TerminalFont: Improves Ghostty font config parsing with fallback font detection

Fixes #1967

Author: CarterLi

src/detection/terminalfont/terminalfont.c

@@ -3,6 +3,7 @@
 #include "common/properties.h"
 #include "common/processing.h"
 #include "detection/terminalshell/terminalshell.h"
+#include "util/debug.h"
 
 static void detectAlacritty(FFTerminalFontResult* terminalFont)
 {
@@ -48,29 +49,82 @@ static void detectAlacritty(FFTerminalFontResult* terminalFont)
     ffFontInitValues(&terminalFont->font, fontName.chars, fontSize.chars);
 }
 
+static bool parseGhosttyConfig(FFstrbuf* path, FFstrbuf* fontName, FFstrbuf* fontNameFallback, FFstrbuf* fontSize)
+{
+    FF_DEBUG("parsing config: %s", path->chars);
+    FF_STRBUF_AUTO_DESTROY buffer = ffStrbufCreate();
+    if (!ffAppendFileBuffer(path->chars, &buffer)) {
+        FF_DEBUG("cannot read config: %s", path->chars);
+        return false;
+    }
+
+    char* line = NULL;
+    size_t len = 0;
+    while (ffStrbufGetline(&line, &len, &buffer))
+    {
+        if (!fontName->length)
+        {
+            if (ffParsePropLine(line, "font-family =", fontName)) {
+                FF_DEBUG("found font-family='%s' in %s", fontName->chars, path->chars);
+                continue;
+            }
+        }
+        else if (!fontNameFallback->length)
+        {
+            if (ffParsePropLine(line, "font-family =", fontNameFallback)) {
+                FF_DEBUG("found fallback font-family='%s' in %s", fontNameFallback->chars, path->chars);
+                continue;
+            }
+        }
+        if (!fontSize->length)
+        {
+            if (ffParsePropLine(line, "font-size =", fontSize)) {
+                FF_DEBUG("found font-size='%s' in %s", fontSize->chars, path->chars);
+                continue;
+            }
+        }
+    }
+    return true;
+}
+
 static void detectGhostty(FFTerminalFontResult* terminalFont)
 {
+    FF_DEBUG("detectGhostty: start");
+    FF_STRBUF_AUTO_DESTROY configPath = ffStrbufCreate();
     FF_STRBUF_AUTO_DESTROY fontName = ffStrbufCreate();
+    FF_STRBUF_AUTO_DESTROY fontNameFallback = ffStrbufCreate();
     FF_STRBUF_AUTO_DESTROY fontSize = ffStrbufCreate();
 
-    FFpropquery fontQueryToml[] = {
-        {"font-family =", &fontName},
-        {"font-size =", &fontSize},
-    };
-
     #if __APPLE__
-    ffParsePropFileConfigValues("com.mitchellh.ghostty/config", 2, fontQueryToml);
+    ffStrbufSet(&configPath, &instance.state.platform.homeDir);
+    ffStrbufAppendS(&configPath, "Library/Application Support/com.mitchellh.ghostty/config");
+    parseGhosttyConfig(&configPath, &fontName, &fontNameFallback, &fontSize);
     #endif
 
-    ffParsePropFileConfigValues("ghostty/config", 2, fontQueryToml);
+    if (instance.state.platform.configDirs.length > 0)
+    {
+        ffStrbufSet(&configPath, FF_LIST_GET(FFstrbuf, instance.state.platform.configDirs, 0));
+        ffStrbufAppendS(&configPath, "ghostty/config");
+        parseGhosttyConfig(&configPath, &fontName, &fontNameFallback, &fontSize);
+    }
 
-    if(fontName.length == 0)
+    if(fontName.length == 0) {
         ffStrbufAppendS(&fontName, "JetBrainsMono Nerd Font");
+        FF_DEBUG("using default family='%s'", fontName.chars);
+    }
 
-    if(fontSize.length == 0)
+    if(fontSize.length == 0) {
         ffStrbufAppendS(&fontSize, "13");
+        FF_DEBUG("using default size='%s'", fontSize.chars);
+    }
 
     ffFontInitValues(&terminalFont->font, fontName.chars, fontSize.chars);
+    if(fontNameFallback.length > 0) {
+        FF_DEBUG("applying fallback family='%s'", fontNameFallback.chars);
+        ffFontInitValues(&terminalFont->fallback, fontNameFallback.chars, NULL);
+    }
+    FF_DEBUG("result family='%s' size='%s'%s", fontName.chars, fontSize.chars, fontNameFallback.length ? " (with fallback)" : "");
+    FF_DEBUG("detectGhostty: end");
 }
 
 FF_MAYBE_UNUSED static void detectTTY(FFTerminalFontResult* terminalFont)