From 938179d29360dc155cc882fd07a05198fef41bac Mon Sep 17 00:00:00 2001
From: Chris Waldon <christopher.waldon.dev@gmail.com>
Date: Wed, 16 Mar 2022 16:01:35 -0400
Subject: [PATCH] font/gofont: add font collection using the new shaper

This commit adds a font collection that uses the new
text shaper so that constructing material.Themes atop
it is equally simple to using the old shaper.

You can use material.NewTheme(gofont.CollectionHB()) with
this commit applied.

References: https://todo.sr.ht/~eliasnaur/gio/146
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
---
 font/gofont/gofont.go | 36 ++++++++++++++++++++++++++++++++++--
 1 file changed, 34 insertions(+), 2 deletions(-)

diff --git a/font/gofont/gofont.go b/font/gofont/gofont.go
index a06efeb8..7c7555d0 100644
--- a/font/gofont/gofont.go
+++ b/font/gofont/gofont.go
@@ -29,8 +29,10 @@ import (
 )
 
 var (
-	once       sync.Once
-	collection []text.FontFace
+	once         sync.Once
+	collection   []text.FontFace
+	onceHB       sync.Once
+	collectionHB []text.FontFace
 )
 
 func Collection() []text.FontFace {
@@ -54,6 +56,36 @@ func Collection() []text.FontFace {
 	return collection
 }
 
+func CollectionHB() []text.FontFace {
+	onceHB.Do(func() {
+		registerHB(text.Font{}, goregular.TTF)
+		registerHB(text.Font{Style: text.Italic}, goitalic.TTF)
+		registerHB(text.Font{Weight: text.Bold}, gobold.TTF)
+		registerHB(text.Font{Style: text.Italic, Weight: text.Bold}, gobolditalic.TTF)
+		registerHB(text.Font{Weight: text.Medium}, gomedium.TTF)
+		registerHB(text.Font{Weight: text.Medium, Style: text.Italic}, gomediumitalic.TTF)
+		registerHB(text.Font{Variant: "Mono"}, gomono.TTF)
+		registerHB(text.Font{Variant: "Mono", Weight: text.Bold}, gomonobold.TTF)
+		registerHB(text.Font{Variant: "Mono", Weight: text.Bold, Style: text.Italic}, gomonobolditalic.TTF)
+		registerHB(text.Font{Variant: "Mono", Style: text.Italic}, gomonoitalic.TTF)
+		registerHB(text.Font{Variant: "Smallcaps"}, gosmallcaps.TTF)
+		registerHB(text.Font{Variant: "Smallcaps", Style: text.Italic}, gosmallcapsitalic.TTF)
+		// Ensure that any outside appends will not reuse the backing store.
+		n := len(collectionHB)
+		collectionHB = collectionHB[:n:n]
+	})
+	return collectionHB
+}
+
+func registerHB(fnt text.Font, ttf []byte) {
+	face, err := opentype.ParseHarfbuzz(ttf)
+	if err != nil {
+		panic(fmt.Errorf("failed to parse font: %v", err))
+	}
+	fnt.Typeface = "Go"
+	collectionHB = append(collectionHB, text.FontFace{Font: fnt, Face: face})
+}
+
 func register(fnt text.Font, ttf []byte) {
 	face, err := opentype.Parse(ttf)
 	if err != nil {