Add the concept of a BuildLogger - A BuildListener with the following

- An output level used to filter build events
- Access to the ant output print stream
- An emacs mode.

Update DefaultLogger to the new interface. In its emacs mode, output
is unadorned by the [taskname] tags

Add -logger option to allow the logger class to be changed
Add -emacs option to control the logger's emacsMode setting


git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@267836 13f79535-47bb-0310-9956-ffa450edef68

src/main/org/apache/tools/ant/BuildLogger.java

@@ -0,0 +1,92 @@
+/*
+ * The Apache Software License, Version 1.1
+ *
+ * Copyright (c) 1999 The Apache Software Foundation.  All rights
+ * reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. The end-user documentation included with the redistribution, if
+ *    any, must include the following acknowlegement:
+ *       "This product includes software developed by the
+ *        Apache Software Foundation (http://www.apache.org/)."
+ *    Alternately, this acknowlegement may appear in the software itself,
+ *    if and wherever such third-party acknowlegements normally appear.
+ *
+ * 4. The names "The Jakarta Project", "Tomcat", and "Apache Software
+ *    Foundation" must not be used to endorse or promote products derived
+ *    from this software without prior written permission. For written
+ *    permission, please contact apache@apache.org.
+ *
+ * 5. Products derived from this software may not be called "Apache"
+ *    nor may "Apache" appear in their names without prior written
+ *    permission of the Apache Group.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation.  For more
+ * information on the Apache Software Foundation, please see
+ * <http://www.apache.org/>.
+ */
+
+package org.apache.tools.ant;
+
+import java.io.*;
+
+/**
+ * Interface used by Ant to log the build output. 
+ *
+ * A build logger is a build listener which has the 'right' to send output to the
+ * ant log, which is usually System.out unles redirected by the -logfile option.
+ *
+ * @author Conor MacNeill
+ */
+public interface BuildLogger extends BuildListener {
+    /**
+     * Set the msgOutputLevel this logger is to respond to.
+     *
+     * Only messages with a message level lower than or equal to the given level are 
+     * output to the log.
+     *
+     * @param level the logging level for the logger.
+     */
+    public void setMessageOutputLevel(int level);
+    
+    /**
+     * Set the output stream to which this logger is to send its output.
+     *
+     * @param output the output stream for the logger.
+     */
+    public void setOutputPrintStream(PrintStream output);
+    
+    /**
+     * Set this logger to produce emacs (and other editor) friendly output.
+     *
+     * @param emacsMode true if output is to be unadorned so that emacs and other
+     * editors can parse files names, etc.
+     */
+    public void setEmacsMode(boolean emacsMode);
+}

src/main/org/apache/tools/ant/DefaultLogger.java

@@ -61,24 +61,48 @@ import java.io.*;
  *  only writes which targets are being executed, and
  *  any messages that get logged.
  */
-public class DefaultLogger implements BuildListener {
+public class DefaultLogger implements BuildLogger {
     private static int LEFT_COLUMN_SIZE = 12;
 
     private PrintStream out;
     private int msgOutputLevel;
     private long startTime = System.currentTimeMillis();
 
+    private boolean emacsMode = false;
 
     /**
-     *  Constructs a new logger which will write to the specified
-     *  PrintStream. Messages with a priority lower (higher?) than
-     *  msgOutputLevel will be ignored.
+     * Set the msgOutputLevel this logger is to respond to.
+     *
+     * Only messages with a message level lower than or equal to the given level are 
+     * output to the log.
+     *
+     * @param level the logging level for the logger.
      */
-    public DefaultLogger(PrintStream out, int msgOutputLevel) {
-        this.out = out;
-        this.msgOutputLevel = msgOutputLevel;
+    public void setMessageOutputLevel(int level) {
+        this.msgOutputLevel = level;
     }
 
+    
+    /**
+     * Set the output stream to which this logger is to send its output.
+     *
+     * @param output the output stream for the logger.
+     */
+    public void setOutputPrintStream(PrintStream output) {
+        this.out = output;
+    }
+
+    /**
+     * Set this logger to produce emacs (and other editor) friendly output.
+     *
+     * @param emacsMode true if output is to be unadorned so that emacs and other
+     * editors can parse files names, etc.
+     */
+    public void setEmacsMode(boolean emacsMode) {
+        this.emacsMode = emacsMode;
+    }
+
+
     public void buildStarted(BuildEvent event) {
         startTime = System.currentTimeMillis();
     }
@@ -133,11 +157,13 @@ public class DefaultLogger implements BuildListener {
             if (event.getTask() != null) {
                 String name = event.getTask().getTaskName();
 
-                String msg = "[" + name + "] ";
-                for (int i = 0; i < (LEFT_COLUMN_SIZE - msg.length()); i++) {
-                    out.print(" ");
+                if (!emacsMode) {
+                    String msg = "[" + name + "] ";
+                    for (int i = 0; i < (LEFT_COLUMN_SIZE - msg.length()); i++) {
+                        out.print(" ");
+                    }
+                    out.print(msg);
                 }
-                out.print(msg);
             }
 
             // Print the message

src/main/org/apache/tools/ant/Main.java

@@ -90,6 +90,18 @@ public class Main {
     /** Names of classes to add as listeners to project */
     private Vector listeners = new Vector(5);
 
+    /**
+     * The Ant logger class. There may be only one logger. It will have the
+     * right to use the 'out' PrintStream. The class must implements the BuildLogger 
+     * interface
+     */
+    private String loggerClassname = null;
+
+    /**
+     * Indicates whether output to the log is to be unadorned.
+     */
+    private boolean emacsMode = false;
+
     /**
      * Indicates if this ant should be run.
      */
@@ -190,6 +202,14 @@ public class Main {
                     value = args[++i];
 
                 definedProps.put(name, value);
+            } else if (arg.equals("-logger")) {
+                if (loggerClassname != null) {
+                    System.out.println("Only one logger class may be specified.");
+                    return;
+                }
+                loggerClassname = args[++i];
+            } else if (arg.equals("-emacs")) {
+                emacsMode = true;
             } else if (arg.startsWith("-")) {
                 // we don't have any more args to recognize!
                 String msg = "Unknown arg: " + arg;
@@ -224,7 +244,6 @@ public class Main {
     /**
      * Executes the build.
      */
-
     private void runBuild() throws BuildException {
 
         if (!readyToRun) {
@@ -294,7 +313,7 @@ public class Main {
     protected void addBuildListeners(Project project) {
 
         // Add the default listener
-        project.addBuildListener(createDefaultBuildListener());
+        project.addBuildListener(createLogger());
 
         for (int i = 0; i < listeners.size(); i++) {
             String className = (String) listeners.elementAt(i);
@@ -310,10 +329,34 @@ public class Main {
     }
 
     /**
-     *  Creates the default build listener for displaying output to the screen.
+     *  Creates the default build logger for sending build events to the ant log.
      */
-    private BuildListener createDefaultBuildListener() {
-        return new DefaultLogger(out, msgOutputLevel);
+    private BuildLogger createLogger() {
+        BuildLogger logger = null;
+        if (loggerClassname != null) {
+            try {
+                logger = (BuildLogger)(Class.forName(loggerClassname).newInstance());
+            }
+            catch (ClassCastException e) {
+                System.err.println("The specified logger class " + loggerClassname + 
+                                         " does not implement the BuildLogger interface");
+                throw new RuntimeException();
+            }
+            catch (Exception e) {
+                System.err.println("Unable to instantiate specified logger class " + 
+                                           loggerClassname + " : " + e.getClass().getName());
+                throw new RuntimeException();
+            }
+        }
+        else {
+            logger = new DefaultLogger();
+        }
+        
+        logger.setMessageOutputLevel(msgOutputLevel);
+        logger.setOutputPrintStream(out);
+        logger.setEmacsMode(emacsMode);
+        
+        return logger;
     }
 
     /**
@@ -328,7 +371,9 @@ public class Main {
         msg.append("  -version               print the version information and exit" + lSep);
         msg.append("  -quiet                 be extra quiet" + lSep);
         msg.append("  -verbose               be extra verbose" + lSep);
+        msg.append("  -emacs                 produce logging information without adornments" + lSep);
         msg.append("  -logfile <file>        use given file for log" + lSep);
+        msg.append("  -logger <classname>    the class which is to perform logging" + lSep);
         msg.append("  -listener <classname>  add an instance of class as a project listener" + lSep);
         msg.append("  -buildfile <file>      use given buildfile" + lSep);
         msg.append("  -D<property>=<value>   use value for given property" + lSep);

src/main/org/apache/tools/ant/taskdefs/Ant.java

@@ -120,7 +120,10 @@ public class Ant extends Task {
         if (output != null) {
             try {
                 PrintStream out = new PrintStream(new FileOutputStream(output));
-                p1.addBuildListener(new DefaultLogger(out, Project.MSG_INFO));
+                DefaultLogger logger = new DefaultLogger();
+                logger.setMessageOutputLevel(Project.MSG_INFO);
+                logger.setOutputPrintStream(out);
+                p1.addBuildListener(logger);
             }
             catch( IOException ex ) {
                 log( "Ant: Can't set output to " + output );