- Added support for setting the terminal foreground color.

- Some improvements to error handling.

readme.md

@@ -6,6 +6,7 @@ Provides Java bindings for various native APIs.
 * Determine if stdout/stderr are attached to a terminal.
 * Query the terminal size.
 * Switch between bold and normal mode on the terminal.
+* Change foreground color on the terminal.
 
 Currently only ported to OS X (10.7.4) and Linux (Ubuntu 12.04).
 

src/main/cpp/posixFunctions.c

@@ -8,10 +8,24 @@
 #include <curses.h>
 #include <term.h>
 
-void markFailed(JNIEnv *env, jobject result) {
+/*
+ * Marks the given result as failed, using the current value of errno
+ */
+void mark_failed_with_errno(JNIEnv *env, const char* message, jobject result) {
     jclass destClass = env->GetObjectClass(result);
-    jmethodID method = env->GetMethodID(destClass, "failed", "(I)V");
+    jmethodID method = env->GetMethodID(destClass, "failed", "(Ljava/lang/String;I)V");
-    env->CallVoidMethod(result, method, errno);
+    jstring message_str = env->NewStringUTF(message);
+    env->CallVoidMethod(result, method, message_str, errno);
+}
+
+/*
+ * Marks the given result as failed, using the given error message
+ */
+void mark_failed_with_message(JNIEnv *env, const char* message, jobject result) {
+    jclass destClass = env->GetObjectClass(result);
+    jmethodID method = env->GetMethodID(destClass, "failed", "(Ljava/lang/String;)V");
+    jstring message_str = env->NewStringUTF(message);
+    env->CallVoidMethod(result, method, message_str);
 }
 
 /*
@@ -20,7 +34,7 @@ void markFailed(JNIEnv *env, jobject result) {
 
 JNIEXPORT jint JNICALL
 Java_net_rubygrapefruit_platform_internal_NativeLibraryFunctions_getVersion(JNIEnv *env, jclass target) {
-    return 1;
+    return 2;
 }
 
 /*
@@ -31,8 +45,9 @@ JNIEXPORT void JNICALL
 Java_net_rubygrapefruit_platform_internal_PosixFileFunctions_chmod(JNIEnv *env, jclass target, jstring path, jint mode, jobject result) {
     const char* pathUtf8 = env->GetStringUTFChars(path, NULL);
     int retval = chmod(pathUtf8, mode);
+    env->ReleaseStringUTFChars(path, pathUtf8);
     if (retval != 0) {
-        markFailed(env, result);
+        mark_failed_with_errno(env, "could not chmod file", result);
     }
 }
 
@@ -41,8 +56,9 @@ Java_net_rubygrapefruit_platform_internal_PosixFileFunctions_stat(JNIEnv *env, j
     struct stat fileInfo;
     const char* pathUtf8 = env->GetStringUTFChars(path, NULL);
     int retval = stat(pathUtf8, &fileInfo);
+    env->ReleaseStringUTFChars(path, pathUtf8);
     if (retval != 0) {
-        markFailed(env, result);
+        mark_failed_with_errno(env, "could not stat file", result);
         return;
     }
     jclass destClass = env->GetObjectClass(dest);
@@ -79,7 +95,7 @@ Java_net_rubygrapefruit_platform_internal_PosixTerminalFunctions_getTerminalSize
     struct winsize screen_size;
     int retval = ioctl(output+1, TIOCGWINSZ, &screen_size);
     if (retval != 0) {
-        markFailed(env, result);
+        mark_failed_with_errno(env, "could not fetch terminal size", result);
         return;
     }
     jclass dimensionClass = env->GetObjectClass(dimension);
@@ -102,25 +118,29 @@ int write_to_terminal(int ch) {
 void write_capability(JNIEnv *env, const char* capability, jobject result) {
     char* cap = tgetstr((char*)capability, NULL);
     if (cap == NULL) {
-        markFailed(env, result);
+        mark_failed_with_message(env, "unknown terminal capability", result);
         return;
     }
     if (tputs(cap, 1, write_to_terminal) == ERR) {
-        markFailed(env, result);
+        mark_failed_with_message(env, "could not write to terminal", result);
         return;
     }
 }
 
 JNIEXPORT void JNICALL
 Java_net_rubygrapefruit_platform_internal_TerminfoFunctions_initTerminal(JNIEnv *env, jclass target, jint output, jobject result) {
+    if (!isatty(output+1)) {
+        mark_failed_with_message(env, "not a terminal", result);
+        return;
+    }
     char* termType = getenv("TERM");
     if (termType == NULL) {
-        markFailed(env, result);
+        mark_failed_with_message(env, "$TERM not set", result);
         return;
     }
     int retval = tgetent(NULL, termType);
     if (retval != 1) {
-        markFailed(env, result);
+        mark_failed_with_message(env, "could not get termcap entry", result);
         return;
     }
     current_terminal = output + 1;
@@ -128,11 +148,31 @@ Java_net_rubygrapefruit_platform_internal_TerminfoFunctions_initTerminal(JNIEnv
 }
 
 JNIEXPORT void JNICALL
-Java_net_rubygrapefruit_platform_internal_TerminfoFunctions_bold(JNIEnv *env, jclass target, jint output, jobject result) {
+Java_net_rubygrapefruit_platform_internal_TerminfoFunctions_bold(JNIEnv *env, jclass target, jobject result) {
     write_capability(env, "md", result);
 }
 
 JNIEXPORT void JNICALL
-Java_net_rubygrapefruit_platform_internal_TerminfoFunctions_normal(JNIEnv *env, jclass target, jint output, jobject result) {
+Java_net_rubygrapefruit_platform_internal_TerminfoFunctions_reset(JNIEnv *env, jclass target, jobject result) {
     write_capability(env, "me", result);
 }
+
+JNIEXPORT void JNICALL
+Java_net_rubygrapefruit_platform_internal_TerminfoFunctions_foreground(JNIEnv *env, jclass target, jint color, jobject result) {
+    char* capability = tgetstr((char*)"AF", NULL);
+    if (capability == NULL) {
+        mark_failed_with_message(env, "unknown terminal capability", result);
+        return;
+    }
+
+    capability = tparm(capability, color, 0, 0, 0, 0, 0, 0, 0, 0);
+    if (capability == NULL) {
+        mark_failed_with_message(env, "could not format terminal capability string", result);
+        return;
+    }
+
+    if (tputs(capability, 1, write_to_terminal) == ERR) {
+        mark_failed_with_message(env, "could not write to terminal", result);
+        return;
+    }
+}

src/main/java/net/rubygrapefruit/platform/Main.java

@@ -15,11 +15,24 @@ public class Main {
             Terminal terminal = terminalAccess.getTerminal(TerminalAccess.Output.Stdout);
             TerminalSize terminalSize = terminal.getTerminalSize();
             System.out.println("* terminal size: " + terminalSize.getCols() + " cols x " + terminalSize.getRows() + " rows");
+            System.out.println();
+            System.out.println("TERMINAL OUTPUT");
             System.out.print("[normal] ");
             terminal.bold();
             System.out.print("[bold]");
             terminal.normal();
             System.out.println(" [normal]");
+
+            System.out.println("here are the colors:");
+            for (Terminal.Color color : Terminal.Color.values()) {
+                terminal.foreground(color);
+                System.out.print(String.format("[%s] ", color.toString().toLowerCase()));
+                terminal.bold();
+                System.out.print(String.format("[%s]", color.toString().toLowerCase()));
+                terminal.normal();
+                System.out.println();
+            }
+            System.out.println();
         }
     }
 }

src/main/java/net/rubygrapefruit/platform/Platform.java

@@ -52,7 +52,7 @@ public class Platform {
             FunctionResult result = new FunctionResult();
             PosixFileFunctions.chmod(file.getPath(), perms, result);
             if (result.isFailed()) {
-                throw new NativeException(String.format("Could not set UNIX mode on %s. Errno is %d.", file, result.getErrno()));
+                throw new NativeException(String.format("Could not set UNIX mode on %s: %s", file, result.getMessage()));
             }
         }
 
@@ -62,7 +62,7 @@ public class Platform {
             FileStat stat = new FileStat();
             PosixFileFunctions.stat(file.getPath(), stat, result);
             if (result.isFailed()) {
-                throw new NativeException(String.format("Could not get UNIX mode on %s. Errno is %d.", file, result.getErrno()));
+                throw new NativeException(String.format("Could not get UNIX mode on %s: %s", file, result.getMessage()));
             }
             return stat.mode;
         }
@@ -100,6 +100,7 @@ public class Platform {
     private static class DefaultTerminal implements Terminal {
         private final TerminalAccess.Output output;
         private final PrintStream stream;
+        private Color foreground;
 
         public DefaultTerminal(TerminalAccess.Output output) {
             this.output = output;
@@ -111,9 +112,14 @@ public class Platform {
             FunctionResult result = new FunctionResult();
             TerminfoFunctions.initTerminal(output.ordinal(), result);
             if (result.isFailed()) {
-                throw new NativeException(String.format("Could not open terminal. Errno is %d.",
+                throw new NativeException(String.format("Could not open terminal: %s", result.getMessage()));
-                        result.getErrno()));
             }
+            Runtime.getRuntime().addShutdownHook(new Thread(){
+                @Override
+                public void run() {
+                    reset();
+                }
+            });
         }
 
         @Override
@@ -122,40 +128,50 @@ public class Platform {
             FunctionResult result = new FunctionResult();
             PosixTerminalFunctions.getTerminalSize(output.ordinal(), terminalSize, result);
             if (result.isFailed()) {
-                throw new NativeException(String.format("Could not get terminal size. Errno is %d.",
+                throw new NativeException(String.format("Could not get terminal size: %s", result.getMessage()));
-                        result.getErrno()));
             }
             return terminalSize;
         }
 
+        @Override
+        public Terminal foreground(Color color) {
+            stream.flush();
+            FunctionResult result = new FunctionResult();
+            TerminfoFunctions.foreground(color.ordinal(), result);
+            if (result.isFailed()) {
+                throw new NativeException(String.format("Could not switch foreground color: %s", result.getMessage()));
+            }
+            foreground = color;
+            return this;
+        }
+
         @Override
         public Terminal bold() {
             stream.flush();
             FunctionResult result = new FunctionResult();
-            TerminfoFunctions.bold(output.ordinal(), result);
+            TerminfoFunctions.bold(result);
             if (result.isFailed()) {
-                throw new NativeException(String.format("Could not switch to bold mode. Errno is %d.",
+                throw new NativeException(String.format("Could not switch to bold mode: %s", result.getMessage()));
-                        result.getErrno()));
             }
             return this;
         }
 
-        @Override
-        public Terminal bold(String output) {
-            bold();
-            stream.print(output);
-            normal();
-            return this;
-        }
-
         @Override
         public Terminal normal() {
+            reset();
+            if (foreground != null) {
+                foreground(foreground);
+            }
+            return this;
+        }
+
+        @Override
+        public Terminal reset() {
             stream.flush();
             FunctionResult result = new FunctionResult();
-            TerminfoFunctions.normal(output.ordinal(), result);
+            TerminfoFunctions.reset(result);
             if (result.isFailed()) {
-                throw new NativeException(String.format("Could not switch to normal mode. Errno is %d.",
+                throw new NativeException(String.format("Could not reset terminal: %s", result.getMessage()));
-                        result.getErrno()));
             }
             return this;
         }

src/main/java/net/rubygrapefruit/platform/Terminal.java

@@ -1,20 +1,32 @@
 package net.rubygrapefruit.platform;
 
 public interface Terminal {
+    enum Color {
+        Black, Red, Green, Yellow, Blue, Magenta, Cyan, White
+    }
+
+    /**
+     * Returns the size of the terminal.
+     */
     TerminalSize getTerminalSize();
 
+    /**
+     * Sets the terminal foreground color.
+     */
+    Terminal foreground(Color color);
+
     /**
      * Switches the terminal to bold mode.
      */
     Terminal bold();
 
-    /**
-     * Switches the terminal to bold mode, outputs the given text, then switches to normal mode.
-     */
-    Terminal bold(String output);
-
     /**
      * Switches the terminal to normal mode.
      */
     Terminal normal();
+
+    /**
+     * Switches the terminal to normal mode and restores default colors.
+     */
+    Terminal reset();
 }

src/main/java/net/rubygrapefruit/platform/internal/FunctionResult.java

@@ -1,17 +1,26 @@
 package net.rubygrapefruit.platform.internal;
 
 public class FunctionResult {
+    String message;
     int errno;
 
-    void failed(int errno) {
+    void failed(String message, int errno) {
+        this.message = message;
         this.errno = errno;
     }
 
-    public boolean isFailed() {
+    void failed(String message) {
-        return errno != 0;
+        this.message = message;
     }
 
-    public int getErrno() {
+    public boolean isFailed() {
-        return errno;
+        return message != null;
+    }
+
+    public String getMessage() {
+        if (errno != 0) {
+            return String.format("%s (errno %d)", message, errno);
+        }
+        return message;
     }
 }

src/main/java/net/rubygrapefruit/platform/internal/NativeLibraryFunctions.java

@@ -1,7 +1,7 @@
 package net.rubygrapefruit.platform.internal;
 
 public class NativeLibraryFunctions {
-    public static final int VERSION = 1;
+    public static final int VERSION = 2;
 
     public static native int getVersion();
 }

src/main/java/net/rubygrapefruit/platform/internal/TerminfoFunctions.java

@@ -6,7 +6,12 @@ public class TerminfoFunctions {
      */
     public static native void initTerminal(int filedes, FunctionResult result);
 
-    public static native void bold(int filedes, FunctionResult result);
+    public static native void bold(FunctionResult result);
 
-    public static native void normal(int filedes, FunctionResult result);
+    public static native void reset(FunctionResult result);
+
+    /**
+     * Set the foreground color to the given ansi color.
+     */
+    public static native void foreground(int ansiColor, FunctionResult result);
 }

src/test/groovy/net/rubygrapefruit/platform/PosixFileTest.groovy

@@ -36,7 +36,7 @@ class PosixFileTest extends Specification {
 
         then:
         NativeException e = thrown()
-        e.message == "Could not set UNIX mode on $file. Errno is 2."
+        e.message == "Could not set UNIX mode on $file: could not chmod file (errno 2)"
     }
 
     def "throws exception on failure to get mode"() {
@@ -47,6 +47,6 @@ class PosixFileTest extends Specification {
 
         then:
         NativeException e = thrown()
-        e.message == "Could not get UNIX mode on $file. Errno is 2."
+        e.message == "Could not get UNIX mode on $file: could not stat file (errno 2)"
     }
 }

src/test/groovy/net/rubygrapefruit/platform/TerminalTest.groovy

@@ -20,6 +20,6 @@ class TerminalTest extends Specification {
 
         then:
         NativeException e = thrown()
-        e.message.startsWith('Could not open terminal. Errno is ')
+        e.message == 'Could not open terminal: not a terminal'
     }
 }