support rendering of code minings at the very end of the document

if the last line at the end of the document is empty

Fixes: #2157

Author: tobias-melcher

bundles/org.eclipse.jface.text/src/org/eclipse/jface/text/source/inlined/InlinedAnnotationDrawingStrategy.java

@@ -28,6 +28,7 @@
 import org.eclipse.jface.internal.text.codemining.CodeMiningLineHeaderAnnotation;
 
 import org.eclipse.jface.text.ITextViewer;
+import org.eclipse.jface.text.Position;
 import org.eclipse.jface.text.source.Annotation;
 import org.eclipse.jface.text.source.AnnotationPainter.IDrawingStrategy;
 
@@ -99,7 +100,7 @@ private Font getAnnotationFont(StyledText textWidget) {
 		if (annotationFont == null) {
 			annotationFont = createInlineAnnotationFont(textWidget);
 			textWidget.setData(INLINE_ANNOTATION_FONT, annotationFont);
-			textWidget.addDisposeListener(e -> ((Font)textWidget.getData(INLINE_ANNOTATION_FONT)).dispose());
+			textWidget.addDisposeListener(e -> ((Font) textWidget.getData(INLINE_ANNOTATION_FONT)).dispose());
 		}
 		return annotationFont;
 	}
@@ -154,7 +155,8 @@ public static void draw(AbstractInlinedAnnotation annotation, GC gc, StyledText
 	private static void draw(LineHeaderAnnotation annotation, GC gc, StyledText textWidget, int offset, int length,
 			Color color) {
 		int line= textWidget.getLineAtOffset(offset);
-		if (isDeleted(annotation)) {
+		int charCount= textWidget.getCharCount();
+		if (isDeleted(annotation, charCount)) {
 			// When annotation is deleted, update metrics to null to remove extra spaces of the line header annotation.
 			if (textWidget.getLineVerticalIndent(line) > 0)
 				textWidget.setLineVerticalIndent(line, 0);
@@ -180,9 +182,16 @@ private static void draw(LineHeaderAnnotation annotation, GC gc, StyledText text
 				textWidget.setLineVerticalIndent(line, 0);
 			}
 			// Compute the location of the annotation
-			Rectangle bounds= textWidget.getTextBounds(offset, offset);
-			int x= bounds.x;
-			int y= bounds.y;
+			int x, y;
+			if (offset < charCount) {
+				Rectangle bounds= textWidget.getTextBounds(offset, offset);
+				x= bounds.x;
+				y= bounds.y;
+			} else {
+				Point locAtOff= textWidget.getLocationAtOffset(offset);
+				x= locAtOff.x;
+				y= locAtOff.y - height;
+			}
 			// Draw the line header annotation
 			gc.setBackground(textWidget.getBackground());
 			annotation.setLocation(x, y);
@@ -193,7 +202,16 @@ private static void draw(LineHeaderAnnotation annotation, GC gc, StyledText text
 			Rectangle client= textWidget.getClientArea();
 			textWidget.redraw(0, bounds.y, client.width, bounds.height, false);
 		} else {
-			textWidget.redrawRange(offset, length, true);
+			if (offset >= charCount) {
+				if (charCount > 0) {
+					textWidget.redrawRange(charCount - 1, 1, true);
+				} else {
+					Rectangle client= textWidget.getClientArea();
+					textWidget.redraw(0, 0, client.width, client.height, false);
+				}
+			} else {
+				textWidget.redrawRange(offset, length, true);
+			}
 		}
 	}
 
@@ -212,7 +230,11 @@ private static void draw(LineContentAnnotation annotation, GC gc, StyledText tex
 			Color color) {
 		if (annotation instanceof CodeMiningLineContentAnnotation a) {
 			if (a.isAfterPosition()) {
-				drawAsLeftOf1stCharacter(annotation, gc, textWidget, widgetOffset, length, color);
+				if (widgetOffset < textWidget.getCharCount()) {
+					drawAsLeftOf1stCharacter(annotation, gc, textWidget, widgetOffset, length, color);
+				} else {
+					drawAtEndOfDocumentInFirstColumn(annotation, gc, textWidget, widgetOffset, length, color);
+				}
 				return;
 			}
 		}
@@ -226,7 +248,7 @@ private static void draw(LineContentAnnotation annotation, GC gc, StyledText tex
 	}
 
 	private static void drawAfterLine(LineContentAnnotation annotation, GC gc, StyledText textWidget, int widgetOffset, int length, Color color) {
-		if (isDeleted(annotation)) {
+		if (isDeleted(annotation, textWidget.getCharCount())) {
 			return;
 		}
 		if (gc != null) {
@@ -247,14 +269,43 @@ private static void drawAfterLine(LineContentAnnotation annotation, GC gc, Style
 		}
 	}
 
+	private static void drawAtEndOfDocumentInFirstColumn(LineContentAnnotation annotation, GC gc, StyledText textWidget, int widgetOffset, int length, Color color) {
+		if (isDeleted(annotation, textWidget.getCharCount())) {
+			return;
+		}
+		if (gc != null) {
+			Point locAtOff= textWidget.getLocationAtOffset(widgetOffset);
+			int x= locAtOff.x;
+			int y= locAtOff.y;
+			annotation.setLocation(x, y);
+			annotation.draw(gc, textWidget, widgetOffset, length, color, x, y);
+			int width= annotation.getWidth();
+			if (width != 0) {
+				if (!gc.getClipping().contains(x, y)) {
+					Rectangle client= textWidget.getClientArea();
+					int height= textWidget.getLineHeight();
+					textWidget.redraw(x, y, client.width, height, false);
+				}
+			}
+		} else {
+			int charCount= textWidget.getCharCount();
+			if (charCount > 0) {
+				textWidget.redrawRange(charCount - 1, 1, true);
+			} else {
+				Rectangle client= textWidget.getClientArea();
+				textWidget.redraw(0, 0, client.width, client.height, false);
+			}
+		}
+	}
+
 	protected static void drawAsLeftOf1stCharacter(LineContentAnnotation annotation, GC gc, StyledText textWidget, int widgetOffset, int length, Color color) {
 		StyleRange style= null;
 		try {
 			style= textWidget.getStyleRangeAtOffset(widgetOffset);
 		} catch (Exception e) {
 			return;
 		}
-		if (isDeleted(annotation)) {
+		if (isDeleted(annotation, textWidget.getCharCount())) {
 			// When annotation is deleted, update metrics to null to remove extra spaces of the line content annotation.
 			if (style != null && style.metrics != null) {
 				style.metrics= null;
@@ -369,7 +420,7 @@ protected static void drawAsRightOfPreviousCharacter(LineContentAnnotation annot
 		} catch (Exception e) {
 			return;
 		}
-		if (isDeleted(annotation)) {
+		if (isDeleted(annotation, textWidget.getCharCount())) {
 			// When annotation is deleted, update metrics to null to remove extra spaces of the line content annotation.
 			if (style != null && style.metrics != null) {
 				style.metrics= null;
@@ -449,7 +500,17 @@ protected static void drawAsRightOfPreviousCharacter(LineContentAnnotation annot
 	 * @param annotation the inlined annotation to check
 	 * @return <code>true</code> if inlined annotation is deleted and <code>false</code> otherwise.
 	 */
-	private static boolean isDeleted(AbstractInlinedAnnotation annotation) {
-		return annotation.isMarkedDeleted() || annotation.getPosition().isDeleted() || annotation.getPosition().getLength() == 0;
+	private static boolean isDeleted(AbstractInlinedAnnotation annotation,int maxOffset) {
+		if (annotation.isMarkedDeleted()) {
+			return true;
+		}
+		Position pos= annotation.getPosition();
+		if (pos.isDeleted()) {
+			return true;
+		}
+		if (pos.getLength() == 0 && pos.getOffset() < maxOffset) {
+			return true;
+		}
+		return false;
 	}
 }

tests/org.eclipse.jface.text.tests/src/org/eclipse/jface/text/tests/codemining/CodeMiningTest.java

@@ -35,6 +35,7 @@
 import org.eclipse.swt.graphics.GC;
 import org.eclipse.swt.graphics.Image;
 import org.eclipse.swt.graphics.ImageData;
+import org.eclipse.swt.graphics.Point;
 import org.eclipse.swt.graphics.Rectangle;
 import org.eclipse.swt.layout.FillLayout;
 import org.eclipse.swt.widgets.Display;
@@ -250,6 +251,71 @@ protected boolean condition() {
 		}.waitForCondition(fViewer.getTextWidget().getDisplay(), 1000));
 	}
 
+	@Test
+	public void testLineHeaderCodeMiningAtEndOfDocumentWithEmptyLine() throws Exception {
+		String source= "first\nsecond\n";
+		fViewer.getDocument().set(source);
+		fViewer.setCodeMiningProviders(new ICodeMiningProvider[] { new ICodeMiningProvider() {
+			@Override
+			public CompletableFuture<List<? extends ICodeMining>> provideCodeMinings(ITextViewer viewer, IProgressMonitor monitor) {
+				List<ICodeMining> minings= new ArrayList<>();
+				try {
+					minings.add(new LineHeaderCodeMining(new Position(source.length(), 0), this, null) {
+						@Override
+						public String getLabel() {
+							return "multiline first line\nmultiline second line\nmultiline third line\nmultiline fourth line";
+						}
+					});
+				} catch (BadLocationException e) {
+					e.printStackTrace();
+				}
+				return CompletableFuture.completedFuture(minings);
+			}
+
+			@Override
+			public void dispose() {
+			}
+		} });
+		Assert.assertTrue("Code mining is not visible at end of document", new DisplayHelper() {
+			@Override
+			protected boolean condition() {
+				try {
+					return hasCodeMiningPrintedAfterTextOnLine(fViewer, 2);
+				} catch (BadLocationException e) {
+					e.printStackTrace();
+					return false;
+				}
+			}
+		}.waitForCondition(fViewer.getTextWidget().getDisplay(), 10_000));
+	}
+
+	@Test
+	public void testCodeMiningAtEndOfDocumentWithEmptyLine() throws Exception {
+		String source= "first\nsecond\n";
+		fViewer.getDocument().set(source);
+		fViewer.setCodeMiningProviders(new ICodeMiningProvider[] { new ICodeMiningProvider() {
+			@Override
+			public CompletableFuture<List<? extends ICodeMining>> provideCodeMinings(ITextViewer viewer, IProgressMonitor monitor) {
+				return CompletableFuture.completedFuture(Collections.singletonList(new StaticContentLineCodeMining(new Position(source.length(), 0), true, "mining", this)));
+			}
+
+			@Override
+			public void dispose() {
+			}
+		} });
+		Assert.assertTrue("Code mining is not visible at end of document", new DisplayHelper() {
+			@Override
+			protected boolean condition() {
+				try {
+					return hasCodeMiningPrintedAfterTextOnLine(fViewer, 2);
+				} catch (BadLocationException e) {
+					e.printStackTrace();
+					return false;
+				}
+			}
+		}.waitForCondition(fViewer.getTextWidget().getDisplay(), 10_000));
+	}
+
 	@Test
 	public void testCodeMiningEndOfLine() {
 		fViewer.getDocument().set("a\n");
@@ -389,7 +455,18 @@ private static boolean hasCodeMiningPrintedAfterTextOnLine(ITextViewer viewer, i
 		if (lineLength < 0) {
 			lineLength= 0;
 		}
-		Rectangle secondLineBounds= widget.getTextBounds(document.getLineOffset(line), document.getLineOffset(line) + lineLength);
+		Rectangle secondLineBounds= null;
+		int lineOffset= document.getLineOffset(line);
+		if (lineOffset >= document.getLength()) {
+			int off= document.getLength() - 1;
+			secondLineBounds= widget.getTextBounds(off, off + lineLength);
+			Point l= widget.getLocationAtOffset(lineOffset);
+			int lineVerticalIndent= widget.getLineVerticalIndent(line);
+			secondLineBounds.x= l.x;
+			secondLineBounds.y= l.y - lineVerticalIndent;
+		} else {
+			secondLineBounds= widget.getTextBounds(lineOffset, lineOffset + lineLength);
+		}
 		Image image = new Image(widget.getDisplay(), widget.getSize().x, widget.getSize().y);
 		GC gc = new GC(widget);
 		gc.copyArea(image, 0, 0);

tests/org.eclipse.jface.text.tests/src/org/eclipse/jface/text/tests/codemining/StaticContentLineCodeMining.java

@@ -24,6 +24,11 @@ public StaticContentLineCodeMining(Position position, String message, ICodeMinin
 		setLabel(message);
 	}
 
+	public StaticContentLineCodeMining(Position position, boolean afterPosition, String message, ICodeMiningProvider provider) {
+		super(position, afterPosition, provider);
+		setLabel(message);
+	}
+
 	public StaticContentLineCodeMining(int i, char c, ICodeMiningProvider repeatLettersCodeMiningProvider) {
 		super(new Position(i, 1), repeatLettersCodeMiningProvider);
 		setLabel(Character.toString(c));