Use the WebKit default fonts when specifying generic font families.

This pipes through a new preferences object that the font system can use.
It now picks up these faces as well as the default font size.

Clarify this behavior in the interface.

TEST=manual (font example included).
BUG=none
Review URL: http://codereview.chromium.org/7053022

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@86870 0039d316-1c4b-4281-b951-d872f2087c98

12 files changed, 192 insertions, 12 deletions

diff --git a/ppapi/c/dev/ppb_font_dev.h b/ppapi/c/dev/ppb_font_dev.h
index 48b990c..fd2652e 100644
--- a/ppapi/c/dev/ppb_font_dev.h
+++ b/ppapi/c/dev/ppb_font_dev.h
@@ -56,18 +56,31 @@ PP_COMPILE_ASSERT_SIZE_IN_BYTES(PP_FontWeight_Dev, 4);
 struct PP_FontDescription_Dev {
   /**
    * Font face name as a string. This can also be an undefined var, in which
-   * case the generic family will be obeyed.
+   * case the generic family will be obeyed. If the face is not available on
+   * the system, the browser will attempt to do font fallback or pick a default
+   * font.
    */
   struct PP_Var face;
 
   /**
-   * When face is an undefined var, this specifies the generic font family type
-   * to use. If the face is specified, this will be ignored.
+   * When Create()ing a font and the face is an undefined var, the family
+   * specifies the generic font family type to use. If the face is specified,
+   * this will be ignored.
+   *
+   * When Describe()ing a font, the family will be the value you passed in when
+   * the font was created. In other words, if you specify a face name, the
+   * family will not be updated to reflect whether the font name you requested
+   * is serif or sans serif.
    */
   PP_FontFamily_Dev family;
 
   /**
    * Size in pixels.
+   *
+   * You can specify 0 to get the default font size. The default font size
+   * may vary depending on the requested font. The typical example is that
+   * the user may have a different font size for the default monospace font to
+   * give it a similar optical size to the proportionally spaced fonts.
    */
   uint32_t size;
 
diff --git a/ppapi/examples/font/simple_font.cc b/ppapi/examples/font/simple_font.cc
index c1bfdef..a5f8914 100644
--- a/ppapi/examples/font/simple_font.cc
+++ b/ppapi/examples/font/simple_font.cc
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include <stdio.h>
+
 #include "ppapi/cpp/completion_callback.h"
 #include "ppapi/cpp/dev/font_dev.h"
 #include "ppapi/cpp/graphics_2d.h"
@@ -31,22 +33,71 @@ class MyInstance : public pp::Instance {
 
     pp::FontDescription_Dev desc;
     desc.set_family(PP_FONTFAMILY_SANSSERIF);
-    desc.set_size(30);
+    desc.set_size(100);
     pp::Font_Dev font(this, desc);
 
+    // Draw some large, alpha blended text, including Arabic shaping.
     pp::Rect text_clip(position.size());  // Use entire bounds for clip.
     font.DrawTextAt(&image,
         pp::TextRun_Dev("\xD9\x85\xD8\xB1\xD8\xAD\xD8\xA8\xD8\xA7\xE2\x80\x8E",
                          true, true),
-        pp::Point(10, 40), 0xFF008000, clip, false);
-    font.DrawTextAt(&image, pp::TextRun_Dev("Hello"),
-        pp::Point(10, 80), 0xFF000080, text_clip, false);
+        pp::Point(20, 100), 0x80008000, clip, false);
+
+    // Draw the default font names and sizes.
+    int y = 160;
+    {
+      pp::FontDescription_Dev desc;
+      pp::Font_Dev default_font(this, desc);
+      default_font.DrawSimpleText(
+          &image, DescribeFont(default_font, "Default font"),
+          pp::Point(10, y), 0xFF000000);
+      y += 20;
+    }
+    {
+      pp::FontDescription_Dev desc;
+      desc.set_family(PP_FONTFAMILY_SERIF);
+      pp::Font_Dev serif_font(this, desc);
+      serif_font.DrawSimpleText(
+          &image, DescribeFont(serif_font, "Serif font"),
+          pp::Point(10, y), 0xFF000000);
+      y += 20;
+    }
+    {
+      pp::FontDescription_Dev desc;
+      desc.set_family(PP_FONTFAMILY_SANSSERIF);
+      pp::Font_Dev sans_serif_font(this, desc);
+      sans_serif_font.DrawSimpleText(
+          &image, DescribeFont(sans_serif_font, "Sans serif font"),
+          pp::Point(10, y), 0xFF000000);
+      y += 20;
+    }
+    {
+      pp::FontDescription_Dev desc;
+      desc.set_family(PP_FONTFAMILY_MONOSPACE);
+      pp::Font_Dev monospace_font(this, desc);
+      monospace_font.DrawSimpleText(
+          &image, DescribeFont(monospace_font, "Monospace font"),
+          pp::Point(10, y), 0xFF000000);
+      y += 20;
+    }
 
     device.PaintImageData(image, pp::Point(0, 0));
     device.Flush(pp::CompletionCallback(&DummyCompletionCallback, NULL));
   }
 
  private:
+  // Returns a string describing the given font, using the given title.
+  std::string DescribeFont(const pp::Font_Dev& font, const char* title) {
+    pp::FontDescription_Dev desc;
+    PP_FontMetrics_Dev metrics;
+    font.Describe(&desc, &metrics);
+
+    char buf[256];
+    sprintf(buf, "%s = %s %dpt",
+            title, desc.face().AsString().c_str(), desc.size());
+    return std::string(buf);
+  }
+
   pp::Size last_size_;
 };
 
diff --git a/ppapi/ppapi_shared.gypi b/ppapi/ppapi_shared.gypi
index 386159b..4568b56 100644
--- a/ppapi/ppapi_shared.gypi
+++ b/ppapi/ppapi_shared.gypi
@@ -35,6 +35,8 @@
         'shared_impl/font_impl.h',
         'shared_impl/image_data_impl.cc',
         'shared_impl/image_data_impl.h',
+        'shared_impl/ppapi_preferences.cc',
+        'shared_impl/ppapi_preferences.h',
         'shared_impl/tracker_base.cc',
         'shared_impl/tracker_base.h',
         'shared_impl/url_util_impl.cc',
diff --git a/ppapi/proxy/host_dispatcher.cc b/ppapi/proxy/host_dispatcher.cc
index 4658fdb..c00390b 100644
--- a/ppapi/proxy/host_dispatcher.cc
+++ b/ppapi/proxy/host_dispatcher.cc
@@ -92,9 +92,11 @@ HostDispatcher::~HostDispatcher() {
 bool HostDispatcher::InitHostWithChannel(
     Delegate* delegate,
     const IPC::ChannelHandle& channel_handle,
-    bool is_client) {
+    bool is_client,
+    const ppapi::Preferences& preferences) {
   if (!Dispatcher::InitWithChannel(delegate, channel_handle, is_client))
     return false;
+  Send(new PpapiMsg_SetPreferences(preferences));
   return true;
 }
 
diff --git a/ppapi/proxy/host_dispatcher.h b/ppapi/proxy/host_dispatcher.h
index 608223d..55ba56b 100644
--- a/ppapi/proxy/host_dispatcher.h
+++ b/ppapi/proxy/host_dispatcher.h
@@ -27,6 +27,10 @@ namespace IPC {
 class SyncChannel;
 }
 
+namespace ppapi {
+struct Preferences;
+}
+
 namespace pp {
 namespace proxy {
 
@@ -48,7 +52,8 @@ class HostDispatcher : public Dispatcher {
   // transferred.
   virtual bool InitHostWithChannel(Delegate* delegate,
                                    const IPC::ChannelHandle& channel_handle,
-                                   bool is_client);
+                                   bool is_client,
+                                   const ppapi::Preferences& preferences);
 
   // The host side maintains a mapping from PP_Instance to Dispatcher so
   // that we can send the messages to the right channel.
diff --git a/ppapi/proxy/plugin_dispatcher.cc b/ppapi/proxy/plugin_dispatcher.cc
index dee2610..4ce47c6 100644
--- a/ppapi/proxy/plugin_dispatcher.cc
+++ b/ppapi/proxy/plugin_dispatcher.cc
@@ -40,7 +40,8 @@ InstanceToDispatcherMap* g_instance_to_dispatcher = NULL;
 PluginDispatcher::PluginDispatcher(base::ProcessHandle remote_process_handle,
                                    GetInterfaceFunc get_interface)
     : Dispatcher(remote_process_handle, get_interface),
-      plugin_delegate_(NULL) {
+      plugin_delegate_(NULL),
+      received_preferences_(false) {
   SetSerializationRules(new PluginVarSerializationRules);
 
   // As a plugin, we always support the PPP_Class interface. There's no
@@ -122,6 +123,7 @@ bool PluginDispatcher::OnMessageReceived(const IPC::Message& msg) {
     bool handled = true;
     IPC_BEGIN_MESSAGE_MAP(PluginDispatcher, msg)
       IPC_MESSAGE_HANDLER(PpapiMsg_SupportsInterface, OnMsgSupportsInterface)
+      IPC_MESSAGE_HANDLER(PpapiMsg_SetPreferences, OnMsgSetPreferences)
     IPC_END_MESSAGE_MAP()
     return handled;
   }
@@ -274,6 +276,20 @@ void PluginDispatcher::OnMsgSupportsInterface(
   *result = true;
 }
 
+void PluginDispatcher::OnMsgSetPreferences(const ::ppapi::Preferences& prefs) {
+  // The renderer may send us preferences more than once (currently this
+  // happens every time a new plugin instance is created). Since we don't have
+  // a way to signal to the plugin that the preferences have changed, changing
+  // the default fonts and such in the middle of a running plugin could be
+  // confusing to it. As a result, we never allow the preferences to be changed
+  // once they're set. The user will have to restart to get new font prefs
+  // propogated to plugins.
+  if (!received_preferences_) {
+    received_preferences_ = true;
+    preferences_ = prefs;
+  }
+}
+
 }  // namespace proxy
 }  // namespace pp
 
diff --git a/ppapi/proxy/plugin_dispatcher.h b/ppapi/proxy/plugin_dispatcher.h
index 29460fa..1964d94 100644
--- a/ppapi/proxy/plugin_dispatcher.h
+++ b/ppapi/proxy/plugin_dispatcher.h
@@ -15,6 +15,7 @@
 #include "ppapi/c/pp_instance.h"
 #include "ppapi/proxy/dispatcher.h"
 #include "ppapi/shared_impl/function_group_base.h"
+#include "ppapi/shared_impl/ppapi_preferences.h"
 
 class MessageLoop;
 
@@ -22,6 +23,10 @@ namespace base {
 class WaitableEvent;
 }
 
+namespace ppapi {
+struct Preferences;
+}
+
 namespace pp {
 namespace proxy {
 
@@ -108,6 +113,9 @@ class PluginDispatcher : public Dispatcher {
   // Returns the WebKitForwarding object used to forward events to WebKit.
   ppapi::WebKitForwarding* GetWebKitForwarding();
 
+  // Returns the Preferences.
+  const ppapi::Preferences& preferences() const { return preferences_; }
+
   // Returns the "new-style" function API for the given interface ID, creating
   // it if necessary.
   // TODO(brettw) this is in progress. It should be merged with the target
@@ -124,6 +132,7 @@ class PluginDispatcher : public Dispatcher {
 
   // IPC message handlers.
   void OnMsgSupportsInterface(const std::string& interface_name, bool* result);
+  void OnMsgSetPreferences(const ::ppapi::Preferences& prefs);
 
   PluginDelegate* plugin_delegate_;
 
@@ -140,6 +149,11 @@ class PluginDispatcher : public Dispatcher {
   typedef base::hash_map<PP_Instance, InstanceData> InstanceDataMap;
   InstanceDataMap instance_map_;
 
+  // The preferences sent from the host. We only want to set this once, which
+  // is what the received_preferences_ indicates. See OnMsgSetPreferences.
+  bool received_preferences_;
+  ppapi::Preferences preferences_;
+
   DISALLOW_COPY_AND_ASSIGN(PluginDispatcher);
 };
 
diff --git a/ppapi/proxy/ppapi_messages.h b/ppapi/proxy/ppapi_messages.h
index cd65fe8..49f0045 100644
--- a/ppapi/proxy/ppapi_messages.h
+++ b/ppapi/proxy/ppapi_messages.h
@@ -29,6 +29,7 @@
 #include "ppapi/proxy/ppapi_param_traits.h"
 #include "ppapi/proxy/serialized_flash_menu.h"
 #include "ppapi/proxy/serialized_structs.h"
+#include "ppapi/shared_impl/ppapi_preferences.h"
 
 #define IPC_MESSAGE_START PpapiMsgStart
 
@@ -47,6 +48,15 @@ IPC_STRUCT_TRAITS_BEGIN(PP_Rect)
   IPC_STRUCT_TRAITS_MEMBER(size)
 IPC_STRUCT_TRAITS_END()
 
+IPC_STRUCT_TRAITS_BEGIN(::ppapi::Preferences)
+  IPC_STRUCT_TRAITS_MEMBER(standard_font_family)
+  IPC_STRUCT_TRAITS_MEMBER(fixed_font_family)
+  IPC_STRUCT_TRAITS_MEMBER(serif_font_family)
+  IPC_STRUCT_TRAITS_MEMBER(sans_serif_font_family)
+  IPC_STRUCT_TRAITS_MEMBER(default_font_size)
+  IPC_STRUCT_TRAITS_MEMBER(default_fixed_font_size)
+IPC_STRUCT_TRAITS_END()
+
 // These are from the browser to the plugin.
 // Loads the given plugin.
 IPC_MESSAGE_CONTROL1(PpapiMsg_LoadPlugin, FilePath /* path */)
@@ -75,6 +85,10 @@ IPC_SYNC_MESSAGE_CONTROL1_1(PpapiMsg_ReserveInstanceId,
                             PP_Instance /* instance */,
                             bool /* usable */)
 
+// Passes the WebKit preferences to the plugin.
+IPC_MESSAGE_CONTROL1(PpapiMsg_SetPreferences,
+                     ::ppapi::Preferences)
+
 // Sent in both directions to see if the other side supports the given
 // interface.
 IPC_SYNC_MESSAGE_CONTROL1_1(PpapiMsg_SupportsInterface,
diff --git a/ppapi/proxy/ppb_font_proxy.cc b/ppapi/proxy/ppb_font_proxy.cc
index 53eac45..eab4494 100644
--- a/ppapi/proxy/ppb_font_proxy.cc
+++ b/ppapi/proxy/ppb_font_proxy.cc
@@ -10,6 +10,7 @@
 #include "ppapi/proxy/ppapi_messages.h"
 #include "ppapi/proxy/ppb_image_data_proxy.h"
 #include "ppapi/proxy/serialized_var.h"
+#include "ppapi/shared_impl/ppapi_preferences.h"
 #include "ppapi/shared_impl/resource_object_base.h"
 #include "ppapi/thunk/enter.h"
 #include "ppapi/thunk/ppb_image_data_api.h"
@@ -104,7 +105,9 @@ Font::Font(const HostResource& resource,
   RunOnWebKitThread(base::Bind(&WebKitForwarding::CreateFontForwarding,
                                base::Unretained(forwarding),
                                &webkit_event_, desc,
-                               face ? *face : std::string(), &result));
+                               face ? *face : std::string(),
+                               GetDispatcher()->preferences(),
+                               &result));
   font_forwarding_.reset(result);
 }
 
diff --git a/ppapi/shared_impl/ppapi_preferences.cc b/ppapi/shared_impl/ppapi_preferences.cc
new file mode 100644
index 0000000..1448806
--- /dev/null
+++ b/ppapi/shared_impl/ppapi_preferences.cc
@@ -0,0 +1,28 @@
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ppapi/shared_impl/ppapi_preferences.h"
+
+#include "webkit/glue/webpreferences.h"
+
+namespace ppapi {
+
+Preferences::Preferences()
+    : default_font_size(0),
+      default_fixed_font_size(0) {
+}
+
+Preferences::Preferences(const WebPreferences& prefs)
+    : standard_font_family(prefs.standard_font_family),
+      fixed_font_family(prefs.fixed_font_family),
+      serif_font_family(prefs.serif_font_family),
+      sans_serif_font_family(prefs.sans_serif_font_family),
+      default_font_size(prefs.default_font_size),
+      default_fixed_font_size(prefs.default_fixed_font_size) {
+}
+
+Preferences::~Preferences() {
+}
+
+}  // namespace ppapi
diff --git a/ppapi/shared_impl/ppapi_preferences.h b/ppapi/shared_impl/ppapi_preferences.h
new file mode 100644
index 0000000..e026290
--- /dev/null
+++ b/ppapi/shared_impl/ppapi_preferences.h
@@ -0,0 +1,30 @@
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef PPAPI_SHARED_IMPL_PPAPI_PREFERENCES_H_
+#define PPAPI_SHARED_IMPL_PPAPI_PREFERENCES_H_
+
+#include "base/string16.h"
+
+struct WebPreferences;
+
+namespace ppapi {
+
+struct Preferences {
+ public:
+  Preferences();
+  explicit Preferences(const WebPreferences& prefs);
+  ~Preferences();
+
+  string16 standard_font_family;
+  string16 fixed_font_family;
+  string16 serif_font_family;
+  string16 sans_serif_font_family;
+  int default_font_size;
+  int default_fixed_font_size;
+};
+
+}  // namespace ppapi
+
+#endif  // PPAPI_SHARED_IMPL_PPAPI_PREFERENCES_H_
diff --git a/ppapi/shared_impl/webkit_forwarding.h b/ppapi/shared_impl/webkit_forwarding.h
index 4f45344..2094523 100644
--- a/ppapi/shared_impl/webkit_forwarding.h
+++ b/ppapi/shared_impl/webkit_forwarding.h
@@ -25,6 +25,8 @@ class PlatformCanvas;
 
 namespace ppapi {
 
+struct Preferences;
+
 class WebKitForwarding {
  public:
   class Font {
@@ -93,8 +95,8 @@ class WebKitForwarding {
   virtual void CreateFontForwarding(base::WaitableEvent* event,
                                     const PP_FontDescription_Dev& desc,
                                     const std::string& desc_face,
+                                    const Preferences& prefs,
                                     Font** result) = 0;
-
 };
 
 }  // namespace ppapi