react-native/ReactAndroid/src/main/java/com/facebook/react/packagerconnection/PackagerConnectionSettings.java

/**
 * Copyright (c) 2015-present, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 */

package com.facebook.react.packagerconnection;

import javax.annotation.Nullable;

import android.content.Context;
import android.content.SharedPreferences;
import android.preference.PreferenceManager;
import android.text.TextUtils;

import com.facebook.common.logging.FLog;
import com.facebook.infer.annotation.Assertions;
import com.facebook.react.modules.systeminfo.AndroidInfoHelpers;

public class PackagerConnectionSettings {
  private static final String TAG = PackagerConnectionSettings.class.getSimpleName();
  private static final String PREFS_DEBUG_SERVER_HOST_KEY = "debug_http_host";

  private final SharedPreferences mPreferences;
  private final String mPackageName;

  public PackagerConnectionSettings(Context applicationContext) {
    mPreferences = PreferenceManager.getDefaultSharedPreferences(applicationContext);
    mPackageName = applicationContext.getPackageName();
  }

  public String getDebugServerHost() {
    // Check host setting first. If empty try to detect emulator type and use default
    // hostname for those
    String hostFromSettings = mPreferences.getString(PREFS_DEBUG_SERVER_HOST_KEY, null);

    if (!TextUtils.isEmpty(hostFromSettings)) {
      return Assertions.assertNotNull(hostFromSettings);
    }

    String host = AndroidInfoHelpers.getServerHost();

    if (host.equals(AndroidInfoHelpers.DEVICE_LOCALHOST)) {
      FLog.w(
        TAG,
        "You seem to be running on device. Run 'adb reverse tcp:8081 tcp:8081' " +
          "to forward the debug server's port to the device.");
    }

    return host;
  }

  public @Nullable String getPackageName() {
    return mPackageName;
  }
}