- Added Terminal.supportsTextAttributes(), supportsColor() and supportCursorMotion().

- Changed semantics for Terminal.normal(), bold(), foreground() and reset() so that they are no-ops when not supported.
- Fixed test app not to blow up on unsupported capability.

src/main/cpp/generic.cpp

@@ -17,5 +17,5 @@ void mark_failed_with_code(JNIEnv *env, const char* message, int error_code, job
 
 JNIEXPORT jint JNICALL
 Java_net_rubygrapefruit_platform_internal_jni_NativeLibraryFunctions_getVersion(JNIEnv *env, jclass target) {
-    return 3;
+    return 4;
 }

src/main/cpp/posix.cpp

@@ -115,9 +115,9 @@ int write_to_terminal(TERMINAL_CHAR_TYPE ch) {
 
 const char* getcap(const char* capability) {
     char* cap = tgetstr((char*)capability, NULL);
-    if (cap == NULL) {
+//    if (cap == NULL) {
-        printf("unknown capability '%s'\n", capability);
+//        printf("unknown capability '%s'\n", capability);
-    }
+//    }
     return cap;
 }
 
@@ -151,7 +151,7 @@ void write_param_capability(JNIEnv *env, const char* capability, int count, jobj
 }
 
 JNIEXPORT void JNICALL
-Java_net_rubygrapefruit_platform_internal_jni_TerminfoFunctions_initTerminal(JNIEnv *env, jclass target, jint output, jobject result) {
+Java_net_rubygrapefruit_platform_internal_jni_TerminfoFunctions_initTerminal(JNIEnv *env, jclass target, jint output, jobject capabilities, jobject result) {
     if (!isatty(output+1)) {
         mark_failed_with_message(env, "not a terminal", result);
         return;
@@ -167,18 +167,42 @@ Java_net_rubygrapefruit_platform_internal_jni_TerminfoFunctions_initTerminal(JNI
             mark_failed_with_message(env, "could not get termcap entry", result);
             return;
         }
+
+        jclass destClass = env->GetObjectClass(capabilities);
+        jfieldID field = env->GetFieldID(destClass, "terminalName", "Ljava/lang/String;");
+        jstring jtermType = env->NewStringUTF(termType);
+        env->SetObjectField(capabilities, field, jtermType);
+
+        // Text attributes
         terminal_capabilities[NORMAL_TEXT] = getcap("me");
         terminal_capabilities[BRIGHT_TEXT] = getcap("md");
+        field = env->GetFieldID(destClass, "textAttributes", "Z");
+        env->SetBooleanField(capabilities, field, terminal_capabilities[NORMAL_TEXT] != NULL && terminal_capabilities[BRIGHT_TEXT] != NULL);
+
+        // Colors
         terminal_capabilities[FOREGROUND_COLOR] = getcap("AF");
+        field = env->GetFieldID(destClass, "colors", "Z");
+        env->SetBooleanField(capabilities, field, terminal_capabilities[FOREGROUND_COLOR] != NULL);
+
+        // Cursor motion
         terminal_capabilities[CURSOR_UP] = getcap("up");
         terminal_capabilities[CURSOR_DOWN] = getcap("do");
         terminal_capabilities[CURSOR_LEFT] = getcap("le");
         terminal_capabilities[CURSOR_RIGHT] = getcap("nd");
         terminal_capabilities[CURSOR_START_LINE] = getcap("cr");
         terminal_capabilities[CLEAR_END_OF_LINE] = getcap("ce");
+        field = env->GetFieldID(destClass, "cursorMotion", "Z");
+        env->SetBooleanField(capabilities, field, terminal_capabilities[CURSOR_UP] != NULL
+                                && terminal_capabilities[CURSOR_DOWN] != NULL
+                                && terminal_capabilities[CURSOR_RIGHT] != NULL
+                                && terminal_capabilities[CURSOR_LEFT] != NULL
+                                && terminal_capabilities[CURSOR_START_LINE] != NULL
+                                && terminal_capabilities[CLEAR_END_OF_LINE] != NULL);
     }
     current_terminal = output + 1;
-    write_capability(env, terminal_capabilities[NORMAL_TEXT], result);
+    if (terminal_capabilities[NORMAL_TEXT] != NULL) {
+        write_capability(env, terminal_capabilities[NORMAL_TEXT], result);
+    }
 }
 
 JNIEXPORT void JNICALL
@@ -188,7 +212,9 @@ Java_net_rubygrapefruit_platform_internal_jni_TerminfoFunctions_bold(JNIEnv *env
 
 JNIEXPORT void JNICALL
 Java_net_rubygrapefruit_platform_internal_jni_TerminfoFunctions_reset(JNIEnv *env, jclass target, jobject result) {
-    write_capability(env, terminal_capabilities[NORMAL_TEXT], result);
+    if (terminal_capabilities[NORMAL_TEXT] != NULL) {
+        write_capability(env, terminal_capabilities[NORMAL_TEXT], result);
+    }
 }
 
 JNIEXPORT void JNICALL

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

@@ -4,6 +4,7 @@ public class Main {
     public static void main(String[] args) {
         System.out.println();
         System.out.println("* OS: " + System.getProperty("os.name") + ' ' + System.getProperty("os.version") + ' ' + System.getProperty("os.arch"));
+        System.out.println("* JVM: " + System.getProperty("java.vm.vendor") + ' ' + System.getProperty("java.version"));
 
         Process process = Native.get(Process.class);
         System.out.println("* PID: " + process.getProcessId());
@@ -17,8 +18,11 @@ 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("* text attributes: " + (terminal.supportsTextAttributes() ? "yes" : "no"));
+            System.out.println("* color: " + (terminal.supportsColor() ? "yes" : "no"));
+            System.out.println("* cursor motion: " + (terminal.supportsCursorMotion() ? "yes" : "no"));
             System.out.println();
-            System.out.println("TERMINAL OUTPUT");
+            System.out.println("TEXT ATTRIBUTES");
             System.out.print("[normal] ");
             terminal.bold();
             System.out.print("[bold]");
@@ -39,28 +43,29 @@ public class Main {
             System.out.println();
             terminal.reset();
 
-            System.out.println("CURSOR MOVEMENT");
+            if (terminal.supportsCursorMotion()) {
-            System.out.println("                    ");
+                System.out.println("CURSOR MOVEMENT");
-            System.out.println("                    ");
+                System.out.println("                    ");
-            System.out.println("                    ");
+                System.out.println("                    ");
-            System.out.print("[delete me]");
+                System.out.print("[delete me]");
 
-            terminal.cursorLeft(11);
+                terminal.cursorLeft(11);
-            terminal.cursorUp(1);
+                terminal.cursorUp(1);
-            terminal.cursorRight(10);
+                terminal.cursorRight(10);
-            System.out.print("[4]");
+                System.out.print("[4]");
-            terminal.cursorUp(1);
+                terminal.cursorUp(1);
-            terminal.cursorLeft(3);
+                terminal.cursorLeft(3);
-            System.out.print("[2]");
+                System.out.print("[2]");
-            terminal.cursorLeft(13);
+                terminal.cursorLeft(13);
-            System.out.print("[1]");
+                System.out.print("[1]");
-            terminal.cursorLeft(3);
+                terminal.cursorLeft(3);
-            terminal.cursorDown(1);
+                terminal.cursorDown(1);
-            System.out.print("[3]");
+                System.out.print("[3]");
-            terminal.cursorDown(1);
+                terminal.cursorDown(1);
-            terminal.cursorStartOfLine();
+                terminal.cursorStartOfLine();
-            terminal.clearToEndOfLine();
+                terminal.clearToEndOfLine();
-            System.out.println("done!");
+                System.out.println("done!");
+            }
         }
 
         System.out.println();

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

@@ -11,35 +11,51 @@ public interface Terminal {
     }
 
     /**
-     * Returns the size of the terminal.
+     * Returns true if this terminal supports setting text attributes, such as bold.
+     */
+    boolean supportsTextAttributes();
+
+    /**
+     * Returns true if this terminal supports setting output colors.
+     */
+    boolean supportsColor();
+
+    /**
+     * Returns true if this terminal supports moving the cursor.
+     */
+    boolean supportsCursorMotion();
+
+    /**
+     * Returns the size of the terminal. Supported by all terminals.
      *
      * @throws NativeException On failure.
      */
     TerminalSize getTerminalSize() throws NativeException;
 
     /**
-     * Sets the terminal foreground color.
+     * Sets the terminal foreground color, if supported. Does nothing if this terminal does not support setting the
+     * foreground color.
      *
      * @throws NativeException On failure.
      */
     Terminal foreground(Color color) throws NativeException;
 
     /**
-     * Switches the terminal to bold mode.
+     * Switches the terminal to bold mode, if supported. Does nothing if this terminal does not support bold mode.
      *
      * @throws NativeException On failure.
      */
     Terminal bold() throws NativeException;
 
     /**
-     * Switches the terminal to normal mode.
+     * Switches the terminal to normal mode. Supported by all terminals.
      *
      * @throws NativeException On failure.
      */
     Terminal normal() throws NativeException;
 
     /**
-     * Switches the terminal to normal mode and restores default colors.
+     * Switches the terminal to normal mode and restores default colors. Supported by all terminals.
      *
      * @throws NativeException On failure.
      */
@@ -48,42 +64,42 @@ public interface Terminal {
     /**
      * Moves the cursor the given number of characters to the left.
      *
-     * @throws NativeException On failure.
+     * @throws NativeException On failure, or if this terminal does not support cursor motion.
      */
     Terminal cursorLeft(int count) throws NativeException;
 
     /**
      * Moves the cursor the given number of characters to the right.
      *
-     * @throws NativeException On failure.
+     * @throws NativeException On failure, or if this terminal does not support cursor motion.
      */
     Terminal cursorRight(int count) throws NativeException;
 
     /**
      * Moves the cursor the given number of characters up.
      *
-     * @throws NativeException On failure.
+     * @throws NativeException On failure, or if this terminal does not support cursor motion.
      */
     Terminal cursorUp(int count) throws NativeException;
 
     /**
      * Moves the cursor the given number of characters down.
      *
-     * @throws NativeException On failure.
+     * @throws NativeException On failure, or if this terminal does not support cursor motion.
      */
     Terminal cursorDown(int count) throws NativeException;
 
     /**
      * Moves the cursor to the start of the current line.
      *
-     * @throws NativeException On failure.
+     * @throws NativeException On failure, or if this terminal does not support cursor motion.
      */
     Terminal cursorStartOfLine() throws NativeException;
 
     /**
      * Clears characters from the cursor position to the end of the current line.
      *
-     * @throws NativeException On failure.
+     * @throws NativeException On failure, or if this terminal does not support clearing.
      */
     Terminal clearToEndOfLine() throws NativeException;
 }

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

@@ -0,0 +1,8 @@
+package net.rubygrapefruit.platform.internal;
+
+public class TerminalCapabilities {
+    String terminalName;
+    boolean textAttributes;
+    boolean colors;
+    boolean cursorMotion;
+}

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

@@ -12,6 +12,7 @@ import java.io.PrintStream;
 public class TerminfoTerminal extends AbstractTerminal {
     private final TerminalAccess.Output output;
     private final PrintStream stream;
+    private final TerminalCapabilities capabilities = new TerminalCapabilities();
     private Color foreground;
 
     public TerminfoTerminal(TerminalAccess.Output output) {
@@ -28,7 +29,7 @@ public class TerminfoTerminal extends AbstractTerminal {
     protected void doInit() {
         stream.flush();
         FunctionResult result = new FunctionResult();
-        TerminfoFunctions.initTerminal(output.ordinal(), result);
+        TerminfoFunctions.initTerminal(output.ordinal(), capabilities, result);
         if (result.isFailed()) {
             throw new NativeException(String.format("Could not open terminal for %s: %s", this, result.getMessage()));
         }
@@ -45,13 +46,33 @@ public class TerminfoTerminal extends AbstractTerminal {
         return terminalSize;
     }
 
+    @Override
+    public boolean supportsColor() {
+        return capabilities.colors;
+    }
+
+    @Override
+    public boolean supportsCursorMotion() {
+        return capabilities.cursorMotion;
+    }
+
+    @Override
+    public boolean supportsTextAttributes() {
+        return capabilities.textAttributes;
+    }
+
     @Override
     public Terminal foreground(Color color) {
+        if (!capabilities.colors) {
+            return this;
+        }
+
         stream.flush();
         FunctionResult result = new FunctionResult();
         TerminfoFunctions.foreground(color.ordinal(), result);
         if (result.isFailed()) {
-            throw new NativeException(String.format("Could not switch foreground color for %s: %s", this, result.getMessage()));
+            throw new NativeException(String.format("Could not switch foreground color for %s: %s", this,
+                    result.getMessage()));
         }
         foreground = color;
         return this;
@@ -59,11 +80,16 @@ public class TerminfoTerminal extends AbstractTerminal {
 
     @Override
     public Terminal bold() {
+        if (!capabilities.textAttributes) {
+            return this;
+        }
+
         stream.flush();
         FunctionResult result = new FunctionResult();
         TerminfoFunctions.bold(result);
         if (result.isFailed()) {
-            throw new NativeException(String.format("Could not switch to bold mode for %s: %s", this, result.getMessage()));
+            throw new NativeException(String.format("Could not switch to bold mode for %s: %s", this,
+                    result.getMessage()));
         }
         return this;
     }

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

@@ -1,141 +1,155 @@
-package net.rubygrapefruit.platform.internal;
+package net.rubygrapefruit.platform.internal;
-
+
-import net.rubygrapefruit.platform.NativeException;
+import net.rubygrapefruit.platform.NativeException;
-import net.rubygrapefruit.platform.Terminal;
+import net.rubygrapefruit.platform.Terminal;
-import net.rubygrapefruit.platform.TerminalAccess;
+import net.rubygrapefruit.platform.TerminalAccess;
-import net.rubygrapefruit.platform.TerminalSize;
+import net.rubygrapefruit.platform.TerminalSize;
-import net.rubygrapefruit.platform.internal.jni.TerminfoFunctions;
+import net.rubygrapefruit.platform.internal.jni.WindowsConsoleFunctions;
-import net.rubygrapefruit.platform.internal.jni.WindowsConsoleFunctions;
+
-
+public class WindowsTerminal extends AbstractTerminal {
-public class WindowsTerminal extends AbstractTerminal {
+    private final TerminalAccess.Output output;
-    private final TerminalAccess.Output output;
+
-
+    public WindowsTerminal(TerminalAccess.Output output) {
-    public WindowsTerminal(TerminalAccess.Output output) {
+        this.output = output;
-        this.output = output;
+    }
-    }
+
-
+    @Override
-    @Override
+    public String toString() {
-    public String toString() {
+        return output.toString().toLowerCase();
-        return output.toString().toLowerCase();
+    }
-    }
+
-
+    @Override
-    @Override
+    protected void doInit() {
-    protected void doInit() {
+        FunctionResult result = new FunctionResult();
-        FunctionResult result = new FunctionResult();
+        WindowsConsoleFunctions.initConsole(output.ordinal(), result);
-        WindowsConsoleFunctions.initConsole(output.ordinal(), result);
+        if (result.isFailed()) {
-        if (result.isFailed()) {
+            throw new NativeException(String.format("Could not open console for %s: %s", this, result.getMessage()));
-            throw new NativeException(String.format("Could not open console for %s: %s", this, result.getMessage()));
+        }
-        }
+    }
-    }
+
-
+    @Override
-    @Override
+    public boolean supportsColor() {
-    public TerminalSize getTerminalSize() {
+        return true;
-        FunctionResult result = new FunctionResult();
+    }
-        MutableTerminalSize size = new MutableTerminalSize();
+
-        WindowsConsoleFunctions.getConsoleSize(output.ordinal(), size, result);
+    @Override
-        if (result.isFailed()) {
+    public boolean supportsTextAttributes() {
-            throw new NativeException(String.format("Could not determine console size for %s: %s", this, result.getMessage()));
+        return true;
-        }
+    }
-        return size;
+
-    }
+    @Override
-
+    public boolean supportsCursorMotion() {
-    @Override
+        return true;
-    public Terminal bold() {
+    }
-        FunctionResult result = new FunctionResult();
+
-        WindowsConsoleFunctions.bold(result);
+    @Override
-        if (result.isFailed()) {
+    public TerminalSize getTerminalSize() {
-            throw new NativeException(String.format("Could not switch console to bold mode for %s: %s", this, result.getMessage()));
+        FunctionResult result = new FunctionResult();
-        }
+        MutableTerminalSize size = new MutableTerminalSize();
-        return this;
+        WindowsConsoleFunctions.getConsoleSize(output.ordinal(), size, result);
-    }
+        if (result.isFailed()) {
-
+            throw new NativeException(String.format("Could not determine console size for %s: %s", this, result.getMessage()));
-    @Override
+        }
-    public Terminal foreground(Color color) {
+        return size;
-        FunctionResult result = new FunctionResult();
+    }
-        WindowsConsoleFunctions.foreground(color.ordinal(), result);
+
-        if (result.isFailed()) {
+    @Override
-            throw new NativeException(String.format("Could not change console foreground color for %s: %s", this, result.getMessage()));
+    public Terminal bold() {
-        }
+        FunctionResult result = new FunctionResult();
-        return this;
+        WindowsConsoleFunctions.bold(result);
-    }
+        if (result.isFailed()) {
-
+            throw new NativeException(String.format("Could not switch console to bold mode for %s: %s", this, result.getMessage()));
-    @Override
+        }
-    public Terminal normal() {
+        return this;
-        FunctionResult result = new FunctionResult();
+    }
-        WindowsConsoleFunctions.normal(result);
+
-        if (result.isFailed()) {
+    @Override
-            throw new NativeException(String.format("Could not switch console to normal mode for %s: %s", this, result.getMessage()));
+    public Terminal foreground(Color color) {
-        }
+        FunctionResult result = new FunctionResult();
-        return this;
+        WindowsConsoleFunctions.foreground(color.ordinal(), result);
-    }
+        if (result.isFailed()) {
-
+            throw new NativeException(String.format("Could not change console foreground color for %s: %s", this, result.getMessage()));
-    @Override
+        }
-    public Terminal reset() {
+        return this;
-        FunctionResult result = new FunctionResult();
+    }
-        WindowsConsoleFunctions.reset(result);
+
-        if (result.isFailed()) {
+    @Override
-            throw new NativeException(String.format("Could not reset console for %s: %s", this, result.getMessage()));
+    public Terminal normal() {
-        }
+        FunctionResult result = new FunctionResult();
-        return this;
+        WindowsConsoleFunctions.normal(result);
-    }
+        if (result.isFailed()) {
-
+            throw new NativeException(String.format("Could not switch console to normal mode for %s: %s", this, result.getMessage()));
-    @Override
+        }
-    public Terminal cursorDown(int count) throws NativeException {
+        return this;
-        FunctionResult result = new FunctionResult();
+    }
-        WindowsConsoleFunctions.down(count, result);
+
-        if (result.isFailed()) {
+    @Override
-            throw new NativeException(String.format("Could not move cursor down for %s: %s", this, result.getMessage()));
+    public Terminal reset() {
-        }
+        FunctionResult result = new FunctionResult();
-        return this;
+        WindowsConsoleFunctions.reset(result);
-    }
+        if (result.isFailed()) {
-
+            throw new NativeException(String.format("Could not reset console for %s: %s", this, result.getMessage()));
-    @Override
+        }
-    public Terminal cursorUp(int count) throws NativeException {
+        return this;
-        FunctionResult result = new FunctionResult();
+    }
-        WindowsConsoleFunctions.up(count, result);
+
-        if (result.isFailed()) {
+    @Override
-            throw new NativeException(String.format("Could not move cursor up for %s: %s", this, result.getMessage()));
+    public Terminal cursorDown(int count) throws NativeException {
-        }
+        FunctionResult result = new FunctionResult();
-        return this;
+        WindowsConsoleFunctions.down(count, result);
-    }
+        if (result.isFailed()) {
-
+            throw new NativeException(String.format("Could not move cursor down for %s: %s", this, result.getMessage()));
-    @Override
+        }
-    public Terminal cursorLeft(int count) throws NativeException {
+        return this;
-        FunctionResult result = new FunctionResult();
+    }
-        WindowsConsoleFunctions.left(count, result);
+
-        if (result.isFailed()) {
+    @Override
-            throw new NativeException(String.format("Could not move cursor left for %s: %s", this, result.getMessage()));
+    public Terminal cursorUp(int count) throws NativeException {
-        }
+        FunctionResult result = new FunctionResult();
-        return this;
+        WindowsConsoleFunctions.up(count, result);
-    }
+        if (result.isFailed()) {
-
+            throw new NativeException(String.format("Could not move cursor up for %s: %s", this, result.getMessage()));
-    @Override
+        }
-    public Terminal cursorRight(int count) throws NativeException {
+        return this;
-        FunctionResult result = new FunctionResult();
+    }
-        WindowsConsoleFunctions.right(count, result);
+
-        if (result.isFailed()) {
+    @Override
-            throw new NativeException(String.format("Could not move cursor right for %s: %s", this, result.getMessage()));
+    public Terminal cursorLeft(int count) throws NativeException {
-        }
+        FunctionResult result = new FunctionResult();
-        return this;
+        WindowsConsoleFunctions.left(count, result);
-    }
+        if (result.isFailed()) {
-
+            throw new NativeException(String.format("Could not move cursor left for %s: %s", this, result.getMessage()));
-    @Override
+        }
-    public Terminal cursorStartOfLine() throws NativeException {
+        return this;
-        FunctionResult result = new FunctionResult();
+    }
-        WindowsConsoleFunctions.startLine(result);
+
-        if (result.isFailed()) {
+    @Override
-            throw new NativeException(String.format("Could not move cursor to start of line for %s: %s", this, result.getMessage()));
+    public Terminal cursorRight(int count) throws NativeException {
-        }
+        FunctionResult result = new FunctionResult();
-        return this;
+        WindowsConsoleFunctions.right(count, result);
-    }
+        if (result.isFailed()) {
-
+            throw new NativeException(String.format("Could not move cursor right for %s: %s", this, result.getMessage()));
-    @Override
+        }
-    public Terminal clearToEndOfLine() throws NativeException {
+        return this;
-        FunctionResult result = new FunctionResult();
+    }
-        WindowsConsoleFunctions.clearToEndOfLine(result);
+
-        if (result.isFailed()) {
+    @Override
-            throw new NativeException(String.format("Could clear to end of line for %s: %s", this, result.getMessage()));
+    public Terminal cursorStartOfLine() throws NativeException {
-        }
+        FunctionResult result = new FunctionResult();
-        return this;
+        WindowsConsoleFunctions.startLine(result);
-    }
+        if (result.isFailed()) {
-}
+            throw new NativeException(String.format("Could not move cursor to start of line for %s: %s", this, result.getMessage()));
+        }
+        return this;
+    }
+
+    @Override
+    public Terminal clearToEndOfLine() throws NativeException {
+        FunctionResult result = new FunctionResult();
+        WindowsConsoleFunctions.clearToEndOfLine(result);
+        if (result.isFailed()) {
+            throw new NativeException(String.format("Could clear to end of line for %s: %s", this, result.getMessage()));
+        }
+        return this;
+    }
+}

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

@@ -1,7 +1,7 @@
 package net.rubygrapefruit.platform.internal.jni;
 
 public class NativeLibraryFunctions {
-    public static final int VERSION = 3;
+    public static final int VERSION = 4;
 
     public static native int getVersion();
 }

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

@@ -1,12 +1,13 @@
 package net.rubygrapefruit.platform.internal.jni;
 
 import net.rubygrapefruit.platform.internal.FunctionResult;
+import net.rubygrapefruit.platform.internal.TerminalCapabilities;
 
 public class TerminfoFunctions {
     /**
      * Sets up terminal info and switches output to normal mode.
      */
-    public static native void initTerminal(int filedes, FunctionResult result);
+    public static native void initTerminal(int filedes, TerminalCapabilities terminalCapabilities, FunctionResult result);
 
     public static native void bold(FunctionResult result);