Demonstrates EditMode's snapping feature in conjunction with orthogonal edges.

This demo can be used to toggle the snapping feature on and off. It shows how a custom SnapLine (the red vertical line) can be used to snap nodes and edges to other entities. Toggling the button in the toolbar toggles snapping on and off, the sliders can be used to adjust the preferred distance between nodes and edges. This will influence the "preferred distance snap lines."

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package demo.view.viewmode;

import demo.view.DemoBase;
import y.base.Node;
import y.geom.YPoint;
import y.view.CreateEdgeMode;
import y.view.Drawable;
import y.view.EditMode;
import y.view.MoveSelectionMode;
import y.view.SnapLine;
import y.view.Graph2DView;
import y.view.MoveSnapContext;

import javax.swing.BorderFactory;
import javax.swing.JSlider;
import javax.swing.JToggleButton;
import javax.swing.JToolBar;
import javax.swing.SwingConstants;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.EventQueue;
import java.util.Locale;

/**
 * Demonstrates {@link EditMode}'s snapping feature in conjunction with orthogonal edges. <br>
 * This demo can be used to toggle the snapping feature on and off. It shows how a custom {@link SnapLine}
 * (the red vertical line) can be used to snap nodes and edges to other entities.
 * Toggling the "Snapping" button in the toolbar toggles snapping on and off, the sliders can be used to adjust the
 * preferred distance between nodes and edges. This will influence the "preferred distance snap lines."<br>
 * Toggling the "Grid" button in the toolbar toggles the grid on and off. Note that
 * {@link Graph2DView#setGridMode(boolean) enabling the grid on the view} has the effect that nodes can only
 * be placed on grid positions, thus it prevents the other snapping rules from being applied. The grid in this
 * demo uses the {@link MoveSnapContext#setUsingGridSnapping(boolean) newer grid snapping feature} instead, which
 * coexists nicely with other snapping rules.
 * @see <a href="http://docs.yworks.com/yfiles/doc/developers-guide/mvc_controller.html#snapping">Section User Interaction</a> in the yFiles for Java Developer's Guide
 */
public class SnapLineDemo extends DemoBase {

  private EditMode editMode;
  private JToggleButton snapLineButton;
  private JToggleButton showGridButton;
  private SnappingConfiguration snappingConfiguration;

  /**
   * A custom single snap line that will displayed in the view and used by the {@link MoveSelectionMode}'s
   * {@link MoveSnapContext}.
   */
  private SnapLine snapLine;

  public SnapLineDemo() {
    // Initialize snapping.
    snappingConfiguration = createDefaultSnappingConfiguration();
    snappingConfiguration.configureView(view);
    snappingConfiguration.configureEditMode(editMode);

    setUsingSnapping(true);

    final Node n1 = view.getGraph2D().createNode(40, 30, "1");
    final Node n2 = view.getGraph2D().createNode(40, 90, "2");
    final Node n3 = view.getGraph2D().createNode(40, 210,"3");
    view.getGraph2D().createEdge(n1, n2);
    view.getGraph2D().createEdge(n2, n3);
    view.updateWorldRect();
  }

  protected void initialize() {
    super.initialize();

    snapLine = new SnapLine(SnapLine.VERTICAL, SnapLine.CENTER, new YPoint(200, 200), 0, 400, null, 1.0d);
    view.getGraph2D().addDrawable(new Drawable() {
      public void paint(Graphics2D g) {
        g.setColor(Color.red);
        snapLine.paint(g);
      }

      public Rectangle getBounds() {
        return snapLine.getBounds();
      }
    });
  }


  protected JToolBar createToolBar() {
    JToolBar toolBar = super.createToolBar();
    toolBar.addSeparator(TOOLBAR_SMALL_SEPARATOR);

    snapLineButton = new JToggleButton("Snapping");
    snapLineButton.setIcon(getIconResource("resource/mode_snapping.png"));
    toolBar.add(snapLineButton);
    toolBar.addSeparator(TOOLBAR_SMALL_SEPARATOR);

    showGridButton = new JToggleButton("Grid");
    showGridButton.setIcon(getIconResource("resource/mode_grid.png"));
    toolBar.add(showGridButton);

    final JSlider s1 = new JSlider(SwingConstants.HORIZONTAL, 0, 80, 30);
    s1.setBorder(BorderFactory.createTitledBorder("Node To Node"));
    s1.setMaximumSize(new Dimension(200, 100));
    toolBar.add(s1);
    final JSlider s2 = new JSlider(SwingConstants.HORIZONTAL, 0, 80, 20);
    s2.setBorder(BorderFactory.createTitledBorder("Node To Edge"));
    s2.setMaximumSize(new Dimension(200, 100));
    toolBar.add(s2);
    final JSlider s3 = new JSlider(SwingConstants.HORIZONTAL, 0, 80, 20);
    s3.setBorder(BorderFactory.createTitledBorder("Edge To Edge"));
    s3.setMaximumSize(new Dimension(200, 100));
    toolBar.add(s3);
    final ChangeListener listener = new ChangeListener() {
      public void stateChanged(ChangeEvent e) {
        snappingConfiguration.setSnappingEnabled(snapLineButton.isSelected());
        snappingConfiguration.setRemovingInnerBends(snapLineButton.isSelected());
        snappingConfiguration.setNodeToNodeDistance(s1.getValue());
        snappingConfiguration.setNodeToEdgeDistance(s2.getValue());
        snappingConfiguration.setEdgeToEdgeDistance(s3.getValue());
        snappingConfiguration.setGridSnappingEnabled(showGridButton.isSelected());

        snappingConfiguration.configureView(view);
        snappingConfiguration.configureEditMode(editMode);
      }
    };
    s1.addChangeListener(listener);
    s2.addChangeListener(listener);
    s3.addChangeListener(listener);
    snapLineButton.addChangeListener(listener);
    showGridButton.addChangeListener(listener);

    return toolBar;
  }

  protected EditMode createEditMode() {
    editMode = super.createEditMode();
    ((MoveSelectionMode) editMode.getMoveSelectionMode()).getSnapContext().addSnapLine(snapLine);

    // Edges are always orthogonal in this demo.
    editMode.setOrthogonalEdgeRouting(true);
    ((CreateEdgeMode)editMode.getCreateEdgeMode()).setOrthogonalEdgeCreation(true);

    return editMode;
  }

  public boolean isUsingSnapping() {
    return snapLineButton.isSelected();
  }

  public void setUsingSnapping(boolean usingSnapping) {
    this.snapLineButton.setSelected(usingSnapping);
  }

  public static void main(String[] args) {
    EventQueue.invokeLater(new Runnable() {
      public void run() {
        Locale.setDefault(Locale.ENGLISH);
        initLnF();
        (new SnapLineDemo()).start("SnapLine Demo");
      }
    });
  }
}