1 files changed, 39 insertions, 0 deletions
diff --git a/tui/builder.go b/tui/builder.go
new file mode 100644
index 0000000..e969cec
--- /dev/null
+++ b/tui/builder.go
@@ -0,0 +1,39 @@
+package tui
+
+import (
+	"github.com/rivo/uniseg"
+)
+
+type builder struct {
+	runs []textRun
+	width int
+}
+
+func (b *builder) add(s string, style *Style) {
+	b.width += uniseg.StringWidth(s)
+	if len(b.runs) == 0 || style != b.runs[len(b.runs) - 1].style {
+		b.runs = append(b.runs, textRun {s, style, false})
+	} else {
+		run := b.runs[len(b.runs) - 1]
+		run.text += s
+		b.runs[len(b.runs) - 1] = run
+	}
+}
+
+func (b *builder) addRun(run textRun) {
+	b.width += uniseg.StringWidth(run.text)
+	b.runs = append(b.runs, run)
+}
+
+func (b *builder) addRuns(runs []textRun) {
+	for _, run := range runs {
+		b.addRun(run)
+	}
+}
+
+func (b *builder) flush() []textRun {
+	runs := b.runs
+	b.width = 0
+	b.runs = nil
+	return runs
+}