Question

I’ve been using SWT for a few years, but i can’t seem to figure this one out:

I need to SPLIT a VIEW into 2 “zones”: LEFT and RIGHT
So i use a Composite with GridLayout with 2 columns to do it.

Inside the RIGHT composite i have a FIXED number of columns (created inside another GridLayout composite) but inside the LEFT composite i need to create a DYNAMIC number of columns that spans on the composite limit…

Is there a way to achieve this?

I tried a RowLayout inside left composite, but these 2 don’t match :-\

Thanks

Answer 1

As it is not clear what you mean by

1. columns that spans on the composite limit
2. I tried a RowLayout inside left composite, but these 2 don’t match

Therefore I am assuming that you want a dynamically changing gridlayout for your left composite. See the code below, specially the button.addSelectionListener().

import java.util.Random;

import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Shell;

public class DynamicComposite 
{
    public static void main(String[] args) {
        new DynamicComposite().start();
    }

    private Composite compositeLeft;
    private Composite compositeRight;
    private Random rand;

    public void start()
    {
        rand = new Random(System.currentTimeMillis()); 

        Display display = new Display();
        Shell shell = new Shell(display);
        shell.setLayout(new GridLayout(2, true));
        shell.setText("Dynamic Columns");

        createRightComposite(shell);
        createLeftComposite(shell);
        createButtonComposite(shell);

        shell.open();
        while (!shell.isDisposed()) {
            if (!display.readAndDispatch())
                display.sleep();
        }
        display.dispose();
    }

    private void createButtonComposite(Shell shell) 
    {
        Label l = new Label(shell, SWT.SEPARATOR|SWT.HORIZONTAL);
        GridData gridData = new GridData(SWT.FILL, SWT.FILL, true, false);
        gridData.horizontalSpan = 2;
        l.setLayoutData(gridData);

        Button button = new Button(shell, SWT.PUSH);
        gridData = new GridData(SWT.CENTER, SWT.CENTER, true, false);
        gridData.horizontalSpan = 2;
        button.setLayoutData(gridData);
        button.setText("Change Columns !!");

        button.addSelectionListener(new SelectionAdapter() {
            public void widgetSelected(SelectionEvent e) {
                if(compositeLeft == null || compositeLeft.isDisposed())
                    return;

                GridLayout layout = (GridLayout)compositeLeft.getLayout();
                int col = rand.nextInt(7);
                if(col == 0)
                    col = 1;
                layout.numColumns = col;
                //compositeLeft.setLayout(layout);
                compositeLeft.layout(); // You need to re-layout your composite
            }
        });
    }

    private void createRightComposite(Shell shell) 
    {
        compositeLeft = new Composite(shell, SWT.NONE);
        GridLayout gridLayout = new GridLayout(3, true);
        gridLayout.marginWidth = 0;
        gridLayout.marginHeight = 0;
        gridLayout.marginLeft = 0;
        gridLayout.marginRight= 0;
        gridLayout.marginTop = 0;
        gridLayout.marginBottom = 0;
        gridLayout.horizontalSpacing = 0;

        gridLayout.verticalSpacing = 0;
        gridLayout.horizontalSpacing = 0;
        compositeLeft.setLayout(gridLayout);
        GridData gridData = new GridData(SWT.FILL, SWT.FILL, true, true);
        compositeLeft.setLayoutData(gridData);

        int counter = 17;
        for(int i=0; i<counter; i++)
        {
            Button button = new Button(compositeLeft, SWT.PUSH);
            button.setText("Button " + (i+1));
            GridData bData = new GridData(SWT.FILL, SWT.FILL, true, false);
            button.setLayoutData(bData);
        }
    }

    private void createLeftComposite(Shell shell) 
    {
        compositeRight = new Composite(shell, SWT.NONE);
        GridLayout gridLayout = new GridLayout(3, true);
        gridLayout.marginWidth = 0;
        gridLayout.marginHeight = 0;
        gridLayout.marginLeft = 0;
        gridLayout.marginRight= 0;
        gridLayout.marginTop = 0;
        gridLayout.marginBottom = 0;
        gridLayout.horizontalSpacing = 0;
        compositeRight.setLayout(gridLayout);

        GridData gridData = new GridData(SWT.FILL, SWT.FILL, true, true);
        compositeRight.setLayoutData(gridData);

        int counter = 7;
        for(int i=0; i<counter; i++)
        {
            Button button = new Button(compositeRight, SWT.PUSH);
            button.setText("Button " + (i+1));
            GridData bData = new GridData(SWT.FILL, SWT.FILL, true, false);
            button.setLayoutData(bData);
        }
    }
}