--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dwtx/jface/text/CursorLinePainter.d	Sat Aug 23 19:10:48 2008 +0200
@@ -0,0 +1,262 @@
+/*******************************************************************************
+ * Copyright (c) 2000, 2008 IBM Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     IBM Corporation - initial API and implementation
+ * Port to the D programming language:
+ *     Frank Benoit <benoit@tionex.de>
+ *******************************************************************************/
+
+module dwtx.jface.text.CursorLinePainter;
+
+import dwt.dwthelper.utils;
+
+
+
+
+import dwt.custom.LineBackgroundEvent;
+import dwt.custom.LineBackgroundListener;
+import dwt.custom.StyledText;
+import dwt.graphics.Color;
+import dwt.graphics.Point;
+
+
+/**
+ * A painter the draws the background of the caret line in a configured color.
+ * <p>
+ * Clients usually instantiate and configure object of this class.</p>
+ * <p>
+ * This class is not intended to be subclassed.</p>
+ *
+ * @since 2.1
+ * @noextend This class is not intended to be subclassed by clients.
+ */
+public class CursorLinePainter : IPainter, LineBackgroundListener {
+
+    /** The viewer the painter works on */
+    private final ITextViewer fViewer;
+    /** The cursor line back ground color */
+    private Color fHighlightColor;
+    /** The paint position manager for managing the line coordinates */
+    private IPaintPositionManager fPositionManager;
+
+    /** Keeps track of the line to be painted */
+    private Position fCurrentLine= new Position(0, 0);
+    /** Keeps track of the line to be cleared */
+    private Position fLastLine= new Position(0, 0);
+    /** Keeps track of the line number of the last painted line */
+    private int fLastLineNumber= -1;
+    /** Indicates whether this painter is active */
+    private bool fIsActive;
+
+    /**
+     * Creates a new painter for the given source viewer.
+     *
+     * @param textViewer the source viewer for which to create a painter
+     */
+    public CursorLinePainter(ITextViewer textViewer) {
+        fViewer= textViewer;
+    }
+
+    /**
+     * Sets the color in which to draw the background of the cursor line.
+     *
+     * @param highlightColor the color in which to draw the background of the cursor line
+     */
+    public void setHighlightColor(Color highlightColor) {
+        fHighlightColor= highlightColor;
+    }
+
+    /*
+     * @see LineBackgroundListener#lineGetBackground(LineBackgroundEvent)
+     */
+    public void lineGetBackground(LineBackgroundEvent event) {
+        // don't use cached line information because of asynchronous painting
+
+        StyledText textWidget= fViewer.getTextWidget();
+        if (textWidget !is null) {
+
+            int caret= textWidget.getCaretOffset();
+            int length= event.lineText.length();
+
+            if (event.lineOffset <= caret && caret <= event.lineOffset + length)
+                event.lineBackground= fHighlightColor;
+            else
+                event.lineBackground= textWidget.getBackground();
+        }
+    }
+
+    /**
+     * Updates all the cached information about the lines to be painted and to be cleared. Returns <code>true</code>
+     * if the line number of the cursor line has changed.
+     *
+     * @return <code>true</code> if cursor line changed
+     */
+    private bool updateHighlightLine() {
+        try {
+
+            IDocument document= fViewer.getDocument();
+            int modelCaret= getModelCaret();
+            int lineNumber= document.getLineOfOffset(modelCaret);
+
+            // redraw if the current line number is different from the last line number we painted
+            // initially fLastLineNumber is -1
+            if (lineNumber !is fLastLineNumber || !fCurrentLine.overlapsWith(modelCaret, 0)) {
+
+                fLastLine.offset= fCurrentLine.offset;
+                fLastLine.length= fCurrentLine.length;
+                fLastLine.isDeleted= fCurrentLine.isDeleted;
+
+                if (fCurrentLine.isDeleted) {
+                    fCurrentLine.isDeleted= false;
+                    fPositionManager.managePosition(fCurrentLine);
+                }
+
+                fCurrentLine.offset= document.getLineOffset(lineNumber);
+                if (lineNumber is document.getNumberOfLines() - 1)
+                    fCurrentLine.length= document.getLength() - fCurrentLine.offset;
+                else
+                    fCurrentLine.length= document.getLineOffset(lineNumber + 1) - fCurrentLine.offset;
+
+                fLastLineNumber= lineNumber;
+                return true;
+
+            }
+
+        } catch (BadLocationException e) {
+        }
+
+        return false;
+    }
+
+    /**
+     * Returns the location of the caret as offset in the source viewer's
+     * input document.
+     *
+     * @return the caret location
+     */
+    private int getModelCaret() {
+        int widgetCaret= fViewer.getTextWidget().getCaretOffset();
+        if (fViewer instanceof ITextViewerExtension5) {
+            ITextViewerExtension5 extension= (ITextViewerExtension5) fViewer;
+            return extension.widgetOffset2ModelOffset(widgetCaret);
+        }
+        IRegion visible= fViewer.getVisibleRegion();
+        return widgetCaret + visible.getOffset();
+    }
+
+    /**
+     * Assumes the given position to specify offset and length of a line to be painted.
+     *
+     * @param position the specification of the line  to be painted
+     */
+    private void drawHighlightLine(Position position) {
+
+        // if the position that is about to be drawn was deleted then we can't
+        if (position.isDeleted())
+            return;
+
+        int widgetOffset= 0;
+        if (fViewer instanceof ITextViewerExtension5) {
+
+            ITextViewerExtension5 extension= (ITextViewerExtension5) fViewer;
+            widgetOffset= extension.modelOffset2WidgetOffset(position.getOffset());
+            if (widgetOffset is -1)
+                return;
+
+        } else {
+
+            IRegion visible= fViewer.getVisibleRegion();
+            widgetOffset= position.getOffset() - visible.getOffset();
+            if (widgetOffset < 0 || visible.getLength() < widgetOffset )
+                return;
+        }
+
+        StyledText textWidget= fViewer.getTextWidget();
+        // check for https://bugs.eclipse.org/bugs/show_bug.cgi?id=64898
+        // this is a guard against the symptoms but not the actual solution
+        if (0 <= widgetOffset && widgetOffset <= textWidget.getCharCount()) {
+            Point upperLeft= textWidget.getLocationAtOffset(widgetOffset);
+            int width= textWidget.getClientArea().width + textWidget.getHorizontalPixel();
+            int height= textWidget.getLineHeight(widgetOffset);
+            textWidget.redraw(0, upperLeft.y, width, height, false);
+        }
+    }
+
+    /*
+     * @see IPainter#deactivate(bool)
+     */
+    public void deactivate(bool redraw) {
+        if (fIsActive) {
+            fIsActive= false;
+
+            /* on turning off the feature one has to paint the currently
+             * highlighted line with the standard background color
+             */
+            if (redraw)
+                drawHighlightLine(fCurrentLine);
+
+            fViewer.getTextWidget().removeLineBackgroundListener(this);
+
+            if (fPositionManager !is null)
+                fPositionManager.unmanagePosition(fCurrentLine);
+
+            fLastLineNumber= -1;
+            fCurrentLine.offset= 0;
+            fCurrentLine.length= 0;
+        }
+    }
+
+    /*
+     * @see IPainter#dispose()
+     */
+    public void dispose() {
+    }
+
+    /*
+     * @see IPainter#paint(int)
+     */
+    public void paint(int reason) {
+        if (fViewer.getDocument() is null) {
+            deactivate(false);
+            return;
+        }
+
+        StyledText textWidget= fViewer.getTextWidget();
+
+        // check selection
+        Point selection= textWidget.getSelection();
+        int startLine= textWidget.getLineAtOffset(selection.x);
+        int endLine= textWidget.getLineAtOffset(selection.y);
+        if (startLine !is endLine) {
+            deactivate(true);
+            return;
+        }
+
+        // initialization
+        if (!fIsActive) {
+            textWidget.addLineBackgroundListener(this);
+            fPositionManager.managePosition(fCurrentLine);
+            fIsActive= true;
+        }
+
+        //redraw line highlight only if it hasn't been drawn yet on the respective line
+        if (updateHighlightLine()) {
+            // clear last line
+            drawHighlightLine(fLastLine);
+            // draw new line
+            drawHighlightLine(fCurrentLine);
+        }
+    }
+
+    /*
+     * @see IPainter#setPositionManager(IPaintPositionManager)
+     */
+    public void setPositionManager(IPaintPositionManager manager) {
+        fPositionManager = manager;
+    }
+}