content: /*
   * Copyright (C) 2011 The Android Open Source Project
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package android.hardware;
  
  import android.annotation.UnsupportedAppUsage;
  import android.os.ParcelFileDescriptor;
  
  import java.io.FileDescriptor;
  import java.io.IOException;
  
  import java.nio.ByteBuffer;
  
  /**
   * @hide
   */
  public class SerialPort {
  
      private static final String TAG = "SerialPort";
  
      // used by the JNI code
      @UnsupportedAppUsage
      private int mNativeContext;
      private final String mName;
      private ParcelFileDescriptor mFileDescriptor;
  
      /**
       * SerialPort should only be instantiated by SerialManager
       * @hide
       */
      public SerialPort(String name) {
          mName = name;
      }
  
      /**
       * SerialPort should only be instantiated by SerialManager
       * Speed must be one of 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800, 9600,
       * 19200, 38400, 57600, 115200, 230400, 460800, 500000, 576000, 921600, 1000000, 1152000,
       * 1500000, 2000000, 2500000, 3000000, 3500000, 4000000
       *
       * @hide
       */
      public void open(ParcelFileDescriptor pfd, int speed) throws IOException {
          native_open(pfd.getFileDescriptor(), speed);
          mFileDescriptor = pfd;
      }
  
      /**
       * Closes the serial port
       */
      @UnsupportedAppUsage
      public void close() throws IOException {
          if (mFileDescriptor != null) {
              mFileDescriptor.close();
              mFileDescriptor = null;
          }
          native_close();
      }
  
      /**
       * Returns the name of the serial port
       *
       * @return the serial port's name
       */
      public String getName() {
          return mName;
      }
  
      /**
       * Reads data into the provided buffer.
       * Note that the value returned by {@link java.nio.Buffer#position()} on this buffer is
       * unchanged after a call to this method.
       *
       * @param buffer to read into
       * @return number of bytes read
       */
      public int read(ByteBuffer buffer) throws IOException {
          if (buffer.isDirect()) {
              return native_read_direct(buffer, buffer.remaining());
          } else if (buffer.hasArray()) {
              return native_read_array(buffer.array(), buffer.remaining());
          } else {
              throw new IllegalArgumentException("buffer is not direct and has no array");
          }
      }
  
      /**
       * Writes data from provided buffer.
       * Note that the value returned by {@link java.nio.Buffer#position()} on this buffer is
       * unchanged after a call to this method.
       *
       * @param buffer to write
       * @param length number of bytes to write
       */
      @UnsupportedAppUsage
      public void write(ByteBuffer buffer, int length) throws IOException {
          if (buffer.isDirect()) {
              native_write_direct(buffer, length);
          } else if (buffer.hasArray()) {
              native_write_array(buffer.array(), length);
          } else {
              throw new IllegalArgumentException("buffer is not direct and has no array");
          }
      }
  
      /**
       * Sends a stream of zero valued bits for 0.25 to 0.5 seconds
       */
      public void sendBreak() {
          native_send_break();
      }
  
      private native void native_open(FileDescriptor pfd, int speed) throws IOException;
      private native void native_close();
      private native int native_read_array(byte[] buffer, int length) throws IOException;
      private native int native_read_direct(ByteBuffer buffer, int length) throws IOException;
      private native void native_write_array(byte[] buffer, int length) throws IOException;
      private native void native_write_direct(ByteBuffer buffer, int length) throws IOException;
      private native void native_send_break();
  }
  