/*
* Licensed Materials - Property of Rogue Wave Software, Inc.
* © Copyright Rogue Wave Software, Inc. 2014, 2015
* © Copyright IBM Corp. 2009, 2014
* © Copyright ILOG 1996, 2009
* All Rights Reserved.
*
* Note to U.S. Government Users Restricted Rights:
* The Software and Documentation were developed at private expense and
* are "Commercial Items" as that term is defined at 48 CFR 2.101,
* consisting of "Commercial Computer Software" and
* "Commercial Computer Software Documentation", as such terms are
* used in 48 CFR 12.212 or 48 CFR 227.7202-1 through 227.7202-4,
* as applicable.
*/
import ilog.views.diagrammer.IlvDiagrammer;
import ilog.views.diagrammer.application.IlvDiagrammerViewBar;
import ilog.views.diagrammer.application.IlvDiagrammerAction;
import ilog.views.sdm.IlvSDMEngine;
import ilog.views.sdm.renderer.graphlayout.IlvGraphLayoutRenderer;
import ilog.views.sdm.util.IlvSDMMutableStyleSheet;
import ilog.views.graphlayout.IlvGraphLayout;
import ilog.views.graphlayout.IlvGraphLayoutReport;
import ilog.views.graphlayout.GraphLayoutEvent;
import ilog.views.graphlayout.GraphLayoutEventListener;
import ilog.views.graphlayout.random.IlvRandomLayout;
import ilog.views.IlvGrid;
import ilog.views.IlvPoint;
import ilog.views.IlvTransformer;
import ilog.views.util.IlvProductUtil;
import ilog.views.util.swing.IlvSwingUtil;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.net.URL;
/**
* This is a very simple applet/application that uses the
* <code>IlvDiagrammer</code> to perform a grid layout.
* It loads a style sheet containing the grid layout specification.
* It allows to set various grid layout parameters by using the
* <code>IlvSDMMutableStyleSheet</code>.
*/
public class GridLayoutApplet extends JApplet
{
{
// This sample uses JViews Diagrammer features. When deploying an
// application that includes this code, you need to be in possession
// of a Rogue Wave JViews Diagrammer Deployment license.
IlvProductUtil.DeploymentLicenseRequired(
IlvProductUtil.JViews_Diagrammer_Deployment);
}
/** The diagrammer */
IlvDiagrammer diagrammer = new IlvDiagrammer();
/** A graph layout event listener */
LayoutIterationListener layoutListener = new LayoutIterationListener();
/** The style sheet for temporary changes */
IlvSDMMutableStyleSheet styleSheet = new IlvSDMMutableStyleSheet(
diagrammer.getEngine(), true, false);
/** An IlvGrid object to help understanding the grid mode */
IlvGrid grid = new LineGrid();
/** The default offset */
static final float DEFAULT_OFFSET = 80.f;
/** Text fields for the offset parameters */
JTextField hGridOffset = new JTextField("" + DEFAULT_OFFSET, 5);
JTextField vGridOffset = new JTextField("" + DEFAULT_OFFSET, 5);
/** A text field to display messages */
JTextField msgLine = new JTextField();
/**
* Initializes the applet/application.
*/
public void init()
{
// we use the standard diagrammer toolbar
IlvDiagrammerViewBar toolbar = new IlvDiagrammerViewBar();
// various settings of the diagrammer
diagrammer.setSelectMode(true);
diagrammer.setScrollable(true);
diagrammer.setEditingAllowed(true);
diagrammer.setMinimumZoom(0.02f);
diagrammer.setMaximumZoom(10f);
diagrammer.getView().setBackground(Color.white);
diagrammer.getView().setForeground(SystemColor.windowText);
// help recognition of the grid
diagrammer.getView().setGrid(grid);
grid.setOrigin(new IlvPoint(0, 0));
grid.setColor(new Color(255, 153, 153));
grid.setHorizontalSpacing(80);
grid.setVerticalSpacing(80);
grid.setActive(false);
grid.setVisible(true);
// create the file selector
JComboBox fileSelector = new JComboBox();
fileSelector.addItem("small");
fileSelector.addItem("medium");
fileSelector.addItem("large");
fileSelector.setToolTipText("Select a sample graph");
fileSelector.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent event) {
JComboBox comboBox = (JComboBox)event.getSource();
String fileName = (String)comboBox.getSelectedItem();
loadDataFile(fileName);
}
});
// create the randomize button
JButton randomizeButton = new JButton("Random");
randomizeButton.setToolTipText("Randomize the node positions");
randomizeButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent evt) {
randomize();
}});
// create the layout button
JButton layoutButton = new JButton("Layout");
layoutButton.setToolTipText("Perform a grid layout");
layoutButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent evt) {
// before performing layout, make sure that the values in the text
// fields are transfered to the style sheet
styleSheet.setAdjusting(true);
try {
setOffset("horizontalGridOffset", hGridOffset);
setOffset("verticalGridOffset", vGridOffset);
} finally {
styleSheet.setAdjusting(false);
}
performLayout();
}});
// create the panel for the layout buttons
JPanel layoutButtonPanel = new JPanel();
layoutButtonPanel.setLayout(new FlowLayout());
layoutButtonPanel.add(randomizeButton);
layoutButtonPanel.add(layoutButton);
// create the top panel with the toolbar and the file selector
JPanel topPanel = new JPanel();
topPanel.setLayout(new FlowLayout(FlowLayout.LEFT));
topPanel.add(toolbar);
topPanel.add(new JLabel("Select graph:"));
topPanel.add(fileSelector);
// create the bottom panel with the layout buttons and the message line
JPanel bottomPanel = new JPanel();
bottomPanel.setLayout(new BorderLayout());
bottomPanel.add(layoutButtonPanel, BorderLayout.NORTH);
bottomPanel.add(createParameterPanel(), BorderLayout.CENTER);
bottomPanel.add(msgLine, BorderLayout.SOUTH);
msgLine.setEditable(false);
// put diagrammer, top panel and bottom panel together
getContentPane().setLayout(new BorderLayout(0, 0));
getContentPane().add(diagrammer, BorderLayout.CENTER);
getContentPane().add(topPanel, BorderLayout.NORTH);
getContentPane().add(bottomPanel, BorderLayout.SOUTH);
try {
// load the main style file
diagrammer.setStyleSheet(
IlvSwingUtil.getRelativeURL(this, "data/grid.css"));
// load a mutable style file that we use for temporary style changes
diagrammer.getEngine().setStyleSheets(1, styleSheet.toString());
} catch (Exception e) {
showMessage(e.getMessage());
}
// load the initial sample grapher
loadDataFile("small");
// add the layout listener to the current graph layout. This must be done
// here after reading the style file, because before reading the style file,
// the layout instance is not yet instantiated.
getGraphLayout().addGraphLayoutEventListener(layoutListener);
}
/**
* Called when this applet is being reclaimed in order to destroy
* any resources that it has allocated.
*/
public void destroy()
{
super.destroy();
// This method is intended to workaround memory management issues
// in the Sun JRE. Please refer to the method documentation for more
// details and a description of the known issues.
IlvSwingUtil.cleanupApplet();
}
/**
* Creates the layout parameter panel.
*/
private JPanel createParameterPanel()
{
JPanel panel = new JPanel();
panel.setLayout(new BorderLayout());
// - - - - - - - - - - - - - - - - -
// the offset panel with all offsets
JPanel offsetPanel = new JPanel();
offsetPanel.setLayout(new GridLayout(2, 2));
// the horizontal grid offsets
final JLabel hGridOffsetLabel = new JLabel(" Horizontal:");
offsetPanel.add(hGridOffsetLabel);
offsetPanel.add(hGridOffset);
hGridOffset.setToolTipText("Select the horizontal grid offset");
hGridOffset.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
setOffset("horizontalGridOffset", (JTextField)e.getSource());
}
});
// the vertical grid offsets
final JLabel vGridOffsetLabel = new JLabel(" Vertical:");
offsetPanel.add(vGridOffsetLabel);
offsetPanel.add(vGridOffset);
vGridOffset.setToolTipText("Select the vertical grid offset");
vGridOffset.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
setOffset("verticalGridOffset", (JTextField)e.getSource());
}
});
// - - - - - - - - - - - - - - - - -
// the panel with check boxes
JPanel checkBoxPanel = new JPanel();
JCheckBox incrementalOption = new JCheckBox("Incremental", false);
checkBoxPanel.add(incrementalOption);
incrementalOption.setToolTipText("Enable or disable the incremental mode");
incrementalOption.addItemListener(new ItemListener() {
public void itemStateChanged(ItemEvent e) {
setIncrementalMode(e.getStateChange() == ItemEvent.SELECTED);
}
});
JCheckBox preserveFixedNodesOption = new JCheckBox("Fix Selected", false);
checkBoxPanel.add(preserveFixedNodesOption);
preserveFixedNodesOption.setToolTipText(
"Enable or disable that selected nodes don't move");
preserveFixedNodesOption.addItemListener(new ItemListener() {
public void itemStateChanged(ItemEvent e) {
setSelectedAreFixed(e.getStateChange() == ItemEvent.SELECTED);
}
});
final JCheckBox showGridOption = new JCheckBox("Show grid", true);
checkBoxPanel.add(showGridOption);
showGridOption.setToolTipText("Display or hide the grid");
showGridOption.addItemListener(new ItemListener() {
public void itemStateChanged(ItemEvent e) {
showGrid(e.getStateChange() == ItemEvent.SELECTED);
}
});
// - - - - - - - - - - - - - - - - -
// the panel with choice boxes
JPanel selectionPanel = new JPanel();
selectionPanel.setLayout(new GridLayout(3, 2));
// horizontal global alignment parameter
final JLabel horizAlignmentLabel = new JLabel("Horizontal Alignment:");
final JComboBox hAlignmentChooser = new JComboBox();
selectionPanel.add(horizAlignmentLabel);
selectionPanel.add(hAlignmentChooser);
hAlignmentChooser.addItem("Center ");
hAlignmentChooser.addItem("Left");
hAlignmentChooser.addItem("Right");
hAlignmentChooser.setSelectedIndex(0);
hAlignmentChooser.setToolTipText("Select the horizontal alignment mode");
hAlignmentChooser.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent event) {
JComboBox comboBox = (JComboBox)event.getSource();
String mode = (String)comboBox.getSelectedItem();
setGlobalHorizontalAlignment(mode);
}
});
// vertical global alignment parameter
final JLabel vertAlignmentLabel = new JLabel("Vertical Alignment:");
final JComboBox vAlignmentChooser = new JComboBox();
selectionPanel.add(vertAlignmentLabel);
selectionPanel.add(vAlignmentChooser);
vAlignmentChooser.addItem("Center");
vAlignmentChooser.addItem("Top");
vAlignmentChooser.addItem("Bottom");
vAlignmentChooser.setSelectedIndex(0);
vAlignmentChooser.setToolTipText("Select the vertical alignment mode");
vAlignmentChooser.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent event) {
JComboBox comboBox = (JComboBox)event.getSource();
String mode = (String)comboBox.getSelectedItem();
setGlobalVerticalAlignment(mode);
}
});
// layout mode
JComboBox layoutModeSelector = new JComboBox();
selectionPanel.add(new JLabel("Layout Mode:"));
selectionPanel.add(layoutModeSelector);
layoutModeSelector.addItem("Grid (fixed width)");
layoutModeSelector.addItem("Grid (fixed height)");
layoutModeSelector.addItem("Rows");
layoutModeSelector.addItem("Columns");
layoutModeSelector.setSelectedIndex(0);
layoutModeSelector.setToolTipText("Select the layout mode");
layoutModeSelector.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent event) {
JComboBox comboBox = (JComboBox)event.getSource();
String mode = (String)comboBox.getSelectedItem();
setLayoutMode(mode, showGridOption,
vGridOffsetLabel, vGridOffset,
hGridOffsetLabel, hGridOffset,
horizAlignmentLabel, hAlignmentChooser,
vertAlignmentLabel, vAlignmentChooser);
}
});
// - - - - - - - - - - - - - - - - -
// put all together
panel.add(selectionPanel, BorderLayout.WEST);
panel.add(offsetPanel, BorderLayout.EAST);
panel.add(checkBoxPanel, BorderLayout.SOUTH);
return panel;
}
/**
* Load a sample data file.
* @param fileNameBase The base of the filename, excluding the path prefix
* and the extension suffix.
*/
private void loadDataFile(String fileNameBase)
{
try {
showMessage("Reading " + fileNameBase + ".xml ...");
diagrammer.setDataFile(
IlvSwingUtil.getRelativeURL(this, "data/" + fileNameBase + ".xml"));
showMessage("Reading " + fileNameBase + ".xml done.");
} catch (Exception e) {
showMessage(e.getMessage());
}
}
/**
* Sets the horizontal or vertical offset from a textfield.
*/
private void setOffset(String property, JTextField valueSelector)
{
try {
// get the value of the parameter from the valueSelector
float value = Float.valueOf(valueSelector.getText().trim()).floatValue();
// write again to be sure the right value is shown
valueSelector.setText("" + value);
// set the new value of the layout property
styleSheet.setDeclaration("GraphLayout", property, "" + value);
// sets the grid offset also in the visible grid
if (property.equals("horizontalGridOffset"))
grid.setHorizontalSpacing(value);
if (property.equals("verticalGridOffset"))
grid.setVerticalSpacing(value);
// redraw the view
diagrammer.getView().repaint();
} catch (Exception ex) {
showMessage("Illegal " + property + ": " + ex.getMessage());
}
}
/**
* Sets the incremental mode.
*/
private void setIncrementalMode(boolean flag)
{
styleSheet.setDeclaration("GraphLayout", "incrementalMode",
(flag ? "true" : "false"));
}
/**
* Sets whether nodes specified as fixes (that is, nodes that are selected)
* are really fixed.
*/
private void setSelectedAreFixed(boolean flag)
{
// don't set preserveFixedNodes because it is automatically set by
// the graph layout renderer depending on the existence of the Fixed
// property on a node.
styleSheet.setDeclaration("node:selected", "Fixed",
(flag ? "true" : "false"));
}
/**
* Enables or disabled the display of a grid.
*/
private void showGrid(boolean show)
{
boolean visible = grid.isVisible();
if (visible != show) {
grid.setVisible(show);
diagrammer.getView().repaint();
}
}
/**
* Sets the horizontal alignment.
*/
private void setGlobalHorizontalAlignment(String mode)
{
if (mode.equals("Center")) {
styleSheet.setDeclaration("GraphLayout", "globalHorizontalAlignment",
"CENTER");
} else if (mode.equals("Left")) {
styleSheet.setDeclaration("GraphLayout", "globalHorizontalAlignment",
"LEFT");
} else if (mode.equals("Right")) {
styleSheet.setDeclaration("GraphLayout", "globalHorizontalAlignment",
"RIGHT");
}
}
/**
* Sets the vertical alignment.
*/
private void setGlobalVerticalAlignment(String mode)
{
if (mode.equals("Center")) {
styleSheet.setDeclaration("GraphLayout", "globalVerticalAlignment",
"CENTER");
} else if (mode.equals("Top")) {
styleSheet.setDeclaration("GraphLayout", "globalVerticalAlignment",
"TOP");
} else if (mode.equals("Bottom")) {
styleSheet.setDeclaration("GraphLayout", "globalVerticalAlignment",
"BOTTOM");
}
}
/**
* Sets the layout mode.
*/
private void setLayoutMode(String mode,
JCheckBox showGridOption,
JComponent vGridOffsetLabel,
JComponent vGridOffset,
JComponent hGridOffsetLabel,
JComponent hGridOffset,
JComponent horizAlignmentLabel,
JComponent hAlignmentChooser,
JComponent vertAlignmentLabel,
JComponent vAlignmentChooser)
{
if (mode.equals("Grid (fixed width)")) {
vGridOffsetLabel.setEnabled(true);
vGridOffset.setEnabled(true);
hGridOffsetLabel.setEnabled(true);
hGridOffset.setEnabled(true);
showGridOption.setEnabled(true);
showGrid(showGridOption.isSelected());
horizAlignmentLabel.setEnabled(true);
hAlignmentChooser.setEnabled(true);
vertAlignmentLabel.setEnabled(true);
vAlignmentChooser.setEnabled(true);
styleSheet.setDeclaration("GraphLayout", "layoutMode",
"TILE_TO_GRID_FIXED_WIDTH");
} else if (mode.equals("Grid (fixed height)")) {
vGridOffsetLabel.setEnabled(true);
vGridOffset.setEnabled(true);
hGridOffsetLabel.setEnabled(true);
hGridOffset.setEnabled(true);
showGridOption.setEnabled(true);
showGrid(showGridOption.isSelected());
horizAlignmentLabel.setEnabled(true);
hAlignmentChooser.setEnabled(true);
vertAlignmentLabel.setEnabled(true);
vAlignmentChooser.setEnabled(true);
styleSheet.setDeclaration("GraphLayout", "layoutMode",
"TILE_TO_GRID_FIXED_HEIGHT");
} else if (mode.equals("Rows")) {
vGridOffsetLabel.setEnabled(false);
vGridOffset.setEnabled(false);
hGridOffsetLabel.setEnabled(false);
hGridOffset.setEnabled(false);
showGridOption.setEnabled(false);
showGrid(false);
horizAlignmentLabel.setEnabled(false);
hAlignmentChooser.setEnabled(false);
vertAlignmentLabel.setEnabled(true);
vAlignmentChooser.setEnabled(true);
styleSheet.setDeclaration("GraphLayout", "layoutMode",
"TILE_TO_ROWS");
} else if (mode.equals("Columns")) {
vGridOffsetLabel.setEnabled(false);
vGridOffset.setEnabled(false);
hGridOffsetLabel.setEnabled(false);
hGridOffset.setEnabled(false);
showGridOption.setEnabled(false);
showGrid(false);
horizAlignmentLabel.setEnabled(true);
hAlignmentChooser.setEnabled(true);
vertAlignmentLabel.setEnabled(false);
vAlignmentChooser.setEnabled(false);
styleSheet.setDeclaration("GraphLayout", "layoutMode",
"TILE_TO_COLUMNS");
}
}
/**
* Performs the grid layout.
* The layout type is stored in the CSS file, therefore we don't need to
* set the grid layout explicitely. After loading the graph and the CSS
* style sheet, the grid layout is already instantiated.
*/
private void performLayout()
{
showMessage("Layout started...");
// initialize the iteration listener
layoutListener.initialize(getGraphLayout());
// Perform Grid Layout as node layout. Grid layout always handles nodes
// and links at the same time, therefore a separate link layout is not
// necessary.
if (diagrammer.isNodeLayoutAvailable()) {
// perform the layout
diagrammer.layoutAllNodes();
// show the layout report information about the return code
IlvGraphLayoutReport report = getGraphLayout().getLayoutReport();
if (report != null) {
showMessage(report.codeToString(report.getCode()) + ".");
}
}
}
/**
* Randomize the node positions.
*/
private void randomize()
{
// clear previous message
showMessage("");
// create a new random layout
IlvRandomLayout randomLayout = new IlvRandomLayout();
// save the old layout instance
IlvGraphLayout oldLayout = getGraphLayout();
// tell the diagrammer to temporarily use the random layout, which
// disabled the grid layout.
setGraphLayout(randomLayout);
if (diagrammer.isNodeLayoutAvailable()) {
// perform the layout
diagrammer.layoutAllNodes();
}
// restore the old layout instance
setGraphLayout(oldLayout);
}
/**
* Returns the graph layout currently used by the diagrammer.
*/
private IlvGraphLayout getGraphLayout()
{
IlvGraphLayoutRenderer renderer =
(IlvGraphLayoutRenderer)diagrammer.getEngine().getNodeLayoutRenderer();
return renderer == null ? null : renderer.getGraphLayout();
}
/**
* Sets the graph layout currently used by the diagrammer.
*/
private void setGraphLayout(IlvGraphLayout layout)
{
IlvGraphLayoutRenderer renderer =
(IlvGraphLayoutRenderer)diagrammer.getEngine().getNodeLayoutRenderer();
if (renderer == null)
return;
renderer.setGraphLayout(layout);
}
/**
* Displays a message.
*/
void showMessage(String message)
{
// the message is displayed in the message line
msgLine.setText(message);
msgLine.paintImmediately(0, 0, msgLine.getWidth(), msgLine.getHeight());
}
/**
* Allows you to run the demo as a standalone application.
*/
public static void main(String[] args)
{
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
GridLayoutApplet applet = new GridLayoutApplet();
applet.init();
JFrame frame = new JFrame("Grid Layout Example");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(500, 600);
frame.getContentPane().add(applet);
frame.setVisible(true);
}
});
}
// --------------------------------------------------------------------------
/**
* A subclass of ilog.views.IlvGrid that draws lines instead of points.
*/
private class LineGrid
extends IlvGrid
{
/**
* Creates a new grid.
* The origin of the grid is the point (0,0). The horizontal
* and verical spacing are 10. The grid is active and visible.
*/
public LineGrid()
{
super();
}
/**
* Creates a new grid.
* @param color the color of the grid points.
* @param origin the coordinates of the upper-left corner of the grid in the
* manager coordinates system.
* @param hspacing spacing of grid points along the horizontal axis.
* @param vspacing spacing of grid points along the vertical axis.
* @param visible Specifies whether the grid is visible (<code>true</code>) of invisible.
* @param active Specifies whether the grid is active (<code>true</code>) of inactive.
* @see IlvManagerView#setGrid
*/
public LineGrid(Color color, IlvPoint origin, float hspacing,
float vspacing, boolean visible, boolean active)
{
super(color, origin, hspacing, vspacing, visible, active);
}
/**
* Draws the grid.
* This method is called by the view (<code>IlvManagerView</code>)
* to draw the grid.
* @param dst the Graphics object to perform the drawing of the grid.
* @param t the transformer used to draw to grid.
* @param rect The area where the grid will be drawn. Note that the
* grid is drawn only at the intersection of this area with the clipping
* area provided in the <code>dst</code> parameter.
* When the grid is used in an <code>IlvManagerView</code>, this
* parameter is the bounding rectangle of the view.
*/
protected void draw(Graphics dst, IlvTransformer t, Rectangle rect)
{
if (!isVisible())
return;
Shape oldclip = dst.getClip();
Rectangle theclip = oldclip.getBounds();
Rectangle areaToDraw = theclip.intersection(rect);
if (areaToDraw.width == 0 || areaToDraw.height == 0)
return;
dst.clipRect(areaToDraw.x, areaToDraw.y, areaToDraw.width, areaToDraw.height);
// the origin
IlvPoint orig = new IlvPoint();
// the spacing parameters
IlvPoint spacing = new IlvPoint(getHorizontalSpacing() * getHorizontalShown(),
getVerticalSpacing() * getHorizontalShown());
if (t != null) {
t.apply(orig);
t.apply(spacing);
}
// in view coords
float spacingX = Math.abs(orig.x - spacing.x);
float spacingY = Math.abs(orig.y - spacing.y);
if (spacingX < 4 || spacingY < 4)
return;
float minX = areaToDraw.x;
float maxX = areaToDraw.x + areaToDraw.width;
float minY = areaToDraw.y;
float maxY = areaToDraw.y + areaToDraw.height;
IlvPoint originPoint = getOrigin();
if (t != null)
t.apply(originPoint);
int nX = (int)Math.ceil((minX - originPoint.x) / spacingX);
int nY = (int)Math.ceil((minY - originPoint.y) / spacingY);
float fromX = originPoint.x + nX * spacingX;
float fromY = originPoint.y + nY * spacingY;
dst.setColor(getColor());
// draw horizontal lines
for (double y = fromY; y <= maxY; y += spacingY)
dst.drawLine((int)Math.floor(minX),
(int)Math.floor(y),
(int)Math.floor(maxX),
(int)Math.floor(y));
// draw vertical lines
for (double x = fromX; x <= maxX; x += spacingX)
dst.drawLine((int)Math.floor(x),
(int)Math.floor(minY),
(int)Math.floor(x),
(int)Math.floor(maxY));
dst.setClip(oldclip);
}
}
// --------------------------------------------------------------------------
/**
* A graph layout iteration listener. Implementing the interface
* GraphLayoutEventListener gives you the possibility to receive
* during the layout information about the behavior of the layout
* algorithm. This information is contained in the graph layout event.
*
* In our case, we will simply print a dot each time the method
* layoutStepPerformed is called, that is after each iteration of
* the Bus Layout algorithm.
*/
class LayoutIterationListener
implements GraphLayoutEventListener
{
private IlvGraphLayout layout;
private String toShow = "";
private static final int MAX_LENGTH = 50;
/**
* This method is automatically called by the layout algorithm.
*/
public void layoutStepPerformed(GraphLayoutEvent event)
{
// the status area has a limited width, so we are forced to
// reinitialize the message string
if (toShow.length() > MAX_LENGTH)
toShow = "";
toShow += ".";
showMessage(toShow);
}
/**
* Initialize the listener.
* This method must be called before the layout is started.
*/
void initialize(IlvGraphLayout l)
{
if (layout != l) {
if (layout != null)
layout.removeGraphLayoutEventListener(this);
layout = l;
if (layout != null)
layout.addGraphLayoutEventListener(this);
}
toShow = "";
}
}
}