/**

* Copyright (c) 2007, Gaudenz Alder

*/

package com.mxgraph.view;

import java.awt.Graphics;

import java.awt.Point;

import java.awt.Rectangle;

import java.awt.Shape;

import java.beans.PropertyChangeListener;

import java.beans.PropertyChangeSupport;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Collection;

import java.util.HashSet;

import java.util.Hashtable;

import java.util.Iterator;

import java.util.LinkedHashSet;

import java.util.LinkedList;

import java.util.List;

import java.util.Map;

import java.util.Set;

import java.util.logging.Level;

import java.util.logging.Logger;

import org.w3c.dom.Element;

import com.mxgraph.canvas.mxGraphics2DCanvas;

import com.mxgraph.canvas.mxICanvas;

import com.mxgraph.canvas.mxImageCanvas;

import com.mxgraph.model.mxCell;

import com.mxgraph.model.mxGeometry;

import com.mxgraph.model.mxGraphModel;

import com.mxgraph.model.mxGraphModel.Filter;

import com.mxgraph.model.mxGraphModel.mxChildChange;

import com.mxgraph.model.mxGraphModel.mxCollapseChange;

import com.mxgraph.model.mxGraphModel.mxGeometryChange;

import com.mxgraph.model.mxGraphModel.mxRootChange;

import com.mxgraph.model.mxGraphModel.mxStyleChange;

import com.mxgraph.model.mxGraphModel.mxTerminalChange;

import com.mxgraph.model.mxGraphModel.mxValueChange;

import com.mxgraph.model.mxGraphModel.mxVisibleChange;

import com.mxgraph.model.mxICell;

import com.mxgraph.model.mxIGraphModel;

import com.mxgraph.util.mxConstants;

import com.mxgraph.util.mxEvent;

import com.mxgraph.util.mxEventObject;

import com.mxgraph.util.mxEventSource;

import com.mxgraph.util.mxImageBundle;

import com.mxgraph.util.mxPoint;

import com.mxgraph.util.mxRectangle;

import com.mxgraph.util.mxResources;

import com.mxgraph.util.mxStyleUtils;

import com.mxgraph.util.mxUndoableEdit;

import com.mxgraph.util.mxUndoableEdit.mxUndoableChange;

import com.mxgraph.util.mxUtils;

/**

* Implements a graph object that allows to create diagrams from a graph model

* and stylesheet.

*

* <h3>Images</h3>

* To create an image from a graph, use the following code for a given

* XML document (doc) and File (file):

*

* <code>

* Image img = mxCellRenderer.createBufferedImage(

* graph, null, 1, Color.WHITE, false, null);

* ImageIO.write(img, "png", file);

* </code>

*

* If the XML is given as a string rather than a document, the document can

* be obtained using mxUtils.parse.

*

* This class fires the following events:

*

* mxEvent.ROOT fires if the root in the model has changed. This event has no

* properties.

*

* mxEvent.ALIGN_CELLS fires between begin- and endUpdate in alignCells. The

* <code>cells</code> and <code>align</code> properties contain the respective

* arguments that were passed to alignCells.

*

* mxEvent.FLIP_EDGE fires between begin- and endUpdate in flipEdge. The

* <code>edge</code> property contains the edge passed to flipEdge.

*

* mxEvent.ORDER_CELLS fires between begin- and endUpdate in orderCells. The

* <code>cells</code> and <code>back</code> properties contain the respective

* arguments that were passed to orderCells.

*

* mxEvent.CELLS_ORDERED fires between begin- and endUpdate in cellsOrdered.

* The <code>cells</code> and <code>back</code> arguments contain the

* respective arguments that were passed to cellsOrdered.

*

* mxEvent.GROUP_CELLS fires between begin- and endUpdate in groupCells. The

* <code>group</code>, <code>cells</code> and <code>border</code> arguments

* contain the respective arguments that were passed to groupCells.

*

* mxEvent.UNGROUP_CELLS fires between begin- and endUpdate in ungroupCells.

* The <code>cells</code> property contains the array of cells that was passed

* to ungroupCells.

*

* mxEvent.REMOVE_CELLS_FROM_PARENT fires between begin- and endUpdate in

* removeCellsFromParent. The <code>cells</code> property contains the array of

* cells that was passed to removeCellsFromParent.

*

* mxEvent.ADD_CELLS fires between begin- and endUpdate in addCells. The

* <code>cells</code>, <code>parent</code>, <code>index</code>,

* <code>source</code> and <code>target</code> properties contain the

* respective arguments that were passed to addCells.

*

* mxEvent.CELLS_ADDED fires between begin- and endUpdate in cellsAdded. The

* <code>cells</code>, <code>parent</code>, <code>index</code>,

* <code>source</code>, <code>target</code> and <code>absolute</code>

* properties contain the respective arguments that were passed to cellsAdded.

*

* mxEvent.REMOVE_CELLS fires between begin- and endUpdate in removeCells. The

* <code>cells</code> and <code>includeEdges</code> arguments contain the

* respective arguments that were passed to removeCells.

*

* mxEvent.CELLS_REMOVED fires between begin- and endUpdate in cellsRemoved.

* The <code>cells</code> argument contains the array of cells that was

* removed.

*

* mxEvent.SPLIT_EDGE fires between begin- and endUpdate in splitEdge. The

* <code>edge</code> property contains the edge to be splitted, the

* <code>cells</code>, <code>newEdge</code>, <code>dx</code> and

* <code>dy</code> properties contain the respective arguments that were passed

* to splitEdge.

*

* mxEvent.TOGGLE_CELLS fires between begin- and endUpdate in toggleCells. The

* <code>show</code>, <code>cells</code> and <code>includeEdges</code>

* properties contain the respective arguments that were passed to toggleCells.

*

* mxEvent.FOLD_CELLS fires between begin- and endUpdate in foldCells. The

* <code>collapse</code>, <code>cells</code> and <code>recurse</code>

* properties contain the respective arguments that were passed to foldCells.

*

* mxEvent.CELLS_FOLDED fires between begin- and endUpdate in cellsFolded. The

* <code>collapse</code>, <code>cells</code> and <code>recurse</code>

* properties contain the respective arguments that were passed to cellsFolded.

*

* mxEvent.UPDATE_CELL_SIZE fires between begin- and endUpdate in

* updateCellSize. The <code>cell</code> and <code>ignoreChildren</code>

* properties contain the respective arguments that were passed to

* updateCellSize.

*

* mxEvent.RESIZE_CELLS fires between begin- and endUpdate in resizeCells. The

* <code>cells</code> and <code>bounds</code> properties contain the respective

* arguments that were passed to resizeCells.

*

* mxEvent.CELLS_RESIZED fires between begin- and endUpdate in cellsResized.

* The <code>cells</code> and <code>bounds</code> properties contain the

* respective arguments that were passed to cellsResized.

*

* mxEvent.MOVE_CELLS fires between begin- and endUpdate in moveCells. The

* <code>cells</code>, <code>dx</code>, <code>dy</code>, <code>clone</code>,

* <code>target</code> and <code>location</code> properties contain the

* respective arguments that were passed to moveCells.

*

* mxEvent.CELLS_MOVED fires between begin- and endUpdate in cellsMoved. The

* <code>cells</code>, <code>dx</code>, <code>dy</code> and

* <code>disconnect</code> properties contain the respective arguments that

* were passed to cellsMoved.

*

* mxEvent.CONNECT_CELL fires between begin- and endUpdate in connectCell. The

* <code>edge</code>, <code>terminal</code> and <code>source</code> properties

* contain the respective arguments that were passed to connectCell.

*

* mxEvent.CELL_CONNECTED fires between begin- and endUpdate in cellConnected.

* The <code>edge</code>, <code>terminal</code> and <code>source</code>

* properties contain the respective arguments that were passed to

* cellConnected.

*

* mxEvent.REPAINT fires if a repaint was requested by calling repaint. The

* <code>region</code> property contains the optional mxRectangle that was

* passed to repaint to define the dirty region.

*/

public class mxGraph extends mxEventSource

{

private static final Logger log = Logger.getLogger(mxGraph.class.getName());

/**

* Adds required resources.

*/

static

{

try

{

mxResources.add("com.mxgraph.resources.graph");

}

catch (Exception e)

{

log.log(Level.SEVERE, "Failed to add the resource bundle", e);

}

}

/**

* Holds the version number of this release. Current version

* is 3.9.8.

*/

public static final String VERSION = "3.9.8";

/**

*

*/

public interface mxICellVisitor

{

/**

*

* @param vertex

* @param edge

*/

boolean visit(Object vertex, Object edge);

}

/**

* Property change event handling.

*/

protected PropertyChangeSupport changeSupport = new PropertyChangeSupport(

this);

/**

* Holds the model that contains the cells to be displayed.

*/

protected mxIGraphModel model;

/**

* Holds the view that caches the cell states.

*/

protected mxGraphView view;

/**

* Holds the stylesheet that defines the appearance of the cells.

*/

protected mxStylesheet stylesheet;

/**

* Holds the <mxGraphSelection> that models the current selection.

*/

protected mxGraphSelectionModel selectionModel;

/**

* Specifies the grid size. Default is 10.

*/

protected int gridSize = 10;

/**

* Specifies if the grid is enabled. Default is true.

*/

protected boolean gridEnabled = true;

/**

* Specifies if ports are enabled. This is used in <cellConnected> to update

* the respective style. Default is true.

*/

protected boolean portsEnabled = true;

/**

* Value returned by getOverlap if isAllowOverlapParent returns

* true for the given cell. getOverlap is used in keepInside if

* isKeepInsideParentOnMove returns true. The value specifies the

* portion of the child which is allowed to overlap the parent.

*/

protected double defaultOverlap = 0.5;

/**

* Specifies the default parent to be used to insert new cells.

* This is used in getDefaultParent. Default is null.

*/

protected Object defaultParent;

/**

* Specifies the alternate edge style to be used if the main control point

* on an edge is being doubleclicked. Default is null.

*/

protected String alternateEdgeStyle;

/**

* Specifies the return value for isEnabled. Default is true.

*/

protected boolean enabled = true;

/**

* Specifies the return value for isCell(s)Locked. Default is false.

*/

protected boolean cellsLocked = false;

/**

* Specifies the return value for isCell(s)Editable. Default is true.

*/

protected boolean cellsEditable = true;

/**

* Specifies the return value for isCell(s)Sizable. Default is true.

*/

protected boolean cellsResizable = true;

/**

* Specifies the return value for isCell(s)Movable. Default is true.

*/

protected boolean cellsMovable = true;

/**

* Specifies the return value for isCell(s)Bendable. Default is true.

*/

protected boolean cellsBendable = true;

/**

* Specifies the return value for isCell(s)Selectable. Default is true.

*/

protected boolean cellsSelectable = true;

/**

* Specifies the return value for isCell(s)Deletable. Default is true.

*/

protected boolean cellsDeletable = true;

/**

* Specifies the return value for isCell(s)Cloneable. Default is true.

*/

protected boolean cellsCloneable = true;

/**

* Specifies the return value for isCellDisconntableFromTerminal. Default

* is true.

*/

protected boolean cellsDisconnectable = true;

/**

* Specifies the return value for isLabel(s)Clipped. Default is false.

*/

protected boolean labelsClipped = false;

/**

* Specifies the return value for edges in isLabelMovable. Default is true.

*/

protected boolean edgeLabelsMovable = true;

/**

* Specifies the return value for vertices in isLabelMovable. Default is false.

*/

protected boolean vertexLabelsMovable = false;

/**

* Specifies the return value for isDropEnabled. Default is true.

*/

protected boolean dropEnabled = true;

/**

* Specifies if dropping onto edges should be enabled. Default is true.

*/

protected boolean splitEnabled = true;

/**

* Specifies if the graph should automatically update the cell size

* after an edit. This is used in isAutoSizeCell. Default is false.

*/

protected boolean autoSizeCells = false;

/**

* <mxRectangle> that specifies the area in which all cells in the

* diagram should be placed. Uses in getMaximumGraphBounds. Use a width

* or height of 0 if you only want to give a upper, left corner.

*/

protected mxRectangle maximumGraphBounds = null;

/**

* mxRectangle that specifies the minimum size of the graph canvas inside

* the scrollpane.

*/

protected mxRectangle minimumGraphSize = null;

/**

* Border to be added to the bottom and right side when the container is

* being resized after the graph has been changed. Default is 0.

*/

protected int border = 0;

/**

* Specifies if edges should appear in the foreground regardless of their

* order in the model. This has precendence over keepEdgeInBackground

* Default is false.

*/

protected boolean keepEdgesInForeground = false;

/**

* Specifies if edges should appear in the background regardless of their

* order in the model. Default is false.

*/

protected boolean keepEdgesInBackground = false;

/**

* Specifies if the cell size should be changed to the preferred size when

* a cell is first collapsed. Default is true.

*/

protected boolean collapseToPreferredSize = true;

/**

* Specifies if negative coordinates for vertices are allowed. Default is true.

*/

protected boolean allowNegativeCoordinates = true;

/**

* Specifies the return value for isConstrainChildren. Default is true.

*/

protected boolean constrainChildren = true;

/**

* Specifies if a parent should contain the child bounds after a resize of

* the child. Default is true.

*/

protected boolean extendParents = true;

/**

* Specifies if parents should be extended according to the <extendParents>

* switch if cells are added. Default is true.

*/

protected boolean extendParentsOnAdd = true;

/**

* Specifies if the scale and translate should be reset if

* the root changes in the model. Default is true.

*/

protected boolean resetViewOnRootChange = true;

/**

* Specifies if loops (aka self-references) are allowed.

* Default is false.

*/

protected boolean resetEdgesOnResize = false;

/**

* Specifies if edge control points should be reset after

* the move of a connected cell. Default is false.

*/

protected boolean resetEdgesOnMove = false;

/**

* Specifies if edge control points should be reset after

* the the edge has been reconnected. Default is true.

*/

protected boolean resetEdgesOnConnect = true;

/**

* Specifies if loops (aka self-references) are allowed.

* Default is false.

*/

protected boolean allowLoops = false;

/**

* Specifies the multiplicities to be used for validation of the graph.

*/

protected mxMultiplicity[] multiplicities;

/**

* Specifies the default style for loops.

*/

protected mxEdgeStyle.mxEdgeStyleFunction defaultLoopStyle = mxEdgeStyle.Loop;

/**

* Specifies if multiple edges in the same direction between

* the same pair of vertices are allowed. Default is true.

*/

protected boolean multigraph = true;

/**

* Specifies if edges are connectable. Default is false.

* This overrides the connectable field in edges.

*/

protected boolean connectableEdges = false;

/**

* Specifies if edges with disconnected terminals are

* allowed in the graph. Default is false.

*/

protected boolean allowDanglingEdges = true;

/**

* Specifies if edges that are cloned should be validated and only inserted

* if they are valid. Default is true.

*/

protected boolean cloneInvalidEdges = false;

/**

* Specifies if edges should be disconnected from their terminals when they

* are moved. Default is true.

*/

protected boolean disconnectOnMove = true;

/**

* Specifies if labels should be visible. This is used in

* getLabel. Default is true.

*/

protected boolean labelsVisible = true;

/**

* Specifies the return value for isHtmlLabel. Default is false.

*/

protected boolean htmlLabels = false;

/**

* Specifies if nesting of swimlanes is allowed. Default is true.

*/

protected boolean swimlaneNesting = true;

/**

* Specifies the maximum number of changes that should be processed to find

* the dirty region. If the number of changes is larger, then the complete

* grah is repainted. A value of zero will always compute the dirty region

* for any number of changes. Default is 1000.

*/

protected int changesRepaintThreshold = 1000;

/**

* Specifies if the origin should be automatically updated.

*/

protected boolean autoOrigin = false;

/**

* Holds the current automatic origin.

*/

protected mxPoint origin = new mxPoint();

/**

* Holds the list of bundles.

*/

protected static List<mxImageBundle> imageBundles = new LinkedList<mxImageBundle>();

/**

* Fires repaint events for full repaints.

*/

protected mxIEventListener fullRepaintHandler = new mxIEventListener()

{

public void invoke(Object sender, mxEventObject evt)

{

repaint();

}

};

/**

* Fires repaint events for full repaints.

*/

protected mxIEventListener updateOriginHandler = new mxIEventListener()

{

public void invoke(Object sender, mxEventObject evt)

{

if (isAutoOrigin())

{

updateOrigin();

}

}

};

/**

* Fires repaint events for model changes.

*/

protected mxIEventListener graphModelChangeHandler = new mxIEventListener()

{

public void invoke(Object sender, mxEventObject evt)

{

mxRectangle dirty = graphModelChanged((mxIGraphModel) sender,

(List<mxUndoableChange>) ((mxUndoableEdit) evt

.getProperty("edit")).getChanges());

repaint(dirty);

}

};

/**

* Constructs a new graph with an empty

* {@link com.mxgraph.model.mxGraphModel}.

*/

public mxGraph()

{

this(null, null);

}

/**

* Constructs a new graph for the specified model. If no model is

* specified, then a new, empty {@link com.mxgraph.model.mxGraphModel} is

* used.

*

* @param model Model that contains the graph data

*/

public mxGraph(mxIGraphModel model)

{

this(model, null);

}

/**

* Constructs a new graph for the specified model. If no model is

* specified, then a new, empty {@link com.mxgraph.model.mxGraphModel} is

* used.

*

* @param stylesheet The stylesheet to use for the graph.

*/

public mxGraph(mxStylesheet stylesheet)

{

this(null, stylesheet);

}

/**

* Constructs a new graph for the specified model. If no model is

* specified, then a new, empty {@link com.mxgraph.model.mxGraphModel} is

* used.

*

* @param model Model that contains the graph data

*/

public mxGraph(mxIGraphModel model, mxStylesheet stylesheet)

{

selectionModel = createSelectionModel();

setModel((model != null) ? model : new mxGraphModel());

setStylesheet((stylesheet != null) ? stylesheet : createStylesheet());

setView(createGraphView());

}

/**

* Constructs a new selection model to be used in this graph.

*/

protected mxGraphSelectionModel createSelectionModel()

{

return new mxGraphSelectionModel(this);

}

/**

* Constructs a new stylesheet to be used in this graph.

*/

protected mxStylesheet createStylesheet()

{

return new mxStylesheet();

}

/**

* Constructs a new view to be used in this graph.

*/

protected mxGraphView createGraphView()

{

return new mxGraphView(this);

}

/**

* Returns the graph model that contains the graph data.

*

* @return Returns the model that contains the graph data

*/

public mxIGraphModel getModel()

{

return model;

}

/**

* Sets the graph model that contains the data, and fires an

* mxEvent.CHANGE followed by an mxEvent.REPAINT event.

*

* @param value Model that contains the graph data

*/

public void setModel(mxIGraphModel value)

{

if (model != null)

{

model.removeListener(graphModelChangeHandler);

}

Object oldModel = model;

model = value;

if (view != null)

{

view.revalidate();

}

model.addListener(mxEvent.CHANGE, graphModelChangeHandler);

changeSupport.firePropertyChange("model", oldModel, model);

repaint();

}

/**

* Returns the view that contains the cell states.

*

* @return Returns the view that contains the cell states

*/

public mxGraphView getView()

{

return view;

}

/**

* Sets the view that contains the cell states.

*

* @param value View that contains the cell states

*/

public void setView(mxGraphView value)

{

if (view != null)

{

view.removeListener(fullRepaintHandler);

view.removeListener(updateOriginHandler);

}

Object oldView = view;

view = value;

if (view != null)

{

view.revalidate();

}

// Listens to changes in the view

view.addListener(mxEvent.SCALE, fullRepaintHandler);

view.addListener(mxEvent.SCALE, updateOriginHandler);

view.addListener(mxEvent.TRANSLATE, fullRepaintHandler);

view.addListener(mxEvent.SCALE_AND_TRANSLATE, fullRepaintHandler);

view.addListener(mxEvent.SCALE_AND_TRANSLATE, updateOriginHandler);

view.addListener(mxEvent.UP, fullRepaintHandler);

view.addListener(mxEvent.DOWN, fullRepaintHandler);

changeSupport.firePropertyChange("view", oldView, view);

}

/**

* Returns the stylesheet that provides the style.

*

* @return Returns the stylesheet that provides the style.

*/

public mxStylesheet getStylesheet()

{

return stylesheet;

}

/**

* Sets the stylesheet that provides the style.

*

* @param value Stylesheet that provides the style.

*/

public void setStylesheet(mxStylesheet value)

{

mxStylesheet oldValue = stylesheet;

stylesheet = value;

changeSupport.firePropertyChange("stylesheet", oldValue, stylesheet);

}

/**

* Returns the cells to be selected for the given list of changes.

*/

public Object[] getSelectionCellsForChanges(List<mxUndoableChange> changes)

{

List<Object> cells = new ArrayList<Object>();

Iterator<mxUndoableChange> it = changes.iterator();

while (it.hasNext())

{

Object change = it.next();

if (change instanceof mxChildChange)

{

cells.add(((mxChildChange) change).getChild());

}

else if (change instanceof mxTerminalChange)

{

cells.add(((mxTerminalChange) change).getCell());

}

else if (change instanceof mxValueChange)

{

cells.add(((mxValueChange) change).getCell());

}

else if (change instanceof mxStyleChange)

{

cells.add(((mxStyleChange) change).getCell());

}

else if (change instanceof mxGeometryChange)

{

cells.add(((mxGeometryChange) change).getCell());

}

else if (change instanceof mxCollapseChange)

{

cells.add(((mxCollapseChange) change).getCell());

}

else if (change instanceof mxVisibleChange)

{

mxVisibleChange vc = (mxVisibleChange) change;

if (vc.isVisible())

{

cells.add(((mxVisibleChange) change).getCell());

}

}

}

return mxGraphModel.getTopmostCells(model, cells.toArray());

}

/**

* Called when the graph model changes. Invokes processChange on each

* item of the given array to update the view accordingly.

*/

public mxRectangle graphModelChanged(mxIGraphModel sender,

List<mxUndoableChange> changes)

{

int thresh = getChangesRepaintThreshold();

boolean ignoreDirty = thresh > 0 && changes.size() > thresh;

// Ignores dirty rectangle if there was a root change

if (!ignoreDirty)

{

Iterator<mxUndoableChange> it = changes.iterator();

while (it.hasNext())

{

if (it.next() instanceof mxRootChange)

{

ignoreDirty = true;

break;

}

}

}

mxRectangle dirty = processChanges(changes, true, ignoreDirty);

view.validate();

if (isAutoOrigin())

{

updateOrigin();

}

if (!ignoreDirty)

{

mxRectangle tmp = processChanges(changes, false, ignoreDirty);

if (tmp != null)

{

if (dirty == null)

{

dirty = tmp;

}

else

{

dirty.add(tmp);

}

}

}

removeSelectionCells(getRemovedCellsForChanges(changes));

return dirty;

}

/**

* Extends the canvas by doing another validation with a shifted

* global translation if the bounds of the graph are below (0,0).

*

* The first validation is required to compute the bounds of the graph

* while the second validation is required to apply the new translate.

*/

protected void updateOrigin()

{

mxRectangle bounds = getGraphBounds();

if (bounds != null)

{

double scale = getView().getScale();

double x = bounds.getX() / scale - getBorder();

double y = bounds.getY() / scale - getBorder();

if (x < 0 || y < 0)

{

double x0 = Math.min(0, x);

double y0 = Math.min(0, y);

origin.setX(origin.getX() + x0);

origin.setY(origin.getY() + y0);

mxPoint t = getView().getTranslate();

getView().setTranslate(

new mxPoint(t.getX() - x0, t.getY() - y0));

}

else if ((x > 0 || y > 0)

&& (origin.getX() < 0 || origin.getY() < 0))

{

double dx = Math.min(-origin.getX(), x);

double dy = Math.min(-origin.getY(), y);

origin.setX(origin.getX() + dx);

origin.setY(origin.getY() + dy);

mxPoint t = getView().getTranslate();

getView().setTranslate(

new mxPoint(t.getX() - dx, t.getY() - dy));

}

}

}

/**

* Returns the cells that have been removed from the model.

*/

public Object[] getRemovedCellsForChanges(List<mxUndoableChange> changes)

{

List<Object> result = new ArrayList<Object>();

Iterator<mxUndoableChange> it = changes.iterator();

while (it.hasNext())

{

Object change = it.next();

if (change instanceof mxRootChange)

{

break;

}

else if (change instanceof mxChildChange)

{

mxChildChange cc = (mxChildChange) change;

if (cc.getParent() == null)

{

result.addAll(mxGraphModel.getDescendants(model,

cc.getChild()));

}

}

else if (change instanceof mxVisibleChange)

{

Object cell = ((mxVisibleChange) change).getCell();

result.addAll(mxGraphModel.getDescendants(model, cell));

}

}

return result.toArray();

}

/**

* Processes the changes and returns the minimal rectangle to be

* repainted in the buffer. A return value of null means no repaint

* is required.

*/

public mxRectangle processChanges(List<mxUndoableChange> changes,

boolean invalidate, boolean ignoreDirty)

{

mxRectangle bounds = null;

Iterator<mxUndoableChange> it = changes.iterator();

while (it.hasNext())

{

mxRectangle rect = processChange(it.next(), invalidate, ignoreDirty);

if (bounds == null)

{

bounds = rect;

}

else

{

bounds.add(rect);

}

}

return bounds;

}

/**

* Processes the given change and invalidates the respective cached data

* in <view>. This fires a <root> event if the root has changed in the

* model.

*/

public mxRectangle processChange(mxUndoableChange change,

boolean invalidate, boolean ignoreDirty)

{

mxRectangle result = null;

if (change instanceof mxRootChange)

{

result = (ignoreDirty) ? null : getGraphBounds();

if (invalidate)

{

clearSelection();

removeStateForCell(((mxRootChange) change).getPrevious());

if (isResetViewOnRootChange())

{

view.setEventsEnabled(false);

try

{

view.scaleAndTranslate(1, 0, 0);

}

finally

{

view.setEventsEnabled(true);

}

}

}

fireEvent(new mxEventObject(mxEvent.ROOT));

}

else if (change instanceof mxChildChange)

{

mxChildChange cc = (mxChildChange) change;