aerc/widgets/msglist.go
Simon Ser 5685a17674 lib/ui: introduce Invalidatable
Many Drawable implementations have their own Invalidate and OnInvalidate
functions, with an unexported onInvalidate field. However OnInvalidate and
Invalidate are usually not called in the same goroutine. This results in a race
on this field, e.g.:

    Read at 0x00c000094748 by goroutine 7:
      git.sr.ht/~sircmpwn/aerc2/widgets.NewDirectoryList.func1()
          /home/simon/src/aerc2/widgets/dirlist.go:85 +0x56
      git.sr.ht/~sircmpwn/aerc2/widgets.(*Spinner).Start.func1()
          /home/simon/src/aerc2/widgets/spinner.go:93 +0x1bb

    Previous write at 0x00c000094748 by main goroutine:
      [failed to restore the stack]

    Goroutine 7 (running) created at:
      git.sr.ht/~sircmpwn/aerc2/widgets.(*Spinner).Start()
          /home/simon/src/aerc2/widgets/spinner.go:46 +0x8f
      git.sr.ht/~sircmpwn/aerc2/widgets.NewDirectoryList()
          /home/simon/src/aerc2/widgets/dirlist.go:37 +0x286
      git.sr.ht/~sircmpwn/aerc2/widgets.NewAccountView()
          /home/simon/src/aerc2/widgets/account.go:50 +0x5ca
      git.sr.ht/~sircmpwn/aerc2/widgets.NewAerc()
          /home/simon/src/aerc2/widgets/aerc.go:60 +0x800
      main.main()
          /home/simon/src/aerc2/aerc.go:65 +0x33e

To fix this, introduce a new type, Invalidatable, which protects the field.
Unfortunately the Drawable must be passed to the callback function in
Invalidate, so we still need to re-implement this in each Invalidatable user.
2019-04-27 14:30:28 -04:00

186 lines
3.6 KiB
Go

package widgets
import (
"log"
"github.com/gdamore/tcell"
"git.sr.ht/~sircmpwn/aerc2/config"
"git.sr.ht/~sircmpwn/aerc2/lib"
"git.sr.ht/~sircmpwn/aerc2/lib/ui"
"git.sr.ht/~sircmpwn/aerc2/worker/types"
)
type MessageList struct {
ui.Invalidatable
conf *config.AercConfig
logger *log.Logger
height int
scroll int
selected int
spinner *Spinner
store *lib.MessageStore
}
// TODO: fish in config
func NewMessageList(logger *log.Logger) *MessageList {
ml := &MessageList{
logger: logger,
selected: 0,
spinner: NewSpinner(),
}
ml.spinner.OnInvalidate(func(_ ui.Drawable) {
ml.Invalidate()
})
// TODO: stop spinner, probably
ml.spinner.Start()
return ml
}
func (ml *MessageList) Invalidate() {
ml.DoInvalidate(ml)
}
func (ml *MessageList) Draw(ctx *ui.Context) {
ml.height = ctx.Height()
ctx.Fill(0, 0, ctx.Width(), ctx.Height(), ' ', tcell.StyleDefault)
if ml.store == nil {
ml.spinner.Draw(ctx)
return
}
var (
needsHeaders []uint32
row int = 0
)
for i := len(ml.store.Uids) - 1 - ml.scroll; i >= 0; i-- {
uid := ml.store.Uids[i]
msg := ml.store.Messages[uid]
if row >= ctx.Height() {
break
}
if msg == nil {
needsHeaders = append(needsHeaders, uid)
ml.spinner.Draw(ctx.Subcontext(0, row, ctx.Width(), 1))
row += 1
continue
}
style := tcell.StyleDefault
if row == ml.selected-ml.scroll {
style = style.Reverse(true)
}
if _, ok := ml.store.Deleted[msg.Uid]; ok {
style = style.Foreground(tcell.ColorGray)
}
ctx.Fill(0, row, ctx.Width(), 1, ' ', style)
ctx.Printf(0, row, style, "%s", msg.Envelope.Subject)
row += 1
}
if len(ml.store.Uids) == 0 {
msg := "(no messages)"
ctx.Printf((ctx.Width()/2)-(len(msg)/2), 0,
tcell.StyleDefault, "%s", msg)
}
if len(needsHeaders) != 0 {
ml.store.FetchHeaders(needsHeaders, nil)
ml.spinner.Start()
} else {
ml.spinner.Stop()
}
}
func (ml *MessageList) Height() int {
return ml.height
}
func (ml *MessageList) storeUpdate(store *lib.MessageStore) {
if ml.store != store {
return
}
if len(ml.store.Uids) > 0 {
for ml.selected >= len(ml.store.Uids) {
ml.Prev()
}
}
ml.Invalidate()
}
func (ml *MessageList) SetStore(store *lib.MessageStore) {
if ml.store == store {
ml.scroll = 0
ml.selected = 0
}
ml.store = store
if store != nil {
ml.spinner.Stop()
ml.store.OnUpdate(ml.storeUpdate)
} else {
ml.spinner.Start()
}
ml.Invalidate()
}
func (ml *MessageList) Store() *lib.MessageStore {
return ml.store
}
func (ml *MessageList) Empty() bool {
return ml.store == nil || len(ml.store.Uids) == 0
}
func (ml *MessageList) Selected() *types.MessageInfo {
return ml.store.Messages[ml.store.Uids[len(ml.store.Uids)-ml.selected-1]]
}
func (ml *MessageList) Select(index int) {
ml.selected = index
for ; ml.selected < 0; ml.selected = len(ml.store.Uids) + ml.selected {
}
if ml.selected > len(ml.store.Uids) {
ml.selected = len(ml.store.Uids)
}
// I'm too lazy to do the math right now
for ml.selected-ml.scroll >= ml.Height() {
ml.scroll += 1
}
for ml.selected-ml.scroll < 0 {
ml.scroll -= 1
}
}
func (ml *MessageList) nextPrev(delta int) {
if ml.store == nil || len(ml.store.Uids) == 0 {
return
}
ml.selected += delta
if ml.selected < 0 {
ml.selected = 0
}
if ml.selected >= len(ml.store.Uids) {
ml.selected = len(ml.store.Uids) - 1
}
if ml.Height() != 0 {
if ml.selected-ml.scroll >= ml.Height() {
ml.scroll += 1
} else if ml.selected-ml.scroll < 0 {
ml.scroll -= 1
}
}
ml.Invalidate()
}
func (ml *MessageList) Next() {
ml.nextPrev(1)
}
func (ml *MessageList) Prev() {
ml.nextPrev(-1)
}