Bug 651981. Return a JSVal from GfxInfo. r=bjacob,jorendorff

widget/public/nsIGfxInfo.idl

@@ -148,5 +148,8 @@ interface nsIGfxInfo : nsISupports
 
   // only useful on X11
   [noscript, notxpcom] void GetData();
+
+  [implicit_jscontext]
+  jsval getInfo();
 };
 

widget/src/xpwidgets/GfxInfoBase.cpp

@@ -863,3 +863,63 @@ NS_IMETHODIMP GfxInfoBase::GetFailures(PRUint32 *failureCount NS_OUTPARAM, char
 
   return NS_OK;
 }
+
+nsTArray<GfxInfoCollectorBase*> *sCollectors;
+
+static void
+InitCollectors()
+{
+  if (!sCollectors)
+    sCollectors = new nsTArray<GfxInfoCollectorBase*>;
+}
+
+nsresult GfxInfoBase::GetInfo(JSContext* aCx, jsval* aResult)
+{
+  InitCollectors();
+  InfoObject obj(aCx);
+
+  for (PRUint32 i = 0; i < sCollectors->Length(); i++) {
+    (*sCollectors)[i]->GetInfo(obj);
+  }
+
+  // Some example property definitions
+  // obj.DefineProperty("wordCacheSize", gfxTextRunWordCache::Count());
+  // obj.DefineProperty("renderer", mRendererIDsString);
+  // obj.DefineProperty("five", 5);
+
+  if (!obj.mOk) {
+    return NS_ERROR_FAILURE;
+  }
+
+  *aResult = OBJECT_TO_JSVAL(obj.mObj);
+  return NS_OK;
+}
+
+void
+GfxInfoBase::AddCollector(GfxInfoCollectorBase* collector)
+{
+  InitCollectors();
+  sCollectors->AppendElement(collector);
+}
+
+void
+GfxInfoBase::RemoveCollector(GfxInfoCollectorBase* collector)
+{
+  InitCollectors();
+  for (PRUint32 i = 0; i < sCollectors->Length(); i++) {
+    if ((*sCollectors)[i] == collector) {
+      sCollectors->RemoveElementAt(i);
+      break;
+    }
+  }
+}
+
+GfxInfoCollectorBase::GfxInfoCollectorBase()
+{
+  GfxInfoBase::AddCollector(this);
+}
+
+GfxInfoCollectorBase::~GfxInfoCollectorBase()
+{
+  GfxInfoBase::RemoveCollector(this);
+}

widget/src/xpwidgets/GfxInfoBase.h

@@ -47,6 +47,7 @@
 #include "GfxDriverInfo.h"
 #include "nsTArray.h"
 #include "nsString.h"
+#include "GfxInfoCollector.h"
 
 namespace mozilla {
 namespace widget {  
@@ -75,6 +76,7 @@ public:
 
   NS_SCRIPTABLE NS_IMETHOD GetFailures(PRUint32 *failureCount NS_OUTPARAM, char ***failures NS_OUTPARAM);
   NS_IMETHOD_(void) LogFailure(const nsACString &failure);
+  NS_SCRIPTABLE NS_IMETHOD GetInfo(JSContext*, jsval*);
 
   // Initialization function. If you override this, you must call this class's
   // version of Init first.
@@ -92,6 +94,10 @@ public:
   // only useful on X11
   NS_IMETHOD_(void) GetData() { }
 
+  static void AddCollector(GfxInfoCollectorBase* collector);
+  static void RemoveCollector(GfxInfoCollectorBase* collector);
+
+
 protected:
 
   virtual nsresult GetFeatureStatusImpl(PRInt32 aFeature, PRInt32* aStatus,

widget/src/xpwidgets/GfxInfoCollector.h

@@ -0,0 +1,149 @@
+/* vim: se cin sw=2 ts=2 et : */
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is mozilla.org code.
+ *
+ * The Initial Developer of the Original Code is
+ * Mozilla Foundation.
+ * Portions created by the Initial Developer are Copyright (C) 2011
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+#ifndef __mozilla_widget_GfxInfoCollector_h__
+#define __mozilla_widget_GfxInfoCollector_h__
+
+#include "jsapi.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 InfoObject
+{
+  friend class GfxInfoBase;
+
+  public:
+  void DefineProperty(const char *name, int value)
+  {
+    if (!mOk)
+      return;
+
+    mOk = JS_DefineProperty(mCx, mObj, name, INT_TO_JSVAL(value), NULL, NULL, JSPROP_ENUMERATE);
+  }
+
+  void DefineProperty(const char *name, nsAString &value)
+  {
+    if (!mOk)
+      return;
+
+    const nsPromiseFlatString &flat = PromiseFlatString(value);
+    JSString *string = JS_NewUCStringCopyN(mCx, static_cast<const jschar*>(flat.get()), flat.Length());
+    if (!string)
+      mOk = JS_FALSE;
+
+    if (!mOk)
+      return;
+
+    mOk = JS_DefineProperty(mCx, mObj, name, STRING_TO_JSVAL(string), NULL, NULL, JSPROP_ENUMERATE);
+  }
+
+  private:
+  // We need to ensure that this object lives on the stack so that GC sees it properly
+  InfoObject(JSContext *aCx) : mCx(aCx), mOk(JS_TRUE)
+  {
+    mObj = JS_NewObject(mCx, NULL, NULL, NULL);
+    if (!mObj)
+      mOk = JS_FALSE;
+  }
+  InfoObject(InfoObject&);
+
+  JSContext *mCx;
+  JSObject *mObj;
+  JSBool 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) {
+    (mPointer->*mFunc)(obj);
+  }
+
+  protected:
+  T* mPointer;
+  void (T::*mFunc)(InfoObject &obj);
+
+};
+
+}
+}
+
+#endif

widget/src/xpwidgets/Makefile.in

@@ -46,6 +46,9 @@ MODULE		= widget
 LIBRARY_NAME	= xpwidgets_s
 LIBXUL_LIBRARY  = 1
 
+EXPORTS = \
+		GfxInfoCollector.h \
+		$(NULL)
 
 DEFINES += \
   -D_IMPL_NS_WIDGET \