templates: allow inline user styles

Allow custom user-defined styles in a styleset. The styles can take any
name, and must be under the [user] ini section. All attributes apply to
user defined styles.

Example:

	[user]
	red.fg=red
	red.bold=true

Add a .Style function which accepts the name of a user-defined style and
applies it to the string.

	{{.Style "red" "foo"}}

Signed-off-by: Tim Culverhouse <tim@timculverhouse.com>
Acked-by: Robin Jarry <robin@jarry.cc>

3 files changed, 37 insertions, 0 deletions

diff --git a/config/style.go b/config/style.go
index 65c5a3b1..317c77d0 100644
--- a/config/style.go
+++ b/config/style.go
@@ -254,6 +254,7 @@ func (s Style) composeWith(styles []*Style) Style {
 type StyleSet struct {
 	objects  map[StyleObject]*Style
 	selected map[StyleObject]*Style
+	user     map[string]*Style
 	path     string
 }
 
@@ -261,6 +262,7 @@ func NewStyleSet() StyleSet {
 	ss := StyleSet{
 		objects:  make(map[StyleObject]*Style),
 		selected: make(map[StyleObject]*Style),
+		user:     make(map[string]*Style),
 	}
 	for _, so := range StyleNames {
 		ss.objects[so] = new(Style)
@@ -285,6 +287,10 @@ func (ss StyleSet) Selected(so StyleObject) tcell.Style {
 	return ss.selected[so].Get()
 }
 
+func (ss StyleSet) UserStyle(name string) tcell.Style {
+	return ss.user[name].Get()
+}
+
 func (ss StyleSet) Compose(so StyleObject, sos []StyleObject) tcell.Style {
 	base := *ss.objects[so]
 	styles := make([]*Style, len(sos))
@@ -437,6 +443,32 @@ func (ss *StyleSet) ParseStyleSet(file *ini.File) error {
 		}
 	}
 
+	user, err := file.GetSection("user")
+	if err != nil {
+		// This errors if the section doesn't exist, which is ok
+		return nil
+	}
+	for _, key := range user.KeyStrings() {
+		tokens := strings.Split(key, ".")
+		var styleName, attr string
+		switch len(tokens) {
+		case 2:
+			styleName, attr = tokens[0], tokens[1]
+		default:
+			return errors.New("Style parsing error: " + key)
+		}
+		val := user.KeysHash()[key]
+		s, ok := ss.user[styleName]
+		if !ok {
+			// Haven't seen this name before, add it to the map
+			s = &Style{}
+			ss.user[styleName] = s
+		}
+		if err := s.Set(attr, val); err != nil {
+			return err
+		}
+	}
+
 	return nil
 }
 
diff --git a/config/templates.go b/config/templates.go
index bc05be66..f618d365 100644
--- a/config/templates.go
+++ b/config/templates.go
@@ -111,3 +111,4 @@ func (d *dummyData) ContentInfo() string             { return "" }
 func (d *dummyData) StatusInfo() string              { return "" }
 func (d *dummyData) TrayInfo() string                { return "" }
 func (d *dummyData) PendingKeys() string             { return "" }
+func (d *dummyData) Style(string, string) string     { return "" }
diff --git a/config/ui.go b/config/ui.go
index b1330ffd..64469643 100644
--- a/config/ui.go
+++ b/config/ui.go
@@ -629,6 +629,10 @@ func (base *UIConfig) mergeContextual(
 	return base
 }
 
+func (uiConfig *UIConfig) GetUserStyle(name string) tcell.Style {
+	return uiConfig.style.UserStyle(name)
+}
+
 func (uiConfig *UIConfig) GetStyle(so StyleObject) tcell.Style {
 	return uiConfig.style.Get(so)
 }