Add API documentation for methods

* Improved maxClick() and sendClick() error handling
* Edited Grammar
* Updated build.gradle and wrote documentation for the BitcoinKit package. Documented classes included BitcoinKit.kt, MainNet.kt, RegTest.kt, and TestNet.kt.
* Fixed Typo
* Added passphrase to properties
* Dust Calculator documentation
* HashUtils documentation
* Utils documentation and formatting. utils package documentation is completed
* BitcoinInput documentation
* BitcoinInputMarkable documentation
* BitcoinOutput documentation and completion of the IO package

Author: TBCode523

bitcoincore/src/main/java/io/horizontalsystems/bitcoincore/DustCalculator.kt

@@ -3,9 +3,18 @@ package io.horizontalsystems.bitcoincore
 import io.horizontalsystems.bitcoincore.transactions.TransactionSizeCalculator
 import io.horizontalsystems.bitcoincore.transactions.scripts.ScriptType
 
+/**
+ * Calculates the minimum amount of BTC or "dust" required to broadcast a transaction and pay miner fees.
+ * @param dustRelayTxFee
+ * @param sizeCalculator
+ *
+ */
 class DustCalculator(dustRelayTxFee: Int, val sizeCalculator: TransactionSizeCalculator) {
     val minFeeRate = dustRelayTxFee / 1000
-
+/**
+ *@param type The ScriptType (Ex: P2PKH, P2WPKH, P2SH, etc.)
+ *@return The minimum amount of satoshis required to make a transaction.
+ */
     fun dust(type: ScriptType): Int {
         // https://github.com/bitcoin/bitcoin/blob/c536dfbcb00fb15963bf5d507b7017c241718bf6/src/policy/policy.cpp#L18
 

bitcoincore/src/main/java/io/horizontalsystems/bitcoincore/io/BitcoinInput.java

@@ -62,6 +62,9 @@ public int read() throws IOException {
 
     /**
      * Read and fill bytes into byte array.
+     *
+     * @param b Arbitrary byte array
+     * @throws IOException
      */
     public void readFully(byte b[]) throws IOException {
         int off = 0;
@@ -76,22 +79,36 @@ public void readFully(byte b[]) throws IOException {
         }
     }
 
+    /**
+     * Read and castes the read value to byte
+     * @return The converted int
+     * @throws IOException
+     */
     public byte readByte() throws IOException {
         int ch = in.read();
         if (ch < 0) {
             throw new EOFException();
         }
         return (byte) (ch);
     }
-
+    /**
+     * Read and return
+     * @return The read value
+     * @throws IOException
+     */
     public int readUnsignedByte() throws IOException {
         int ch = in.read();
         if (ch < 0) {
             throw new EOFException();
         }
         return ch;
     }
-
+    /**
+     * Read and create a short
+     *
+     * @return Converted Byte Array
+     * @throws IOException
+     */
     public short readShort() throws IOException {
         int ch1 = in.read();
         int ch2 = in.read();
@@ -100,7 +117,12 @@ public short readShort() throws IOException {
         }
         return (short) ((ch2 << 8) + (ch1 << 0));
     }
-
+    /**
+     * Read and create an unsigned short
+     *
+     * @return Converted Byte Array
+     * @throws IOException
+     */
     public int readUnsignedShort() throws IOException {
         int ch1 = in.read();
         int ch2 = in.read();
@@ -118,7 +140,12 @@ public char readChar() throws IOException {
         }
         return (char) ((ch2 << 8) + (ch1 << 0));
     }
-
+    /**
+     * Read and create an int
+     *
+     * @return Converted Byte Array
+     * @throws IOException
+     */
     public int readInt() throws IOException {
         int ch1 = in.read();
         int ch2 = in.read();
@@ -129,7 +156,12 @@ public int readInt() throws IOException {
         }
         return ((ch4 << 24) + (ch3 << 16) + (ch2 << 8) + (ch1 << 0));
     }
-
+    /**
+     * Read and create an unsigned int
+     *
+     * @return Converted Byte Array
+     * @throws IOException
+     */
     public long readUnsignedInt() throws IOException {
         int ch1 = in.read();
         int ch2 = in.read();
@@ -141,7 +173,12 @@ public long readUnsignedInt() throws IOException {
         long ln4 = ch4 & 0x00000000ffffffffL;
         return (ln4 << 24) + (ch3 << 16) + (ch2 << 8) + (ch1 << 0);
     }
-
+    /**
+     * Read and create a long
+     *
+     * @return Converted Byte Array
+     * @throws IOException
+     */
     public long readLong() throws IOException {
         readFully(bufferOf8bytes);
         return (((long) bufferOf8bytes[7] << 56) + ((long) (bufferOf8bytes[6] & 255) << 48)
@@ -150,6 +187,12 @@ public long readLong() throws IOException {
                 + ((bufferOf8bytes[1] & 255) << 8) + ((bufferOf8bytes[0] & 255) << 0));
     }
 
+    /**
+     * Read and create a String
+     *
+     * @return Converted Byte Array with Charset UTF-8 format
+     * @throws IOException
+     */
     public String readString() throws IOException {
         long len = readVarInt();
         if (len == 0) {
@@ -160,6 +203,13 @@ public String readString() throws IOException {
         return new String(buffer, StandardCharsets.UTF_8);
     }
 
+    /**
+     * Read and put values into a byte array
+     *
+     * @param len The desired length of the byte array
+     * @return A byte array with a length of len
+     * @throws IOException
+     */
     public byte[] readBytes(int len) throws IOException {
         if (len == 0) {
             return EMPTY_BYTES;

bitcoincore/src/main/java/io/horizontalsystems/bitcoincore/io/BitcoinInputMarkable.java

@@ -3,20 +3,31 @@
 import java.io.ByteArrayInputStream;
 import java.io.IOException;
 
+/**
+ * A child class of BitcoinInput and extends its functionality.
+ * @see BitcoinInput
+ */
 public final class BitcoinInputMarkable extends BitcoinInput {
-
+    //Stores the length of the data byte array.
     public int count;
-
+    /**
+    @param data Byte array that is going to by read by the InputStream
+    */
     public BitcoinInputMarkable(byte[] data) {
         super(new ByteArrayInputStream(data));
         this.count = data.length;
     }
 
+    /**
+     *Marks the InputStream
+     */
     public void mark() {
         // since the readlimit for ByteArrayInputStream has no meaning set it to 0
         in.mark(0);
     }
-
+    /**
+     *Resets the InputStream
+     */
     public void reset() throws IOException {
         in.reset();
     }

bitcoincore/src/main/java/io/horizontalsystems/bitcoincore/io/BitcoinOutput.java

@@ -8,15 +8,24 @@
  * Output "stream" for bitcoin protocol.
  *
  * @author Michael Liao
+ *
  */
 public final class BitcoinOutput {
 
     private UnsafeByteArrayOutputStream out;
 
+    /**
+     * Creates an instance of UnsafeByteArrayOutputStream of size 1024.
+     */
     public BitcoinOutput() {
         this.out = new UnsafeByteArrayOutputStream(1024);
     }
 
+    /**
+     * Writes a byte array to the OutputStream.
+     * @param bytes Byte array that's to be written.
+     * @return The newly written OutputStream.
+     */
     public BitcoinOutput write(byte[] bytes) {
         try {
             out.write(bytes);
@@ -25,26 +34,42 @@ public BitcoinOutput write(byte[] bytes) {
         }
         return this;
     }
-
+    /**
+     * Writes a byte to the OutputStream.
+     * @param v The byte to be written.
+     * @return The newly written OutputStream.
+     */
     public BitcoinOutput writeByte(int v) {
         out.write(v);
         return this;
     }
-
+    /**
+     * Writes a short to the OutputStream.
+     * @param v The short to be written.
+     * @return The newly written OutputStream.
+     */
     public BitcoinOutput writeShort(short v) {
         out.write(0xff & v);
         out.write(0xff & (v >> 8));
         return this;
     }
-
+    /**
+     * Writes an int to the OutputStream.
+     * @param v Int value.
+     * @return The newly written OutputStream.
+     */
     public BitcoinOutput writeInt(int v) {
         out.write(0xff & v);
         out.write(0xff & (v >> 8));
         out.write(0xff & (v >> 16));
         out.write(0xff & (v >> 24));
         return this;
     }
-
+    /**
+     * Writes a 32-bit int to the OutputStream.
+     * @param v Long value to be converted.
+     * @return The newly written OutputStream.
+     */
     public BitcoinOutput writeInt32(long v) {
         out.write((int)(0xff & v));
         out.write((int)(0xff & (v >> 8)));
@@ -53,6 +78,11 @@ public BitcoinOutput writeInt32(long v) {
         return this;
     }
 
+    /**
+     * Writes a Long to the OutputStream.
+     * @param v Long value to be converted.
+     * @return The newly written OutputStream.
+     */
     public BitcoinOutput writeLong(long v) {
         out.write((int) (0xff & v));
         out.write((int) (0xff & (v >> 8)));
@@ -65,6 +95,11 @@ public BitcoinOutput writeLong(long v) {
         return this;
     }
 
+    /**
+     * Writes a var int to the OutputStream.
+     * @param n Long value to be converted.
+     * @return The newly written OutputStream.
+     */
     public BitcoinOutput writeVarInt(long n) {
         if (n < 0xfd) {
             writeByte((int) n);
@@ -82,18 +117,33 @@ public BitcoinOutput writeVarInt(long n) {
         return this;
     }
 
+    /**
+     *  Writes an unsigned int to the OutputStream.
+     * @param ln Long value to be converted.
+     * @return The newly written OutputStream.
+     */
     public BitcoinOutput writeUnsignedInt(long ln) {
         int n = (int) (0xffffffff & ln);
         writeInt(n);
         return this;
     }
 
+    /**
+     * Writes an unsigned short to the OutputStream.
+     * @param i integer value to be casted as an unsigned short.
+     * @return The newly written OutputStream.
+     */
     public BitcoinOutput writeUnsignedShort(int i) {
         short n = (short) (0xffff & i);
         writeShort(n);
         return this;
     }
 
+    /**
+     * Writes a String to the OutputStream.
+     * @param str String value to be written.
+     * @return The newly written OutputStream.
+     */
     public BitcoinOutput writeString(String str) {
         byte[] bs = str.getBytes(StandardCharsets.UTF_8);
         writeVarInt(bs.length);