Hi there,
This is a skeleton implementation of ZoneView. I implemented all
original ZoneView methods so far, and backed everything up with Mauve
tests.
Sorry, wrong patch. Here it comes now.
2006-08-29 Roman Kennke <[EMAIL PROTECTED]>
* javax/swing/text/ZoneView.java: New class.
/Roman
Index: javax/swing/text/ZoneView.java
===================================================================
RCS file: javax/swing/text/ZoneView.java
diff -N javax/swing/text/ZoneView.java
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ javax/swing/text/ZoneView.java 30 Aug 2006 15:30:35 -0000 1.1
@@ -0,0 +1,317 @@
+/* ZoneView.java -- An effective BoxView subclass
+ Copyright (C) 2006 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING. If not, write to the
+Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library. Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module. An independent module is a module which is not derived from
+or based on this library. If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so. If you do not wish to do so, delete this
+exception statement from your version. */
+
+
+package javax.swing.text;
+
+import java.awt.Shape;
+import java.util.LinkedList;
+
+import javax.swing.event.DocumentEvent;
+
+/**
+ * A View implementation that delays loading of sub views until they are
+ * needed for display or internal transformations. This can be used for
+ * editors that need to handle large documents more effectivly than the
+ * standard [EMAIL PROTECTED] BoxView}.
+ *
+ * @author Roman Kennke ([EMAIL PROTECTED])
+ *
+ * @since 1.3
+ */
+public class ZoneView
+ extends BoxView
+{
+
+ /**
+ * The default zone view implementation. The specs suggest that this is
+ * a subclass of AsyncBoxView, so do we.
+ */
+ private class Zone
+ extends AsyncBoxView
+ {
+ /**
+ * The start position for this zone.
+ */
+ private Position p0;
+
+ /**
+ * The end position for this zone.
+ */
+ private Position p1;
+
+ /**
+ * Creates a new Zone for the specified element, start and end positions.
+ *
+ * @param el the element
+ * @param pos0 the start position
+ * @param pos1 the end position
+ */
+ Zone(Element el, Position pos0, Position pos1)
+ {
+ super(el, ZoneView.this.getAxis());
+ p0 = pos0;
+ p1 = pos1;
+ }
+
+ /**
+ * Returns the start offset of the zone.
+ *
+ * @return the start offset of the zone
+ */
+ public int getStartOffset()
+ {
+ return p0.getOffset();
+ }
+
+ /**
+ * Returns the end offset of the zone.
+ *
+ * @return the end offset of the zone
+ */
+ public int getEndOffset()
+ {
+ return p1.getOffset();
+ }
+ }
+
+ /**
+ * The maximumZoneSize.
+ */
+ private int maximumZoneSize;
+
+ /**
+ * The maximum number of loaded zones.
+ */
+ private int maxZonesLoaded;
+
+ /**
+ * A queue of loaded zones. When the number of loaded zones exceeds the
+ * maximum number of zones, the oldest zone(s) get unloaded.
+ */
+ private LinkedList loadedZones;
+
+ /**
+ * Creates a new ZoneView for the specified element and axis.
+ *
+ * @param element the element for which to create a ZoneView
+ * @param axis the major layout axis for the box
+ */
+ public ZoneView(Element element, int axis)
+ {
+ super(element, axis);
+ maximumZoneSize = 8192;
+ maxZonesLoaded = 3;
+ loadedZones = new LinkedList();
+ }
+
+ /**
+ * Sets the maximum zone size. Note that zones might still become larger
+ * then the size specified when a singe child view is larger for itself,
+ * because zones are formed on child view boundaries.
+ *
+ * @param size the maximum zone size to set
+ *
+ * @see #getMaximumZoneSize()
+ */
+ public void setMaximumZoneSize(int size)
+ {
+ maximumZoneSize = size;
+ }
+
+ /**
+ * Returns the maximum zone size. Note that zones might still become larger
+ * then the size specified when a singe child view is larger for itself,
+ * because zones are formed on child view boundaries.
+ *
+ * @return the maximum zone size
+ *
+ * @see #setMaximumZoneSize(int)
+ */
+ public int getMaximumZoneSize()
+ {
+ return maximumZoneSize;
+ }
+
+ /**
+ * Sets the maximum number of zones that are allowed to be loaded at the
+ * same time. If the new number of allowed zones is smaller then the
+ * previous settings, this unloads all zones the aren't allowed to be
+ * loaded anymore.
+ *
+ * @param num the number of zones allowed to be loaded at the same time
+ *
+ * @throws IllegalArgumentException if <code>num <= 0</code>
+ *
+ * @see #getMaxZonesLoaded()
+ */
+ public void setMaxZonesLoaded(int num)
+ {
+ if (num < 1)
+ throw new IllegalArgumentException("Illegal number of zones");
+ maxZonesLoaded = num;
+ unloadOldestZones();
+ }
+
+ /**
+ * Returns the number of zones that are allowed to be loaded.
+ *
+ * @return the number of zones that are allowed to be loaded
+ *
+ * @see #setMaxZonesLoaded(int)
+ */
+ public int getMaxZonesLoaded()
+ {
+ return maxZonesLoaded;
+ }
+
+ /**
+ * Gets called after a zone has been loaded. This unloads the oldest zone(s)
+ * when the maximum number of zones is reached.
+ *
+ * @param zone the zone that has been loaded
+ */
+ protected void zoneWasLoaded(View zone)
+ {
+ loadedZones.addLast(zone);
+ unloadOldestZones();
+ }
+
+ /**
+ * This unloads the specified zone. This is implemented to simply remove
+ * all child views from that zone.
+ *
+ * @param zone the zone to be unloaded
+ */
+ protected void unloadZone(View zone)
+ {
+ zone.removeAll();
+ }
+
+ /**
+ * Returns <code>true</code> when the specified zone is loaded,
+ * <code>false</code> otherwise. The default implementation checks if
+ * the zone view has child elements.
+ *
+ * @param zone the zone view to check
+ *
+ * @return <code>true</code> when the specified zone is loaded,
+ * <code>false</code> otherwise
+ */
+ protected boolean isZoneLoaded(View zone)
+ {
+ return zone.getViewCount() > 0;
+ }
+
+ /**
+ * Creates a zone for the specified range. Subclasses can override this
+ * to provide a custom implementation for the zones.
+ *
+ * @param p0 the start of the range
+ * @param p1 the end of the range
+ *
+ * @return the zone
+ */
+ protected View createZone(int p0, int p1)
+ {
+ Document doc = getDocument();
+ Position pos0 = null;
+ Position pos1 = null;
+ try
+ {
+ pos0 = doc.createPosition(p0);
+ pos1 = doc.createPosition(p1);
+ }
+ catch (BadLocationException ex)
+ {
+ assert false : "Must not happen";
+ }
+ Zone zone = new Zone(getElement(), pos0, pos1);
+ return zone;
+ }
+
+ /**
+ * A helper method to unload the oldest zones when there are more loaded
+ * zones then allowed.
+ */
+ private void unloadOldestZones()
+ {
+ int maxZones = getMaxZonesLoaded();
+ while (loadedZones.size() > maxZones)
+ {
+ View zone = (View) loadedZones.removeFirst();
+ unloadZone(zone);
+ }
+ }
+
+ // --------------------------------------------------------------------------
+ // CompositeView methods.
+ // --------------------------------------------------------------------------
+
+ protected void loadChildren(ViewFactory vf)
+ {
+ // TODO: Implement this.
+ }
+
+ protected int getViewIndexAtPosition(int pos)
+ {
+ // TODO: Implement this.
+ return -1;
+ }
+
+ // --------------------------------------------------------------------------
+ // View methods.
+ // --------------------------------------------------------------------------
+
+ public void insertUpdate(DocumentEvent e, Shape a, ViewFactory vf)
+ {
+ // TODO: Implement this.
+ }
+
+ public void removeUpdate(DocumentEvent e, Shape a, ViewFactory vf)
+ {
+ // TODO: Implement this.
+ }
+
+ protected boolean updateChildren(DocumentEvent.ElementChange ec,
+ DocumentEvent e, ViewFactory vf)
+ {
+ // TODO: Implement this.
+ return false;
+ }
+
+}
