package tview import "github.com/gdamore/tcell" // Configuration values. const ( FlexRow = iota FlexColumn ) // flexItem holds layout options for one item. type flexItem struct { Item Primitive // The item to be positioned. FixedSize int // The item's fixed size which may not be changed, 0 if it has no fixed size. } // Flex is a basic implementation of a flexbox layout. type Flex struct { x, y, width, height int // The size and position of this primitive. items []flexItem // The items to be positioned. direction int // FlexRow or FlexColumn. } // NewFlex returns a new flexbox layout container with the given primitives. // The items all have no fixed size. If more control is needed, call AddItem(). // The direction argument must be FlexRow or FlexColumn. func NewFlex(direction int, items []Primitive) *Flex { box := &Flex{ width: 15, height: 10, direction: direction, } for _, item := range items { box.items = append(box.items, flexItem{Item: item}) } return box } // AddItem adds a new item to the container. fixedSize is a size that may not be // changed. A value of 0 means that its size may be changed. func (f *Flex) AddItem(item Primitive, fixedSize int) *Flex { f.items = append(f.items, flexItem{Item: item, FixedSize: fixedSize}) return f } // Draw draws this primitive onto the screen. func (f *Flex) Draw(screen tcell.Screen) { // Calculate size and position of the items. // How much space can we distribute? var variables int distSize := f.width if f.direction == FlexRow { distSize = f.height } for _, item := range f.items { if item.FixedSize > 0 { distSize -= item.FixedSize } else { variables++ } } // Calculate positions and draw items. pos := f.x if f.direction == FlexRow { pos = f.y } for _, item := range f.items { size := item.FixedSize if size <= 0 { size = distSize / variables distSize -= size variables-- } if f.direction == FlexColumn { item.Item.SetRect(pos, f.y, size, f.height) } else { item.Item.SetRect(f.x, pos, f.width, size) } pos += size item.Item.Draw(screen) } } // GetRect returns the current position of the primitive, x, y, width, and // height. func (f *Flex) GetRect() (int, int, int, int) { return f.x, f.y, f.width, f.height } // SetRect sets a new position of the primitive. func (f *Flex) SetRect(x, y, width, height int) { f.x = x f.y = y f.width = width f.height = height } // InputHandler returns nil. func (f *Flex) InputHandler() func(event *tcell.EventKey, setFocus func(p Primitive)) { return nil } // Focus is called when this primitive receives focus. func (f *Flex) Focus(delegate func(p Primitive)) { if len(f.items) > 0 { delegate(f.items[0].Item) } } // Blur is called when this primitive loses focus. func (f *Flex) Blur() { }