termui/events.go
2019-01-23 20:16:13 -08:00

176 lines
3.5 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 termui
import (
"strconv"
tb "github.com/nsf/termbox-go"
)
/*
List of events:
mouse events:
<MouseLeft> <MouseRight> <MouseMiddle>
<MouseWheelUp> <MouseWheelDown>
keyboard events:
any uppercase or lowercase letter like j or J
<C-d> etc
<M-d> etc
<Up> <Down> <Left> <Right>
<Insert> <Delete> <Home> <End> <Previous> <Next>
<Backspace> <Tab> <Enter> <Escape> <Space>
<C-<Space>> etc
terminal events:
<Resize>
*/
type EventType int
const (
KeyboardEvent EventType = iota
MouseEvent
ResizeEvent
)
type Event struct {
Type EventType
ID string
Payload interface{}
}
// Mouse payload.
type Mouse struct {
Drag bool
X int
Y int
}
// Resize payload.
type Resize struct {
Width int
Height int
}
// PollEvents gets events from termbox, converts them, then sends them to each of its channels.
func PollEvents() <-chan Event {
ch := make(chan Event)
go func() {
for {
ch <- convertTermboxEvent(tb.PollEvent())
}
}()
return ch
}
// convertTermboxKeyboardEvent converts a termbox keyboard event to a more friendly string format.
// Combines modifiers into the string instead of having them as additional fields in an event.
func convertTermboxKeyboardEvent(e tb.Event) Event {
k := string(e.Ch)
pre := ""
mod := ""
if e.Mod == tb.ModAlt {
mod = "<M-"
}
if e.Ch == 0 {
if e.Key > 0xFFFF-12 {
k = "<f" + strconv.Itoa(0xFFFF-int(e.Key)+1) + ">"
} else if e.Key > 0xFFFF-25 {
ks := []string{"<Insert>", "<Delete>", "<Home>", "<End>", "<Previous>", "<Next>", "<Up>", "<Down>", "<Left>", "<Right>"}
k = ks[0xFFFF-int(e.Key)-12]
}
if e.Key <= 0x7F {
pre = "<C-"
k = string('a' - 1 + int(e.Key))
kmap := map[tb.Key][2]string{
tb.KeyCtrlSpace: {"C-", "<Space>"},
tb.KeyBackspace: {"", "<Backspace>"},
tb.KeyTab: {"", "<Tab>"},
tb.KeyEnter: {"", "<Enter>"},
tb.KeyEsc: {"", "<Escape>"},
tb.KeyCtrlBackslash: {"C-", "\\"},
tb.KeyCtrlSlash: {"C-", "/"},
tb.KeySpace: {"", "<Space>"},
tb.KeyCtrl8: {"C-", "8"},
}
if sk, ok := kmap[e.Key]; ok {
pre = sk[0]
k = sk[1]
}
}
}
if pre != "" {
k += ">"
}
id := pre + mod + k
return Event{
Type: KeyboardEvent,
ID: id,
}
}
func convertTermboxMouseEvent(e tb.Event) Event {
mouseButtonMap := map[tb.Key]string{
tb.MouseLeft: "<MouseLeft>",
tb.MouseMiddle: "<MouseMiddle>",
tb.MouseRight: "<MouseRight>",
tb.MouseRelease: "<MouseRelease>",
tb.MouseWheelUp: "<MouseWheelUp>",
tb.MouseWheelDown: "<MouseWheelDown>",
}
converted, ok := mouseButtonMap[e.Key]
if !ok {
converted = "Unknown_Mouse_Button"
}
Drag := false
if e.Mod == tb.ModMotion {
Drag = true
}
return Event{
Type: MouseEvent,
ID: converted,
Payload: Mouse{
X: e.MouseX,
Y: e.MouseY,
Drag: Drag,
},
}
}
// convertTermboxEvent turns a termbox event into a termui event.
func convertTermboxEvent(e tb.Event) Event {
if e.Type == tb.EventError {
panic(e.Err)
}
var event Event
switch e.Type {
case tb.EventKey:
event = convertTermboxKeyboardEvent(e)
case tb.EventMouse:
event = convertTermboxMouseEvent(e)
case tb.EventResize:
event = Event{
Type: ResizeEvent,
ID: "<Resize>",
Payload: Resize{
Width: e.Width,
Height: e.Height,
},
}
}
return event
}