termui/widgets/list.go

142 lines
3.4 KiB
Go

// Copyright 2017 Zack Guo <zack.y.guo@gmail.com>. All rights reserved.
// Use of this source code is governed by a MIT license that can
// be found in the LICENSE file.
package widgets
import (
"image"
. "github.com/gizak/termui"
)
type List struct {
Block
Rows []string
WrapText bool
TextStyle Style
SelectedRow uint
topRow uint
SelectedRowStyle Style
}
func NewList() *List {
return &List{
Block: *NewBlock(),
TextStyle: Theme.List.Text,
SelectedRowStyle: Theme.List.Text,
}
}
func (self *List) Draw(buf *Buffer) {
self.Block.Draw(buf)
point := self.Inner.Min
if self.SelectedRow >= uint(self.Inner.Max.Y)+self.topRow-2 {
self.topRow = self.SelectedRow - uint(self.Inner.Max.Y) + 2
} else if self.SelectedRow < self.topRow {
self.topRow = self.SelectedRow
}
for row := self.topRow; row < uint(len(self.Rows)) && point.Y < self.Inner.Max.Y; row++ {
cells := ParseText(self.Rows[row], self.TextStyle)
if self.WrapText {
cells = WrapCells(cells, uint(self.Inner.Dx()))
}
for j := 0; j < len(cells) && point.Y < self.Inner.Max.Y; j++ {
style := cells[j].Style
if row == self.SelectedRow {
style = self.SelectedRowStyle
}
if cells[j].Rune == '\n' {
point = image.Pt(self.Inner.Min.X, point.Y+1)
} else {
if point.X+1 == self.Inner.Max.X+1 && len(cells) > self.Inner.Dx() {
buf.SetCell(NewCell(ELLIPSES, style), point.Add(image.Pt(-1, 0)))
break
} else {
buf.SetCell(NewCell(cells[j].Rune, style), point)
point = point.Add(image.Pt(1, 0))
}
}
}
point = image.Pt(self.Inner.Min.X, point.Y+1)
}
if self.topRow > 0 {
buf.SetCell(
NewCell(UP_ARROW, NewStyle(ColorWhite)),
image.Pt(self.Inner.Max.X-1, self.Inner.Min.Y),
)
}
if len(self.Rows) > int(self.topRow)+self.Inner.Dy() {
buf.SetCell(
NewCell(DOWN_ARROW, NewStyle(ColorWhite)),
image.Pt(self.Inner.Max.X-1, self.Inner.Max.Y-1),
)
}
}
func (self *List) ScrollUp() {
if self.SelectedRow > 0 {
self.SelectedRow--
if self.SelectedRow < self.topRow {
self.topRow--
}
}
}
func (self *List) ScrollDown() {
if self.SelectedRow < uint(len(self.Rows))-1 {
self.SelectedRow++
if self.SelectedRow-self.topRow > uint(self.Inner.Dy()-1) {
self.topRow++
}
}
}
// Scrolls by amount given. If amount is < 0, then scroll up.
// There is no need to set self.topRow, as this will be set automatically when drawn,
// since if the selected item is off screen then the topRow variable will change accordingly.
func (self *List) scrollAmount(amount int) {
if len(self.Rows)-int(self.SelectedRow) <= amount {
self.SelectedRow = uint(len(self.Rows)-1)
} else if int(self.SelectedRow)+amount < 0 {
self.SelectedRow = 0
} else {
self.SelectedRow += uint(amount)
}
}
// PageUp scrolls up one whole page.
func (self *List) PageUp() {
// If an item is selected below top row, then go to the top row.
if self.SelectedRow > self.topRow {
self.SelectedRow = self.topRow
} else {
self.scrollAmount(-self.Inner.Dy())
}
}
// PageDown scolls down one whole page.
func (self *List) PageDown() {
self.scrollAmount(self.Inner.Dy())
}
func (self *List) HalfPageUp() {
self.scrollAmount(-int(FloorFloat64(float64(self.Inner.Dy())/2)))
}
func (self *List) HalfPageDown() {
self.scrollAmount(int(FloorFloat64(float64(self.Inner.Dy())/2)))
}
func (self *List) ScrollTop() {
self.SelectedRow = 0
}
func (self *List) ScrollBottom() {
self.SelectedRow = uint(len(self.Rows)-1)
}