Change the DidChangeView update to take a new ViewChanged resource.

ppapi/example/example.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 <math.h>
 #include <stdio.h>  // FIXME(brettw) erase me.
 #ifndef _WIN32
 #include <sys/time.h>
 #else
 #include <windows.h>
@@ skipping 13 matching lines @@
 #include "ppapi/cpp/graphics_2d.h"
 #include "ppapi/cpp/image_data.h"
 #include "ppapi/cpp/input_event.h"
 #include "ppapi/cpp/private/instance_private.h"
 #include "ppapi/cpp/module.h"
 #include "ppapi/cpp/private/var_private.h"
 #include "ppapi/cpp/rect.h"
 #include "ppapi/cpp/url_loader.h"
 #include "ppapi/cpp/url_request_info.h"
 #include "ppapi/cpp/var.h"
+#include "ppapi/cpp/view.h"
 
 static const int kStepsPerCircle = 800;
 
 void FlushCallback(void* data, int32_t result);
 
 void FillRect(pp::ImageData* image, int left, int top, int width, int height,
               uint32_t color) {
   for (int y = std::max(0, top);
        y < std::min(image->size().height() - 1, top + height);
        y++) {
@@ skipping 115 matching lines @@
   char buf_[4096];
   std::string data_;
 };
 
 class MyInstance : public pp::InstancePrivate, public MyFetcherClient {
  public:
   MyInstance(PP_Instance instance)
       : pp::InstancePrivate(instance),
         time_at_last_check_(0.0),
         fetcher_(NULL),
-        width_(0),
-        height_(0),
         animation_counter_(0),
         print_settings_valid_(false),
         showing_custom_cursor_(false),
         cursor_dimension_(50),
         expanding_cursor_(false) {
     RequestInputEvents(PP_INPUTEVENT_CLASS_MOUSE);
   }
 
   virtual ~MyInstance() {
     if (fetcher_) {
@@ skipping 32 matching lines @@
         return true;
       default:
         return false;
     }
   }
 
   virtual pp::Var GetInstanceObject() {
     return pp::VarPrivate(this, new MyScriptableObject(this));
   }
 
-  pp::ImageData PaintImage(int width, int height) {
-    pp::ImageData image(this, PP_IMAGEDATAFORMAT_BGRA_PREMUL,
-                        pp::Size(width, height), false);
+  pp::ImageData PaintImage(const pp::Size& size) {
+    pp::ImageData image(this, PP_IMAGEDATAFORMAT_BGRA_PREMUL, size, false);
     if (image.is_null()) {
-      printf("Couldn't allocate the image data: %d, %d\n", width, height);
+      printf("Couldn't allocate the image data.");
       return image;
     }
 
     // Fill with semitransparent gradient.
     for (int y = 0; y < image.size().height(); y++) {
       char* row = &static_cast<char*>(image.data())[y * image.stride()];
       for (int x = 0; x < image.size().width(); x++) {
         row[x * 4 + 0] = y;
         row[x * 4 + 1] = y;
         row[x * 4 + 2] = 0;
         row[x * 4 + 3] = y;
       }
     }
 
     // Draw the orbiting box.
     float radians = static_cast<float>(animation_counter_) / kStepsPerCircle *
         2 * 3.14159265358979F;
 
-    float radius = static_cast<float>(std::min(width, height)) / 2.0f - 3.0f;
+    float radius =
+        static_cast<float>(std::min(size.width(), size.height())) / 2.0f - 3.0f;
     int x = static_cast<int>(cos(radians) * radius + radius + 2);
     int y = static_cast<int>(sin(radians) * radius + radius + 2);
 
     const uint32_t box_bgra = 0x80000000;  // Alpha 50%.
     FillRect(&image, x - 3, y - 3, 7, 7, box_bgra);
     return image;
   }
 
   void Paint() {
-    pp::ImageData image = PaintImage(width_, height_);
+    pp::ImageData image = PaintImage(device_context_.size());
     if (!image.is_null()) {
       device_context_.ReplaceContents(&image);
       device_context_.Flush(pp::CompletionCallback(&FlushCallback, this));
     } else {
-      printf("NullImage: %d, %d\n", width_, height_);
+      printf("NullImage\n");
     }
   }
 
-  virtual void DidChangeView(const pp::Rect& position, const pp::Rect& clip) {
+  virtual void DidChangeView(const pp::View& view) {
     Log(PP_LOGLEVEL_LOG, "DidChangeView");
-    if (position.size().width() == width_ &&
-        position.size().height() == height_)
+    if (view.GetViewportRect().size() != current_view_.GetViewportRect().size())

[dmichael (off chromium), 2011/12/16 04:14:31]

That's not bad, though it doesn't handle the initial call yet, does it?

You might get away with just storing the 'current_size_'. Then the initial case
would be comparing against a default-constructed Size, and it should work fine.

I also don't see where you set current_view_. Did I miss it?

It would also be helpful to see an example of handling changes in visibility.
That might be more compelling for having a "DidChangeVisibility", maybe even
directly on PPB_View instead of in a separate interface.

[brettw, 2011/12/19 22:53:40]

It does since the current_view_ is intitialized to a null resource and the
default sizes are all 0.

       return;  // We don't care about the position, only the size.
 
-    width_ = position.size().width();
-    height_ = position.size().height();
     printf("DidChangeView relevant change: width=%d height:%d\n",
-           width_, height_);
+           view.GetViewportRect().width(), view.GetViewportRect().height());
 
-    device_context_ = pp::Graphics2D(this, pp::Size(width_, height_), false);
+    device_context_ = pp::Graphics2D(this, view.GetViewportRect.size(), false);
     if (!BindGraphics(device_context_)) {
       printf("Couldn't bind the device context\n");
       return;
     }
 
     Paint();
   }
 
 #if defined(_WIN32)
 struct timeval {
@@ skipping 64 matching lines @@
 
     if (page_range_count != 1)
       return pp::Resource();
 
     // Check if the page numbers are valid. We returned 1 in PrintBegin so we
     // only have 1 page to print.
     if (page_ranges[0].first_page_number || page_ranges[0].last_page_number) {
       return pp::Resource();
     }
 
-    int width = static_cast<int>(
-        (print_settings_.printable_area.size.width / 72.0) *
-         print_settings_.dpi);
-    int height = static_cast<int>(
-        (print_settings_.printable_area.size.height / 72.0) *
-         print_settings_.dpi);
-
-    return PaintImage(width, height);
+    pp::Size size(static_cast<int>(
+            (print_settings_.printable_area.size.width / 72.0) *
+             print_settings_.dpi),
+        static_cast<int>(
+            (print_settings_.printable_area.size.height / 72.0) *
+             print_settings_.dpi));
+    return PaintImage(size);
   }
 
   virtual void PrintEnd() {
     print_settings_valid_ = false;
   }
 
   virtual bool IsScalingDisabled() {
     return false;
   }
 
@@ skipping 83 matching lines @@
           expanding_cursor_ = true;
       }
     }
   }
 
   pp::Var console_;
   pp::Graphics2D device_context_;
 
   double time_at_last_check_;
 
+  pp::View current_view_;
+
   MyFetcher* fetcher_;
 
-  int width_;
-  int height_;
-
   // Incremented for each flush we get.
   int animation_counter_;
   bool print_settings_valid_;
   PP_PrintSettings_Dev print_settings_;
 
   bool showing_custom_cursor_;
   int cursor_dimension_;
   bool expanding_cursor_;
 };
 
@@ skipping 12 matching lines @@
 };
 
 namespace pp {
 
 // Factory function for your specialization of the Module object.
 Module* CreateModule() {
   return new MyModule();
 }
 
 }  // namespace pp