Method selNext

gui/list.go:238–291

selNext selects or highlights the next item, if possible

(sel bool, update bool)

// selNext selects or highlights the next item, if possible
func (li *List) selNext(sel bool, update bool) *ListItem {

	// Checks for empty list
	if len(li.items) == 0 {
		return nil
	}
	// Find currently selected item
	var pos int
	if sel {
		pos = li.selected()
	} else {
		pos = li.highlighted()
	}

	var newItem *ListItem
	newSel := true
	// If no item found, returns first.
	if pos < 0 {
		newItem = li.items[0].(*ListItem)
		if sel {
			newItem.SetSelected(true)
		} else {
			newItem.SetHighlighted(true)
		}
	} else {
		item := li.items[pos].(*ListItem)
		// Item is not the last, get next
		if pos < len(li.items)-1 {
			newItem = li.items[pos+1].(*ListItem)
			if sel {
				item.SetSelected(false)
				newItem.SetSelected(true)
			} else {
				item.SetHighlighted(false)
				newItem.SetHighlighted(true)
			}
			if !li.ItemVisible(pos + 1) {
				li.ScrollDown()
			}
			// Item is the last, don't change
		} else {
			newItem = item
			newSel = false
		}
	}

	if update {
		li.update()
	}
	if sel && newSel {
		li.Dispatch(OnChange, nil)
	}
	return newItem
}

// selPrev selects or highlights the next item, if possible
func (li *List) selPrev(sel bool, update bool) *ListItem {