public void initQuestionButtonPanel() { questionButtonPanel.setWidth("435px"); questionButtonPanel.setHeight("30px"); btnPrev = new Button("Prev"); btnPrev.setHTML("<img src='images/icon16/back.png' />Prev"); btnPrev.setSize("75px", "28px"); btnPrev.setEnabled(false); btnNext = new Button("Next"); btnNext.setHTML("<img src='images/icon16/right.png' />Next"); btnNext.setSize("75px", "28px"); html = new HTML("<center><span class='app-title3'>" + controller.getTitle() + "</></center>"); html.setWidth("285px"); questionButtonPanel.add(btnPrev, 0, 2); questionButtonPanel.add(html, 75, 0); questionButtonPanel.add(btnNext, 360, 2); btnPrev.addClickHandler( new ClickHandler() { public void onClick(ClickEvent event) { if (questionIndex > 0) { questionIndex--; controller = questionList.get(questionIndex); String str = "<center><span class='app-title3'>" + controller.getTitle() + "</span></center>"; html.setHTML(str); if (questionIndex == 0) btnPrev.setEnabled(false); else btnPrev.setEnabled(true); if (questionIndex == questionList.size() - 1) btnNext.setEnabled(false); else btnNext.setEnabled(true); base.remove(panel); panel = controller.getQuestionPanel(); base.add(panel); controller.syncDiagram(); } } }); btnNext.addClickHandler( new ClickHandler() { public void onClick(ClickEvent event) { if (questionIndex < questionList.size() - 1) { questionIndex++; controller = questionList.get(questionIndex); String str = "<center><span class='app-title3'>" + controller.getTitle() + "</span></center>"; html.setHTML(str); if (questionIndex == questionList.size() - 1) btnNext.setEnabled(false); else btnNext.setEnabled(true); if (questionIndex == 0) btnPrev.setEnabled(false); else btnPrev.setEnabled(true); base.remove(panel); panel = controller.getQuestionPanel(); base.add(panel); controller.syncDiagram(); } } }); }