Drawing Principles

An Example

Step 1--Create the drawing class and define its basic methods

The definition of the class ServerBaseRenderer is given below.

How to Extend a Network Element

static class ServerBaseRenderer extends IltNEBaseRenderer {
  private static Dimension NormalSize = new Dimension(25,40);
  private static Dimension SmallSize = new Dimension(13,21);
  public Dimension getPreferredSize (boolean collapsed) {
      if (collapsed)
        return SmallSize;
      else
        return NormalSize;
  }
}

The two fields NormalSize and SmallSize define the normal dimension of the base and its dimension when it is collapsed. Calling getPreferredSize returns the current size of the base.

The following fields are added to initialize numbers that are used to draw the base. Since there is only one method to draw both collapsed and noncollapsed bases, these numbers ease the readability of the code.

// Some factors for drawing:
private static final float _XGrid = 4.0f / 25.0f;
private static final float _YGrid = 4.0f / 40.0f;
private static final float _WGrid = 13.0f / 25.0f;
private static final float _HGrid = 1.0f / 40.0f;
private static final float _VStepGrid = 2.0f / 40.0f;
private static final float _XButton = 19.0f / 25.0f;
private static final float _YButton = 4.0f / 40.0f;
private static final float _WButton = 2.0f / 25.0f;
private static final float _HButton = 2.0f / 40.0f;
private static final float _XDisk = 18.0f / 25.0f;
private static final float _YDisk = 23.0f / 40.0f;
private static final float _WDisk = 3.0f / 25.0f;
private static final float _HDisk = 12.0f / 40.0f;

Standard Palettes

Creating New Palettes

How to Initialize and Use New Palettes

    private static Color GridColor =
      IltrColor.NewColor("server grid color", IltrColor._90PctGrey);
    private static Color ButtonColor =
      IltrColor.NewColor("server button color", Color.blue);
 
    private Ilt2DPalette GridPalette;
    private Ilt2DPalette ButtonPalette;
 
    protected void initResources () {
      super.initResources();
      GridPalette = Ilt2DPalette.NewSimple2DPalette(GridColor);
      ButtonPalette = Ilt2DPalette.NewSimple2DPalette(ButtonColor);
    }

Step 2--Define the drawMain method

How to Define the Main Drawing Method

    public void drawMain (Graphics g, IlvTransformer t, IlvRect rect) {
 
      // Get the corners of the base rectangle.
      int x1 = (int)rect.x;
      int y1 = (int)rect.y;
      int x2 = x1 + (int)rect.width-1;
      int y2 = y1 + (int)rect.height-1;
 
      // Get the state dependent parameters.
      IltDetailLevel detailLevel = getDetailLevel();
      Ilt2DPalette palette = getPalette();
      Ilt2DPalette brightPalette = getBrightPalette();
      Ilt2DPalette darkPalette = getDarkPalette();
      int borderThickness = getBorderThickness();

Here is the code to start drawing the base.

How to Draw the Base of a New Type of Network Element

      if (x1<=x2 && y1<=y2) {
 
        IltGraphicUtil.FillRect(g,t,x1,y1,x2,y2,palette);
 
        // Paint the border
        if (detailLevel.equals(IltDetailLevel.MaximumDetails)) {
        if   (rect.width < 20 && borderThickness > 1)
        IltGraphicUtil.DrawReliefRect (g,t,x1,y1,x2,y2,
                                        brightPalette, darkPalette,
                                        borderThickness);
          else {
        IltGraphicUtil.DrawRect(g,t,x1,y1,x2,y2,
                                 darkPalette,
                                 borderThickness);
       }

        // Paint the grid, button and disk.
        if (detailLevel.equals(IltDetailLevel.MaximumDetails)
            ||  detailLevel.equals(IltDetailLevel.FewDetails)){
          // Grid, button and disk dimensions.
          final int gridWidth = Math.round(rect.width * _WGrid);
          final int gridHeight = Math.round(rect.height * _HGrid);
          final int buttonWidth = Math.round(rect.width * _WButton);
          final int buttonHeight = Math.round(rect.height * _HButton);
          final int diskWidth = Math.round(rect.width * _WDisk);
          final int diskHeight = Math.round(rect.height * _HDisk);
          // Grid rectangle corners.
          final int gx1 = x1 + Math.round(rect.width * _XGrid);
          int gy1 = y1 + Math.round(rect.height * _YGrid);
          final int gx2 = gx1 + gridWidth-1;
          int gy2 = gy1 + gridHeight-1;
          final int gvstep = Math.round(rect.height * _VStepGrid);
          // Button rectangle corners.
          final int bx1 = x1 + Math.round(rect.width * _XButton);
          final int by1 = y1 + Math.round(rect.height * _YButton);
          final int bx2 = bx1 + buttonWidth-1;
          final int by2 = by1 + buttonHeight-1;
          // Disk rectangle corners.
          final int dx1 = x1 + Math.round(rect.width * _XDisk);
          final int dy1 = y1 + Math.round(rect.height * _YDisk);
          final int dx2 = dx1 + diskWidth-1;
          final int dy2 = dy1 + diskHeight-1;
          // Grid and button colors.
          final Ilt2DPalette gridPalette =
            (detailLevel.equals(IltDetailLevel.FewDetails) ? darkPalette
 : GridPalette);
          final Ilt2DPalette buttonPalette =
            (detailLevel.equals(IltDetailLevel.FewDetails) ? darkPalette 
: ButtonPalette);
          // Paint the grid.
          if (gvstep > 1) {
            for (int i = 0; i < 7; i++) {
              IltGraphicUtil._FillRect(g,t, gx1,gy1,gx2,gy2, gridPalette);
              gy1 += gvstep; gy2 += gvstep;
            }
          } else if (gvstep == 1) {
            // Paint a grey rectangle instead of the grid.
            Color rectColor = palette.getForeground();
            Color gridColor = gridPalette.getForeground();
            Color greyColor =
              new Color((rectColor.getRed()+gridColor.getRed())/2,
                        (rectColor.getGreen()+gridColor.getGreen())/2,
                        (rectColor.getBlue()+gridColor.getBlue())/2);
            Ilt2DPalette greyPalette =
              Ilt2DPalette.NewSimple2DPalette(greyColor);
            IltGraphicUtil._FillRect(g,t, gx1,gy1,gx2,gy2+6*gvstep,
                                     greyPalette);
          }
 
          // Paint the button.
          IltGraphicUtil._FillRect(g,t, bx1,by1,bx2,by2, buttonPalette);
 
          // Paint the disk.
          if (detailLevel.equals(IltDetailLevel.FewDetails)) {
            IltGraphicUtil._FillRect(g,t, dx1,dy1,dx2,dy2, darkPalette);
          } else {
            IltGraphicUtil._FillRect(g,t, dx1,dy1,dx2,dy2, palette);
            IltGraphicUtil.DrawReliefRect(g,t, dx1,dy1,dx2,dy2,
                                          brightPalette,darkPalette,
                                          1);
         }

The following code shows the default implementation used for a rectangular base.

How to Implement a Method for Drawing a Rectangular Base

protected void drawExtraBorders (Graphics g, IlvTransformer t, IlvRect rect) {
    { // Draw the alarm border, if needed according to the state.
      Color c = getAlarmBorderColor();
      if (c != null)
        drawExtraBorder(g,t,rect,c,0,IltrThickness.AlarmBorderThickness);
    }
    { // Draw the selection border, if the object is currently selected.
      Color c = getSelectionBorderForeground();
      if (c != null)
        drawExtraBorder(g,t,rect,c,IltrThickness.AlarmBorderThickness,
                        IltrThickness.SelectionBorderThickness);
    }
  }

Step 3--Run the sample program

The main file of this example creates and registers a network element of type server.

How to Create and Register a Network Element Type (using the API)

static IltNetworkElement.Type Server = new IltNetworkElement.Type("Server");
 
  static {
    IltSettings.SetValue("NetworkElement.Type.Server.Renderer", 
                         new IltBaseRendererFactory() {
                           public IltBaseRenderer createValue() {
                             return new ServerBaseRenderer();
                           }
                         }
    );
  }
 
IltDefaultDataSource dataSource = new IltDefaultDataSource();
IltNetworkElement ne = new IltNetworkElement
                      ("NE", Server, new IltOSIObjectState());
ne.setAttributeValue(IltObject.PositionAttribute, new IlpPoint(100,100));
dataSource.addObject(ne);
IlpNetwork network = new IlpNetwork();
network.setDataSource(dataSource);

How to Create and Register a Network Element Type (using CSS)

The new network element type can also be created using global CSS settings, as follows:

setting."ilog.tgo.model.IltNetworkElement"{
  types[0]: @+neType0;
}
Subobject#neType0 {
  class: 'ilog.tgo.model.IltNetworkElement.Type'; 
  name: "Server";
}

To customize the renderer using global CSS settings, you need to first create a renderer factory class and make sure it is included in the search path:

public class MyNERendererFactory implements IltBaseRendererFactory {
   public IltBaseRenderer createValue() {
      return new ServerBaseRenderer();
   }
}

Then, you can customize the renderer in CSS as follows:

setting."ilog.tgo.model.IltNetworkElement.Type"[name="Server"] { 
   renderer: @+neRendererFactory0;
}
Subobject#neRendererFactory0 {
   class: 'MyNERendererFactory';
}

As illustrated in this example, you can create a network element with a specific type or set a type for it afterwards with either one of the following methods:

ne.setType (Server);

or

ne.setAttributeValue (IltNetworkElement.TypeAttribute, Server);