Bug 312959 [Import/Export] importing file from big disk hangs UI
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/wizards/datatransfer/WizardFileSystemResourceImportPage1.java
* Enable or disable the button group.
     */
    protected void enableButtonGroup(boolean enable) {
        selectTypesButton.setEnabled(enable);
        selectAllButton.setEnabled(enable);
        deselectAllButton.setEnabled(enable);
    }
    /**
     *	Answer a boolean indicating whether the specified source currently exists
     *	and is valid
     */
    protected boolean ensureSourceIsValid() {
        if (new File(getSourceDirectoryName()).isDirectory()) {
			return true;
		}
        setErrorMessage(DataTransferMessages.FileImport_invalidSource);
        return false;
    }
    /**
     *	Execute the passed import operation.  Answer a boolean indicating success.
     */
    protected boolean executeImportOperation(ImportOperation op) {
        initializeOperation(op);
        try {
            getContainer().run(true, true, op);
        } catch (InterruptedException e) {
            return false;
        } catch (InvocationTargetException e) {
            displayErrorDialog(e.getTargetException());
            return false;