NOTE: Calling this method starts a GUI user interface thread, which can continue * to run even if the thread that runs the main program ends. If you use this method * in a non-GUI program, it might be necessary to call System.exit(0) at the end of the main() * routine to shut down the Java virtual machine completely. */ public static boolean readUserSelectedFile() { if (fileDialog == null) fileDialog = new JFileChooser(); fileDialog.setDialogTitle("Select File for Input"); int option = fileDialog.showOpenDialog(console); if (option != JFileChooser.APPROVE_OPTION) return false; File selectedFile = fileDialog.getSelectedFile(); BufferedReader newin; try { newin = new BufferedReader( new FileReader(selectedFile) ); } catch (Exception e) { throw new IllegalArgumentException("Can't open file \"" + selectedFile.getName() + "\" for input.\n" + "(Error :" + e + ")"); } if (!readingStandardInput) { // close current file try { in.close(); } catch (Exception e) { } } emptyBuffer(); // Added November 2007 in = newin; inputFileName = selectedFile.getName(); readingStandardInput = false; inputErrorCount = 0; return true; } /** * After this method is called, output will be written to standard output (as it * is in the default state). If a file or stream was previously open for output, it * will be closed. */ public static void writeStandardOutput() { if (writingStandardOutput) return; try { out.close(); } catch (Exception e) { } outputFileName = null; outputErrorCount = 0; out = standardOutput; writingStandardOutput = true; } /** * After this method is called, output will be sent to outputStream, provided it * is non-null. If outputStream is null, then this method has the same effect * as calling writeStandardOutput(); that is, future output will be sent to the * standard output stream. */ public static void writeStream(OutputStream outputStream) { if (outputStream == null) writeStandardOutput(); else writeStream(new PrintWriter(outputStream)); } /** * After this method is called, output will be sent to outputStream, provided it * is non-null. If outputStream is null, then this method has the same effect * as calling writeStandardOutput(); that is, future output will be sent to the * standard output stream. */ public static void writeStream(PrintWriter outputStream) { if (outputStream == null) writeStandardOutput(); else { out = outputStream; outputFileName = null; outputErrorCount = 0; writingStandardOutput = false; } } /** * Opens a file with a specified name for output. If the file name is null, this has * the same effect as calling writeStandardOutput(); that is, output will be sent to standard * output. If an * error occurs while trying to open the file, an exception of type IllegalArgumentException * is thrown. If the file is opened successfully, then after this method is called, * all of the output routines will write to the file, instead of to standard output. * If an error occurs, the output destination is not changed. *
NOTE: Calling this method starts a GUI user interface thread, which can continue * to run even if the thread that runs the main program ends. If you use this method * in a non-GUI program, it might be necessary to call System.exit(0) at the end of the main() * routine to shut down the Java virtual machine completely. */ public static void writeFile(String fileName) { if (fileName == null) // Go back to reading standard output writeStandardOutput(); else { PrintWriter newout; try { newout = new PrintWriter(new FileWriter(fileName)); } catch (Exception e) { throw new IllegalArgumentException("Can't open file \"" + fileName + "\" for output.\n" + "(Error :" + e + ")"); } if (!writingStandardOutput) { try { out.close(); } catch (Exception e) { } } out = newout; writingStandardOutput = false; outputFileName = fileName; outputErrorCount = 0; } } /** * Puts a GUI file-selection dialog box on the screen in which the user can select * an output file. If the user cancels the dialog instead of selecting a file, it is * not considered an error, but the return value of the subroutine is false. * If the user does select a file, but there is an error while trying to open the * file, then an exception of type IllegalArgumentException is thrown. Finally, if * the user selects a file and it is successfully opened, then the return value of the * subroutine is true, and the output routines will write to the file, instead of * to standard output. If the user cancels, or if an error occurs, then the current * output destination is not changed. */ public static boolean writeUserSelectedFile() { if (fileDialog == null) fileDialog = new JFileChooser(); fileDialog.setDialogTitle("Select File for Output"); File selectedFile; while (true) { int option = fileDialog.showSaveDialog(console); if (option != JFileChooser.APPROVE_OPTION) return false; // user canceled selectedFile = fileDialog.getSelectedFile(); if (selectedFile.exists()) { int response = JOptionPane.showConfirmDialog(console, "The file \"" + selectedFile.getName() + "\" already exists. Do you want to replace it?", "Replace existing file?", JOptionPane.YES_NO_OPTION, JOptionPane.WARNING_MESSAGE); if (response == JOptionPane.YES_OPTION) break; } else { break; } } PrintWriter newout; try { newout = new PrintWriter(new FileWriter(selectedFile)); } catch (Exception e) { throw new IllegalArgumentException("Can't open file \"" + selectedFile.getName() + "\" for output.\n" + "(Error :" + e + ")"); } if (!writingStandardOutput) { try { out.close(); } catch (Exception e) { } } out = newout; writingStandardOutput = false; outputFileName = selectedFile.getName(); outputErrorCount = 0; return true; } /** * If TextIO is currently reading from a file, then the return value is the name of the file. * If the class is reading from standard input or from a stream, then the return value is null. */ public static String getInputFileName() { return inputFileName; } /** * If TextIO is currently writing to a file, then the return value is the name of the file. * If the class is writing to standard output or to a stream, then the return value is null. */ public static String getOutputFileName() { return outputFileName; } // *************************** Output Methods ********************************* /** * Write a single value to the current output destination, using the default format * and no extra spaces. This method will handle any type of parameter, even one * whose type is one of the primitive types. */ public static void put(Object x) { out.print(x); out.flush(); if (out.checkError()) outputError("Error while writing output."); } /** * Write a single value to the current output destination, using the default format * and outputting at least minChars characters (with extra spaces added before the * output value if necessary). This method will handle any type of parameter, even one * whose type is one of the primitive types. * @param x The value to be output, which can be of any type. * @param minChars The minimum number of characters to use for the output. If x requires fewer * then this number of characters, then extra spaces are added to the front of x to bring * the total up to minChars. If minChars is less than or equal to zero, then x will be printed * in the minimum number of spaces possible. */ public static void put(Object x, int minChars) { if (minChars <= 0) out.print(x); else { out.printf("%" + minChars + "s", x); out.flush(); } if (out.checkError()) outputError("Error while writing output."); } /** * This is equivalent to put(x), followed by an end-of-line. */ public static void putln(Object x) { out.println(x); out.flush(); if (out.checkError()) outputError("Error while writing output."); } /** * This is equivalent to put(x,minChars), followed by an end-of-line. */ public static void putln(Object x, int minChars) { put(x,minChars); out.println(); out.flush(); if (out.checkError()) outputError("Error while writing output."); } /** * Write an end-of-line character to the current output destination. */ public static void putln() { out.println(); out.flush(); if (out.checkError()) outputError("Error while writing output."); } /** * Writes formatted output values to the current output destination. This method has the * same function as System.out.printf(); the details of formatted output are not discussed * here. The first parameter is a string that describes the format of the output. There * can be any number of additional parameters; these specify the values to be output and * can be of any type. This method will throw an IllegalArgumentException if the * format string is null or if the format string is illegal for the values that are being * output. */ public static void putf(String format, Object... items) { if (format == null) throw new IllegalArgumentException("Null format string in TextIO.putf() method."); try { out.printf(format,items); } catch (IllegalFormatException e) { throw new IllegalArgumentException("Illegal format string in TextIO.putf() method."); } out.flush(); if (out.checkError()) outputError("Error while writing output."); } // *************************** Input Methods ********************************* /** * Test whether the next character in the current input source is an end-of-line. Note that * this method does NOT skip whitespace before testing for end-of-line -- if you want to do * that, call skipBlanks() first. */ public static boolean eoln() { return peek() == '\n'; } /** * Test whether the next character in the current input source is an end-of-file. Note that * this method does NOT skip whitespace before testing for end-of-line -- if you want to do * that, call skipBlanks() or skipWhitespace() first. */ public static boolean eof() { return peek() == EOF; } /** * Reads the next character from the current input source. The character can be a whitespace * character; compare this to the getChar() method, which skips over whitespace and returns the * next non-whitespace character. An end-of-line is always returned as the character '\n', even * when the actual end-of-line in the input source is something else, such as '\r' or "\r\n". * This method will throw an IllegalArgumentException if the input is at end-of-file (which will * not ordinarily happen if reading from standard input). */ public static char getAnyChar() { return readChar(); } /** * Returns the next character in the current input source, without actually removing that * character from the input. The character can be a whitespace character and can be the * end-of-file character (specified by the constant TextIO.EOF).An end-of-line is always returned * as the character '\n', even when the actual end-of-line in the input source is something else, * such as '\r' or "\r\n". This method never causes an error. */ public static char peek() { return lookChar(); } /** * Skips over any whitespace characters, except for end-of-lines. After this method is called, * the next input character is either an end-of-line, an end-of-file, or a non-whitespace character. * This method never causes an error. (Ordinarily, end-of-file is not possible when reading from * standard input.) */ public static void skipBlanks() { char ch=lookChar(); while (ch != EOF && ch != '\n' && Character.isWhitespace(ch)) { readChar(); ch = lookChar(); } } /** * Skips over any whitespace characters, including for end-of-lines. After this method is called, * the next input character is either an end-of-file or a non-whitespace character. * This method never causes an error. (Ordinarily, end-of-file is not possible when reading from * standard input.) */ private static void skipWhitespace() { char ch=lookChar(); while (ch != EOF && Character.isWhitespace(ch)) { readChar(); if (ch == '\n' && readingStandardInput && writingStandardOutput) { out.print("? "); out.flush(); } ch = lookChar(); } } /** * Skips whitespace characters and then reads a value of type byte from input, discarding the rest of * the current line of input (including the next end-of-line character, if any). When using standard IO, * this will not produce an error; the user will be prompted repeatedly for input until a legal value * is input. In other cases, an IllegalArgumentException will be thrown if a legal value is not found. */ public static byte getlnByte() { byte x=getByte(); emptyBuffer(); return x; } /** * Skips whitespace characters and then reads a value of type short from input, discarding the rest of * the current line of input (including the next end-of-line character, if any). When using standard IO, * this will not produce an error; the user will be prompted repeatedly for input until a legal value * is input. In other cases, an IllegalArgumentException will be thrown if a legal value is not found. */ public static short getlnShort() { short x=getShort(); emptyBuffer(); return x; } /** * Skips whitespace characters and then reads a value of type int from input, discarding the rest of * the current line of input (including the next end-of-line character, if any). When using standard IO, * this will not produce an error; the user will be prompted repeatedly for input until a legal value * is input. In other cases, an IllegalArgumentException will be thrown if a legal value is not found. */ public static int getlnInt() { int x=getInt(); emptyBuffer(); return x; } /** * Skips whitespace characters and then reads a value of type long from input, discarding the rest of * the current line of input (including the next end-of-line character, if any). When using standard IO, * this will not produce an error; the user will be prompted repeatedly for input until a legal value * is input. In other cases, an IllegalArgumentException will be thrown if a legal value is not found. */ public static long getlnLong() { long x=getLong(); emptyBuffer(); return x; } /** * Skips whitespace characters and then reads a value of type float from input, discarding the rest of * the current line of input (including the next end-of-line character, if any). When using standard IO, * this will not produce an error; the user will be prompted repeatedly for input until a legal value * is input. In other cases, an IllegalArgumentException will be thrown if a legal value is not found. */ public static float getlnFloat() { float x=getFloat(); emptyBuffer(); return x; } /** * Skips whitespace characters and then reads a value of type double from input, discarding the rest of * the current line of input (including the next end-of-line character, if any). When using standard IO, * this will not produce an error; the user will be prompted repeatedly for input until a legal value * is input. In other cases, an IllegalArgumentException will be thrown if a legal value is not found. */ public static double getlnDouble() { double x=getDouble(); emptyBuffer(); return x; } /** * Skips whitespace characters and then reads a value of type char from input, discarding the rest of * the current line of input (including the next end-of-line character, if any). Note that the value * that is returned will be a non-whitespace character; compare this with the getAnyChar() method. * When using standard IO, this will not produce an error. In other cases, an error can occur if * an end-of-file is encountered. */ public static char getlnChar() { char x=getChar(); emptyBuffer(); return x; } /** * Skips whitespace characters and then reads a value of type boolean from input, discarding the rest of * the current line of input (including the next end-of-line character, if any). When using standard IO, * this will not produce an error; the user will be prompted repeatedly for input until a legal value * is input. In other cases, an IllegalArgumentException will be thrown if a legal value is not found. *
Legal inputs for a boolean input are: true, t, yes, y, 1, false, f, no, n, and 0; letters can be * either upper case or lower case. One "word" of input is read, using the getWord() method, and it * must be one of these; note that the "word" must be terminated by a whitespace character (or end-of-file). */ public static boolean getlnBoolean() { boolean x=getBoolean(); emptyBuffer(); return x; } /** * Skips whitespace characters and then reads one "word" from input, discarding the rest of * the current line of input (including the next end-of-line character, if any). A word is defined as * a sequence of non-whitespace characters (not just letters!). When using standard IO, * this will not produce an error. In other cases, an IllegalArgumentException will be thrown * if an end-of-file is encountered. */ public static String getlnWord() { String x=getWord(); emptyBuffer(); return x; } /** * This is identical to getln(). */ public static String getlnString() { return getln(); } /** * Reads all the characters from the current input source, up to the next end-of-line. The end-of-line * is read but is not included in the return value. Any other whitespace characters on the line are retained, * even if they occur at the start of input. The return value will be an empty string if there are no * no characters before the end-of-line. When using standard IO, this will not produce an error. * In other cases, an IllegalArgumentException will be thrown if an end-of-file is encountered. */ public static String getln() { StringBuffer s = new StringBuffer(100); char ch = readChar(); while (ch != '\n') { s.append(ch); ch = readChar(); } return s.toString(); } /** * Skips whitespace characters and then reads a value of type byte from input. Any additional characters on * the current line of input are retained, and will be read by the next input operation. When using standard IO, * this will not produce an error; the user will be prompted repeatedly for input until a legal value * is input. In other cases, an IllegalArgumentException will be thrown if a legal value is not found. */ public static byte getByte() { return (byte)readInteger(-128L,127L); } /** * Skips whitespace characters and then reads a value of type short from input. Any additional characters on * the current line of input are retained, and will be read by the next input operation. When using standard IO, * this will not produce an error; the user will be prompted repeatedly for input until a legal value * is input. In other cases, an IllegalArgumentException will be thrown if a legal value is not found. */ public static short getShort() { return (short)readInteger(-32768L,32767L); } /** * Skips whitespace characters and then reads a value of type int from input. Any additional characters on * the current line of input are retained, and will be read by the next input operation. When using standard IO, * this will not produce an error; the user will be prompted repeatedly for input until a legal value * is input. In other cases, an IllegalArgumentException will be thrown if a legal value is not found. */ public static int getInt() { return (int)readInteger((long)Integer.MIN_VALUE, (long)Integer.MAX_VALUE); } /** * Skips whitespace characters and then reads a value of type long from input. Any additional characters on * the current line of input are retained, and will be read by the next input operation. When using standard IO, * this will not produce an error; the user will be prompted repeatedly for input until a legal value * is input. In other cases, an IllegalArgumentException will be thrown if a legal value is not found. */ public static long getLong() { return readInteger(Long.MIN_VALUE, Long.MAX_VALUE); } /** * Skips whitespace characters and then reads a single non-whitespace character from input. Any additional characters on * the current line of input are retained, and will be read by the next input operation. When using standard IO, * this will not produce an error. In other cases, an IllegalArgumentException will be thrown if an end-of-file * is encountered. */ public static char getChar() { skipWhitespace(); return readChar(); } /** * Skips whitespace characters and then reads a value of type float from input. Any additional characters on * the current line of input are retained, and will be read by the next input operation. When using standard IO, * this will not produce an error; the user will be prompted repeatedly for input until a legal value * is input. In other cases, an IllegalArgumentException will be thrown if a legal value is not found. */ public static float getFloat() { float x = 0.0F; while (true) { String str = readRealString(); if (str == null) { errorMessage("Floating point number not found.", "Real number in the range " + (-Float.MAX_VALUE) + " to " + Float.MAX_VALUE); } else { try { x = Float.parseFloat(str); } catch (NumberFormatException e) { errorMessage("Illegal floating point input, " + str + ".", "Real number in the range " + (-Float.MAX_VALUE) + " to " + Float.MAX_VALUE); continue; } if (Float.isInfinite(x)) { errorMessage("Floating point input outside of legal range, " + str + ".", "Real number in the range " + (-Float.MAX_VALUE) + " to " + Float.MAX_VALUE); continue; } break; } } inputErrorCount = 0; return x; } /** * Skips whitespace characters and then reads a value of type double from input. Any additional characters on * the current line of input are retained, and will be read by the next input operation. When using standard IO, * this will not produce an error; the user will be prompted repeatedly for input until a legal value * is input. In other cases, an IllegalArgumentException will be thrown if a legal value is not found. */ public static double getDouble() { double x = 0.0; while (true) { String str = readRealString(); if (str == null) { errorMessage("Floating point number not found.", "Real number in the range " + (-Double.MAX_VALUE) + " to " + Double.MAX_VALUE); } else { try { x = Double.parseDouble(str); } catch (NumberFormatException e) { errorMessage("Illegal floating point input, " + str + ".", "Real number in the range " + (-Double.MAX_VALUE) + " to " + Double.MAX_VALUE); continue; } if (Double.isInfinite(x)) { errorMessage("Floating point input outside of legal range, " + str + ".", "Real number in the range " + (-Double.MAX_VALUE) + " to " + Double.MAX_VALUE); continue; } break; } } inputErrorCount = 0; return x; } /** * Skips whitespace characters and then reads one "word" from input. Any additional characters on * the current line of input are retained, and will be read by the next input operation. A word is defined as * a sequence of non-whitespace characters (not just letters!). When using standard IO, * this will not produce an error. In other cases, an IllegalArgumentException will be thrown * if an end-of-file is encountered. */ public static String getWord() { skipWhitespace(); StringBuffer str = new StringBuffer(50); char ch = lookChar(); while (ch == EOF || !Character.isWhitespace(ch)) { str.append(readChar()); ch = lookChar(); } return str.toString(); } /** * Skips whitespace characters and then reads a value of type boolean from input. Any additional characters on * the current line of input are retained, and will be read by the next input operation. When using standard IO, * this will not produce an error; the user will be prompted repeatedly for input until a legal value * is input. In other cases, an IllegalArgumentException will be thrown if a legal value is not found. *
Legal inputs for a boolean input are: true, t, yes, y, 1, false, f, no, n, and 0; letters can be * either upper case or lower case. One "word" of input is read, using the getWord() method, and it * must be one of these; note that the "word" must be terminated by a whitespace character (or end-of-file). */ public static boolean getBoolean() { boolean ans = false; while (true) { String s = getWord(); if ( s.equalsIgnoreCase("true") || s.equalsIgnoreCase("t") || s.equalsIgnoreCase("yes") || s.equalsIgnoreCase("y") || s.equals("1") ) { ans = true; break; } else if ( s.equalsIgnoreCase("false") || s.equalsIgnoreCase("f") || s.equalsIgnoreCase("no") || s.equalsIgnoreCase("n") || s.equals("0") ) { ans = false; break; } else errorMessage("Illegal boolean input value.", "one of: true, false, t, f, yes, no, y, n, 0, or 1"); } inputErrorCount = 0; return ans; } // ***************** Everything beyond this point is private implementation detail ******************* private static String inputFileName; // Name of file that is the current input source, or null if the source is not a file. private static String outputFileName; // Name of file that is the current output destination, or null if the destination is not a file. private static JFileChooser fileDialog; // Dialog used by readUserSelectedFile() and writeUserSelectedFile() private final static BufferedReader standardInput; // wraps the input stream from Console. (Set in static initializer.) private final static PrintWriter standardOutput; // wraps the output stream. (Set in static initializer.) private static BufferedReader in; // Stream that data is read from; the current input source. (Set in static initializer.) private static PrintWriter out; // Stream that data is written to; the current output destination. (Set in static initializer.) private static boolean readingStandardInput = true; private static boolean writingStandardOutput = true; private static int inputErrorCount; // Number of consecutive errors on standard input; reset to 0 when a successful read occurs. private static int outputErrorCount; // Number of errors on standard output since it was selected as the output destination. private static Matcher integerMatcher; // Used for reading integer numbers; created from the integer Regex Pattern. private static Matcher floatMatcher; // Used for reading floating point numbers; created from the floatRegex Pattern. private final static Pattern integerRegex = Pattern.compile("(\\+|-)?[0-9]+"); private final static Pattern floatRegex = Pattern.compile("(\\+|-)?(([0-9]+(\\.[0-9]*)?)|(\\.[0-9]+))((e|E)(\\+|-)?[0-9]+)?"); private static String buffer = null; // One line read from input. private static int pos = 0; // Position of next char in input line that has not yet been processed. private static Console console; // The GUI IO widget used for simulated input/output. static PrintWriter getOut() { return standardOutput; } static BufferedReader getIn() { return standardInput; } private static String readRealString() { // read chars from input following syntax of real numbers skipWhitespace(); if (lookChar() == EOF) return null; if (floatMatcher == null) floatMatcher = floatRegex.matcher(buffer); floatMatcher.region(pos,buffer.length()); if (floatMatcher.lookingAt()) { String str = floatMatcher.group(); pos = floatMatcher.end(); return str; } else return null; } private static String readIntegerString() { // read chars from input following syntax of integers skipWhitespace(); if (lookChar() == EOF) return null; if (integerMatcher == null) integerMatcher = integerRegex.matcher(buffer); integerMatcher.region(pos,buffer.length()); if (integerMatcher.lookingAt()) { String str = integerMatcher.group(); pos = integerMatcher.end(); return str; } else return null; } private static long readInteger(long min, long max) { // read long integer, limited to specified range long x=0; while (true) { String s = readIntegerString(); if (s == null){ errorMessage("Integer value not found in input.", "Integer in the range " + min + " to " + max); } else { String str = s.toString(); try { x = Long.parseLong(str); } catch (NumberFormatException e) { errorMessage("Illegal integer input, " + str + ".", "Integer in the range " + min + " to " + max); continue; } if (x < min || x > max) { errorMessage("Integer input outside of legal range, " + str + ".", "Integer in the range " + min + " to " + max); continue; } break; } } inputErrorCount = 0; return x; } private static void errorMessage(String message, String expecting) { // Report error on input. console.clearTypeAhead(); if (readingStandardInput && writingStandardOutput) { // inform user of error and force user to re-enter. out.println(); out.print(" *** Error in input: " + message + "\n"); out.print(" *** Expecting: " + expecting + "\n"); out.print(" *** Discarding Input: "); if (lookChar() == '\n') out.print("(end-of-line)\n\n"); else { while (lookChar() != '\n') // Discard and echo remaining chars on the current line of input. out.print(readChar()); out.print("\n\n"); } out.print("Please re-enter: "); out.flush(); readChar(); // discard the end-of-line character inputErrorCount++; if (inputErrorCount >= 10) throw new IllegalArgumentException("Too many input consecutive input errors on standard input."); } else if (inputFileName != null) throw new IllegalArgumentException("Error while reading from file \"" + inputFileName + "\":\n" + message + "\nExpecting " + expecting); else throw new IllegalArgumentException("Error while reading from input stream:\n" + message + "\nExpecting " + expecting); } private static char lookChar() { // return next character from input if (buffer == null || pos > buffer.length()) fillBuffer(); if (buffer == null) return EOF; else if (pos == buffer.length()) return '\n'; else return buffer.charAt(pos); } private static char readChar() { // return and discard next character from input char ch = lookChar(); if (buffer == null) { if (readingStandardInput) throw new IllegalArgumentException("Attempt to read past end-of-file in standard input???"); else throw new IllegalArgumentException("Attempt to read past end-of-file in file \"" + inputFileName + "\"."); } pos++; return ch; } private static void fillBuffer() { // Wait for user to type a line and press return, try { buffer = in.readLine(); } catch (Exception e) { if (readingStandardInput) throw new IllegalArgumentException("Error while reading standard input???"); else if (inputFileName != null) throw new IllegalArgumentException("Error while attempting to read from file \"" + inputFileName + "\"."); else throw new IllegalArgumentException("Errow while attempting to read form an input stream."); } pos = 0; floatMatcher = null; integerMatcher = null; } private static void emptyBuffer() { // discard the rest of the current line of input buffer = null; } private static void outputError(String message) { // Report an error on output. if (writingStandardOutput) { System.err.println("Error occurred in TextIO while writing to standard output!!"); outputErrorCount++; if (outputErrorCount >= 10) { outputErrorCount = 0; throw new IllegalArgumentException("Too many errors while writing to standard output."); } } else if (outputFileName != null){ throw new IllegalArgumentException("Error occurred while writing to file \"" + outputFileName+ "\":\n " + message); } else { throw new IllegalArgumentException("Error occurred while writing to output stream:\n " + message); } } // ******************************* Defining the GUI *************************************** /** * A "Console" is a panel which simulates standard input/output. When this GUI TextIO class is used, * a frame will be opened that displays a Console. When the output destination for TextIO is standard * output, the output will appear in the window. When TextIO wants to fill its buffer with a line of input * from standard input, the user will type a line of input in the Console, which will go into the buffer. * There is also a scroll bar that can be used to browse lines that have scorlled off the top (up to 2000 lines). */ private static class Console extends JPanel { JScrollBar scroller; BufferedReader inputStream; PrintWriter outputStream; String[] lines; int topLine; int lineCount; int rows, columns; volatile boolean doingInput; volatile String inputBuffer; volatile boolean cursorOn = true; volatile int inputStartLine, inputStartColumn; volatile String typeAheadBuffer = ""; FontMetrics fontMetrics; int lineSkip; int charWidth; final static int MARGIN = 9; final static Color CURSOR_COLOR = new Color(200,0,0); Console() { Dimension screensize = Toolkit.getDefaultToolkit().getScreenSize(); Font f = new Font("Monospaced", Font.PLAIN, 14); fontMetrics = getFontMetrics(f); if ( fontMetrics.getHeight() * 1.2 * 25 > screensize.height - 50) { f = new Font("Monospaced", Font.PLAIN, 12); fontMetrics = getFontMetrics(f); } lineSkip = (int)(fontMetrics.getHeight() * 1.2); charWidth = fontMetrics.charWidth('W'); setFont(f); setPreferredSize(new Dimension(2*MARGIN + 80*charWidth, 2*MARGIN + (25-1)*lineSkip + fontMetrics.getAscent() + fontMetrics.getDescent())); setBackground(Color.WHITE); setForeground(Color.BLACK); setBorder(BorderFactory.createLineBorder(Color.LIGHT_GRAY, 3)); addFocusListener( new FocusListener() { public void focusLost(FocusEvent evt) { setBorder(BorderFactory.createLineBorder(Color.LIGHT_GRAY,3)); } public void focusGained(FocusEvent evt) { setBorder(BorderFactory.createLineBorder(new Color(0,180,180),3)); } } ); addMouseListener( new MouseAdapter() { public void mousePressed(MouseEvent evt) { requestFocus(); } } ); addKeyListener( new KeyAdapter() { public void keyTyped(KeyEvent evt) { char ch = evt.getKeyChar(); if (ch == KeyEvent.CHAR_UNDEFINED) return; if (!doingInput) { typeAheadBuffer += ch; return; } synchronized(Console.this) { doInputChar(ch); Console.this.notify(); } } } ); lines = new String[2000]; lineCount = 1; lines[0] = ""; scroller = new JScrollBar(JScrollBar.VERTICAL,0,80,0,80); scroller.setEnabled(false); scroller.addAdjustmentListener( new AdjustmentListener() { public void adjustmentValueChanged(AdjustmentEvent evt) { topLine = scroller.getValue(); repaint(); } }); inputStream = new BufferedReader(new CIN()); outputStream = new PrintWriter(new COUT()); } public void paintComponent(Graphics g) { super.paintComponent(g); ((Graphics2D)g).setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON); if (rows == 0) { columns = (getWidth() - 2*MARGIN + 1) / charWidth; rows = 1 + (getHeight() - 2*MARGIN - fontMetrics.getAscent()) / lineSkip; scroller.setBlockIncrement(rows - 2); scrollToEnd(); } for (int i = topLine; i < topLine + rows && i < lineCount; i++) g.drawString(lines[i],MARGIN,MARGIN+(i-topLine)*lineSkip + fontMetrics.getAscent()); if (doingInput && cursorOn) { g.setColor(CURSOR_COLOR); int x = MARGIN + fontMetrics.stringWidth(lines[lineCount-1])+1; int y1 = MARGIN + (lineCount-1-topLine)*lineSkip + fontMetrics.getAscent() + fontMetrics.getDescent(); int y2 = y1 - fontMetrics.getAscent() - fontMetrics.getDescent(); g.drawLine(x,y1,x,y2); g.drawLine(x+1,y1,x+1,y2); } } synchronized void newLine() { try { Thread.sleep(20); } catch (InterruptedException e) { } if (lineCount == lines.length) { for (int i = 0; i < lines.length-1; i++) lines[i] = lines[i+1]; lines[lines.length-1] = ""; if (doingInput) inputStartLine--; } else { lines[lineCount] = ""; lineCount++; } scrollToEnd(); repaint(); } synchronized void putChar(char ch) { if (ch == '\n') { newLine(); return; } if (ch == '\t') ch = ' '; if (!Character.isDefined(ch) || Character.isISOControl(ch)) return; if (columns > 0 && lines[lineCount-1].length() >= columns) newLine(); lines[lineCount-1] += ch; } synchronized void deleteChar() { if (lineCount == 0) return; if (inputStartLine == lineCount-1 && inputStartColumn >= lines[lineCount-1].length()) return; if (lines[lineCount-1].length() > 0) lines[lineCount-1] = lines[lineCount-1].substring(0,lines[lineCount-1].length()-1); else { lineCount--; scrollToEnd(); } } void scrollToEnd() { if (rows == 0) return; if (lineCount <= rows) { topLine = 0; scroller.setEnabled(false); } else { topLine = lineCount - rows; scroller.setEnabled(true); } scroller.setValues(topLine,rows,0,rows+topLine); } synchronized void doInputChar(char ch) { if (ch == 8 || ch == 127) { deleteChar(); if (inputBuffer.length() > 0) inputBuffer = inputBuffer.substring(0,inputBuffer.length()-1); } else if (ch == 13 || ch == 10) { newLine(); doingInput = false; } else { putChar(ch); if (ch == '\t') ch = ' '; if (Character.isDefined(ch) && ! Character.isISOControl(ch)) inputBuffer += ch; } scrollToEnd(); repaint(); } synchronized void clearTypeAhead() { typeAheadBuffer = ""; } class CIN extends Reader { // "Standard input" is replaced in TextIO with an object of this type. String buffer; int pos; public void close() { } public int read(char[] b, int offset, int length) throws IOException { int ct = 0; int ch; do { ch = read(); b[offset + ct] = (char)ch; ct++; } while (ch != 10); return ct; } public int read() { if (buffer != null && pos < buffer.length()) { pos++; return buffer.charAt(pos-1); } synchronized(Console.this) { inputStartLine = lineCount - 1; inputStartColumn = lines[lineCount-1].length(); char ch = 0; scrollToEnd(); inputBuffer = ""; while (typeAheadBuffer.length() > 0) { ch = typeAheadBuffer.charAt(0); typeAheadBuffer = typeAheadBuffer.substring(1); if (ch == 13 || ch == 10) break; doInputChar(ch); repaint(); try { Console.this.wait(25); } catch (InterruptedException e) { } } if (ch != 13 && ch != 10) { doingInput = true; cursorOn = true; requestFocus(); while (doingInput) { try { Console.this.wait(300); cursorOn = !cursorOn; repaint(); } catch (InterruptedException e) { cursorOn = true; repaint(); } } cursorOn = false; repaint(); } buffer = inputBuffer + (char)10; pos = 1; return buffer.charAt(0); } } } class COUT extends Writer { // "Standard output" is replaced in TextIO with an object of this type. public void write(int b) { write(new char[] { (char)(b & 0xFFFF) }, 0, 1); } public void write(char[] b, int offset, int length) { for (int i = offset; i < offset+length; i++) { putChar(b[i]); } } public void write(char[] b) { write(b,0,b.length); } public void close() { } public void flush() { } } } // end nested class Console static { // static initializer opens the GUI TextIO window. JFrame frame = new JFrame("TextIO Console"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); console = new Console(); in = standardInput = console.inputStream; out = standardOutput = console.outputStream; JPanel panel = new JPanel(); panel.setLayout(new BorderLayout(2,2)); panel.setBackground(Color.GRAY); panel.setBorder(BorderFactory.createLineBorder(Color.GRAY,2)); panel.add(console,BorderLayout.CENTER); panel.add(console.scroller,BorderLayout.EAST); frame.setContentPane(panel); frame.pack(); frame.setResizable(false); Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize(); frame.setLocation( (screenSize.width - frame.getWidth())/2, (screenSize.height - frame.getHeight())/2 ); frame.setVisible(true); console.requestFocus(); } } // end of class TextIO