public ViewToolbar(String viewDisplayName, ViewOptions viewOptions, ClickHandler clickHandler) {
super();
assert viewDisplayName != null && viewOptions != null && clickHandler != null;
viewTitle = new Label(viewDisplayName);
btnMinimize =
viewOptions.isMinimizable() ? new ToggleButton(imageBundle.arrow_sm_down().createImage(), imageBundle
.arrow_sm_right().createImage(), clickHandler) : null;
btnPop =
viewOptions.isPopable() ? new ToggleButton(imageBundle.external().createImage(), imageBundle.permalink()
.createImage(), clickHandler) : null;
btnClose = viewOptions.isClosable() ? new PushButton(imageBundle.close().createImage(), clickHandler) : null;
btnRefresh = viewOptions.isRefreshable() ? new PushButton(imageBundle.refresh().createImage(), clickHandler) : null;