gio: add core GResource implementation

gio/gresource.go

@@ -0,0 +1,102 @@
+// package resource wraps operations over GResource
+package gio
+
+// #cgo pkg-config: gio-2.0 glib-2.0 gobject-2.0
+// #include <gio/gio.h>
+// #include <stdlib.h>
+// #include "gresource.go.h"
+import "C"
+import (
+	"errors"
+	"unsafe"
+)
+
+// ResourceLookupFlags is a representation of GTK's GResourceLookupFlags
+type ResourceLookupFlags int
+
+func (f ResourceLookupFlags) native() C.GResourceLookupFlags {
+	return (C.GResourceLookupFlags)(f)
+}
+
+const (
+	G_RESOURCE_LOOKUP_FLAGS_NONE ResourceLookupFlags = C.G_RESOURCE_LOOKUP_FLAGS_NONE
+)
+
+// GResource wraps native GResource object
+//
+// See: https://developer.gnome.org/gio/stable/GResource.html
+type GResource *C.GResource
+
+// LoadGResource is a wrapper around g_resource_load()
+//
+// See: https://developer.gnome.org/gio/stable/GResource.html#g-resource-load
+func LoadGResource(path string) (GResource, error) {
+	cpath := C.CString(path)
+	defer C.free(unsafe.Pointer(cpath))
+	var gerr *C.GError
+
+	resPtr := C.g_resource_load((*C.gchar)(unsafe.Pointer(cpath)), &gerr)
+	if gerr != nil {
+		defer C.g_error_free(gerr)
+		return nil, errors.New(goString(gerr.message))
+	}
+
+	res := wrapGResource(resPtr)
+	return res, nil
+}
+
+// NewGResourceFromData is a wrapper around g_resource_new_from_data()
+//
+// See: https://developer.gnome.org/gio/stable/GResource.html#g-resource-new-from-data
+func NewGResourceFromData(data []byte) (GResource, error) {
+	arrayPtr := (*C.GBytes)(unsafe.Pointer(&data[0]))
+	var gerr *C.GError
+	resPtr := C.g_resource_new_from_data(arrayPtr, &gerr)
+	if gerr != nil {
+		defer C.g_error_free(gerr)
+		return nil, errors.New(goString(gerr.message))
+	}
+
+	res := wrapGResource(resPtr)
+	return res, nil
+}
+
+// Register wraps g_resources_register()
+//
+// See: https://developer.gnome.org/gio/stable/GResource.html#g-resources-register
+func RegisterGResource(res GResource) {
+	C.g_resources_register(res)
+}
+
+// Unregister wraps g_resources_unregister()
+//
+// See: https://developer.gnome.org/gio/stable/GResource.html#g-resources-unregister
+func UnregisterGResource(res GResource) {
+	C.g_resources_unregister(res)
+}
+
+// GResourceEnumerateChildren wraps g_resources_enumerate_children()
+//
+// See: https://developer.gnome.org/gio/stable/GResource.html#g-resources-enumerate-children
+func GResourceEnumerateChildren(path string, flags ResourceLookupFlags) ([]string, error) {
+	cpath := C.CString(path)
+	defer C.free(unsafe.Pointer(cpath))
+	var gerr *C.GError
+	arrChildren := C.g_resources_enumerate_children(cpath, flags.native(), &gerr)
+	if gerr != nil {
+		defer C.g_error_free(gerr)
+		return nil, errors.New(goString(gerr.message))
+	}
+
+	if arrChildren == nil {
+		return nil, errors.New("unexpected nil pointer from g_resources_enumerate_children")
+	}
+
+	arr := toGoStringArray(arrChildren)
+	return arr, nil
+}
+
+func wrapGResource(resPtr *C.GResource) GResource {
+	res := GResource(resPtr)
+	return res
+}

gio/gresource.go.h

@@ -0,0 +1,13 @@
+#pragma once
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <glib.h>
+
+static inline char** next_charptr(char** s) { return (s+1); }
+
+static inline void char_g_strfreev(char** s) {
+    g_strfreev((gchar**) s);
+}

gio/utils.go

@@ -0,0 +1,23 @@
+package gio
+
+// #include <glib.h>
+// #include "gresource.go.h"
+import "C"
+
+// same implementation as package glib
+func toGoStringArray(c **C.char) []string {
+	var strs []string
+	originalc := c
+	defer C.char_g_strfreev(originalc)
+
+	for *c != nil {
+		strs = append(strs, C.GoString((*C.char)(*c)))
+		c = C.next_charptr(c)
+	}
+
+	return strs
+}
+
+func goString(cstr *C.gchar) string {
+	return C.GoString((*C.char)(cstr))
+}