--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dwtx/jface/text/presentation/PresentationReconciler.d	Sat Aug 23 19:10:48 2008 +0200
@@ -0,0 +1,596 @@
+/*******************************************************************************
+ * 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.presentation.PresentationReconciler;
+
+import dwt.dwthelper.utils;
+
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.Map;
+
+import dwt.custom.StyleRange;
+import dwtx.core.runtime.Assert;
+import dwtx.jface.text.BadLocationException;
+import dwtx.jface.text.BadPositionCategoryException;
+import dwtx.jface.text.DefaultPositionUpdater;
+import dwtx.jface.text.DocumentEvent;
+import dwtx.jface.text.DocumentPartitioningChangedEvent;
+import dwtx.jface.text.IDocument;
+import dwtx.jface.text.IDocumentExtension3;
+import dwtx.jface.text.IDocumentListener;
+import dwtx.jface.text.IDocumentPartitioningListener;
+import dwtx.jface.text.IDocumentPartitioningListenerExtension;
+import dwtx.jface.text.IDocumentPartitioningListenerExtension2;
+import dwtx.jface.text.IPositionUpdater;
+import dwtx.jface.text.IRegion;
+import dwtx.jface.text.ITextInputListener;
+import dwtx.jface.text.ITextListener;
+import dwtx.jface.text.ITextViewer;
+import dwtx.jface.text.ITextViewerExtension5;
+import dwtx.jface.text.ITypedRegion;
+import dwtx.jface.text.Region;
+import dwtx.jface.text.TextEvent;
+import dwtx.jface.text.TextPresentation;
+import dwtx.jface.text.TextUtilities;
+import dwtx.jface.text.TypedPosition;
+
+
+
+/**
+ * Standard implementation of <code>IPresentationReconciler</code>. This
+ * implementation assumes that the tasks performed by its presentation damagers
+ * and repairers are lightweight and of low cost. This presentation reconciler
+ * runs in the UI thread and always repairs the complete damage caused by a
+ * document change rather than just the portion overlapping with the viewer's
+ * viewport.
+ * <p>
+ * Usually, clients instantiate this class and configure it before using it.
+ * </p>
+ */
+public class PresentationReconciler : IPresentationReconciler, IPresentationReconcilerExtension {
+
+    /** Prefix of the name of the position category for tracking damage regions. */
+    protected final static String TRACKED_PARTITION= "__reconciler_tracked_partition"; //$NON-NLS-1$
+
+
+    /**
+     * Internal listener class.
+     */
+    class InternalListener :
+            ITextInputListener, IDocumentListener, ITextListener,
+            IDocumentPartitioningListener, IDocumentPartitioningListenerExtension, IDocumentPartitioningListenerExtension2 {
+
+        /** Set to <code>true</code> if between a document about to be changed and a changed event. */
+        private bool fDocumentChanging= false;
+        /**
+         * The cached redraw state of the text viewer.
+         * @since 3.0
+         */
+        private bool fCachedRedrawState= true;
+
+        /*
+         * @see ITextInputListener#inputDocumentAboutToBeChanged(IDocument, IDocument)
+         */
+        public void inputDocumentAboutToBeChanged(IDocument oldDocument, IDocument newDocument) {
+            if (oldDocument !is null) {
+                try {
+
+                    fViewer.removeTextListener(this);
+                    oldDocument.removeDocumentListener(this);
+                    oldDocument.removeDocumentPartitioningListener(this);
+
+                    oldDocument.removePositionUpdater(fPositionUpdater);
+                    oldDocument.removePositionCategory(fPositionCategory);
+
+                } catch (BadPositionCategoryException x) {
+                    // should not happened for former input documents;
+                }
+            }
+        }
+
+        /*
+         * @see ITextInputListener#inputDocumenChanged(IDocument, IDocument)
+         */
+        public void inputDocumentChanged(IDocument oldDocument, IDocument newDocument) {
+
+            fDocumentChanging= false;
+            fCachedRedrawState= true;
+
+            if (newDocument !is null) {
+
+                newDocument.addPositionCategory(fPositionCategory);
+                newDocument.addPositionUpdater(fPositionUpdater);
+
+                newDocument.addDocumentPartitioningListener(this);
+                newDocument.addDocumentListener(this);
+                fViewer.addTextListener(this);
+
+                setDocumentToDamagers(newDocument);
+                setDocumentToRepairers(newDocument);
+                processDamage(new Region(0, newDocument.getLength()), newDocument);
+            }
+        }
+
+        /*
+         * @see IDocumentPartitioningListener#documentPartitioningChanged(IDocument)
+         */
+        public void documentPartitioningChanged(IDocument document) {
+            if (!fDocumentChanging && fCachedRedrawState)
+                processDamage(new Region(0, document.getLength()), document);
+            else
+                fDocumentPartitioningChanged= true;
+        }
+
+        /*
+         * @see IDocumentPartitioningListenerExtension#documentPartitioningChanged(IDocument, IRegion)
+         * @since 2.0
+         */
+        public void documentPartitioningChanged(IDocument document, IRegion changedRegion) {
+            if (!fDocumentChanging && fCachedRedrawState) {
+                processDamage(new Region(changedRegion.getOffset(), changedRegion.getLength()), document);
+            } else {
+                fDocumentPartitioningChanged= true;
+                fChangedDocumentPartitions= changedRegion;
+            }
+        }
+
+        /*
+         * @see dwtx.jface.text.IDocumentPartitioningListenerExtension2#documentPartitioningChanged(dwtx.jface.text.DocumentPartitioningChangedEvent)
+         * @since 3.0
+         */
+        public void documentPartitioningChanged(DocumentPartitioningChangedEvent event) {
+            IRegion changedRegion= event.getChangedRegion(getDocumentPartitioning());
+            if (changedRegion !is null)
+                documentPartitioningChanged(event.getDocument(), changedRegion);
+        }
+
+        /*
+         * @see IDocumentListener#documentAboutToBeChanged(DocumentEvent)
+         */
+        public void documentAboutToBeChanged(DocumentEvent e) {
+
+            fDocumentChanging= true;
+            if (fCachedRedrawState) {
+                try {
+                    int offset= e.getOffset() + e.getLength();
+                    ITypedRegion region= getPartition(e.getDocument(), offset);
+                    fRememberedPosition= new TypedPosition(region);
+                    e.getDocument().addPosition(fPositionCategory, fRememberedPosition);
+                } catch (BadLocationException x) {
+                    // can not happen
+                } catch (BadPositionCategoryException x) {
+                    // should not happen on input elements
+                }
+            }
+        }
+
+        /*
+         * @see IDocumentListener#documentChanged(DocumentEvent)
+         */
+        public void documentChanged(DocumentEvent e) {
+            if (fCachedRedrawState) {
+                try {
+                    e.getDocument().removePosition(fPositionCategory, fRememberedPosition);
+                } catch (BadPositionCategoryException x) {
+                    // can not happen on input documents
+                }
+            }
+            fDocumentChanging= false;
+        }
+
+        /*
+         * @see ITextListener#textChanged(TextEvent)
+         */
+        public void textChanged(TextEvent e) {
+
+            fCachedRedrawState= e.getViewerRedrawState();
+            if (!fCachedRedrawState)
+                return;
+
+            IRegion damage= null;
+            IDocument document= null;
+
+            if (e.getDocumentEvent() is null) {
+                document= fViewer.getDocument();
+                if (document !is null)  {
+                    if (e.getOffset() is 0 && e.getLength() is 0 && e.getText() is null) {
+                        // redraw state change, damage the whole document
+                        damage= new Region(0, document.getLength());
+                    } else {
+                        IRegion region= widgetRegion2ModelRegion(e);
+                        try {
+                            String text= document.get(region.getOffset(), region.getLength());
+                            DocumentEvent de= new DocumentEvent(document, region.getOffset(), region.getLength(), text);
+                            damage= getDamage(de, false);
+                        } catch (BadLocationException x) {
+                        }
+                    }
+                }
+            } else  {
+                DocumentEvent de= e.getDocumentEvent();
+                document= de.getDocument();
+                damage= getDamage(de, true);
+            }
+
+            if (damage !is null && document !is null)
+                processDamage(damage, document);
+
+            fDocumentPartitioningChanged= false;
+            fChangedDocumentPartitions= null;
+        }
+
+        /**
+         * Translates the given text event into the corresponding range of the viewer's document.
+         *
+         * @param e the text event
+         * @return the widget region corresponding the region of the given event
+         * @since 2.1
+         */
+        protected IRegion widgetRegion2ModelRegion(TextEvent e) {
+
+            String text= e.getText();
+            int length= text is null ? 0 : text.length();
+
+            if (fViewer instanceof ITextViewerExtension5) {
+                ITextViewerExtension5 extension= (ITextViewerExtension5) fViewer;
+                return extension.widgetRange2ModelRange(new Region(e.getOffset(), length));
+            }
+
+            IRegion visible= fViewer.getVisibleRegion();
+            IRegion region= new Region(e.getOffset() + visible.getOffset(), length);
+            return region;
+        }
+    }
+
+    /** The map of presentation damagers. */
+    private Map fDamagers;
+    /** The map of presentation repairers. */
+    private Map fRepairers;
+    /** The target viewer. */
+    private ITextViewer fViewer;
+    /** The internal listener. */
+    private InternalListener fInternalListener= new InternalListener();
+    /** The name of the position category to track damage regions. */
+    private String fPositionCategory;
+    /** The position updated for the damage regions' position category. */
+    private IPositionUpdater fPositionUpdater;
+    /** The positions representing the damage regions. */
+    private TypedPosition fRememberedPosition;
+    /** Flag indicating the receipt of a partitioning changed notification. */
+    private bool fDocumentPartitioningChanged= false;
+    /** The range covering the changed partitioning. */
+    private IRegion fChangedDocumentPartitions= null;
+    /**
+     * The partitioning used by this presentation reconciler.
+     * @since 3.0
+     */
+    private String fPartitioning;
+
+    /**
+     * Creates a new presentation reconciler. There are no damagers or repairers
+     * registered with this reconciler by default. The default partitioning
+     * <code>IDocumentExtension3.DEFAULT_PARTITIONING</code> is used.
+     */
+    public PresentationReconciler() {
+        super();
+        fPartitioning= IDocumentExtension3.DEFAULT_PARTITIONING;
+        fPositionCategory= TRACKED_PARTITION + hashCode();
+        fPositionUpdater= new DefaultPositionUpdater(fPositionCategory);
+    }
+
+    /**
+     * Sets the document partitioning for this presentation reconciler.
+     *
+     * @param partitioning the document partitioning for this presentation reconciler.
+     * @since 3.0
+     */
+    public void setDocumentPartitioning(String partitioning) {
+        Assert.isNotNull(partitioning);
+        fPartitioning= partitioning;
+    }
+
+    /*
+     * @see dwtx.jface.text.presentation.IPresentationReconcilerExtension#geDocumenttPartitioning()
+     * @since 3.0
+     */
+    public String getDocumentPartitioning() {
+        return fPartitioning;
+    }
+
+    /**
+     * Registers the given presentation damager for a particular content type.
+     * If there is already a damager registered for this type, the old damager
+     * is removed first.
+     *
+     * @param damager the presentation damager to register, or <code>null</code> to remove an existing one
+     * @param contentType the content type under which to register
+     */
+    public void setDamager(IPresentationDamager damager, String contentType) {
+
+        Assert.isNotNull(contentType);
+
+        if (fDamagers is null)
+            fDamagers= new HashMap();
+
+        if (damager is null)
+            fDamagers.remove(contentType);
+        else
+            fDamagers.put(contentType, damager);
+    }
+
+    /**
+     * Registers the given presentation repairer for a particular content type.
+     * If there is already a repairer registered for this type, the old repairer
+     * is removed first.
+     *
+     * @param repairer the presentation repairer to register, or <code>null</code> to remove an existing one
+     * @param contentType the content type under which to register
+     */
+    public void setRepairer(IPresentationRepairer repairer, String contentType) {
+
+        Assert.isNotNull(contentType);
+
+        if (fRepairers is null)
+            fRepairers= new HashMap();
+
+        if (repairer is null)
+            fRepairers.remove(contentType);
+        else
+            fRepairers.put(contentType, repairer);
+    }
+
+    /*
+     * @see IPresentationReconciler#install(ITextViewer)
+     */
+    public void install(ITextViewer viewer) {
+        Assert.isNotNull(viewer);
+
+        fViewer= viewer;
+        fViewer.addTextInputListener(fInternalListener);
+        
+        IDocument document= viewer.getDocument();
+        if (document !is null)
+            fInternalListener.inputDocumentChanged(null, document);
+    }
+
+    /*
+     * @see IPresentationReconciler#uninstall()
+     */
+    public void uninstall() {
+        fViewer.removeTextInputListener(fInternalListener);
+
+        // Ensure we uninstall all listeners
+        fInternalListener.inputDocumentAboutToBeChanged(fViewer.getDocument(), null);
+    }
+
+    /*
+     * @see IPresentationReconciler#getDamager(String)
+     */
+    public IPresentationDamager getDamager(String contentType) {
+
+        if (fDamagers is null)
+            return null;
+
+        return (IPresentationDamager) fDamagers.get(contentType);
+    }
+
+    /*
+     * @see IPresentationReconciler#getRepairer(String)
+     */
+    public IPresentationRepairer getRepairer(String contentType) {
+
+        if (fRepairers is null)
+            return null;
+
+        return (IPresentationRepairer) fRepairers.get(contentType);
+    }
+
+    /**
+     * Informs all registered damagers about the document on which they will work.
+     *
+     * @param document the document on which to work
+     */
+    protected void setDocumentToDamagers(IDocument document) {
+        if (fDamagers !is null) {
+            Iterator e= fDamagers.values().iterator();
+            while (e.hasNext()) {
+                IPresentationDamager damager= (IPresentationDamager) e.next();
+                damager.setDocument(document);
+            }
+        }
+    }
+
+    /**
+     * Informs all registered repairers about the document on which they will work.
+     *
+     * @param document the document on which to work
+     */
+    protected void setDocumentToRepairers(IDocument document) {
+        if (fRepairers !is null) {
+            Iterator e= fRepairers.values().iterator();
+            while (e.hasNext()) {
+                IPresentationRepairer repairer= (IPresentationRepairer) e.next();
+                repairer.setDocument(document);
+            }
+        }
+    }
+
+    /**
+     * Constructs a "repair description" for the given damage and returns this
+     * description as a text presentation. For this, it queries the partitioning
+     * of the damage region and asks the appropriate presentation repairer for
+     * each partition to construct the "repair description" for this partition.
+     *
+     * @param damage the damage to be repaired
+     * @param document the document whose presentation must be repaired
+     * @return the presentation repair description as text presentation or
+     *         <code>null</code> if the partitioning could not be computed
+     */
+    protected TextPresentation createPresentation(IRegion damage, IDocument document) {
+        try {
+            if (fRepairers is null || fRepairers.isEmpty()) {
+                TextPresentation presentation= new TextPresentation(damage, 100);
+                presentation.setDefaultStyleRange(new StyleRange(damage.getOffset(), damage.getLength(), null, null));
+                return presentation;
+            }
+
+            TextPresentation presentation= new TextPresentation(damage, 1000);
+
+            ITypedRegion[] partitioning= TextUtilities.computePartitioning(document, getDocumentPartitioning(), damage.getOffset(), damage.getLength(), false);
+            for (int i= 0; i < partitioning.length; i++) {
+                ITypedRegion r= partitioning[i];
+                IPresentationRepairer repairer= getRepairer(r.getType());
+                if (repairer !is null)
+                    repairer.createPresentation(presentation, r);
+            }
+
+            return presentation;
+
+        } catch (BadLocationException x) {
+            return null;
+        }
+    }
+
+
+    /**
+     * Checks for the first and the last affected partition affected by a
+     * document event and calls their damagers. Invalidates everything from the
+     * start of the damage for the first partition until the end of the damage
+     * for the last partition.
+     *
+     * @param e the event describing the document change
+     * @param optimize <code>true</code> if partition changes should be
+     *        considered for optimization
+     * @return the damaged caused by the change or <code>null</code> if
+     *         computing the partitioning failed
+     * @since 3.0
+     */
+    private IRegion getDamage(DocumentEvent e, bool optimize) {
+        int length= e.getText() is null ? 0 : e.getText().length();
+        
+        if (fDamagers is null || fDamagers.isEmpty()) {
+            length= Math.max(e.getLength(), length);
+            length= Math.min(e.getDocument().getLength() - e.getOffset(), length);
+            return new Region(e.getOffset(), length);
+        }
+
+        bool isDeletion= length is 0;
+        IRegion damage= null;
+        try {
+            int offset= e.getOffset();
+            if (isDeletion)
+                offset= Math.max(0, offset - 1);
+            ITypedRegion partition= getPartition(e.getDocument(), offset);
+            IPresentationDamager damager= getDamager(partition.getType());
+            if (damager is null)
+                return null;
+
+            IRegion r= damager.getDamageRegion(partition, e, fDocumentPartitioningChanged);
+
+            if (!fDocumentPartitioningChanged && optimize && !isDeletion) {
+                damage= r;
+            } else {
+
+                int damageEnd= getDamageEndOffset(e);
+
+                int parititionDamageEnd= -1;
+                if (fChangedDocumentPartitions !is null)
+                    parititionDamageEnd= fChangedDocumentPartitions.getOffset() + fChangedDocumentPartitions.getLength();
+
+                int end= Math.max(damageEnd, parititionDamageEnd);
+
+                damage= end is -1 ? r : new Region(r.getOffset(), end - r.getOffset());
+            }
+
+        } catch (BadLocationException x) {
+        }
+
+        return damage;
+    }
+
+    /**
+     * Returns the end offset of the damage. If a partition has been split by
+     * the given document event also the second half of the original
+     * partition must be considered. This is achieved by using the remembered
+     * partition range.
+     *
+     * @param e the event describing the change
+     * @return the damage end offset (excluding)
+     * @exception BadLocationException if method accesses invalid offset
+     */
+    private int getDamageEndOffset(DocumentEvent e) throws BadLocationException {
+
+        IDocument d= e.getDocument();
+
+        int length= 0;
+        if (e.getText() !is null) {
+            length= e.getText().length();
+            if (length > 0)
+                -- length;
+        }
+
+        ITypedRegion partition= getPartition(d, e.getOffset() + length);
+        int endOffset= partition.getOffset() + partition.getLength();
+        if (endOffset is e.getOffset())
+            return -1;
+
+        int end= fRememberedPosition is null ? -1 : fRememberedPosition.getOffset() + fRememberedPosition.getLength();
+        if (endOffset < end && end < d.getLength())
+            partition= getPartition(d, end);
+
+        IPresentationDamager damager= getDamager(partition.getType());
+        if (damager is null)
+            return -1;
+
+        IRegion r= damager.getDamageRegion(partition, e, fDocumentPartitioningChanged);
+
+        return r.getOffset() + r.getLength();
+    }
+
+    /**
+     * Processes the given damage.
+     * @param damage the damage to be repaired
+     * @param document the document whose presentation must be repaired
+     */
+    private void processDamage(IRegion damage, IDocument document) {
+        if (damage !is null && damage.getLength() > 0) {
+            TextPresentation p= createPresentation(damage, document);
+            if (p !is null)
+                applyTextRegionCollection(p);
+        }
+    }
+
+    /**
+     * Applies the given text presentation to the text viewer the presentation
+     * reconciler is installed on.
+     *
+     * @param presentation the text presentation to be applied to the text viewer
+     */
+    private void applyTextRegionCollection(TextPresentation presentation) {
+        fViewer.changeTextPresentation(presentation, false);
+    }
+
+    /**
+     * Returns the partition for the given offset in the given document.
+     *
+     * @param document the document
+     * @param offset the offset
+     * @return the partition
+     * @throws BadLocationException if offset is invalid in the given document
+     * @since 3.0
+     */
+    private ITypedRegion getPartition(IDocument document, int offset) throws BadLocationException {
+        return TextUtilities.getPartition(document, getDocumentPartitioning(), offset, false);
+    }
+}