Add PPB_PDF API to load scaled image resources

chrome/renderer/pepper/ppb_pdf_impl.cc

 // Copyright (c) 2012 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 "chrome/renderer/pepper/ppb_pdf_impl.h"
 
 #include "base/command_line.h"
 #include "base/metrics/histogram.h"
 #include "base/utf_string_conversions.h"
 #include "build/build_config.h"
@@ skipping 11 matching lines @@
 #include "ppapi/shared_impl/resource.h"
 #include "ppapi/shared_impl/resource_tracker.h"
 #include "ppapi/shared_impl/var.h"
 #include "skia/ext/platform_canvas.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebDocument.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebElement.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebFrame.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebPluginContainer.h"
 #include "ui/base/l10n/l10n_util.h"
+#include "ui/base/layout.h"
 #include "ui/base/resource/resource_bundle.h"
+#include "ui/gfx/image/image_skia.h"
+#include "ui/gfx/image/image_skia_rep.h"
 #include "unicode/usearch.h"
 #include "webkit/plugins/ppapi/host_globals.h"
 #include "webkit/plugins/ppapi/plugin_delegate.h"
 #include "webkit/plugins/ppapi/ppapi_plugin_instance.h"
 #include "webkit/plugins/ppapi/ppb_image_data_impl.h"
 
 using ppapi::PpapiGlobals;
 using webkit::ppapi::HostGlobals;
 using webkit::ppapi::PluginInstance;
 using WebKit::WebElement;
@@ skipping 313 matching lines @@
   switch (feature) {
     case PP_PDFFEATURE_HIDPI:
       if (CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kEnableHighDPIPDFPlugin))
         result = PP_TRUE;
       break;
   }
   return result;
 }
 
+PP_Resource GetResourceImageForScale(PP_Instance instance_id,

[brettw, 2012/08/01 21:20:51]

This is mostly copied fromGetResourceImage. I wonder if we can re-implement the
old GetResourceImage to be:
  return GetResourceImageForScale(..., 1.0);
?

[Josh Horwich, 2012/08/01 21:53:52]

Done.

+                                     PP_ResourceImage image_id,
+                                     float scale) {
+  int res_id = 0;
+  for (size_t i = 0; i < arraysize(kResourceImageMap); ++i) {
+    if (kResourceImageMap[i].pp_id == image_id) {
+      res_id = kResourceImageMap[i].res_id;
+      break;
+    }
+  }
+  if (res_id == 0)
+    return 0;
+
+  ui::ScaleFactor scale_factor = ui::GetScaleFactorFromScale(scale);
+
+  gfx::ImageSkia* res_image_skia =
+      ResourceBundle::GetSharedInstance().GetImageSkiaNamed(res_id);
+
+  if (!res_image_skia)
+    return 0;
+
+  // Validate the instance.
+  if (!content::GetHostGlobals()->GetInstance(instance_id))
+    return 0;
+
+  if (!res_image_skia->HasRepresentation(scale_factor))
+    return 0;
+
+  gfx::ImageSkiaRep image_skia_rep = res_image_skia->GetRepresentation(
+      scale_factor);
+
+  scoped_refptr<webkit::ppapi::PPB_ImageData_Impl> image_data(
+      new webkit::ppapi::PPB_ImageData_Impl(
+          instance_id,
+          webkit::ppapi::PPB_ImageData_Impl::PLATFORM));
+  if (!image_data->Init(
+          webkit::ppapi::PPB_ImageData_Impl::GetNativeImageDataFormat(),
+          image_skia_rep.pixel_width(),
+          image_skia_rep.pixel_height(),
+          false)) {
+    return 0;
+  }
+
+  webkit::ppapi::ImageDataAutoMapper mapper(image_data);
+  if (!mapper.is_valid())
+    return 0;
+
+  skia::PlatformCanvas* canvas = image_data->GetPlatformCanvas();
+  // Note: Do not skBitmap::copyTo the canvas bitmap directly because it will
+  // ignore the allocated pixels in shared memory and re-allocate a new buffer.
+  canvas->writePixels(image_skia_rep.sk_bitmap(), 0, 0);
+
+  return image_data->GetReference();
+}
+
 const PPB_PDF ppb_pdf = {
   &GetLocalizedString,
   &GetResourceImage,
   &GetFontFileWithFallback,
   &GetFontTableForPrivateFontFile,
   &SearchString,
   &DidStartLoading,
   &DidStopLoading,
   &SetContentRestriction,
   &HistogramPDFPageCount,
   &UserMetricsRecordAction,
   &HasUnsupportedFeature,
   &SaveAs,
   &PPB_PDF_Impl::InvokePrintingForInstance,
-  &IsFeatureEnabled
+  &IsFeatureEnabled,
+  &GetResourceImageForScale
 };
 
 }  // namespace
 
 // static
 const PPB_PDF* PPB_PDF_Impl::GetInterface() {
   return &ppb_pdf;
 }
 
 // static
 void PPB_PDF_Impl::InvokePrintingForInstance(PP_Instance instance_id) {
 #if defined(ENABLE_PRINTING)
   PluginInstance* instance = HostGlobals::Get()->GetInstance(instance_id);
   if (!instance)
     return;
 
   WebKit::WebElement element = instance->container()->element();
   WebKit::WebView* view = element.document().frame()->view();
   content::RenderView* render_view = content::RenderView::FromWebView(view);
 
   PrintWebViewHelper* print_view_helper = PrintWebViewHelper::Get(render_view);
   if (print_view_helper)
     print_view_helper->PrintNode(element);
 #endif
 }