Moved hacky terminal fiddling code into a separate class.

git-svn-id: https://samskivert.googlecode.com/svn/trunk@775 6335cc39-0255-0410-8fd6-9bcaacd3b74c
2002-06-06 20:52:36 +00:00
parent 2db5f69858
commit 6ae292ba71
1 changed files with 130 additions and 0 deletions
@@ -0,0 +1,130 @@
+//
+// $Id: TermUtil.java,v 1.1 2002/06/06 20:52:36 mdb Exp $
+
+package com.samskivert.util;
+
+import java.awt.Dimension;
+
+import java.io.BufferedInputStream;
+import java.io.DataInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import java.util.regex.PatternSyntaxException;
+
+/**
+ * Provides access to the very platform specific concept of the terminal
+ * (ie. vt100, xterm, etc.) in which our code is running. Bear in mind
+ * that applications will commonly not be running in a terminal and this
+ * code should only be used when the operating environment is well known.
+ * It is generally useful to make things behave more nicely for the
+ * developer while developing.
+ */
+public class TermUtil
+{
+    /** VT100 formatting code to enabled bold text. */
+    public static final String BOLD = "\033[1m";
+
+    /** VT100 formatting code to enabled reverse video text. */
+    public static final String REVERSE = "\033[7m";
+
+    /** VT100 formatting code to enabled underlined text. */
+    public static final String UNDERLINE = "\033[4m";
+
+    /** VT100 formatting code to revert to plain text. */
+    public static final String PLAIN = "\033[m";
+
+    /**
+     * Returns a string that wraps the supplied string in the VT100 esacpe
+     * codes necessary to make it bold.
+     */
+    public static String makeBold (String text)
+    {
+        return BOLD + text + PLAIN;
+    }
+
+    /**
+     * Returns a string that wraps the supplied string in the VT100 esacpe
+     * codes necessary to make it underlined.
+     */
+    public static String makeUnderlined (String text)
+    {
+        return UNDERLINE + text + PLAIN;
+    }
+
+    /**
+     * Returns a string that wraps the supplied string in the VT100 esacpe
+     * codes necessary to display it in reverse video.
+     */
+    public static String makeReverseVideo (String text)
+    {
+        return REVERSE + text + PLAIN;
+    }
+
+    /**
+     * Attempts to obtain the dimensions of the terminal in which the
+     * application is running (the units are columns by lines, for example
+     * 80 by 24).
+     *
+     * @return the terminal dimensions or null if we were unable to obtain
+     * the dimensions.
+     */
+    public static Dimension getTerminalSize ()
+    {
+        // we may eventually have a variety of methods for obtaining
+        // terminal size, but for now there's only one
+        return getSizeViaResize();
+    }
+
+    /**
+     * Tries to obtain the terminal dimensions by running 'resize'.
+     */
+    protected static Dimension getSizeViaResize ()
+    {
+        try {
+            Process proc = Runtime.getRuntime().exec("resize");
+            InputStream in = proc.getInputStream();
+            BufferedInputStream bin = new BufferedInputStream(in);
+            DataInputStream din = new DataInputStream(bin);
+            Pattern regex = Pattern.compile("([0-9]+)");
+            String line;
+            int columns = -1, lines = -1;
+            while ((line = din.readLine()) != null) {
+                if (line.indexOf("COLUMNS") != -1) {
+                    Matcher match = regex.matcher(line);
+                    if (match.find()) {
+                        columns = safeToInt(match.group());
+                    }
+                } else if (line.indexOf("LINES") != -1) {
+                    Matcher match = regex.matcher(line);
+                    if (match.find()) {
+                        lines = safeToInt(match.group());
+                    }
+                }
+            }
+
+            if (columns != -1 && lines != -1) {
+                return new Dimension(columns, lines);
+            }
+
+        } catch (PatternSyntaxException pse) {
+        } catch (SecurityException se) {
+        } catch (IOException ioe) {
+        }
+        return null;
+    }
+
+    /** Converts the string to an integer, returning -1 on any error. */
+    protected static int safeToInt (String intstr)
+    {
+        if (!StringUtil.blank(intstr)) {
+            try {
+                return Integer.parseInt(intstr);
+            } catch (NumberFormatException nfe) {
+            }
+        }
+        return -1;
+    }
+}