Add Pepper TrueType font API call to enumerate fonts in a given family.

ppapi/proxy/truetype_font_singleton_resource.cc

Index: ppapi/proxy/truetype_font_singleton_resource.cc
diff --git a/ppapi/proxy/truetype_font_singleton_resource.cc b/ppapi/proxy/truetype_font_singleton_resource.cc
index b812bf1647fc1186a2dfcc8bc6d2899965630ed4..5b5f7138e1007477750748d3e5f15ead698705c4 100644
--- a/ppapi/proxy/truetype_font_singleton_resource.cc
+++ b/ppapi/proxy/truetype_font_singleton_resource.cc
@@ -39,6 +39,23 @@ int32_t TrueTypeFontSingletonResource::GetFontFamilies(
   return PP_OK_COMPLETIONPENDING;
 }
 
+int32_t TrueTypeFontSingletonResource::GetFontsInFamily(
+      PP_Instance instance,
+      PP_Var family,
+      const PP_ArrayOutput& output,
+      const scoped_refptr<TrackedCallback>& callback) {
+  scoped_refptr<StringVar> family_var = StringVar::FromPPVar(family);
+  const uint32_t kMaxFamilySizeInBytes = 1024;
+  if (!family_var || family_var->value().size() > kMaxFamilySizeInBytes)
+    return PP_ERROR_BADARGUMENT;
+  Call<PpapiPluginMsg_TrueTypeFontSingleton_GetFontsInFamilyReply>(BROWSER,
+      PpapiHostMsg_TrueTypeFontSingleton_GetFontsInFamily(family_var->value()),
+      base::Bind(
+          &TrueTypeFontSingletonResource::OnPluginMsgGetFontsInFamilyComplete,
+          this, callback, output));
+  return PP_OK_COMPLETIONPENDING;
+}
+
 void TrueTypeFontSingletonResource::OnPluginMsgGetFontFamiliesComplete(
     scoped_refptr<TrackedCallback> callback,
     PP_ArrayOutput array_output,
@@ -64,5 +81,31 @@ void TrueTypeFontSingletonResource::OnPluginMsgGetFontFamiliesComplete(
   callback->Run(result);
 }
 
+void TrueTypeFontSingletonResource::OnPluginMsgGetFontsInFamilyComplete(
+    scoped_refptr<TrackedCallback> callback,
+    PP_ArrayOutput array_output,
+    const ResourceMessageReplyParams& params,
+    const std::vector<SerializedTrueTypeFontDesc>& fonts) {
+  // The result code should contain the data size if it's positive.

[dmichael (off chromium), 2013/04/12 23:34:18]

It's possible that you can get here in a situation where the callback has
already been aborted. I.e., the plugin requested the Fonts in the family but
then the resource got released. In that case, the callback will own the only
ref-count for this resource and for the TrackedCallback.

Maybe in this situation it would be better to not do the output allocation and
stuff? I think it gets leaked, since the callback won't be run a second time.

[bbudge, 2013/04/13 00:44:44]

Is that possible on a singleton resource?
On 2013/04/12 23:34:18, dmichael wrote:

[dmichael (off chromium), 2013/04/15 18:11:44]

Oh, forgot about that. Yes, I think that would still happen on instance
shutdown.

I'm thinking you can avoid it by just checking if the callback is pending:
if (!TrackedCallback::IsPending(callback)) {
  // (Clean up Vars)
  return;
}

[bbudge, 2013/04/17 23:49:19]

I added the check at the beginning of this method and the one above too.
On 2013/04/15 18:11:44, dmichael wrote:

+  int32_t result = params.result();
+  DCHECK((result < 0 && fonts.size() == 0) ||
+         result == static_cast<int32_t>(fonts.size()));
+  ArrayWriter output;
+  output.set_pp_array_output(array_output);
+  if (output.is_valid()) {
+    // Convvert the message data to an array of PP_TrueTypeFontDesc_Dev structs.

[dmichael (off chromium), 2013/04/12 23:34:18]

nit: Convvert->Convert

[bbudge, 2013/04/13 00:44:44]

Done.

+    // The embedded family PP_Var is null so we don't worry about refs.

[dmichael (off chromium), 2013/04/12 23:34:18]

The family is NULL? That seems like it might be confusing (even though it seems
like apps won't often use it in this case)

[bbudge, 2013/04/13 00:44:44]

I initially thought I could sidestep problems with the embedded PP_Var, but I
think it's likely plugins will want to use these descriptors to create fonts, so
I now set the name. Do I need to do anything special here? There's no
StoreVectorOfStructWithEmbeddedVar call.

On 2013/04/12 23:34:18, dmichael wrote:

+    std::vector<PP_TrueTypeFontDesc_Dev> pp_fonts(fonts.size());
+    for (size_t i = 0; i < fonts.size(); i++)
+      fonts[i].CopyToPPTrueTypeFontDesc(&pp_fonts[i]);
+
+    output.StoreVector(pp_fonts);
+  } else {
+    result = PP_ERROR_FAILED;
+  }
+
+  callback->Run(result);
+}
+
 }  // namespace proxy
 }  // namespace ppapi