From de9813233f4d1d5565a0403017cc09ad781ae75e Mon Sep 17 00:00:00 2001
From: Larpon <Larpon@users.noreply.github.com>
Date: Sat, 6 Feb 2021 17:36:43 +0100
Subject: [PATCH] gg: support getting system font on Android (#8611)

---
 vlib/gg/text_rendering.v | 42 +++++++++++++++++++++++++++++++++++-----
 1 file changed, 37 insertions(+), 5 deletions(-)

diff --git a/vlib/gg/text_rendering.v b/vlib/gg/text_rendering.v
index 2e51611196..8ee5122807 100644
--- a/vlib/gg/text_rendering.v
+++ b/vlib/gg/text_rendering.v
@@ -82,17 +82,24 @@ fn new_ft(c FTConfig) ?&FT {
 			// Load default font
 		}
 	}
-	$if !android {
-		if c.font_path == '' || !os.exists(c.font_path) {
+
+	if c.font_path == '' || !os.exists(c.font_path) {
+		$if !android {
 			println('failed to load font "$c.font_path"')
 			return none
 		}
 	}
+
 	mut bytes := []byte{}
 	$if android {
-		bytes = os.read_apk_asset(c.font_path) or {
-			println('failed to load font "$c.font_path"')
-			return none
+		// First try any filesystem paths
+		bytes = os.read_bytes(c.font_path) or { []byte{} }
+		if bytes.len == 0 {
+			// ... then try the APK asset path
+			bytes = os.read_apk_asset(c.font_path) or {
+				println('failed to load font "$c.font_path"')
+				return none
+			}
 		}
 	} $else {
 		bytes = os.read_bytes(c.font_path) or {
@@ -258,6 +265,31 @@ pub fn system_font_path() string {
 			}
 		}
 	}
+	$if android {
+		xml_files := ['/system/etc/system_fonts.xml', '/system/etc/fonts.xml', '/etc/system_fonts.xml',
+			'/etc/fonts.xml', '/data/fonts/fonts.xml', '/etc/fallback_fonts.xml']
+		font_locations := ['/system/fonts', '/data/fonts']
+		for xml_file in xml_files {
+			if os.is_file(xml_file) && os.is_readable(xml_file) {
+				xml := os.read_file(xml_file) or { continue }
+				lines := xml.split('\n')
+				mut candidate_font := ''
+				for line in lines {
+					if line.contains('<font') {
+						candidate_font = line.all_after('>').all_before('<').trim(' \n\t\r')
+						if candidate_font.contains('.ttf') {
+							for location in font_locations {
+								candidate_path := os.join_path(location, candidate_font)
+								if os.is_file(candidate_path) && os.is_readable(candidate_path) {
+									return candidate_path
+								}
+							}
+						}
+					}
+				}
+			}
+		}
+	}
 	s := os.exec('fc-list') or { panic('failed to fetch system fonts') }
 	system_fonts := s.output.split('\n')
 	for line in system_fonts {