config: Strongly type context type

The go compiler can't help much with untyped int constants.
Even though the only valid constants are 0-3 it will happily accept 4 as input.

Let's let the go compiler worry about correctness here. This also allows people
not very familiar with the code to use it properly via auto completion.

3 files changed, 10 insertions, 7 deletions

diff --git a/config/config.go b/config/config.go
index 0b46014..0393e46 100644
--- a/config/config.go
+++ b/config/config.go
@@ -46,14 +46,16 @@ type UIConfig struct {
 	CompletionPopovers  bool          `ini:"completion-popovers"`
 }
 
+type ContextType int
+
 const (
-	UI_CONTEXT_FOLDER = iota
+	UI_CONTEXT_FOLDER ContextType = iota
 	UI_CONTEXT_ACCOUNT
 	UI_CONTEXT_SUBJECT
 )
 
 type UIConfigContext struct {
-	ContextType int
+	ContextType ContextType
 	Regex       *regexp.Regexp
 	UiConfig    UIConfig
 }
@@ -602,7 +604,8 @@ func parseLayout(layout string) [][]string {
 	return l
 }
 
-func (config *AercConfig) mergeContextualUi(baseUi *UIConfig, contextType int, s string) {
+func (config *AercConfig) mergeContextualUi(baseUi *UIConfig,
+	contextType ContextType, s string) {
 	for _, contextualUi := range config.ContextualUis {
 		if contextualUi.ContextType != contextType {
 			continue
@@ -617,7 +620,7 @@ func (config *AercConfig) mergeContextualUi(baseUi *UIConfig, contextType int, s
 	}
 }
 
-func (config *AercConfig) GetUiConfig(params map[int]string) UIConfig {
+func (config *AercConfig) GetUiConfig(params map[ContextType]string) UIConfig {
 	baseUi := config.Ui
 
 	for k, v := range params {
diff --git a/widgets/account.go b/widgets/account.go
index 66320a3..455c28e 100644
--- a/widgets/account.go
+++ b/widgets/account.go
@@ -32,7 +32,7 @@ type AccountView struct {
 }
 
 func (acct *AccountView) UiConfig() config.UIConfig {
-	return acct.conf.GetUiConfig(map[int]string{
+	return acct.conf.GetUiConfig(map[config.ContextType]string{
 		config.UI_CONTEXT_ACCOUNT: acct.AccountConfig().Name,
 		config.UI_CONTEXT_FOLDER:  acct.Directories().Selected(),
 	})
@@ -41,7 +41,7 @@ func (acct *AccountView) UiConfig() config.UIConfig {
 func NewAccountView(aerc *Aerc, conf *config.AercConfig, acct *config.AccountConfig,
 	logger *log.Logger, host TabHost) *AccountView {
 
-	acctUiConf := conf.GetUiConfig(map[int]string{
+	acctUiConf := conf.GetUiConfig(map[config.ContextType]string{
 		config.UI_CONTEXT_ACCOUNT: acct.Name,
 	})
 
diff --git a/widgets/msglist.go b/widgets/msglist.go
index 24a9940..9aff0d4 100644
--- a/widgets/msglist.go
+++ b/widgets/msglist.go
@@ -106,7 +106,7 @@ func (ml *MessageList) Draw(ctx *ui.Context) {
 		}
 
 		ctx.Fill(0, row, ctx.Width(), 1, ' ', style)
-		uiConfig := ml.conf.GetUiConfig(map[int]string{
+		uiConfig := ml.conf.GetUiConfig(map[config.ContextType]string{
 			config.UI_CONTEXT_ACCOUNT: ml.aerc.SelectedAccount().AccountConfig().Name,
 			config.UI_CONTEXT_FOLDER:  ml.aerc.SelectedAccount().Directories().Selected(),
 			config.UI_CONTEXT_SUBJECT: msg.Envelope.Subject,