michael@0: /* vim: se cin sw=2 ts=2 et : */
michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
michael@0:  *
michael@0:  * This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #ifndef __mozilla_widget_GfxInfoCollector_h__
michael@0: #define __mozilla_widget_GfxInfoCollector_h__
michael@0: 
michael@0: #include "mozilla/Attributes.h"
michael@0: #include "nsStringFwd.h"
michael@0: #include "js/RootingAPI.h"
michael@0: 
michael@0: namespace mozilla {
michael@0: namespace widget {
michael@0: 
michael@0: 
michael@0: /* this is handy wrapper around JSAPI to make it more pleasant to use.
michael@0:  * We collect the JSAPI errors and so that callers don't need to */
michael@0: class MOZ_STACK_CLASS InfoObject
michael@0: {
michael@0:   friend class GfxInfoBase;
michael@0: 
michael@0:   public:
michael@0:   void DefineProperty(const char *name, int value);
michael@0:   void DefineProperty(const char *name, nsAString &value);
michael@0:   void DefineProperty(const char *name, const char *value);
michael@0: 
michael@0:   private:
michael@0:   // We need to ensure that this object lives on the stack so that GC sees it properly
michael@0:   InfoObject(JSContext *aCx);
michael@0:   InfoObject(InfoObject&);
michael@0: 
michael@0:   JSContext *mCx;
michael@0:   JS::Rooted<JSObject*> mObj;
michael@0:   bool mOk;
michael@0: };
michael@0: 
michael@0: /*
michael@0: 
michael@0:    Here's an example usage:
michael@0: 
michael@0:    class Foo {
michael@0:    Foo::Foo() : mInfoCollector(this, &Foo::GetAweseomeness) {}
michael@0: 
michael@0:    void GetAwesomeness(InfoObject &obj) {
michael@0:      obj.DefineProperty("awesome", mAwesome);
michael@0:    }
michael@0: 
michael@0:    int mAwesome;
michael@0: 
michael@0:    GfxInfoCollector<Foo> mInfoCollector;
michael@0:    }
michael@0: 
michael@0:    This will define a property on the object
michael@0:    returned from calling getInfo() on a
michael@0:    GfxInfo object. e.g.
michael@0: 
michael@0:        gfxInfo = Cc["@mozilla.org/gfx/info;1"].getService(Ci.nsIGfxInfo);
michael@0:        info = gfxInfo.getInfo();
michael@0:        if (info.awesome)
michael@0:           alert(info.awesome);
michael@0: 
michael@0: */
michael@0: 
michael@0: class GfxInfoCollectorBase
michael@0: {
michael@0:   public:
michael@0:   GfxInfoCollectorBase();
michael@0:   virtual void GetInfo(InfoObject &obj) = 0;
michael@0:   virtual ~GfxInfoCollectorBase();
michael@0: };
michael@0: 
michael@0: template<class T>
michael@0: class GfxInfoCollector : public GfxInfoCollectorBase
michael@0: {
michael@0:   public:
michael@0:   GfxInfoCollector(T* aPointer, void (T::*aFunc)(InfoObject &obj)) : mPointer(aPointer), mFunc(aFunc) {
michael@0:   }
michael@0:   virtual void GetInfo(InfoObject &obj) {
michael@0:     (mPointer->*mFunc)(obj);
michael@0:   }
michael@0: 
michael@0:   protected:
michael@0:   T* mPointer;
michael@0:   void (T::*mFunc)(InfoObject &obj);
michael@0: 
michael@0: };
michael@0: 
michael@0: }
michael@0: }
michael@0: 
michael@0: #endif