Fix bobbylight#534, bobbylight#106 Customizable token painting

RSyntaxTextArea/src/main/java/org/fife/ui/rsyntaxtextarea/DefaultTokenPainter.java

@@ -21,8 +21,9 @@
  *
  * @author Robert Futrell
  * @version 1.0
+ * @see VisibleWhitespaceTokenPainter
  */
-class DefaultTokenPainter implements TokenPainter {
+public class DefaultTokenPainter implements TokenPainter {
 
 	/**
 	 * Rectangle used for filling token backgrounds.

RSyntaxTextArea/src/main/java/org/fife/ui/rsyntaxtextarea/DefaultTokenPainterFactory.java

@@ -0,0 +1,26 @@
+/*
+ * This library is distributed under a modified BSD license.  See the included
+ * LICENSE file for details.
+ */
+package org.fife.ui.rsyntaxtextarea;
+
+
+/**
+ * Standard implementation of a token painter factory.
+ *
+ * @author Robert Futrell
+ * @version 1.0
+ * @see DefaultTokenPainter
+ * @see VisibleWhitespaceTokenPainter
+ */
+public class DefaultTokenPainterFactory implements TokenPainterFactory {
+
+
+	@Override
+	public TokenPainter getTokenPainter(RSyntaxTextArea textArea) {
+		return textArea.isWhitespaceVisible() ? new VisibleWhitespaceTokenPainter() :
+			new DefaultTokenPainter();
+	}
+
+
+}

RSyntaxTextArea/src/main/java/org/fife/ui/rsyntaxtextarea/RSyntaxTextArea.java

@@ -83,6 +83,7 @@
  *       <li>Protobuf files
  *       <li>Python
  *       <li>Ruby
+ *       <li>Rust
  *       <li>SAS
  *       <li>Scala
  *       <li>SQL
@@ -324,6 +325,9 @@ public class RSyntaxTextArea extends RTextArea implements SyntaxConstants {
 
 	private boolean insertPairedCharacters;
 
+	private TokenPainterFactory tokenPainterFactory;
+
+
 	/**
 	 * Constructor.
 	 */
@@ -797,6 +801,17 @@ protected RTextAreaUI createRTextAreaUI() {
 	}
 
 
+	/**
+	 * Called whenever whitespace visibility changes. Returns the
+	 * token painter to use for this text area.
+	 *
+	 * @return The token painter to use.
+	 */
+	protected TokenPainter createTokenPainter() {
+		return tokenPainterFactory.getTokenPainter(this);
+	}
+
+
 	/**
 	 * If the caret is on a bracket, this method finds the matching bracket,
 	 * and if it exists, highlights it.
@@ -2018,7 +2033,8 @@ protected void init() {
 		super.init();
 		metricsNeverRefreshed = true;
 
-		tokenPainter = new DefaultTokenPainter();
+		tokenPainterFactory = new DefaultTokenPainterFactory();
+		tokenPainter = tokenPainterFactory.getTokenPainter(this);
 
 		// NOTE: Our actions are created here instead of in a static block
 		// so they are only created when the first RTextArea is instantiated,
@@ -3190,6 +3206,18 @@ public void setTabLineColor(Color c) {
 	}
 
 
+	/**
+	 * Sets the token painter factory to use.
+	 *
+	 * @param tpf The new token painter factory. This should not
+	 *        be {@code null}.
+	 */
+	public void setTokenPainterFactory(TokenPainterFactory tpf) {
+		tokenPainterFactory = tpf;
+		tokenPainter = createTokenPainter();
+	}
+
+
 	/**
 	 * Sets whether "focusable" tool tips are used instead of standard ones.
 	 * Focusable tool tips are tool tips that the user can click on,
@@ -3238,8 +3266,7 @@ public void setUseSelectedTextColor(boolean use) {
 	public void setWhitespaceVisible(boolean visible) {
 		if (whitespaceVisible!=visible) {
 			this.whitespaceVisible = visible;
-			tokenPainter = visible ? new VisibleWhitespaceTokenPainter() :
-					new DefaultTokenPainter();
+			tokenPainter = createTokenPainter();
 			repaint();
 			firePropertyChange(VISIBLE_WHITESPACE_PROPERTY, !visible, visible);
 		}

RSyntaxTextArea/src/main/java/org/fife/ui/rsyntaxtextarea/TokenPainter.java

@@ -21,7 +21,7 @@
  * @author Robert Futrell
  * @version 1.0
  */
-interface TokenPainter {
+public interface TokenPainter {
 
 
 	/**

RSyntaxTextArea/src/main/java/org/fife/ui/rsyntaxtextarea/TokenPainterFactory.java

@@ -0,0 +1,26 @@
+/*
+ * This library is distributed under a modified BSD license.  See the included
+ * LICENSE file for details.
+ */
+package org.fife.ui.rsyntaxtextarea;
+
+
+/**
+ * Returns the {@link TokenPainter} to use for a text area.
+ *
+ * @author Robert Futrell
+ * @version 1.0
+ */
+public interface TokenPainterFactory {
+
+
+	/**
+	 * Returns the text area to use.
+	 *
+	 * @param textArea The text area.
+	 * @return The token painter.
+	 */
+	TokenPainter getTokenPainter(RSyntaxTextArea textArea);
+
+
+}

RSyntaxTextArea/src/main/java/org/fife/ui/rsyntaxtextarea/VisibleWhitespaceTokenPainter.java

@@ -44,8 +44,9 @@
  *
  * @author Robert Futrell
  * @version 1.0
+ * @see DefaultTokenPainter
  */
-class VisibleWhitespaceTokenPainter extends DefaultTokenPainter {
+public class VisibleWhitespaceTokenPainter extends DefaultTokenPainter {
 
 
 	@Override
@@ -77,9 +78,9 @@ protected float paintImpl(Token token, Graphics2D g, float x, float y,
 
 					// Fill in background.
 					nextX = x+fm.charsWidth(text, flushIndex,flushLen);
-					float nextNextX = e.nextTabStop(nextX, 0);
+					float nextTabStop = e.nextTabStop(nextX, 0);
 					if (bg!=null) {
-						paintBackground(x,y, nextNextX-x,height, g,
+						paintBackground(x,y, nextTabStop-x,height, g,
 										ascent, host, bg);
 					}
 					g.setColor(fg);
@@ -91,15 +92,8 @@ protected float paintImpl(Token token, Graphics2D g, float x, float y,
 					}
 					flushIndex = i + 1;
 
-					// Draw an arrow representing the tab.
-					int halfHeight = height / 2;
-					int quarterHeight = halfHeight / 2;
-					int ymid = (int)y - ascent + halfHeight;
-					g.drawLine((int)nextX,ymid, (int)nextNextX,ymid);
-					g.drawLine((int)nextNextX,ymid, (int)nextNextX-4,ymid-quarterHeight);
-					g.drawLine((int)nextNextX,ymid, (int)nextNextX-4,ymid+quarterHeight);
-
-					x = nextNextX;
+					paintTabText(g, nextX, y, nextTabStop, ascent, height);
+					x = nextTabStop;
 					break;
 
 				case ' ':
@@ -130,10 +124,7 @@ protected float paintImpl(Token token, Graphics2D g, float x, float y,
 						flushLen = 0;
 					}
 
-					// Paint a dot representing the space.
-					int dotX = (int)(nextX - width/2f); // "2.0f" for FindBugs
-					int dotY = (int)(y - ascent + height/2f); // Ditto
-					g.drawLine(dotX, dotY, dotX, dotY);
+					paintSpaceText(g, nextX, y, ascent, width, height);
 					flushIndex = i + 1;
 					x = nextX;
 					break;
@@ -179,4 +170,45 @@ protected float paintImpl(Token token, Graphics2D g, float x, float y,
 	}
 
 
+	/**
+	 * Draws the textual indication of a space, i.e. a single dot. The
+	 * background has already been filled in properly, and the foreground
+	 * color properly set.
+	 *
+	 * @param g The graphics context.
+	 * @param x The x-value at which to paint.
+	 * @param y The y-value of the current line.
+	 * @param ascent The ascent of the current font.
+	 * @param width The width of the space character.
+	 * @param height The height of the current line of text being painted.
+	 */
+	protected void paintSpaceText(Graphics2D g, float x, float y, int ascent,
+								  int width, int height) {
+		int dotX = (int)(x - width/2f);
+		int dotY = (int)(y - ascent + height/2f);
+		g.drawLine(dotX, dotY, dotX, dotY);
+	}
+
+
+	/**
+	 * Draws the text representing a tab. The background has already been
+	 * filled in if necessary, and the foreground color properly set.
+	 *
+	 * @param g The graphics context.
+	 * @param x The x-value at which to paint.
+	 * @param y The y-value of the current line.
+	 * @param nextTabStop Where the next tab stop would start.
+	 * @param ascent The ascent of the current font.
+	 * @param height The height of the line of text being painted.
+	 */
+	protected void paintTabText(Graphics2D g, float x, float y,
+						float nextTabStop, int ascent, int height) {
+		int x2 = (int)nextTabStop - 3;
+		if (x2 >= (int)x) {
+			int halfHeight = height / 2;
+			int ymid = (int) y - ascent + halfHeight;
+			g.drawLine((int) x, ymid, x2, ymid);
+		}
+	}
+
 }

RSyntaxTextArea/src/test/java/org/fife/ui/rsyntaxtextarea/DefaultTokenPainterFactoryTest.java

@@ -0,0 +1,44 @@
+/*
+ * This library is distributed under a modified BSD license.  See the included
+ * LICENSE file for details.
+ */
+package org.fife.ui.rsyntaxtextarea;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+
+/**
+ * Unit tests for the {@link DefaultTokenPainterFactory} class.
+ *
+ * @author Robert Futrell
+ * @version 1.0
+ */
+class DefaultTokenPainterFactoryTest extends AbstractRSyntaxTextAreaTest {
+
+	private RSyntaxTextArea textArea;
+	private DefaultTokenPainterFactory factory;
+
+
+	@BeforeEach
+	void setUp() {
+		textArea = createTextArea();
+		factory = new DefaultTokenPainterFactory();
+	}
+
+
+	@Test
+	void testGetTokenPainter_dontShowWhitespace() {
+		Assertions.assertEquals(DefaultTokenPainter.class,
+			factory.getTokenPainter(textArea).getClass());
+	}
+
+
+	@Test
+	void testGetTokenPainter_showWhitespace() {
+		textArea.setWhitespaceVisible(true);
+		Assertions.assertEquals(VisibleWhitespaceTokenPainter.class,
+			factory.getTokenPainter(textArea).getClass());
+	}
+}