LibGfx: Start adding a class for handling ICC color profiles

For now, this checks the magic number and reads file version and
device class.

Userland/Libraries/LibGfx/ICCProfile.h

@@ -0,0 +1,70 @@
+/*
+ * Copyright (c) 2022, Nico Weber <thakis@chromium.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/Error.h>
+#include <AK/Format.h>
+#include <AK/NonnullRefPtr.h>
+#include <AK/RefCounted.h>
+#include <AK/Span.h>
+
+namespace Gfx::ICC {
+
+// ICC v4, 7.2.4 Profile version field
+class Version {
+public:
+    Version() = default;
+    Version(u8 major, u8 minor_and_bugfix)
+        : m_major_version(major)
+        , m_minor_and_bugfix_version(minor_and_bugfix)
+    {
+    }
+
+    u8 major_version() const { return m_major_version; }
+    u8 minor_version() const { return m_minor_and_bugfix_version >> 4; }
+    u8 bugfix_version() const { return m_minor_and_bugfix_version & 0xf; }
+
+private:
+    u8 m_major_version = 0;
+    u8 m_minor_and_bugfix_version = 0;
+};
+
+// ICC v4, 7.2.5 Profile/device class field
+enum class DeviceClass : u32 {
+    InputDevce = 0x73636E72,    // 'scnr'
+    DisplayDevice = 0x6D6E7472, // 'mntr'
+    OutputDevice = 0x70727472,  // 'prtr'
+    DeviceLink = 0x6C696E6B,    // 'link'
+    ColorSpace = 0x73706163,    // 'spac'
+    Abstract = 0x61627374,      // 'abst'
+    NamedColor = 0x6E6D636C,    // 'nmcl'
+};
+char const* device_class_name(DeviceClass);
+
+class Profile : public RefCounted<Profile> {
+public:
+    static ErrorOr<NonnullRefPtr<Profile>> try_load_from_externally_owned_memory(ReadonlyBytes bytes);
+
+    Version version() const { return m_version; }
+    DeviceClass device_class() const { return m_device_class; }
+
+private:
+    Version m_version;
+    DeviceClass m_device_class;
+};
+
+}
+
+namespace AK {
+template<>
+struct Formatter<Gfx::ICC::Version> : Formatter<FormatString> {
+    ErrorOr<void> format(FormatBuilder& builder, Gfx::ICC::Version const& version)
+    {
+        return Formatter<FormatString>::format(builder, "{}.{}.{}"sv, version.major_version(), version.minor_version(), version.bugfix_version());
+    }
+};
+}