widget/GfxInfoCollector.h
author Brindusan Cristian <cbrindusan@mozilla.com>
Tue, 05 Mar 2019 22:42:15 +0200
changeset 520316 be4b780a7783cdf7d3ead37c98917dc0d2e94a1d
parent 505383 6f3709b3878117466168c40affa7bca0b60cf75b
child 530873 e1993a1f09ac53cd1a04fdf6a87f8cad8e44f73e
permissions -rw-r--r--
Backed out 5 changesets (bug 1508976, bug 1522581) for android geckoview bustages at /usr/bin/python2.7. CLOSED TREE Backed out changeset 7a6be593b0be (bug 1522581) Backed out changeset c47b37ac1775 (bug 1522581) Backed out changeset 91c31d2a7706 (bug 1508976) Backed out changeset da57df805c56 (bug 1508976) Backed out changeset 4e5d97c93515 (bug 1508976)

/* vim: se cin sw=2 ts=2 et : */
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef __mozilla_widget_GfxInfoCollector_h__
#define __mozilla_widget_GfxInfoCollector_h__

#include "mozilla/Attributes.h"
#include "nsStringFwd.h"
#include "js/RootingAPI.h"

namespace mozilla {
namespace widget {

/* this is handy wrapper around JSAPI to make it more pleasant to use.
 * We collect the JSAPI errors and so that callers don't need to */
class MOZ_STACK_CLASS InfoObject {
  friend class GfxInfoBase;

 public:
  void DefineProperty(const char *name, int value);
  void DefineProperty(const char *name, nsAString &value);
  void DefineProperty(const char *name, const char *value);

 private:
  // We need to ensure that this object lives on the stack so that GC sees it
  // properly
  explicit InfoObject(JSContext *aCx);
  InfoObject(InfoObject &);

  JSContext *mCx;
  JS::Rooted<JSObject *> mObj;
  bool mOk;
};

/*

   Here's an example usage:

   class Foo {
   Foo::Foo() : mInfoCollector(this, &Foo::GetAweseomeness) {}

   void GetAwesomeness(InfoObject &obj) {
     obj.DefineProperty("awesome", mAwesome);
   }

   int mAwesome;

   GfxInfoCollector<Foo> mInfoCollector;
   }

   This will define a property on the object
   returned from calling getInfo() on a
   GfxInfo object. e.g.

       gfxInfo = Cc["@mozilla.org/gfx/info;1"].getService(Ci.nsIGfxInfo);
       info = gfxInfo.getInfo();
       if (info.awesome)
          alert(info.awesome);

*/

class GfxInfoCollectorBase {
 public:
  GfxInfoCollectorBase();
  virtual void GetInfo(InfoObject &obj) = 0;
  virtual ~GfxInfoCollectorBase();
};

template <class T>
class GfxInfoCollector : public GfxInfoCollectorBase {
 public:
  GfxInfoCollector(T *aPointer, void (T::*aFunc)(InfoObject &obj))
      : mPointer(aPointer), mFunc(aFunc) {}
  virtual void GetInfo(InfoObject &obj) override { (mPointer->*mFunc)(obj); }

 protected:
  T *mPointer;
  void (T::*mFunc)(InfoObject &obj);
};

}  // namespace widget
}  // namespace mozilla

#endif