Bug 273489 [Mac] We should not nest sheets
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/ide/dialogs/PathVariableDialog.java
}
    /**
     * Opens a dialog where the user can select a folder path.
     */
    private void selectFolder() {
        DirectoryDialog dialog = new DirectoryDialog(getShell(), SWT.SHEET);
        dialog.setText(IDEWorkbenchMessages.PathVariableDialog_selectFolderTitle);
        dialog.setMessage(IDEWorkbenchMessages.PathVariableDialog_selectFolderMessage);
        dialog.setFilterPath(variableValue);
        String res = dialog.open();
        if (res != null) {
            variableValue = new Path(res).makeAbsolute().toOSString();
            variableValueField.setText(variableValue);
        }
    }
    /**
     * Opens a dialog where the user can select a file path.
     */
    private void selectFile() {
        FileDialog dialog = new FileDialog(getShell(), SWT.SHEET);
        dialog.setText(IDEWorkbenchMessages.PathVariableDialog_selectFileTitle);
        dialog.setFilterPath(variableValue);
        String res = dialog.open();
        if (res != null) {
            variableValue = new Path(res).makeAbsolute().toOSString();
            variableValueField.setText(variableValue);
        }
    }
    /**
     * Adds buttons to this dialog's button bar.