diff options
Diffstat (limited to 'vendor/github.com/manifoldco/promptui/list/list.go')
-rw-r--r-- | vendor/github.com/manifoldco/promptui/list/list.go | 237 |
1 files changed, 237 insertions, 0 deletions
diff --git a/vendor/github.com/manifoldco/promptui/list/list.go b/vendor/github.com/manifoldco/promptui/list/list.go new file mode 100644 index 000000000..c98a39cfa --- /dev/null +++ b/vendor/github.com/manifoldco/promptui/list/list.go @@ -0,0 +1,237 @@ +package list + +import ( + "fmt" + "reflect" + "strings" +) + +// Searcher is a base function signature that is used inside select when activating the search mode. +// If defined, it is called on each items of the select and should return a boolean for whether or not +// the item fits the searched term. +type Searcher func(input string, index int) bool + +// NotFound is an index returned when no item was selected. This could +// happen due to a search without results. +const NotFound = -1 + +// List holds a collection of items that can be displayed with an N number of +// visible items. The list can be moved up, down by one item of time or an +// entire page (ie: visible size). It keeps track of the current selected item. +type List struct { + items []*interface{} + scope []*interface{} + cursor int // cursor holds the index of the current selected item + size int // size is the number of visible options + start int + Searcher Searcher +} + +// New creates and initializes a list of searchable items. The items attribute must be a slice type with a +// size greater than 0. Error will be returned if those two conditions are not met. +func New(items interface{}, size int) (*List, error) { + if size < 1 { + return nil, fmt.Errorf("list size %d must be greater than 0", size) + } + + if items == nil || reflect.TypeOf(items).Kind() != reflect.Slice { + return nil, fmt.Errorf("items %v is not a slice", items) + } + + slice := reflect.ValueOf(items) + values := make([]*interface{}, slice.Len()) + + for i := range values { + item := slice.Index(i).Interface() + values[i] = &item + } + + return &List{size: size, items: values, scope: values}, nil +} + +// Prev moves the visible list back one item. If the selected item is out of +// view, the new select item becomes the last visible item. If the list is +// already at the top, nothing happens. +func (l *List) Prev() { + if l.cursor > 0 { + l.cursor-- + } + + if l.start > l.cursor { + l.start = l.cursor + } +} + +// Search allows the list to be filtered by a given term. The list must +// implement the searcher function signature for this functionality to work. +func (l *List) Search(term string) { + term = strings.Trim(term, " ") + l.cursor = 0 + l.start = 0 + l.search(term) +} + +// CancelSearch stops the current search and returns the list to its +// original order. +func (l *List) CancelSearch() { + l.cursor = 0 + l.start = 0 + l.scope = l.items +} + +func (l *List) search(term string) { + var scope []*interface{} + + for i, item := range l.items { + if l.Searcher(term, i) { + scope = append(scope, item) + } + } + + l.scope = scope +} + +// Start returns the current render start position of the list. +func (l *List) Start() int { + return l.start +} + +// SetStart sets the current scroll position. Values out of bounds will be +// clamped. +func (l *List) SetStart(i int) { + if i < 0 { + i = 0 + } + if i > l.cursor { + l.start = l.cursor + } else { + l.start = i + } +} + +// SetCursor sets the position of the cursor in the list. Values out of bounds +// will be clamped. +func (l *List) SetCursor(i int) { + max := len(l.scope) - 1 + if i >= max { + i = max + } + if i < 0 { + i = 0 + } + l.cursor = i + + if l.start > l.cursor { + l.start = l.cursor + } else if l.start+l.size <= l.cursor { + l.start = l.cursor - l.size + 1 + } +} + +// Next moves the visible list forward one item. If the selected item is out of +// view, the new select item becomes the first visible item. If the list is +// already at the bottom, nothing happens. +func (l *List) Next() { + max := len(l.scope) - 1 + + if l.cursor < max { + l.cursor++ + } + + if l.start+l.size <= l.cursor { + l.start = l.cursor - l.size + 1 + } +} + +// PageUp moves the visible list backward by x items. Where x is the size of the +// visible items on the list. The selected item becomes the first visible item. +// If the list is already at the bottom, the selected item becomes the last +// visible item. +func (l *List) PageUp() { + start := l.start - l.size + if start < 0 { + l.start = 0 + } else { + l.start = start + } + + cursor := l.start + + if cursor < l.cursor { + l.cursor = cursor + } +} + +// PageDown moves the visible list forward by x items. Where x is the size of +// the visible items on the list. The selected item becomes the first visible +// item. +func (l *List) PageDown() { + start := l.start + l.size + max := len(l.scope) - l.size + + switch { + case len(l.scope) < l.size: + l.start = 0 + case start > max: + l.start = max + default: + l.start = start + } + + cursor := l.start + + if cursor == l.cursor { + l.cursor = len(l.scope) - 1 + } else if cursor > l.cursor { + l.cursor = cursor + } +} + +// CanPageDown returns whether a list can still PageDown(). +func (l *List) CanPageDown() bool { + max := len(l.scope) + return l.start+l.size < max +} + +// CanPageUp returns whether a list can still PageUp(). +func (l *List) CanPageUp() bool { + return l.start > 0 +} + +// Index returns the index of the item currently selected inside the searched list. If no item is selected, +// the NotFound (-1) index is returned. +func (l *List) Index() int { + selected := l.scope[l.cursor] + + for i, item := range l.items { + if item == selected { + return i + } + } + + return NotFound +} + +// Items returns a slice equal to the size of the list with the current visible +// items and the index of the active item in this list. +func (l *List) Items() ([]interface{}, int) { + var result []interface{} + max := len(l.scope) + end := l.start + l.size + + if end > max { + end = max + } + + active := NotFound + + for i, j := l.start, 0; i < end; i, j = i+1, j+1 { + if l.cursor == i { + active = j + } + + result = append(result, *l.scope[i]) + } + + return result, active +} |