# HG changeset patch
# User Jaroslav Tulach <jaroslav.tulach@apidesign.org>
# Date 1386692055 -3600
# Node ID a0a31f8f7dc161b873640dfd3dc9761b4bc87410
# Parent  9718335431b73c2ecb69c1a66d203e94e926c31c
Tim wanted functional System.out, so let's make it do something useful

diff -r 9718335431b7 -r a0a31f8f7dc1 rt/emul/compact/src/main/java/java/lang/System.java
--- a/rt/emul/compact/src/main/java/java/lang/System.java	Fri Nov 22 14:20:49 2013 +0100
+++ b/rt/emul/compact/src/main/java/java/lang/System.java	Tue Dec 10 17:14:15 2013 +0100
@@ -17,9 +17,11 @@
  */
 package java.lang;
 
+import java.io.BufferedOutputStream;
 import java.io.ByteArrayInputStream;
-import java.io.ByteArrayOutputStream;
+import java.io.IOException;
 import java.io.InputStream;
+import java.io.OutputStream;
 import java.io.PrintStream;
 import java.util.Properties;
 import org.apidesign.bck2brwsr.core.JavaScriptBody;
@@ -88,9 +90,42 @@
 
     public final static PrintStream err;
     
+    public static void setOut(PrintStream out) {
+        throw new SecurityException();
+    }
+
+    public static void setIn(InputStream in) {
+        throw new SecurityException();
+    }
+
+    public static void setErr(PrintStream err) {
+        throw new SecurityException();
+    }
+    
     static {
         in = new ByteArrayInputStream(new byte[0]);
-        out = err = new PrintStream(new ByteArrayOutputStream());
+        out = new PrintStream(new BufferedOutputStream(new SystemStream("log")));
+        err = new PrintStream(new BufferedOutputStream(new SystemStream("warn")));
     }
-    
+
+    private static final class SystemStream extends OutputStream {
+        private final String method;
+
+        public SystemStream(String method) {
+            this.method = method;
+        }
+
+        @Override
+        public void write(byte b[], int off, int len) throws IOException {
+            write(method, new String(b, off, len, "UTF-8"));
+        }
+
+        @JavaScriptBody(args = { "method", "b" }, body = "if (typeof console !== 'undefined') console[method](b.toString());")
+        private static native void write(String method, String b);
+
+        @Override
+        public void write(int b) throws IOException {
+            write(new byte[] { (byte)b });
+        }
+    } // end of SystemStream
 }
diff -r 9718335431b7 -r a0a31f8f7dc1 rt/emul/compact/src/test/java/org/apidesign/bck2brwsr/tck/SystemTest.java
--- a/rt/emul/compact/src/test/java/org/apidesign/bck2brwsr/tck/SystemTest.java	Fri Nov 22 14:20:49 2013 +0100
+++ b/rt/emul/compact/src/test/java/org/apidesign/bck2brwsr/tck/SystemTest.java	Tue Dec 10 17:14:15 2013 +0100
@@ -17,6 +17,9 @@
  */
 package org.apidesign.bck2brwsr.tck;
 
+import java.io.ByteArrayOutputStream;
+import java.io.PrintStream;
+import org.apidesign.bck2brwsr.core.JavaScriptBody;
 import org.apidesign.bck2brwsr.vmtest.Compare;
 import org.apidesign.bck2brwsr.vmtest.VMTest;
 import org.testng.annotations.Factory;
@@ -30,6 +33,30 @@
         return System.getProperty("os.name") != null;
     }
 
+    @Compare public String captureStdOut() throws Exception {
+        Object capture = initCapture();
+        System.out.println("Ahoj");
+        return textCapture(capture);
+    }
+    
+    @JavaScriptBody(args = {}, body = ""
+        + "var lines = [];"
+        + "console.log = function(l) { lines.push(l); };"
+        + "return lines;")
+    Object initCapture() {
+        ByteArrayOutputStream os = new ByteArrayOutputStream();
+        PrintStream ps = new PrintStream(os);
+        
+        System.setOut(ps);
+        return os;
+    }
+    
+    @JavaScriptBody(args = { "o" }, body = "return o.join('');")
+    String textCapture(Object o) throws java.io.IOException {
+        ByteArrayOutputStream b = (ByteArrayOutputStream) o;
+        return new String(b.toByteArray(), "UTF-8");
+    }
+    
     @Factory public static Object[] create() {
         return VMTest.create(SystemTest.class);
     }