Creating a composite graphic

Programmer's documentation > Rogue Wave JViews Framework Essential Features > Composite Graphics > Creating a composite graphic

The corresponding code is supplied in the codefragments/composite/src/Composite.java source file of the installed product. For details, see <installdir> /jviews-framework/codefragments/composite/index.html.

This tutorial contains the following stages:

Stage 1 - Starting the composite graphic

Stage 2 - Creating an attachment layout

Stage 3 - Creating the first child graphic

Stage 4 - Attaching a child graphic

Stage 5 - Using a stacker layout

Stage 6 - Using a centered layout

Stage 1 - Starting the composite graphic

To create a composite graphic object:

1. Import the composite graphics package:

import ilog.views.graphic.composite.* ;

2. Create a composite graphic object.

IlvCompositeGraphic composite = new IlvCompositeGraphic();

Stage 2 - Creating an attachment layout

The attachment layout enables you to attach the child graphics to the first one by choosing symbolic points of their bounding boxes.

To create the attachment layout:

1. Import the layout package:

import ilog.views.graphic.composite.layout.*;

2. Create the attachment layout.

IlvAttachmentLayout layout = new IlvAttachmentLayout();

composite.setLayout(layout);

Stage 3 - Creating the first child graphic

The first child graphic of the IlvCompositeGraphic object will be the reference for positioning other child graphics. In this example, the first child graphic is an IlvRectangle object.

To create the first child object:

Create a rectangle object:

IlvRectangle rectangle = new IlvRectangle(new IlvRect(0,0,40,40),true,true);

composite.setChildren(0,rectangle)

The first child is at position 0. The attachment layout uses this first child to attach the other children (sibling graphics) of the composite graphic.

Stage 4 - Attaching a child graphic

A label can be attached as a child graphic.

There are nine different attachment locations available, as illustrated in the following figure.

Attachment Locations

To label your composite graphic:

1. Attach an additional child graphic to the first one.

IlvText text = new IlvText();

text.setLabel("Composite Graphic");

composite.setChildren(1,text);

2. Place the label below the rectangle:

composite.setConstraints(1,

new IlvAttachmentConstraint(IlvAttachmentLocation.TopCenter,

IlvAttachmentLocation.BottomCenter));

Here, the top center of the text (an IlvText) is anchored to the bottom center of the first child graphic which is, in this example, an IlvRectangle object.

If you run your example now, you can see the following composite, in which the “Composite Graphic” label is attached to the blue rectangle with horizontal symmetry:

Composite graphics with attachments

Stage 5 - Using a stacker layout

As well as using the Attachment Layout to position two objects with respect to each other within the composite graphic object, you can use the Stacker Layout to align objects.

To use the Stacker Layout to align three icons:

1. Create one more composite graphic named rectangles to hold the three small rectangles. Its role will be to align these rectangles horizontally.

IlvCompositeGraphic rectangles = new IlvCompositeGraphic();

2. Create a stacker layout and pass it to the Composite Graphic object.

IlvStackerLayout stacker = new IlvStackerLayout(SwingConstants.RIGHT,SwingConstants.BOTTOM,3);

rectangles.setLayout(stacker);

3. Create the three rectangles and set them as child graphics of the rectangles composite graphic.

IlvRectangle r1 = new IlvRectangle(new IlvRect(0,0,5,5),true,true);

r1.setBackground(Color.red);

rectangles.setChildren(0,r1);

IlvRectangle r2 = new IlvRectangle(new IlvRect(0,0,5,5),true,true);

r2.setBackground(Color.yellow);

rectangles.setChildren(1,r2);

IlvRectangle r3 = new IlvRectangle(new IlvRect(0,0,5,5),true,true);

r3.setBackground(Color.green);

rectangles.setChildren(2,r3);

4. Make the rectangles composite graphic as a child graphic of the main composite graphic built in the previous stages.

composite.setChildren(2,rectangles);

composite.setConstraints(2,new IlvAttachmentConstraint(IlvAttachmentLocation.BottomLeft,IlvAttachmentLocation.TopRight));

At the end of this stage, you should obtain the following result:

Stacker Layout

Stage 6 - Using a centered layout

Unlike center attachment (see Attachment Locations), Centered Layout has the specific feature of handling two graphics, the outer graphic and the inner graphic. More precisely, in Centered Layout, the composite is a container that lays out two children: the first, at index position 0, is the outer graphic, the second one, at index position 1, is the inner graphic. The outer graphic will be resized by the composite in such way that the inner graphic remains at the center of the outer graphic.

This example creates a Balloon made of a yellow ellipse containing the text “Balloon” and adds it as a new child of the composite graphic built in the previous stages. Balloon is a new composite graphic that uses Centered Layout to position the text and the ellipse with respect to each other. In the following steps, you create the composite graphic as a new object (the Balloon), the outer graphic (the ellipse), the inner graphic (the text), then you attach the Balloon to the main composite graphic.

To create the balloon and center the text:

1. Create the Balloon composite graphic with Centered Layout:

IlvCompositeGraphic balloon = new IlvCompositeGraphic();

IlvCenteredLayout centered = new IlvCenteredLayout(new Insets(5,5,5,5));

balloon.setLayout(centered);

2. Create the outer graphic as an instance of IlvEllipse:

The outer graphic is always the first child, at position 0, of the composite graphic with Centered Layout. This child is resized by the composite to the size of the inner graphic extended by the inset given to the Centered Layout ((5,5,5,5)) at step 1.

IlvEllipse ellipse = new IlvEllipse();

ellipse.setFillOn(true);

ellipse.setBackground(Color.yellow);

balloon.setChildren(0,ellipse);

3. Create the inner graphic as an instance of IlvText:

The inner graphic is always the second child, at position 1, of the composite graphic with Centered Layout.

IlvText balloonText = new IlvText(new IlvPoint(0,0),"Balloon");

balloon.setChildren(1,balloonText);

4. Attach the Balloon to the main composite graphic using IlvAttachmentConstraint:

composite.setChildren(3,balloon);

composite.setConstraints(3,new IlvAttachmentConstraint(IlvAttachmentLocation.BottomCenter,IlvAttachmentLocation.TopLeft));

At the end of this stage, you should obtain the composite graphic illustrated in Centered Layout:

Centered Layout