src/content/browser/renderer_host/pepper/pepper_browser_font_singleton_host.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "content/browser/renderer_host/pepper/pepper_browser_font_singleton_host.h"
   6
   7 #include "base/threading/sequenced_worker_pool.h"
   8 #include "base/values.h"
   9 #include "content/common/font_list.h"
  10 #include "content/public/browser/browser_ppapi_host.h"
  11 #include "content/public/browser/browser_thread.h"
  12 #include "ppapi/host/dispatch_host_message.h"
  13 #include "ppapi/host/resource_message_filter.h"
  14 #include "ppapi/proxy/ppapi_messages.h"
  15
  16 namespace content {
  17
  18 namespace {
  19
  20 // Handles the font list request on the blocking pool.
  21 class FontMessageFilter : public ppapi::host::ResourceMessageFilter {
  22  public:
  23   FontMessageFilter();
  24
  25   // ppapi::host::ResourceMessageFilter implementation.
  26   virtual scoped_refptr<base::TaskRunner> OverrideTaskRunnerForMessage(
  27       const IPC::Message& msg) OVERRIDE;
  28   virtual int32_t OnResourceMessageReceived(
  29       const IPC::Message& msg,
  30       ppapi::host::HostMessageContext* context) OVERRIDE;
  31
  32  private:
  33   virtual ~FontMessageFilter();
  34
  35   // Message handler.
  36   int32_t OnHostMsgGetFontFamilies(ppapi::host::HostMessageContext* context);
  37
  38   DISALLOW_COPY_AND_ASSIGN(FontMessageFilter);
  39 };
  40
  41 FontMessageFilter::FontMessageFilter() {}
  42
  43 FontMessageFilter::~FontMessageFilter() {}
  44
  45 scoped_refptr<base::TaskRunner> FontMessageFilter::OverrideTaskRunnerForMessage(
  46     const IPC::Message& msg) {
  47   // Use the blocking pool to get the font list (currently the only message)
  48   // Since getting the font list is non-threadsafe on Linux (for versions of
  49   // Pango predating 2013), use a sequenced task runner.
  50   base::SequencedWorkerPool* pool = BrowserThread::GetBlockingPool();
  51   return pool->GetSequencedTaskRunner(
  52       pool->GetNamedSequenceToken(kFontListSequenceToken));
  53 }
  54
  55 int32_t FontMessageFilter::OnResourceMessageReceived(
  56     const IPC::Message& msg,
  57     ppapi::host::HostMessageContext* context) {
  58   IPC_BEGIN_MESSAGE_MAP(FontMessageFilter, msg)
  59   PPAPI_DISPATCH_HOST_RESOURCE_CALL_0(
  60       PpapiHostMsg_BrowserFontSingleton_GetFontFamilies,
  61       OnHostMsgGetFontFamilies)
  62   IPC_END_MESSAGE_MAP()
  63   return PP_ERROR_FAILED;
  64 }
  65
  66 int32_t FontMessageFilter::OnHostMsgGetFontFamilies(
  67     ppapi::host::HostMessageContext* context) {
  68   // OK to use "slow blocking" version since we're on the blocking pool.
  69   scoped_ptr<base::ListValue> list(GetFontList_SlowBlocking());
  70
  71   std::string output;
  72   for (size_t i = 0; i < list->GetSize(); i++) {
  73     base::ListValue* cur_font;
  74     if (!list->GetList(i, &cur_font))
  75       continue;
  76
  77     // Each entry is actually a list of (font name, localized name).
  78     // We only care about the regular name.
  79     std::string font_name;
  80     if (!cur_font->GetString(0, &font_name))
  81       continue;
  82
  83     // Font names are separated with nulls. We also want an explicit null at
  84     // the end of the string (Pepper strings aren't null terminated so since
  85     // we specify there will be a null, it should actually be in the string).
  86     output.append(font_name);
  87     output.push_back(0);
  88   }
  89
  90   context->reply_msg =
  91       PpapiPluginMsg_BrowserFontSingleton_GetFontFamiliesReply(output);
  92   return PP_OK;
  93 }
  94
  95 }  // namespace
  96
  97 PepperBrowserFontSingletonHost::PepperBrowserFontSingletonHost(
  98     BrowserPpapiHost* host,
  99     PP_Instance instance,
 100     PP_Resource resource)
 101     : ResourceHost(host->GetPpapiHost(), instance, resource) {
 102   AddFilter(scoped_refptr<ppapi::host::ResourceMessageFilter>(
 103       new FontMessageFilter()));
 104 }
 105
 106 PepperBrowserFontSingletonHost::~PepperBrowserFontSingletonHost() {}
 107
 108 }  // namespace content