonSyntaxException e ) {
                e.printStackTrace();
                setPreferences(context, PREF_DATALOAD_ERROR_FLAG, true);
                if (helper != null) helper.recordErrorLog(ERROR_TYPE_DATALOAD, name, "getJsonArrayFromStorage", "0", getStringFromException(e));
                data = getJsonArrayFromAsset(context, name, helper);
            }
            return data;
        }
    }
 

@Test @SuppressLint("HardwareIds") public void testNullDeviceIdKit() {
	final CondomContext condom = CondomContext.wrap(new ContextWrapper(context), "NullDeviceId",
			new CondomOptions().addKit(new NullDeviceIdKit()));
	final TelephonyManager tm = (TelephonyManager) condom.getSystemService(Context.TELEPHONY_SERVICE);
	assertTrue(condom.getApplicationContext().getSystemService(Context.TELEPHONY_SERVICE).getClass().getName().startsWith(NullDeviceIdKit.class.getName()));

	assertPermission(condom, READ_PHONE_STATE, true);

	assertNull(tm.getDeviceId());
	if (SDK_INT >= M) assertNull(tm.getDeviceId(0));
	assertNull(tm.getImei());
	assertNull(tm.getImei(0));
	if (SDK_INT >= O) assertNull(tm.getMeid());
	if (SDK_INT >= O) assertNull(tm.getMeid(0));
	assertNull(tm.getSimSerialNumber());
	assertNull(tm.getLine1Number());
	assertNull(tm.getSubscriberId());
}
 

boolean setGsmState(boolean enabled) throws RemoteException {
    Object manager;
    Method method;

    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT) {
        throw ExceptionCreator.createRemoteException(TAG, "Api before " + Build.VERSION_CODES.KITKAT + " not supported because of WTF", null);
    } else if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
        manager = serviceManager.getIService(Context.CONNECTIVITY_SERVICE, "android.net.IConnectivityManager");
        method = getMethod(ConnectivityManager.class, "setMobileDataEnabled", boolean.class);
        method.setAccessible(true);
        invoke(method, manager, enabled);
        method.setAccessible(false);
    } else {
        manager = serviceManager.getIService(ContextWrapper.TELEPHONY_SERVICE, "com.android.internal.telephony.ITelephony");

        if (enabled) {
            invoke(getMethod(manager.getClass(), "enableDataConnectivity"), manager);
        } else {
            invoke(getMethod(manager.getClass(), "disableDataConnectivity"), manager);
        }
    }
    return true;
}
 

static void showToast(@NonNull final Activity activity, @NonNull final String text) {
    if (Log.isLoggable(LOG_TAG, Log.VERBOSE)) {
        Log.v(LOG_TAG, "About to show toast for activity " + activity + ": " + text);
    }
    activity.runOnUiThread(new Runnable() {
        @Override
        public void run() {
            try {
                Context context = activity.getApplicationContext();
                if (context instanceof ContextWrapper) {
                    Context base = ((ContextWrapper) context).getBaseContext();
                    if (base == null) {
                        if (Log.isLoggable(LOG_TAG, Log.WARN)) {
                            Log.w(LOG_TAG, "Couldn't show toast: no base context");
                        }
                        return;
                    }
                }

                // For longer messages, leave the message up longer
                int duration = Toast.LENGTH_SHORT;
                if (text.length() >= 60 || text.indexOf('\n') != -1) {
                    duration = Toast.LENGTH_LONG;
                }

                // Avoid crashing when not available, e.g.
                //   java.lang.RuntimeException: Can't create handler inside thread that has
                //        not called Looper.prepare()
                Toast.makeText(activity, text, duration).show();
            } catch (Throwable e) {
                if (Log.isLoggable(LOG_TAG, Log.WARN)) {
                    Log.w(LOG_TAG, "Couldn't show toast", e);
                }
            }
        }
    });
}
 

private Activity getActivity() {
    Context context = getContext();
    while (context instanceof ContextWrapper) {
        if (context instanceof Activity) {
            return (Activity)context;
        }
        context = ((ContextWrapper)context).getBaseContext();
    }
    return null;
}
 

/**
 * Extract the activity if the given Context either is or wraps one.
 * Only retrieve the base context if the supplied context is a {@link ContextWrapper} but not
 * an Activity, given that Activity is already a subclass of ContextWrapper.
 * @param context The context to check.
 * @return The {@link Activity} that is extracted through the given Context.
 */
public static Activity activityFromContext(Context context) {
    if (context instanceof Activity) {
        return ((Activity) context);
    } else if (context instanceof ContextWrapper) {
        context = ((ContextWrapper) context).getBaseContext();
        return activityFromContext(context);
    } else {
        return null;
    }
}
 

@Override
public void onActivityCreated(Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);

    ContextWrapper cw = new ContextWrapper(getActivity().getApplicationContext());
    File directory = cw.getDir("imageDir", Context.MODE_PRIVATE);
    mFile = new File(directory, System.currentTimeMillis() + ".png");
}
 

/**
 * 初始化
 * 
 * @param context
 *            上下文
 * @param dop
 *            插件dex的存放目录
 */
void init(ContextWrapper context, String dop, String pluginRootDir) {
    mContext = context.getBaseContext();
    mDexoutputPath = dop;
    if (!TextUtils.isEmpty(pluginRootDir)) {
        mPluginRootDir = new File(pluginRootDir);
        if (!mPluginRootDir.exists()) {
            mPluginRootDir.mkdirs();
        }
    }
    mHandler = new Handler(Looper.getMainLooper());
    Log.d(TAG, "start init environment");
    initEnvironment();
    Log.d(TAG, "after init environment");
}
 

public static void unbindFromService(final ServiceToken token) {
    if (token == null) {
        return;
    }
    final ContextWrapper mContextWrapper = token.mWrappedContext;
    final ServiceBinder mBinder = mConnectionMap.remove(mContextWrapper);
    if (mBinder == null) {
        return;
    }
    mContextWrapper.unbindService(mBinder);
    if (mConnectionMap.isEmpty()) {
        mService = null;
    }
}
 

static void showToast(final Activity activity, final String text) {
	if (Log.isLoggable("InstantRun", 2)) {
		Log.v("InstantRun", "About to show toast for activity " + activity
				+ ": " + text);
	}
	activity.runOnUiThread(new Runnable() {
		public void run() {
			try {
				Context context = activity.getApplicationContext();
				if ((context instanceof ContextWrapper)) {
					Context base = ((ContextWrapper) context)
							.getBaseContext();
					if (base == null) {
						if (Log.isLoggable("InstantRun", 5)) {
							Log.w("InstantRun",
									"Couldn't show toast: no base context");
						}
						return;
					}
				}
				int duration = 0;
				if ((text.length() >= 60) || (text.indexOf('\n') != -1)) {
					duration = 1;
				}
				Toast.makeText(activity, text, duration).show();
			} catch (Throwable e) {
				if (Log.isLoggable("InstantRun", 5)) {
					Log.w("InstantRun", "Couldn't show toast", e);
				}
			}
		}
	});
}
 

private static Activity scanForActivity(Context context) {
    if (context == null) {
        return null;
    }

    if (context instanceof Activity) {
        return (Activity) context;
    } else if (context instanceof ContextWrapper) {
        return scanForActivity(((ContextWrapper) context).getBaseContext());
    }

    return null;
}
 

private Activity getActivity() {
  Context context = getContext();
  while (context instanceof ContextWrapper) {
    if (context instanceof Activity) {
      return (Activity) context;
    }
    context = ((ContextWrapper) context).getBaseContext();
  }
  return null;
}
 

@Nullable
public static Activity scanForActivity(@NonNull Context context) {
    if (context instanceof Activity)
        return (Activity) context;
    else if (context instanceof ContextWrapper)
        return scanForActivity(((ContextWrapper) context).getBaseContext());

    return null;
}
 

@Before
public void setup() {
  mContext1 = getApplicationContext();
  mContext2 = new ContextWrapper(getApplicationContext());
  mActivityController = Robolectric.buildActivity(Activity.class).create();
  mActivity = mActivityController.get();
  mMountContent = new ColorDrawable(Color.RED);
  mNewMountContent = new View(mContext1);
}
 

static Activity scanForActivity(Context context) {
    if (context == null) {
        return null;
    }
    if (context instanceof Activity) {
        return (Activity) context;
    } else if (context instanceof ContextWrapper) {
        return scanForActivity(((ContextWrapper) context).getBaseContext());
    }
    return null;
}
 

@NonNull
private void resolveMethod(@Nullable Context context, @NonNull String name) {
    while (context != null) {
        try {
            if (!context.isRestricted()) {
                final Method method = context.getClass().getMethod(mMethodName, View.class);
                if (method != null) {
                    mResolvedMethod = method;
                    mResolvedContext = context;
                    return;
                }
            }
        } catch (NoSuchMethodException e) {
            // Failed to find method, keep searching up the hierarchy.
        }

        if (context instanceof ContextWrapper) {
            context = ((ContextWrapper) context).getBaseContext();
        } else {
            // Can't search up the hierarchy, null out and fail.
            context = null;
        }
    }

    final int id = mHostView.getId();
    final String idText = id == View.NO_ID ? "" : " with id '"
            + mHostView.getContext().getResources().getResourceEntryName(id) + "'";
    throw new IllegalStateException("Could not find method " + mMethodName
            + "(View) in a parent or ancestor Context for android:onClick "
            + "attribute defined on view " + mHostView.getClass() + idText);
}