}
if (page_down) {
int page = engine_->GetFirstVisiblePage();
+ if (page == -1)
+ return true;
// Engine calculates visible page including delimiter to the page size.
// We need to check here if the page itself is completely out of view and
// scroll to the next one in that case.
return true;
} else if (page_up) {
int page = engine_->GetFirstVisiblePage();
+ if (page == -1)
+ return true;
if (engine_->GetPageRect(page).y() * zoom_ >= v_scrollbar_->GetValue())
page--;
ScrollToPage(page);