add fontconfig_setting extension to read fontconfig from library instead of commands

Author: pgajdos

.gitignore

@@ -1,8 +1,7 @@
 /package/*.tar.bz2
-/src/ext/ft2_rendering/Makefile
-/src/ext/ft2_rendering/*.o
-/src/ext/ft2_rendering/*.so
-/src/ext/ft2_rendering/yast
+/src/ext/*/Makefile
+/src/ext/*/*.o
+/src/ext/*/*.so
 /src/lib/yast
 **/.*.swp
 

src/ext/fontconfig_setting/extconf.rb

@@ -0,0 +1,11 @@
+require 'mkmf'
+
+extension_name = 'fontconfig_setting'
+
+$LDFLAGS << ' ' + `pkg-config --libs fontconfig`
+# there is bug in fontconfig.pc (will fix soon ;)
+$CFLAGS << ' ' + ' -I/usr/include/fontconfig ' + `pkg-config --cflags fontconfig`
+
+dir_config(extension_name)
+create_makefile(extension_name)
+

src/ext/fontconfig_setting/fontconfig-setting.c

@@ -0,0 +1,86 @@
+#include "ruby.h"
+#include <fontconfig.h>
+#include <string.h>
+#include <stdio.h>
+
+const char *blacklist_families[] = {
+      "micro.pcf",
+      "deccurs.pcf",
+      "decsess.pcf",
+      "cursor.pcf",
+    };
+
+#define NBLACK (sizeof(blacklist_families)/sizeof(blacklist_families[0]))
+
+VALUE FontconfigSetting = Qnil;
+
+void Init_fontconfig_setting();
+VALUE method_fc_installed_families(VALUE self, VALUE array_elements);
+VALUE method_fc_is_family_installed(VALUE self, VALUE str_family);
+
+void Init_fontconfig_setting() {
+  FontconfigSetting = rb_define_module("FontconfigSetting");
+  rb_define_method(FontconfigSetting, "fc_installed_families", 
+                   method_fc_installed_families, 1);
+  rb_define_method(FontconfigSetting, "fc_is_family_installed", 
+                   method_fc_is_family_installed, 1);
+}
+
+VALUE method_fc_installed_families(VALUE self, VALUE array_elements) {
+  VALUE str_family_list = rb_ary_new();
+
+  FcObjectSet *objectset;
+  FcFontSet *fontset;
+  FcPattern *empty;
+
+  char *str_pattern;
+  int i, j;
+  VALUE el;
+
+  FcInit();
+  objectset = FcObjectSetCreate();
+  while ((el = rb_ary_shift(array_elements)) != Qnil)
+  {
+    FcObjectSetAdd(objectset, StringValueCStr(el));
+  }
+  empty = FcPatternCreate();
+  fontset = FcFontList (NULL, empty, objectset);
+  FcObjectSetDestroy (objectset);
+  FcPatternDestroy(empty);
+
+  for (i = 0; i < fontset->nfont; i++) 
+  {    
+    str_pattern = (char *)FcPatternFormat(fontset->fonts[i], (const FcChar8 *)"%{=fclist}");
+    for (j = 0; j < NBLACK; j++)
+      if (strcmp(blacklist_families[j], str_pattern) == 0)
+        break;
+    if (j < NBLACK)
+      continue;
+    rb_ary_push(str_family_list, rb_str_new2(str_pattern));
+  }
+
+  return str_family_list;
+}
+
+VALUE method_fc_is_family_installed(VALUE self, VALUE str_family) {
+  FcObjectSet *objectset;
+  FcPattern *pattern;
+  FcFontSet *fontset;
+
+  char *family;
+
+  family = StringValueCStr(str_family);
+
+  FcInit();
+  objectset = FcObjectSetBuild(FC_FAMILY, NULL);
+  pattern = FcNameParse((FcChar8 *)family);
+  fontset = FcFontList (NULL, pattern, objectset);
+  FcPatternDestroy (pattern);
+  FcObjectSetDestroy (objectset);
+
+  if (fontset->nfont > 0)
+    return Qtrue;
+  else
+    return Qfalse;
+}
+

test/fontconfig_setting_spec.rb

@@ -0,0 +1,59 @@
+require_relative "spec-helper"
+require "yast/fontconfig_setting"
+
+describe FontconfigSetting do
+  include FontconfigSetting
+
+  def are_installed(families)
+    families.each do |family|
+      if (!fc_is_family_installed(family))
+        return false
+      end
+    end
+    return true
+  end
+
+  def an_installed_family
+    return fc_installed_families(["family"])[0]    
+  end
+
+  def contain_pattern_entries(families, entries)
+    entries.delete("family")
+    families.each do |family|
+      entries.each do |entry|
+        if (!family.include?(entry + "="))
+          return false
+        end
+      end
+    end
+    return true
+  end
+
+  describe "#fc_is_family_installed" do
+    it "returns false when family is not installed" do
+      family = fc_is_family_installed("foo")
+      expect(family).to be false
+    end
+
+    it "returns true when family is installed" do
+      expect(fc_is_family_installed(an_installed_family()))
+    end    
+  end
+
+  describe "#fc_installed_families" do
+    it "returns non empty list of installed families" do
+      families = fc_installed_families(["family"])
+      expect(families).to be_a(Array)
+      expect(families.length).to be > 0
+      expect(are_installed(families)).to be true
+    end
+
+    it "understands important fontconfig pattern entries" do
+      entries = ["family", "fontformat"]
+      families = fc_installed_families(entries)
+      expect(contain_pattern_entries(families, entries)).to be true
+    end
+  end
+end
+
+