I am currently working on adding a button inside a text box, which I know can be tricky with GWT. For this task, I have a HorizontalPanel where I am inserting the textbox along with other elements. Here is a snippet of my code:
HorizontalPanel bar = new HorizontalPanel();
bar.addStyleName("indexBar");
bar.setVerticalAlignment(HasVerticalAlignment.ALIGN_BOTTOM);
bar.add(new Label("Select Accounts"));
bar.add(accounts);
Label fname = new Label("Search First Name");
fname.setStyleName("firstNameLabel");
firstNameSearch = new TextBox();
bar.add(fname);
bar.add(firstNameSearch);