Use the WebKit default fonts when specifying generic font families.

ppapi/examples/font/simple_font.cc

 // 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 <stdio.h>
+
 #include "ppapi/cpp/completion_callback.h"
 #include "ppapi/cpp/dev/font_dev.h"
 #include "ppapi/cpp/graphics_2d.h"
 #include "ppapi/cpp/image_data.h"
 #include "ppapi/cpp/instance.h"
 #include "ppapi/cpp/module.h"
 #include "ppapi/cpp/rect.h"
 #include "ppapi/cpp/size.h"
 
 static void DummyCompletionCallback(void* /*user_data*/, int32_t /*result*/) {
 }
 
 class MyInstance : public pp::Instance {
  public:
   MyInstance(PP_Instance instance)
       : pp::Instance(instance) {
   }
 
   virtual void DidChangeView(const pp::Rect& position, const pp::Rect& clip) {
     if (position.size() == last_size_)
       return;
     last_size_ = position.size();
 
     pp::ImageData image(this, PP_IMAGEDATAFORMAT_BGRA_PREMUL, last_size_, true);
     pp::Graphics2D device(this, last_size_, false);
     BindGraphics(device);
 
     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];
+    snprintf(buf, sizeof(buf), "%s = %s %dpt",

[yzshen1, 2011/05/25 23:40:11]

I think this is not defined on Windows.
You could use _snprintf on Windows (and please note that it won't set '\0' at
the end on Windows, if the buffer is not big enough).

[brettw, 2011/05/26 17:29:49]

Darn. Since this is just an example and I'd rather keep it simple, I think I'll
just use sprintf.

[yzshen1, 2011/05/26 17:49:51]

Sounds good to me.

On 2011/05/26 17:29:49, brettw wrote:

+            title, desc.face().AsString().c_str(), desc.size());
+    return std::string(buf);
+  }
+
   pp::Size last_size_;
 };
 
 class MyModule : public pp::Module {
  public:
   virtual pp::Instance* CreateInstance(PP_Instance instance) {
     return new MyInstance(instance);
   }
 };
 
 namespace pp {
 
 // Factory function for your specialization of the Module object.
 Module* CreateModule() {
   return new MyModule();
 }
 
 }  // namespace pp