Building a UI Builder?

[Inocencio Oliveira]

Sometimes happened that I figured out how to build a UI builder, like a jasper report or a netbeans matisse are. As harder is to implementing something like that, a builder to create UI. I´m trying to find out some infos but not found. My idea is to create for example a JForm (or something similar), create some dots (to represents rules) and a structure to drag on drop components from a palete.

A justed starded and put via code a JLabel, but not from a palete, and that label one action I can do atm is to move this component surrounding the form. I have a lot of thing to do and thinking about to create a real UI Builder. If I take something functional I can go further next step and mind what I can do with this tool.

[Inocencio Oliveira]

I did a kind of "dot grid" to represent the slots that any dragable component can be fited. Its just a start code, I will try to implement next step some way to drag component to the form. Check the code following...

import java.awt.Canvas;
import java.awt.Graphics;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import javax.swing.JFrame;

/**
 * @author Inocêncio
 */
public class FormBuilder01 extends JFrame {

    public FormBuilder01() {
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setSize(400,400);
        setTitle("Desenhando pontos...");
        
        Pointer pointer = new Pointer();
        add(pointer);
        
        addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) {
                setVisible(false);
                dispose();
                System.exit(0);
            }
        });
        
        setVisible(true);
    }
    
    public static void main(String[] args) {
        new FormBuilder01();
    }

}

class Pointer extends Canvas {
    
    Pointer() {
    }
    
    @Override
    public void paint(Graphics g) {
        int i = 0;

        //desenhando as linhas e colunas
        
        //x - linha
        for (int x = 0; x < 200; x++) {
            //i - colunas
            for (i = 0; i < 300; i++) {
                g.fillArc(i*7, 5 * x, 1, 1, 0, 360);
            }
        }
    }
}

Next step I will try to do something more useful.

[Michael Dunn]

> Building a UI Builder?

a ui builder, built incorrectly, is not a good start.

class Pointer extends Canvas {

Canvas is an AWT component, and whilst the program might work OK now,
the moment you add Swing components alongside the canvas, you will have
painting problems.

http://java.sun.com/products/jfc/tsc/articles/mixing/

[Inocencio Oliveira]

My intention is to build an UI Builder. But I have to concentrate new ideas to build further a real UI builder, but in primor state I´m doing new samples to build different stuffs, first: how to draw dots to represent some grid context, next... (I hope) how to build components at screen that are dragable and fix to scen, and so on.

[eric aro]

You must think different.

A UI builder is nothing but an application like the others. Instead of handling, let say, bank account, you'll handle "beans".

java provides a wide set of generic tools to handle beans. That's you model.

To handle a "Bean" you must put it into a "handler box". Something like a panel, with layeredpane and an opaque glasspane ( with transparent color). This will enable you to generically display beans, but catch all the click, and drag gesture, and even draw overlay.

It's the same for a Container. Except that you'll have to handle the drag and drop based on the actual layout for it. I've never seen a visual builder that can handle "generic" layouts. There is always a Handler class for every LayoutManager. Most of the difference between UI builder comes from the quality of their LayoutManager HandlerSSS

Then, at last, when you have a tree of beans, you can generate code, or XML description, to makes it possible to access the actual view at runtime.