package ui
import (
"sync/atomic"
"github.com/gdamore/tcell/v2"
)
const (
DIRTY int32 = iota
NOT_DIRTY
)
var MsgChannel = make(chan AercMsg, 50)
type AercFuncMsg struct {
Func func()
}
// QueueRedraw marks the UI as invalid and sends a nil message into the
// MsgChannel. Nothing will handle this message, but a redraw will occur
func QueueRedraw() {
Invalidate()
MsgChannel <- nil
}
// QueueFunc queues a function to be called in the main goroutine. This can be
// used to prevent race conditions from delayed functions
func QueueFunc(fn func()) {
MsgChannel <- &AercFuncMsg{Func: fn}
}
// dirty is the dirty state of the UI. Any value other than 0 means the UI is in
// a dirty state. Dirty should only be accessed via atomic operations to
// maintain thread safety
var dirty int32
// Invalidate marks the entire UI as invalid. Invalidate can be called from any
// goroutine
func Invalidate() {
atomic.StoreInt32(&dirty, DIRTY)
}
type UI struct {
Content DrawableInteractive
exit atomic.Value // bool
ctx *Context
screen tcell.Screen
popover *Popover
}
func Initialize(content DrawableInteractive) (*UI, error) {
screen, err := tcell.NewScreen()
if err != nil {
return nil, err
}
if err = screen.Init(); err != nil {
return nil, err
}
screen.Clear()
screen.HideCursor()
screen.EnablePaste()
width, height := screen.Size()
state := UI{
Content: content,
screen: screen,
}
state.ctx = NewContext(width, height, screen, state.onPopover)
state.exit.Store(false)
Invalidate()
if beeper, ok := content.(DrawableInteractiveBeeper); ok {
beeper.OnBeep(screen.Beep)
}
content.Focus(true)
if root, ok := content.(RootDrawable); ok {
root.Initialize(&state)
}
return &state, nil
}
func (state *UI) onPopover(p *Popover) {
state.popover = p
}
func (state *UI) ShouldExit() bool {
return state.exit.Load().(bool)
}
func (state *UI) Exit() {
state.exit.Store(true)
}
func (state *UI) Close() {
state.screen.Fini()
}
func (state *UI) Render() {
dirtyState := atomic.SwapInt32(&dirty, NOT_DIRTY)
if dirtyState == DIRTY {
// reset popover for the next Draw
state.popover = nil
state.Content.Draw(state.ctx)
if state.popover != nil {
// if the Draw resulted in a popover, draw it
state.popover.Draw(state.ctx)
}
state.screen.Show()
}
}
func (state *UI) EnableMouse() {
state.screen.EnableMouse()
}
func (state *UI) ChannelEvents() {
go func() {
for {
MsgChannel <- state.screen.PollEvent()
}
}()
}
func (state *UI) HandleEvent(event tcell.Event) {
if event, ok := event.(*tcell.EventResize); ok {
state.screen.Clear()
width, height := event.Size()
state.ctx = NewContext(width, height, state.screen, state.onPopover)
Invalidate()
}
// if we have a popover, and it can handle the event, it does so
if state.popover == nil || !state.popover.Event(event) {
// otherwise, we send the event to the main content
state.Content.Event(event)
}
}
