aerc/widgets/msgviewer.go

872 lines
21 KiB
Go

package widgets
import (
"bufio"
"errors"
"fmt"
"io"
"os"
"os/exec"
"regexp"
"strings"
"github.com/danwakefield/fnmatch"
"github.com/gdamore/tcell/v2"
"github.com/google/shlex"
"github.com/mattn/go-runewidth"
"git.sr.ht/~rjarry/aerc/config"
"git.sr.ht/~rjarry/aerc/lib"
"git.sr.ht/~rjarry/aerc/lib/auth"
"git.sr.ht/~rjarry/aerc/lib/format"
"git.sr.ht/~rjarry/aerc/lib/parse"
"git.sr.ht/~rjarry/aerc/lib/ui"
"git.sr.ht/~rjarry/aerc/logging"
"git.sr.ht/~rjarry/aerc/models"
)
var ansi = regexp.MustCompile("\x1B\\[[0-?]*[ -/]*[@-~]")
var _ ProvidesMessages = (*MessageViewer)(nil)
type MessageViewer struct {
ui.Invalidatable
acct *AccountView
conf *config.AercConfig
err error
grid *ui.Grid
switcher *PartSwitcher
msg lib.MessageView
uiConfig *config.UIConfig
}
type PartSwitcher struct {
ui.Invalidatable
parts []*PartViewer
selected int
showHeaders bool
alwaysShowMime bool
height int
mv *MessageViewer
}
func NewMessageViewer(acct *AccountView,
conf *config.AercConfig, msg lib.MessageView,
) *MessageViewer {
hf := HeaderLayoutFilter{
layout: HeaderLayout(conf.Viewer.HeaderLayout),
keep: func(msg *models.MessageInfo, header string) bool {
return fmtHeader(msg, header, "2") != ""
},
}
layout := hf.forMessage(msg.MessageInfo())
header, headerHeight := layout.grid(
func(header string) ui.Drawable {
hv := &HeaderView{
conf: conf,
Name: header,
Value: fmtHeader(msg.MessageInfo(), header,
acct.UiConfig().TimestampFormat),
uiConfig: acct.UiConfig(),
}
showInfo := false
if i := strings.IndexRune(header, '+'); i > 0 {
header = header[:i]
hv.Name = header
showInfo = true
}
if parser := auth.New(header); parser != nil {
details, err := parser(msg.MessageInfo().RFC822Headers, acct.AccountConfig().TrustedAuthRes)
if err != nil {
hv.Value = err.Error()
} else {
hv.ValueField = NewAuthInfo(details, showInfo, acct.UiConfig())
}
hv.Invalidate()
}
return hv
},
)
rows := []ui.GridSpec{
{Strategy: ui.SIZE_EXACT, Size: ui.Const(headerHeight)},
}
if msg.MessageDetails() != nil || conf.Ui.IconUnencrypted != "" {
height := 1
if msg.MessageDetails() != nil && msg.MessageDetails().IsSigned && msg.MessageDetails().IsEncrypted {
height = 2
}
rows = append(rows, ui.GridSpec{Strategy: ui.SIZE_EXACT, Size: ui.Const(height)})
}
rows = append(rows, []ui.GridSpec{
{Strategy: ui.SIZE_EXACT, Size: ui.Const(1)},
{Strategy: ui.SIZE_WEIGHT, Size: ui.Const(1)},
}...)
grid := ui.NewGrid().Rows(rows).Columns([]ui.GridSpec{
{Strategy: ui.SIZE_WEIGHT, Size: ui.Const(1)},
})
switcher := &PartSwitcher{}
err := createSwitcher(acct, switcher, conf, msg)
if err != nil {
return &MessageViewer{
err: err,
grid: grid,
msg: msg,
uiConfig: acct.UiConfig(),
}
}
borderStyle := acct.UiConfig().GetStyle(config.STYLE_BORDER)
borderChar := acct.UiConfig().BorderCharHorizontal
grid.AddChild(header).At(0, 0)
if msg.MessageDetails() != nil || conf.Ui.IconUnencrypted != "" {
grid.AddChild(NewPGPInfo(msg.MessageDetails(), acct.UiConfig())).At(1, 0)
grid.AddChild(ui.NewFill(borderChar, borderStyle)).At(2, 0)
grid.AddChild(switcher).At(3, 0)
} else {
grid.AddChild(ui.NewFill(borderChar, borderStyle)).At(1, 0)
grid.AddChild(switcher).At(2, 0)
}
mv := &MessageViewer{
acct: acct,
conf: conf,
grid: grid,
msg: msg,
switcher: switcher,
uiConfig: acct.UiConfig(),
}
switcher.mv = mv
return mv
}
func fmtHeader(msg *models.MessageInfo, header string, timefmt string) string {
if msg == nil || msg.Envelope == nil {
return "error: no envelope for this message"
}
if v := auth.New(header); v != nil {
return "Fetching.."
}
switch header {
case "From":
return format.FormatAddresses(msg.Envelope.From)
case "To":
return format.FormatAddresses(msg.Envelope.To)
case "Cc":
return format.FormatAddresses(msg.Envelope.Cc)
case "Bcc":
return format.FormatAddresses(msg.Envelope.Bcc)
case "Date":
return msg.Envelope.Date.Local().Format(timefmt)
case "Subject":
return msg.Envelope.Subject
case "Labels":
return strings.Join(msg.Labels, ", ")
default:
return msg.RFC822Headers.Get(header)
}
}
func enumerateParts(acct *AccountView, conf *config.AercConfig,
msg lib.MessageView, body *models.BodyStructure,
index []int,
) ([]*PartViewer, error) {
var parts []*PartViewer
for i, part := range body.Parts {
curindex := append(index, i+1)
if part.MIMEType == "multipart" {
// Multipart meta-parts are faked
pv := &PartViewer{part: part}
parts = append(parts, pv)
subParts, err := enumerateParts(
acct, conf, msg, part, curindex)
if err != nil {
return nil, err
}
parts = append(parts, subParts...)
continue
}
pv, err := NewPartViewer(acct, conf, msg, part, curindex)
if err != nil {
return nil, err
}
parts = append(parts, pv)
}
return parts, nil
}
func createSwitcher(acct *AccountView, switcher *PartSwitcher,
conf *config.AercConfig, msg lib.MessageView,
) error {
var err error
switcher.selected = -1
switcher.showHeaders = conf.Viewer.ShowHeaders
switcher.alwaysShowMime = conf.Viewer.AlwaysShowMime
if len(msg.BodyStructure().Parts) == 0 {
switcher.selected = 0
pv, err := NewPartViewer(acct, conf, msg, msg.BodyStructure(), nil)
if err != nil {
return err
}
switcher.parts = []*PartViewer{pv}
pv.OnInvalidate(func(_ ui.Drawable) {
switcher.Invalidate()
})
} else {
switcher.parts, err = enumerateParts(acct, conf, msg,
msg.BodyStructure(), []int{})
if err != nil {
return err
}
selectedPriority := -1
logging.Infof("Selecting best message from %v", conf.Viewer.Alternatives)
for i, pv := range switcher.parts {
pv.OnInvalidate(func(_ ui.Drawable) {
switcher.Invalidate()
})
// Switch to user's preferred mimetype
if switcher.selected == -1 && pv.part.MIMEType != "multipart" {
switcher.selected = i
}
mime := strings.ToLower(pv.part.MIMEType) +
"/" + strings.ToLower(pv.part.MIMESubType)
for idx, m := range conf.Viewer.Alternatives {
if m != mime {
continue
}
priority := len(conf.Viewer.Alternatives) - idx
if priority > selectedPriority {
selectedPriority = priority
switcher.selected = i
}
}
}
}
return nil
}
func (mv *MessageViewer) Draw(ctx *ui.Context) {
if mv.err != nil {
style := mv.acct.UiConfig().GetStyle(config.STYLE_DEFAULT)
ctx.Fill(0, 0, ctx.Width(), ctx.Height(), ' ', style)
ctx.Printf(0, 0, style, "%s", mv.err.Error())
return
}
mv.grid.Draw(ctx)
}
func (mv *MessageViewer) MouseEvent(localX int, localY int, event tcell.Event) {
if mv.err != nil {
return
}
mv.grid.MouseEvent(localX, localY, event)
}
func (mv *MessageViewer) Invalidate() {
mv.grid.Invalidate()
}
func (mv *MessageViewer) OnInvalidate(fn func(d ui.Drawable)) {
mv.grid.OnInvalidate(func(_ ui.Drawable) {
fn(mv)
})
}
func (mv *MessageViewer) Store() *lib.MessageStore {
return mv.msg.Store()
}
func (mv *MessageViewer) SelectedAccount() *AccountView {
return mv.acct
}
func (mv *MessageViewer) MessageView() lib.MessageView {
return mv.msg
}
func (mv *MessageViewer) SelectedMessage() (*models.MessageInfo, error) {
if mv.msg == nil {
return nil, errors.New("no message selected")
}
return mv.msg.MessageInfo(), nil
}
func (mv *MessageViewer) MarkedMessages() ([]uint32, error) {
store := mv.Store()
return store.Marked(), nil
}
func (mv *MessageViewer) ToggleHeaders() {
switcher := mv.switcher
switcher.Cleanup()
mv.conf.Viewer.ShowHeaders = !mv.conf.Viewer.ShowHeaders
err := createSwitcher(mv.acct, switcher, mv.conf, mv.msg)
if err != nil {
logging.Errorf("cannot create switcher: %v", err)
}
switcher.Invalidate()
}
func (mv *MessageViewer) ToggleKeyPassthrough() bool {
mv.conf.Viewer.KeyPassthrough = !mv.conf.Viewer.KeyPassthrough
return mv.conf.Viewer.KeyPassthrough
}
func (mv *MessageViewer) SelectedMessagePart() *PartInfo {
switcher := mv.switcher
part := switcher.parts[switcher.selected]
return &PartInfo{
Index: part.index,
Msg: part.msg.MessageInfo(),
Part: part.part,
Links: part.links,
}
}
func (mv *MessageViewer) AttachmentParts() []*PartInfo {
var attachments []*PartInfo
for _, p := range mv.switcher.parts {
if p.part.Disposition == "attachment" {
pi := &PartInfo{
Index: p.index,
Msg: p.msg.MessageInfo(),
Part: p.part,
}
attachments = append(attachments, pi)
}
}
return attachments
}
func (mv *MessageViewer) PreviousPart() {
switcher := mv.switcher
for {
switcher.selected--
if switcher.selected < 0 {
switcher.selected = len(switcher.parts) - 1
}
if switcher.parts[switcher.selected].part.MIMEType != "multipart" {
break
}
}
mv.Invalidate()
}
func (mv *MessageViewer) NextPart() {
switcher := mv.switcher
for {
switcher.selected++
if switcher.selected >= len(switcher.parts) {
switcher.selected = 0
}
if switcher.parts[switcher.selected].part.MIMEType != "multipart" {
break
}
}
mv.Invalidate()
}
func (mv *MessageViewer) Bindings() string {
if mv.conf.Viewer.KeyPassthrough {
return "view::passthrough"
} else {
return "view"
}
}
func (mv *MessageViewer) Close() error {
mv.switcher.Cleanup()
return nil
}
func (ps *PartSwitcher) Invalidate() {
ps.DoInvalidate(ps)
}
func (ps *PartSwitcher) Focus(focus bool) {
if ps.parts[ps.selected].term != nil {
ps.parts[ps.selected].term.Focus(focus)
}
}
func (ps *PartSwitcher) Event(event tcell.Event) bool {
return ps.parts[ps.selected].Event(event)
}
func (ps *PartSwitcher) Draw(ctx *ui.Context) {
height := len(ps.parts)
if height == 1 && !ps.alwaysShowMime {
ps.parts[ps.selected].Draw(ctx)
return
}
// TODO: cap height and add scrolling for messages with many parts
ps.height = ctx.Height()
y := ctx.Height() - height
for i, part := range ps.parts {
style := ps.mv.uiConfig.GetStyle(config.STYLE_DEFAULT)
if ps.selected == i {
style = ps.mv.uiConfig.GetStyleSelected(config.STYLE_DEFAULT)
}
ctx.Fill(0, y+i, ctx.Width(), 1, ' ', style)
name := fmt.Sprintf("%s/%s",
strings.ToLower(part.part.MIMEType),
strings.ToLower(part.part.MIMESubType))
if filename, ok := part.part.DispositionParams["filename"]; ok {
name += fmt.Sprintf(" (%s)", filename)
} else if filename, ok := part.part.Params["name"]; ok {
// workaround golang not supporting RFC2231 besides ASCII and UTF8
name += fmt.Sprintf(" (%s)", filename)
}
ctx.Printf(len(part.index)*2, y+i, style, "%s", name)
}
ps.parts[ps.selected].Draw(ctx.Subcontext(
0, 0, ctx.Width(), ctx.Height()-height))
}
func (ps *PartSwitcher) MouseEvent(localX int, localY int, event tcell.Event) {
switch event := event.(type) {
case *tcell.EventMouse:
switch event.Buttons() {
case tcell.Button1:
height := len(ps.parts)
y := ps.height - height
if localY < y && ps.parts[ps.selected].term != nil {
ps.parts[ps.selected].term.MouseEvent(localX, localY, event)
}
for i := range ps.parts {
if localY != y+i {
continue
}
if ps.parts[i].part.MIMEType == "multipart" {
continue
}
if ps.parts[ps.selected].term != nil {
ps.parts[ps.selected].term.Focus(false)
}
ps.selected = i
ps.Invalidate()
if ps.parts[ps.selected].term != nil {
ps.parts[ps.selected].term.Focus(true)
}
}
case tcell.WheelDown:
height := len(ps.parts)
y := ps.height - height
if localY < y && ps.parts[ps.selected].term != nil {
ps.parts[ps.selected].term.MouseEvent(localX, localY, event)
}
if ps.parts[ps.selected].term != nil {
ps.parts[ps.selected].term.Focus(false)
}
ps.mv.NextPart()
if ps.parts[ps.selected].term != nil {
ps.parts[ps.selected].term.Focus(true)
}
case tcell.WheelUp:
height := len(ps.parts)
y := ps.height - height
if localY < y && ps.parts[ps.selected].term != nil {
ps.parts[ps.selected].term.MouseEvent(localX, localY, event)
}
if ps.parts[ps.selected].term != nil {
ps.parts[ps.selected].term.Focus(false)
}
ps.mv.PreviousPart()
if ps.parts[ps.selected].term != nil {
ps.parts[ps.selected].term.Focus(true)
}
}
}
}
func (ps *PartSwitcher) Cleanup() {
for _, partViewer := range ps.parts {
partViewer.Cleanup()
}
}
func (mv *MessageViewer) Event(event tcell.Event) bool {
return mv.switcher.Event(event)
}
func (mv *MessageViewer) Focus(focus bool) {
mv.switcher.Focus(focus)
}
type PartViewer struct {
ui.Invalidatable
conf *config.AercConfig
acctConfig *config.AccountConfig
err error
fetched bool
filter *exec.Cmd
index []int
msg lib.MessageView
pager *exec.Cmd
pagerin io.WriteCloser
part *models.BodyStructure
showHeaders bool
sink io.WriteCloser
source io.Reader
term *Terminal
grid *ui.Grid
uiConfig *config.UIConfig
links []string
}
func NewPartViewer(acct *AccountView, conf *config.AercConfig,
msg lib.MessageView, part *models.BodyStructure,
index []int,
) (*PartViewer, error) {
var (
filter *exec.Cmd
pager *exec.Cmd
pipe io.WriteCloser
pagerin io.WriteCloser
term *Terminal
)
cmd, err := shlex.Split(conf.Viewer.Pager)
if err != nil {
return nil, err
}
pager = exec.Command(cmd[0], cmd[1:]...)
info := msg.MessageInfo()
for _, f := range conf.Filters {
mime := strings.ToLower(part.MIMEType) +
"/" + strings.ToLower(part.MIMESubType)
switch f.FilterType {
case config.FILTER_MIMETYPE:
if fnmatch.Match(f.Filter, mime, 0) {
filter = exec.Command("sh", "-c", f.Command)
}
case config.FILTER_HEADER:
var header string
switch f.Header {
case "subject":
header = info.Envelope.Subject
case "from":
header = format.FormatAddresses(info.Envelope.From)
case "to":
header = format.FormatAddresses(info.Envelope.To)
case "cc":
header = format.FormatAddresses(info.Envelope.Cc)
default:
header = msg.MessageInfo().RFC822Headers.Get(f.Header)
}
if f.Regex.Match([]byte(header)) {
filter = exec.Command("sh", "-c", f.Command)
}
}
if filter != nil {
break
}
}
if filter != nil {
if pipe, err = filter.StdinPipe(); err != nil {
return nil, err
}
if pagerin, _ = pager.StdinPipe(); err != nil {
return nil, err
}
if term, err = NewTerminal(pager); err != nil {
return nil, err
}
}
grid := ui.NewGrid().Rows([]ui.GridSpec{
{Strategy: ui.SIZE_EXACT, Size: ui.Const(3)}, // Message
{Strategy: ui.SIZE_WEIGHT, Size: ui.Const(1)},
}).Columns([]ui.GridSpec{
{Strategy: ui.SIZE_WEIGHT, Size: ui.Const(1)},
})
pv := &PartViewer{
conf: conf,
acctConfig: acct.AccountConfig(),
filter: filter,
index: index,
msg: msg,
pager: pager,
pagerin: pagerin,
part: part,
showHeaders: conf.Viewer.ShowHeaders,
sink: pipe,
term: term,
grid: grid,
uiConfig: acct.UiConfig(),
}
if term != nil {
term.OnStart = func() {
pv.attemptCopy()
}
term.OnInvalidate(func(_ ui.Drawable) {
pv.Invalidate()
})
}
return pv, nil
}
func (pv *PartViewer) SetSource(reader io.Reader) {
pv.source = reader
pv.attemptCopy()
}
func (pv *PartViewer) attemptCopy() {
if pv.source == nil || pv.pager == nil || pv.pager.Process == nil {
return
}
if pv.filter != nil {
pv.copyFilterOutToPager() // delayed until we write to the sink
}
go func() {
defer logging.PanicHandler()
pv.writeMailHeaders()
if strings.EqualFold(pv.part.MIMEType, "text") {
// if the content is plain we can strip ansi control chars
pv.copySourceToSinkStripAnsi()
} else {
// if it's binary we have to rely on the filter to be sane
io.Copy(pv.sink, pv.source)
}
pv.sink.Close()
}()
}
func (pv *PartViewer) writeMailHeaders() {
info := pv.msg.MessageInfo()
if pv.showHeaders && info.RFC822Headers != nil {
// header need to bypass the filter, else we run into issues
// with the filter messing with newlines etc.
// hence all writes in this block go directly to the pager
fields := info.RFC822Headers.Fields()
for fields.Next() {
var value string
var err error
if value, err = fields.Text(); err != nil {
// better than nothing, use the non decoded version
value = fields.Value()
}
field := fmt.Sprintf(
"%s: %s\n", fields.Key(), value)
pv.pagerin.Write([]byte(field))
}
// virtual header
if len(info.Labels) != 0 {
labels := fmtHeader(info, "Labels", "")
pv.pagerin.Write([]byte(fmt.Sprintf("Labels: %s\n", labels)))
}
pv.pagerin.Write([]byte{'\n'})
}
}
func (pv *PartViewer) hyperlinks(r io.Reader) (reader io.Reader) {
if !pv.conf.Viewer.ParseHttpLinks {
return r
}
reader, pv.links = parse.HttpLinks(r)
return reader
}
func (pv *PartViewer) copyFilterOutToPager() {
stdout, _ := pv.filter.StdoutPipe()
stderr, _ := pv.filter.StderrPipe()
pv.filter.Start()
ch := make(chan interface{})
go func() {
defer logging.PanicHandler()
_, err := io.Copy(pv.pagerin, stdout)
if err != nil {
pv.err = err
pv.Invalidate()
}
stdout.Close()
ch <- nil
}()
go func() {
defer logging.PanicHandler()
_, err := io.Copy(pv.pagerin, stderr)
if err != nil {
pv.err = err
pv.Invalidate()
}
stderr.Close()
ch <- nil
}()
go func() {
defer logging.PanicHandler()
<-ch
<-ch
pv.filter.Wait()
pv.pagerin.Close()
}()
}
func (pv *PartViewer) copySourceToSinkStripAnsi() {
scanner := bufio.NewScanner(pv.hyperlinks(pv.source))
// some people send around huge html without any newline in between
// this did overflow the default 64KB buffer of bufio.Scanner.
// If something can't fit in a GB there's no hope left
scanner.Buffer(nil, 1024*1024*1024)
for scanner.Scan() {
text := scanner.Text()
text = ansi.ReplaceAllString(text, "")
io.WriteString(pv.sink, text+"\n")
}
if err := scanner.Err(); err != nil {
fmt.Fprintf(os.Stderr, "failed to read line: %v\n", err)
}
}
var noFilterConfiguredCommands = [][]string{
{":open<enter>", "Open using the system handler"},
{":save<space>", "Save to file"},
{":pipe<space>", "Pipe to shell command"},
}
func newNoFilterConfigured(pv *PartViewer) *ui.Grid {
bindings := pv.conf.MergeContextualBinds(
pv.conf.Bindings.MessageView,
config.BIND_CONTEXT_ACCOUNT,
pv.acctConfig.Name,
"view",
)
var actions []string
for _, command := range noFilterConfiguredCommands {
cmd := command[0]
name := command[1]
strokes, _ := config.ParseKeyStrokes(cmd)
var inputs []string
for _, input := range bindings.GetReverseBindings(strokes) {
inputs = append(inputs, config.FormatKeyStrokes(input))
}
actions = append(actions, fmt.Sprintf(" %-6s %-29s %s",
strings.Join(inputs[:], ", "), name, cmd))
}
spec := []ui.GridSpec{
{Strategy: ui.SIZE_EXACT, Size: ui.Const(2)},
}
for i := 0; i < len(actions)-1; i++ {
spec = append(spec, ui.GridSpec{Strategy: ui.SIZE_EXACT, Size: ui.Const(1)})
}
// make the last element fill remaining space
spec = append(spec, ui.GridSpec{Strategy: ui.SIZE_WEIGHT, Size: ui.Const(1)})
grid := ui.NewGrid().Rows(spec).Columns([]ui.GridSpec{
{Strategy: ui.SIZE_WEIGHT, Size: ui.Const(1)},
})
uiConfig := pv.conf.Ui
noFilter := fmt.Sprintf(`No filter configured for this mimetype ('%s/%s')
What would you like to do?`, pv.part.MIMEType, pv.part.MIMESubType)
grid.AddChild(ui.NewText(noFilter,
uiConfig.GetStyle(config.STYLE_TITLE))).At(0, 0)
for i, action := range actions {
grid.AddChild(ui.NewText(action,
uiConfig.GetStyle(config.STYLE_DEFAULT))).At(i+1, 0)
}
return grid
}
func (pv *PartViewer) Invalidate() {
pv.DoInvalidate(pv)
}
func (pv *PartViewer) Draw(ctx *ui.Context) {
style := pv.uiConfig.GetStyle(config.STYLE_DEFAULT)
if pv.filter == nil {
ctx.Fill(0, 0, ctx.Width(), ctx.Height(), ' ', style)
newNoFilterConfigured(pv).Draw(ctx)
return
}
if !pv.fetched {
pv.msg.FetchBodyPart(pv.index, pv.SetSource)
pv.fetched = true
}
if pv.err != nil {
ctx.Fill(0, 0, ctx.Width(), ctx.Height(), ' ', style)
ctx.Printf(0, 0, style, "%s", pv.err.Error())
return
}
pv.term.Draw(ctx)
}
func (pv *PartViewer) Cleanup() {
if pv.pager != nil && pv.pager.Process != nil {
pv.pager.Process.Kill()
pv.pager = nil
}
}
func (pv *PartViewer) Event(event tcell.Event) bool {
if pv.term != nil {
return pv.term.Event(event)
}
return false
}
type HeaderView struct {
ui.Invalidatable
conf *config.AercConfig
Name string
Value string
ValueField ui.Drawable
uiConfig *config.UIConfig
}
func (hv *HeaderView) Draw(ctx *ui.Context) {
name := hv.Name
size := runewidth.StringWidth(name + ":")
lim := ctx.Width() - size - 1
if lim <= 0 || ctx.Height() <= 0 {
return
}
value := runewidth.Truncate(" "+hv.Value, lim, "…")
vstyle := hv.uiConfig.GetStyle(config.STYLE_DEFAULT)
hstyle := hv.uiConfig.GetStyle(config.STYLE_HEADER)
// TODO: Make this more robust and less dumb
if hv.Name == "PGP" {
vstyle = hv.uiConfig.GetStyle(config.STYLE_SUCCESS)
}
ctx.Fill(0, 0, ctx.Width(), ctx.Height(), ' ', vstyle)
ctx.Printf(0, 0, hstyle, "%s:", name)
if hv.ValueField == nil {
ctx.Printf(size, 0, vstyle, "%s", value)
} else {
hv.ValueField.Draw(ctx.Subcontext(size, 0, lim, 1))
}
}
func (hv *HeaderView) Invalidate() {
hv.DoInvalidate(hv)
}