MDSashForm.java

package bndtools.editor.common;

import java.util.ArrayList;
import java.util.Iterator;

import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.SashForm;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Sash;
import org.eclipse.ui.forms.FormColors;
import org.eclipse.ui.forms.IFormColors;
import org.eclipse.ui.forms.IManagedForm;

public class MDSashForm extends SashForm {

    ArrayList<Sash> sashes = new ArrayList<Sash>();
    Listener listener = new Listener() {
        public void handleEvent(Event e) {
            switch (e.type) {
            case SWT.MouseEnter :
                e.widget.setData("hover", Boolean.TRUE); //$NON-NLS-1$
                ((Control) e.widget).redraw();
                break;
            case SWT.MouseExit :
                e.widget.setData("hover", null); //$NON-NLS-1$
                ((Control) e.widget).redraw();
                break;
            case SWT.Paint :
                onSashPaint(e);
                break;
            case SWT.Resize :
                hookSashListeners();
                break;
            default :
                break;
            }
        }
    };

    private Color bg;
    private Color fg;

    public MDSashForm(Composite parent, int style, Color bg, Color fg) {
        super(parent, style);
        this.bg = bg;
        this.fg = fg;
    }

    public MDSashForm(Composite parent, int style, IManagedForm managedForm) {
        super(parent, style);

        FormColors colors = managedForm.getToolkit().getColors();
        bg = colors.getColor(IFormColors.TB_BG);
        fg = colors.getColor(IFormColors.TB_BORDER);
    }

    @Override
    public void layout(boolean changed) {
        super.layout(changed);
        hookSashListeners();
    }

    @Override
    public void layout(Control[] children) {
        super.layout(children);
        hookSashListeners();
    }

    private void hookSashListeners() {
        purgeSashes();
        Control[] children = getChildren();
        for (int i = 0; i < children.length; i++) {
            if (children[i] instanceof Sash) {
                Sash sash = (Sash) children[i];
                if (sashes.contains(sash))
                    continue;
                sash.addListener(SWT.Paint, listener);
                sash.addListener(SWT.MouseEnter, listener);
                sash.addListener(SWT.MouseExit, listener);
                sashes.add(sash);
            }
        }
    }

    private void purgeSashes() {
        for (Iterator<Sash> iter = sashes.iterator(); iter.hasNext();) {
            Sash sash = iter.next();
            if (sash.isDisposed())
                iter.remove();
        }
    }

    private void onSashPaint(Event e) {
        Sash sash = (Sash) e.widget;
        boolean vertical = (sash.getStyle() & SWT.VERTICAL) != 0;
        GC gc = e.gc;
        Boolean hover = (Boolean) sash.getData("hover"); //$NON-NLS-1$
        gc.setBackground(bg);
        gc.setForeground(fg);
        Point size = sash.getSize();
        if (vertical) {
            if (hover != null)
                gc.fillRectangle(0, 0, size.x, size.y);
            // else
            // gc.drawLine(1, 0, 1, size.y-1);
        } else {
            if (hover != null)
                gc.fillRectangle(0, 0, size.x, size.y);
            // else
            // gc.drawLine(0, 1, size.x-1, 1);
        }
    }

    public void hookResizeListener() {
        Control[] children = getChildren();
        for (int i = 0; i < children.length; i++) {
            if (children[i] instanceof Sash)
                continue;
            children[i].addListener(SWT.Resize, listener);
        }
    }
}