- 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/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;
 }