Add UI options to save/pipe messages with unsupported mimetypes

Adds a message indicating the user's ability to :save or :pipe a message
with an unsupported mimetype and also adds a selector widget (similar to
the tutorial).

The selector widget was previously defined in the account wizard module,
so this commit breaks it out into its own module to allow for re-use.

Further, modify the BeginExLine() function to take an argument that
pre-populates the command line, allowing functions to initiate an ex
command without executing it.

Closes #95.

7 files changed, 163 insertions, 123 deletions

diff --git a/lib/ui/textinput.go b/lib/ui/textinput.go
index 39351735..e81e8361 100644
--- a/lib/ui/textinput.go
+++ b/lib/ui/textinput.go
@@ -63,9 +63,10 @@ func (ti *TextInput) StringRight() string {
 	return string(ti.text[ti.index:])
 }
 
-func (ti *TextInput) Set(value string) {
+func (ti *TextInput) Set(value string) *TextInput {
 	ti.text = []rune(value)
 	ti.index = len(ti.text)
+	return ti
 }
 
 func (ti *TextInput) Invalidate() {
diff --git a/widgets/account-wizard.go b/widgets/account-wizard.go
index 904013f9..d7b46b9e 100644
--- a/widgets/account-wizard.go
+++ b/widgets/account-wizard.go
@@ -177,7 +177,7 @@ func NewAccountWizard(conf *config.AercConfig, aerc *Aerc) *AccountWizard {
 		At(7, 0)
 	basics.AddChild(wizard.email).
 		At(8, 0)
-	selecter := newSelecter([]string{"Next"}, 0).
+	selecter := NewSelecter([]string{"Next"}, 0).
 		OnChoose(func(option string) {
 			email := wizard.email.String()
 			if strings.ContainsRune(email, '@') {
@@ -254,7 +254,7 @@ func NewAccountWizard(conf *config.AercConfig, aerc *Aerc) *AccountWizard {
 	incoming.AddChild(
 		ui.NewText("Connection mode").Bold(true)).
 		At(10, 0)
-	imapMode := newSelecter([]string{
+	imapMode := NewSelecter([]string{
 		"IMAP over SSL/TLS",
 		"IMAP with STARTTLS",
 		"Insecure IMAP",
@@ -270,7 +270,7 @@ func NewAccountWizard(conf *config.AercConfig, aerc *Aerc) *AccountWizard {
 		wizard.imapUri()
 	})
 	incoming.AddChild(imapMode).At(11, 0)
-	selecter = newSelecter([]string{"Previous", "Next"}, 1).
+	selecter = NewSelecter([]string{"Previous", "Next"}, 1).
 		OnChoose(wizard.advance)
 	incoming.AddChild(ui.NewFill(' ')).At(12, 0)
 	incoming.AddChild(wizard.imapStr).At(13, 0)
@@ -331,7 +331,7 @@ func NewAccountWizard(conf *config.AercConfig, aerc *Aerc) *AccountWizard {
 	outgoing.AddChild(
 		ui.NewText("Connection mode").Bold(true)).
 		At(10, 0)
-	smtpMode := newSelecter([]string{
+	smtpMode := NewSelecter([]string{
 		"SMTP over SSL/TLS",
 		"SMTP with STARTTLS",
 		"Insecure SMTP",
@@ -347,7 +347,7 @@ func NewAccountWizard(conf *config.AercConfig, aerc *Aerc) *AccountWizard {
 		wizard.smtpUri()
 	})
 	outgoing.AddChild(smtpMode).At(11, 0)
-	selecter = newSelecter([]string{"Previous", "Next"}, 1).
+	selecter = NewSelecter([]string{"Previous", "Next"}, 1).
 		OnChoose(wizard.advance)
 	outgoing.AddChild(ui.NewFill(' ')).At(12, 0)
 	outgoing.AddChild(wizard.smtpStr).At(13, 0)
@@ -355,7 +355,7 @@ func NewAccountWizard(conf *config.AercConfig, aerc *Aerc) *AccountWizard {
 	outgoing.AddChild(
 		ui.NewText("Copy sent messages to 'Sent' folder?").Bold(true)).
 		At(15, 0)
-	copySent := newSelecter([]string{"Yes", "No"}, 0).
+	copySent := NewSelecter([]string{"Yes", "No"}, 0).
 		Chooser(true).OnChoose(func(option string) {
 		switch option {
 		case "Yes":
@@ -385,7 +385,7 @@ func NewAccountWizard(conf *config.AercConfig, aerc *Aerc) *AccountWizard {
 			"You can go back and double check your settings, or choose 'Finish' to\n" +
 			"save your settings to accounts.conf.\n\n" +
 			"To add another account in the future, run ':new-account'."))
-	selecter = newSelecter([]string{
+	selecter = NewSelecter([]string{
 		"Previous",
 		"Finish & open tutorial",
 		"Finish",
@@ -716,102 +716,6 @@ func (wizard *AccountWizard) Event(event tcell.Event) bool {
 	return false
 }
 
-type selecter struct {
-	ui.Invalidatable
-	chooser bool
-	focused bool
-	focus   int
-	options []string
-
-	onChoose func(option string)
-	onSelect func(option string)
-}
-
-func newSelecter(options []string, focus int) *selecter {
-	return &selecter{
-		focus:   focus,
-		options: options,
-	}
-}
-
-func (sel *selecter) Chooser(chooser bool) *selecter {
-	sel.chooser = chooser
-	return sel
-}
-
-func (sel *selecter) Invalidate() {
-	sel.DoInvalidate(sel)
-}
-
-func (sel *selecter) Draw(ctx *ui.Context) {
-	ctx.Fill(0, 0, ctx.Width(), ctx.Height(), ' ', tcell.StyleDefault)
-	x := 2
-	for i, option := range sel.options {
-		style := tcell.StyleDefault
-		if sel.focus == i {
-			if sel.focused {
-				style = style.Reverse(true)
-			} else if sel.chooser {
-				style = style.Bold(true)
-			}
-		}
-		x += ctx.Printf(x, 1, style, "[%s]", option)
-		x += 5
-	}
-}
-
-func (sel *selecter) OnChoose(fn func(option string)) *selecter {
-	sel.onChoose = fn
-	return sel
-}
-
-func (sel *selecter) OnSelect(fn func(option string)) *selecter {
-	sel.onSelect = fn
-	return sel
-}
-
-func (sel *selecter) Selected() string {
-	return sel.options[sel.focus]
-}
-
-func (sel *selecter) Focus(focus bool) {
-	sel.focused = focus
-	sel.Invalidate()
-}
-
-func (sel *selecter) Event(event tcell.Event) bool {
-	switch event := event.(type) {
-	case *tcell.EventKey:
-		switch event.Key() {
-		case tcell.KeyCtrlH:
-			fallthrough
-		case tcell.KeyLeft:
-			if sel.focus > 0 {
-				sel.focus--
-				sel.Invalidate()
-			}
-			if sel.onSelect != nil {
-				sel.onSelect(sel.Selected())
-			}
-		case tcell.KeyCtrlL:
-			fallthrough
-		case tcell.KeyRight:
-			if sel.focus < len(sel.options)-1 {
-				sel.focus++
-				sel.Invalidate()
-			}
-			if sel.onSelect != nil {
-				sel.onSelect(sel.Selected())
-			}
-		case tcell.KeyEnter:
-			if sel.onChoose != nil {
-				sel.onChoose(sel.Selected())
-			}
-		}
-	}
-	return false
-}
-
 func getSRV(host string, services []string) (string, string) {
 	var hostport, srv string
 	for _, srv = range services {
diff --git a/widgets/aerc.go b/widgets/aerc.go
index d324908b..9d955e11 100644
--- a/widgets/aerc.go
+++ b/widgets/aerc.go
@@ -240,7 +240,7 @@ func (aerc *Aerc) Event(event tcell.Event) bool {
 				exKey = aerc.conf.Bindings.Global.ExKey
 			}
 			if event.Key() == exKey.Key && event.Rune() == exKey.Rune {
-				aerc.BeginExCommand()
+				aerc.BeginExCommand("")
 				return true
 			}
 			interactive, ok := aerc.tabs.Tabs[aerc.tabs.Selected].Content.(ui.Interactive)
@@ -370,9 +370,9 @@ func (aerc *Aerc) focus(item ui.Interactive) {
 	}
 }
 
-func (aerc *Aerc) BeginExCommand() {
+func (aerc *Aerc) BeginExCommand(cmd string) {
 	previous := aerc.focused
-	exline := NewExLine(func(cmd string) {
+	exline := NewExLine(cmd, func(cmd string) {
 		parts, err := shlex.Split(cmd)
 		if err != nil {
 			aerc.PushStatus(" "+err.Error(), 10*time.Second).
diff --git a/widgets/exline.go b/widgets/exline.go
index 1482f0e0..f2c7249f 100644
--- a/widgets/exline.go
+++ b/widgets/exline.go
@@ -16,11 +16,11 @@ type ExLine struct {
 	input       *ui.TextInput
 }
 
-func NewExLine(commit func(cmd string), finish func(),
+func NewExLine(cmd string, commit func(cmd string), finish func(),
 	tabcomplete func(cmd string) []string,
 	cmdHistory lib.History) *ExLine {
 
-	input := ui.NewTextInput("").Prompt(":").TabComplete(tabcomplete)
+	input := ui.NewTextInput("").Prompt(":").TabComplete(tabcomplete).Set(cmd)
 	exline := &ExLine{
 		commit:      commit,
 		finish:      finish,
diff --git a/widgets/msgviewer.go b/widgets/msgviewer.go
index 4d41923d..aca7dd44 100644
--- a/widgets/msgviewer.go
+++ b/widgets/msgviewer.go
@@ -68,7 +68,7 @@ func NewMessageViewer(acct *AccountView, conf *config.AercConfig,
 	})
 
 	switcher := &PartSwitcher{}
-	err := createSwitcher(switcher, conf, store, msg)
+	err := createSwitcher(acct, switcher, conf, store, msg)
 	if err != nil {
 		return &MessageViewer{
 			err:  err,
@@ -112,7 +112,7 @@ func fmtHeader(msg *models.MessageInfo, header string) string {
 	}
 }
 
-func enumerateParts(conf *config.AercConfig, store *lib.MessageStore,
+func enumerateParts(acct *AccountView, conf *config.AercConfig, store *lib.MessageStore,
 	msg *models.MessageInfo, body *models.BodyStructure,
 	index []int) ([]*PartViewer, error) {
 
@@ -124,14 +124,14 @@ func enumerateParts(conf *config.AercConfig, store *lib.MessageStore,
 			pv := &PartViewer{part: part}
 			parts = append(parts, pv)
 			subParts, err := enumerateParts(
-				conf, store, msg, part, curindex)
+				acct, conf, store, msg, part, curindex)
 			if err != nil {
 				return nil, err
 			}
 			parts = append(parts, subParts...)
 			continue
 		}
-		pv, err := NewPartViewer(conf, store, msg, part, curindex)
+		pv, err := NewPartViewer(acct, conf, store, msg, part, curindex)
 		if err != nil {
 			return nil, err
 		}
@@ -140,7 +140,7 @@ func enumerateParts(conf *config.AercConfig, store *lib.MessageStore,
 	return parts, nil
 }
 
-func createSwitcher(switcher *PartSwitcher, conf *config.AercConfig,
+func createSwitcher(acct *AccountView, switcher *PartSwitcher, conf *config.AercConfig,
 	store *lib.MessageStore, msg *models.MessageInfo) error {
 
 	var err error
@@ -150,7 +150,7 @@ func createSwitcher(switcher *PartSwitcher, conf *config.AercConfig,
 
 	if len(msg.BodyStructure.Parts) == 0 {
 		switcher.selected = 0
-		pv, err := NewPartViewer(conf, store, msg, msg.BodyStructure, []int{1})
+		pv, err := NewPartViewer(acct, conf, store, msg, msg.BodyStructure, []int{1})
 		if err != nil {
 			return err
 		}
@@ -159,7 +159,7 @@ func createSwitcher(switcher *PartSwitcher, conf *config.AercConfig,
 			switcher.Invalidate()
 		})
 	} else {
-		switcher.parts, err = enumerateParts(conf, store,
+		switcher.parts, err = enumerateParts(acct, conf, store,
 			msg, msg.BodyStructure, []int{})
 		if err != nil {
 			return err
@@ -236,7 +236,7 @@ func (mv *MessageViewer) ToggleHeaders() {
 	switcher := mv.switcher
 	mv.conf.Viewer.ShowHeaders = !mv.conf.Viewer.ShowHeaders
 	err := createSwitcher(
-		switcher, mv.conf, mv.store, mv.msg)
+		mv.acct, switcher, mv.conf, mv.store, mv.msg)
 	if err != nil {
 		mv.acct.Logger().Printf(
 			"warning: error during create switcher - %v", err)
@@ -299,10 +299,7 @@ func (ps *PartSwitcher) Focus(focus bool) {
 }
 
 func (ps *PartSwitcher) Event(event tcell.Event) bool {
-	if ps.parts[ps.selected].term != nil {
-		return ps.parts[ps.selected].term.Event(event)
-	}
-	return false
+	return ps.parts[ps.selected].Event(event)
 }
 
 func (ps *PartSwitcher) Draw(ctx *ui.Context) {
@@ -414,9 +411,11 @@ type PartViewer struct {
 	source      io.Reader
 	store       *lib.MessageStore
 	term        *Terminal
+	selecter    *Selecter
+	grid        *ui.Grid
 }
 
-func NewPartViewer(conf *config.AercConfig,
+func NewPartViewer(acct *AccountView, conf *config.AercConfig,
 	store *lib.MessageStore, msg *models.MessageInfo,
 	part *models.BodyStructure,
 	index []int) (*PartViewer, error) {
@@ -475,6 +474,26 @@ func NewPartViewer(conf *config.AercConfig,
 		}
 	}
 
+	grid := ui.NewGrid().Rows([]ui.GridSpec{
+		{ui.SIZE_EXACT, 3}, // Message
+		{ui.SIZE_EXACT, 1}, // Selector
+		{ui.SIZE_WEIGHT, 1},
+	}).Columns([]ui.GridSpec{
+		{ui.SIZE_WEIGHT, 1},
+	})
+
+	selecter := NewSelecter([]string{"Save message", "Pipe to command"}, 0).
+		OnChoose(func(option string) {
+			switch option {
+			case "Save message":
+				acct.aerc.BeginExCommand("save ")
+			case "Pipe to command":
+				acct.aerc.BeginExCommand("pipe ")
+			}
+		})
+
+	grid.AddChild(selecter).At(2, 0)
+
 	pv := &PartViewer{
 		filter:      filter,
 		index:       index,
@@ -486,6 +505,8 @@ func NewPartViewer(conf *config.AercConfig,
 		sink:        pipe,
 		store:       store,
 		term:        term,
+		selecter:    selecter,
+		grid:        grid,
 	}
 
 	if term != nil {
@@ -590,6 +611,10 @@ func (pv *PartViewer) Draw(ctx *ui.Context) {
 		ctx.Fill(0, 0, ctx.Width(), ctx.Height(), ' ', tcell.StyleDefault)
 		ctx.Printf(0, 0, tcell.StyleDefault.Foreground(tcell.ColorRed),
 			"No filter configured for this mimetype")
+		ctx.Printf(0, 2, tcell.StyleDefault,
+			"You can still :save the message or :pipe it to an external command")
+		pv.selecter.Focus(true)
+		pv.grid.Draw(ctx)
 		return
 	}
 	if !pv.fetched {
@@ -611,6 +636,13 @@ func (pv *PartViewer) Cleanup() {
 	}
 }
 
+func (pv *PartViewer) Event(event tcell.Event) bool {
+	if pv.term != nil {
+		return pv.term.Event(event)
+	}
+	return pv.selecter.Event(event)
+}
+
 type HeaderView struct {
 	ui.Invalidatable
 	Name  string
diff --git a/widgets/selecter.go b/widgets/selecter.go
new file mode 100644
index 00000000..7fae9cda
--- /dev/null
+++ b/widgets/selecter.go
@@ -0,0 +1,103 @@
+package widgets
+
+import (
+	"github.com/gdamore/tcell"
+
+	"git.sr.ht/~sircmpwn/aerc/lib/ui"
+)
+
+type Selecter struct {
+	ui.Invalidatable
+	chooser bool
+	focused bool
+	focus   int
+	options []string
+
+	onChoose func(option string)
+	onSelect func(option string)
+}
+
+func NewSelecter(options []string, focus int) *Selecter {
+	return &Selecter{
+		focus:   focus,
+		options: options,
+	}
+}
+
+func (sel *Selecter) Chooser(chooser bool) *Selecter {
+	sel.chooser = chooser
+	return sel
+}
+
+func (sel *Selecter) Invalidate() {
+	sel.DoInvalidate(sel)
+}
+
+func (sel *Selecter) Draw(ctx *ui.Context) {
+	ctx.Fill(0, 0, ctx.Width(), ctx.Height(), ' ', tcell.StyleDefault)
+	x := 2
+	for i, option := range sel.options {
+		style := tcell.StyleDefault
+		if sel.focus == i {
+			if sel.focused {
+				style = style.Reverse(true)
+			} else if sel.chooser {
+				style = style.Bold(true)
+			}
+		}
+		x += ctx.Printf(x, 1, style, "[%s]", option)
+		x += 5
+	}
+}
+
+func (sel *Selecter) OnChoose(fn func(option string)) *Selecter {
+	sel.onChoose = fn
+	return sel
+}
+
+func (sel *Selecter) OnSelect(fn func(option string)) *Selecter {
+	sel.onSelect = fn
+	return sel
+}
+
+func (sel *Selecter) Selected() string {
+	return sel.options[sel.focus]
+}
+
+func (sel *Selecter) Focus(focus bool) {
+	sel.focused = focus
+	sel.Invalidate()
+}
+
+func (sel *Selecter) Event(event tcell.Event) bool {
+	switch event := event.(type) {
+	case *tcell.EventKey:
+		switch event.Key() {
+		case tcell.KeyCtrlH:
+			fallthrough
+		case tcell.KeyLeft:
+			if sel.focus > 0 {
+				sel.focus--
+				sel.Invalidate()
+			}
+			if sel.onSelect != nil {
+				sel.onSelect(sel.Selected())
+			}
+		case tcell.KeyCtrlL:
+			fallthrough
+		case tcell.KeyRight:
+			if sel.focus < len(sel.options)-1 {
+				sel.focus++
+				sel.Invalidate()
+			}
+			if sel.onSelect != nil {
+				sel.onSelect(sel.Selected())
+			}
+		case tcell.KeyEnter:
+			if sel.onChoose != nil {
+				sel.onChoose(sel.Selected())
+			}
+		}
+	}
+	return false
+}
diff --git a/widgets/tabhost.go b/widgets/tabhost.go
index 2c33cf8d..0ac67e5b 100644
--- a/widgets/tabhost.go
+++ b/widgets/tabhost.go
@@ -5,7 +5,7 @@ import (
 )
 
 type TabHost interface {
-	BeginExCommand()
+	BeginExCommand(cmd string)
 	SetStatus(status string) *StatusMessage
 	PushStatus(text string, expiry time.Duration) *StatusMessage
 	Beep()