complete: allow disabling automatic completion

Allow setting complete-min-chars = 0 to disable automatic completion.
By default, the available completion choices can be displayed with <tab>
or <c-o> when in the composer. These keys may be configured using the
special $complete entry in binds.conf.

Signed-off-by: Robin Jarry <robin@jarry.cc>

7 files changed, 52 insertions, 29 deletions

diff --git a/app/compose.go b/app/compose.go
index 101a5765..60e17cf4 100644
--- a/app/compose.go
+++ b/app/compose.go
@@ -239,6 +239,7 @@ func (c *Composer) buildComposeHeader(cmpl *completer.Completer) {
 					cmpl.ForHeader(h),
 					uiConfig.CompletionDelay,
 					uiConfig.CompletionMinChars,
+					&config.Binds.Compose.CompleteKey,
 				)
 			}
 			c.editors[h] = e
@@ -271,6 +272,7 @@ func (c *Composer) buildComposeHeader(cmpl *completer.Completer) {
 						cmpl.ForHeader(h),
 						uiConfig.CompletionDelay,
 						uiConfig.CompletionMinChars,
+						&config.Binds.Compose.CompleteKey,
 					)
 				}
 				c.editors[h] = e
@@ -1414,6 +1416,7 @@ func (c *Composer) addEditor(header string, value string, appendHeader bool) str
 				c.completer.ForHeader(header),
 				uiConfig.CompletionDelay,
 				uiConfig.CompletionMinChars,
+				&config.Binds.Compose.CompleteKey,
 			)
 		}
 		c.editors[header] = e
diff --git a/app/exline.go b/app/exline.go
index b941b100..61fc340a 100644
--- a/app/exline.go
+++ b/app/exline.go
@@ -26,6 +26,7 @@ func NewExLine(cmd string, commit func(cmd string), finish func(),
 			tabcomplete,
 			config.Ui.CompletionDelay,
 			config.Ui.CompletionMinChars,
+			&config.Binds.Global.CompleteKey,
 		)
 	}
 	exline := &ExLine{
@@ -43,6 +44,7 @@ func (x *ExLine) TabComplete(tabComplete func(string) ([]string, string)) {
 		tabComplete,
 		config.Ui.CompletionDelay,
 		config.Ui.CompletionMinChars,
+		&config.Binds.Global.CompleteKey,
 	)
 }
 
@@ -55,6 +57,7 @@ func NewPrompt(prompt string, commit func(text string),
 			tabcomplete,
 			config.Ui.CompletionDelay,
 			config.Ui.CompletionMinChars,
+			&config.Binds.Global.CompleteKey,
 		)
 	}
 	exline := &ExLine{
diff --git a/config/binds.conf b/config/binds.conf
index c0e28af9..147f0559 100644
--- a/config/binds.conf
+++ b/config/binds.conf
@@ -114,6 +114,7 @@ $ex = <C-x>
 # view
 $noinherit = true
 $ex = <C-x>
+$complete = <C-o>
 <C-k> = :prev-field<Enter>
 <C-Up> = :prev-field<Enter>
 <C-j> = :next-field<Enter>
diff --git a/config/binds.go b/config/binds.go
index 1b2799f2..bc77e655 100644
--- a/config/binds.go
+++ b/config/binds.go
@@ -57,6 +57,8 @@ type KeyBindings struct {
 	Globals bool
 	// Which key opens the ex line (default is :)
 	ExKey KeyStroke
+	// Which key triggers completion (default is <tab>)
+	CompleteKey KeyStroke
 
 	// private
 	contextualBinds  []*BindingConfigContext
@@ -154,7 +156,8 @@ func parseBinds(root string) error {
 func LoadBindingSection(sec *ini.Section) (*KeyBindings, error) {
 	bindings := NewKeyBindings()
 	for key, value := range sec.KeysHash() {
-		if key == "$ex" {
+		switch key {
+		case "$ex":
 			strokes, err := ParseKeyStrokes(value)
 			if err != nil {
 				return nil, err
@@ -163,9 +166,7 @@ func LoadBindingSection(sec *ini.Section) (*KeyBindings, error) {
 				return nil, errors.New("Invalid binding")
 			}
 			bindings.ExKey = strokes[0]
-			continue
-		}
-		if key == "$noinherit" {
+		case "$noinherit":
 			if value == "false" {
 				continue
 			}
@@ -173,13 +174,22 @@ func LoadBindingSection(sec *ini.Section) (*KeyBindings, error) {
 				return nil, errors.New("Invalid binding")
 			}
 			bindings.Globals = false
-			continue
-		}
-		binding, err := ParseBinding(key, value)
-		if err != nil {
-			return nil, err
+		case "$complete":
+			strokes, err := ParseKeyStrokes(value)
+			if err != nil {
+				return nil, err
+			}
+			if len(strokes) != 1 {
+				return nil, errors.New("Invalid binding")
+			}
+			bindings.CompleteKey = strokes[0]
+		default:
+			binding, err := ParseBinding(key, value)
+			if err != nil {
+				return nil, err
+			}
+			bindings.Add(binding)
 		}
-		bindings.Add(binding)
 	}
 	return bindings, nil
 }
@@ -266,6 +276,7 @@ func LoadBinds(binds *ini.File, baseName string, baseGroup **KeyBindings) error
 func NewKeyBindings() *KeyBindings {
 	return &KeyBindings{
 		ExKey:            KeyStroke{tcell.ModNone, tcell.KeyRune, ':'},
+		CompleteKey:      KeyStroke{tcell.ModNone, tcell.KeyTab, 0},
 		Globals:          true,
 		contextualCache:  make(map[bindsContextKey]*KeyBindings),
 		contextualCounts: make(map[bindsContextType]int),
@@ -281,6 +292,7 @@ func MergeBindings(bindings ...*KeyBindings) *KeyBindings {
 		}
 	}
 	merged.ExKey = bindings[0].ExKey
+	merged.CompleteKey = bindings[0].CompleteKey
 	merged.Globals = bindings[0].Globals
 	return merged
 }
diff --git a/doc/aerc-binds.5.scd b/doc/aerc-binds.5.scd
index 8ce59cf0..a989cd05 100644
--- a/doc/aerc-binds.5.scd
+++ b/doc/aerc-binds.5.scd
@@ -103,6 +103,12 @@ available in each binding context:
 
 	Default: _:_
 
+*$complete* = _<key-stroke>_
+	This can be set to a keystroke which will trigger command completion in
+	this context for text inputs that support it.
+
+	Default: _<tab>_
+
 # SUPPORTED KEYS
 
 In addition to letters and some characters (e.g. *a*, *RR*, *gu*, *?*, *!*,
diff --git a/doc/aerc-config.5.scd b/doc/aerc-config.5.scd
index a45e2443..36514c1f 100644
--- a/doc/aerc-config.5.scd
+++ b/doc/aerc-config.5.scd
@@ -283,6 +283,10 @@ These options are configured in the *[ui]* section of _aerc.conf_.
 	The minimum required characters to allow auto-completion to be triggered
 	after *completion-delay*.
 
+	Setting this to _0_ disables automatic completion, leaving only the
+	manually triggered completion with the *$complete* key (see
+	*aerc-binds*(5) for more details).
+
 	Default: _1_
 
 *border-char-vertical* = _"<char>"_++
diff --git a/lib/ui/textinput.go b/lib/ui/textinput.go
index dd946aec..ab448d59 100644
--- a/lib/ui/textinput.go
+++ b/lib/ui/textinput.go
@@ -35,6 +35,7 @@ type TextInput struct {
 	completeDelay     time.Duration
 	completeDebouncer *time.Timer
 	completeMinChars  int
+	completeKey       *config.KeyStroke
 	uiConfig          *config.UIConfig
 }
 
@@ -62,12 +63,12 @@ func (ti *TextInput) Prompt(prompt string) *TextInput {
 
 func (ti *TextInput) TabComplete(
 	tabcomplete func(s string) ([]string, string),
-	d time.Duration,
-	minChars int,
+	d time.Duration, minChars int, key *config.KeyStroke,
 ) *TextInput {
 	ti.tabcomplete = tabcomplete
 	ti.completeDelay = d
 	ti.completeMinChars = minChars
+	ti.completeKey = key
 	return ti
 }
 
@@ -303,7 +304,7 @@ func (ti *TextInput) onFocusLost() {
 }
 
 func (ti *TextInput) updateCompletions() {
-	if ti.tabcomplete == nil {
+	if ti.tabcomplete == nil || ti.completeMinChars == 0 {
 		// no completer
 		return
 	}
@@ -344,55 +345,48 @@ func (ti *TextInput) Event(event tcell.Event) bool {
 	ti.Lock()
 	defer ti.Unlock()
 	if event, ok := event.(*tcell.EventKey); ok {
+		c := ti.completeKey
+		if c != nil && c.Key == event.Key() && c.Modifiers == event.Modifiers() {
+			ti.showCompletions()
+			return true
+		}
+
+		ti.invalidateCompletions()
+
 		switch event.Key() {
 		case tcell.KeyBackspace, tcell.KeyBackspace2:
-			ti.invalidateCompletions()
 			ti.backspace()
 		case tcell.KeyCtrlD, tcell.KeyDelete:
-			ti.invalidateCompletions()
 			ti.deleteChar()
 		case tcell.KeyCtrlB, tcell.KeyLeft:
-			ti.invalidateCompletions()
 			if ti.index > 0 {
 				ti.index--
 				ti.ensureScroll()
 				ti.Invalidate()
 			}
 		case tcell.KeyCtrlF, tcell.KeyRight:
-			ti.invalidateCompletions()
 			if ti.index < len(ti.text) {
 				ti.index++
 				ti.ensureScroll()
 				ti.Invalidate()
 			}
 		case tcell.KeyCtrlA, tcell.KeyHome:
-			ti.invalidateCompletions()
 			ti.index = 0
 			ti.ensureScroll()
 			ti.Invalidate()
 		case tcell.KeyCtrlE, tcell.KeyEnd:
-			ti.invalidateCompletions()
 			ti.index = len(ti.text)
 			ti.ensureScroll()
 			ti.Invalidate()
 		case tcell.KeyCtrlK:
-			ti.invalidateCompletions()
 			ti.deleteLineForward()
 		case tcell.KeyCtrlW:
-			ti.invalidateCompletions()
 			ti.deleteWord()
 		case tcell.KeyCtrlU:
-			ti.invalidateCompletions()
 			ti.deleteLineBackward()
 		case tcell.KeyESC:
-			if ti.completions != nil {
-				ti.invalidateCompletions()
-				ti.Invalidate()
-			}
-		case tcell.KeyTab:
-			ti.showCompletions()
+			ti.Invalidate()
 		case tcell.KeyRune:
-			ti.invalidateCompletions()
 			ti.insert(event.Rune())
 		}
 	}