Bug 694851: enhance fz_load_system_font

For SumatraPDF, the following changes are required:
* fz_load_system_font is called from pdf_load_builtin_font as well so
  that Arial, Courier New, etc. can be loaded from the system instead
  of their Nimbus replacements. In order to distinguish between calls
  from pdf_load_builtin_font and pdf_load_substitute_font, an
  is_substitute argument is added.
* fz_load_system_cjk_font is added and called from
  pdf_load_substitute_cjk_font so that a better replacement font can
  be loaded instead of DroidSansFallback.
* Both fz_load_system_font and fz_load_system_cjk_font return fz_font*
  instead of fz_buffer* so that implementers aren't required to load
  fonts into memory (SumatraPDF uses fz_new_font_from_file for system
  fonts).

In addition to that, fz_load_system_font_func is renamed to
fz_load_system_font_funcs since it now accepts two functions, and the
PDF_ROS_* constants are renamed to FZ_ADOBE_* (collection names aren't
passed as const char* so that implementers know which collections to
expect). For convenience, fz_load_*_font also never throws since
currently all callers have further fallbacks available.

1 files changed, 37 insertions, 4 deletions

diff --git a/source/fitz/font.c b/source/fitz/font.c
index b1ba1b02..6027164c 100644
--- a/source/fitz/font.c
+++ b/source/fitz/font.c
@@ -188,6 +188,7 @@ struct fz_font_context_s {
 	FT_Library ftlib;
 	int ftlib_refs;
 	fz_load_system_font_func load_font;
+	fz_load_system_cjk_font_func load_cjk_font;
 };
 
 #undef __FTERRORS_H__
@@ -233,16 +234,48 @@ void fz_drop_font_context(fz_context *ctx)
 		fz_free(ctx, ctx->font);
 }
 
-void fz_install_load_system_font_func(fz_context *ctx, fz_load_system_font_func f)
+void fz_install_load_system_font_funcs(fz_context *ctx, fz_load_system_font_func f, fz_load_system_cjk_font_func f_cjk)
 {
 	ctx->font->load_font = f;
+	ctx->font->load_cjk_font = f_cjk;
 }
 
-fz_buffer *fz_load_system_font(fz_context *ctx, const char *name)
+fz_font *fz_load_system_font(fz_context *ctx, const char *name, int is_substitute)
 {
+	fz_font *font = NULL;
+
 	if (ctx->font->load_font)
-		return ctx->font->load_font(ctx, name);
-	return NULL;
+	{
+		fz_try(ctx)
+		{
+			font = ctx->font->load_font(ctx, name, is_substitute);
+		}
+		fz_catch(ctx)
+		{
+			font = NULL;
+		}
+	}
+
+	return font;
+}
+
+fz_font *fz_load_system_cjk_font(fz_context *ctx, const char *name, int ros, int serif)
+{
+	fz_font *font = NULL;
+
+	if (ctx->font->load_cjk_font)
+	{
+		fz_try(ctx)
+		{
+			font = ctx->font->load_cjk_font(ctx, name, ros, serif);
+		}
+		fz_catch(ctx)
+		{
+			font = NULL;
+		}
+	}
+
+	return font;
 }
 
 static const struct ft_error ft_errors[] =