Fixed clipping printing with EMF.

printing/emf_win.h

 // 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 PRINTING_EMF_WIN_H_
 #define PRINTING_EMF_WIN_H_
 
 #include <windows.h>
 
 #include <vector>
@@ skipping 95 matching lines @@
 
   // Valid when generating EMF data through a virtual HDC.
   HDC hdc_;
 
   int page_count_;
 
   DISALLOW_COPY_AND_ASSIGN(Emf);
 };
 
 struct Emf::EnumerationContext {
+  EnumerationContext();

[Albert Bodenhamer, 2012/06/18 19:08:53]

If you're going to add a constructor, make this a class.

The construstor just 0's it out.  Maybe just assign = {0} when you use this
structure?

[Vitaly Buka (NO REVIEWS), 2012/06/18 19:33:06]

Actually according out coding style even methods allows in structures. But
"Methods should not provide behavior but should only be used to set up the data
members, e.g., constructor, destructor, Initialize(), Reset(), Validate()."
http://google-styleguide.googlecode.com/svn/trunk/cppguide.xml#Structs_vs._Cl...

There are examples of structs with constructors in chrome code.

I believe struct with constructor is safer here than without, but class is
redundant here because it's just accessors.

On 2012/06/18 19:08:53, Albert Bodenhamer wrote:

+
   HANDLETABLE* handle_table;
   int objects_count;
   HDC hdc;
+  const XFORM* base_matrix;
+  int dc_on_page_start;
 };
 
 // One EMF record. It keeps pointers to the EMF buffer held by Emf::emf_.
 // The entries become invalid once Emf::CloseEmf() is called.
 class PRINTING_EXPORT Emf::Record {
  public:
   // Plays the record.
-  bool Play() const;
+  bool Play(EnumerationContext* context) const;
 
   // Plays the record working around quirks with SetLayout,
   // SetWorldTransform and ModifyWorldTransform. See implementation for details.
-  bool SafePlayback(const XFORM* base_matrix) const;
+  bool SafePlayback(EnumerationContext* context) const;
 
   // Access the underlying EMF record.
   const ENHMETARECORD* record() const { return record_; }
 
  protected:
-  Record(const EnumerationContext* context,
-         const ENHMETARECORD* record);
+  explicit Record(const ENHMETARECORD* record);
 
  private:
   friend class Emf;
   friend class Enumerator;
   const ENHMETARECORD* record_;
-  const EnumerationContext* context_;
 };
 
 // Retrieves individual records out of a Emf buffer. The main use is to skip
 // over records that are unsupported on a specific printer or to play back
 // only a part of an EMF buffer.
 class PRINTING_EXPORT Emf::Enumerator {
  public:
   // Iterator type used for iterating the records.
   typedef std::vector<Record>::const_iterator const_iterator;
 
   // Enumerates the records at construction time. |hdc| and |rect| are
   // both optional at the same time or must both be valid.
   // Warning: |emf| must be kept valid for the time this object is alive.
   Enumerator(const Emf& emf, HDC hdc, const RECT* rect);
 
   // Retrieves the first Record.
   const_iterator begin() const;
 
   // Retrieves the end of the array.
   const_iterator end() const;
 
  private:
+  FRIEND_TEST_ALL_PREFIXES(EmfPrintingTest, Enumerate);
+
   // Processes one EMF record and saves it in the items_ array.
   static int CALLBACK EnhMetaFileProc(HDC hdc,
                                       HANDLETABLE* handle_table,
                                       const ENHMETARECORD* record,
                                       int objects_count,
                                       LPARAM param);
 
   // The collection of every EMF records in the currently loaded EMF buffer.
   // Initialized by Enumerate(). It keeps pointers to the EMF buffer held by
   // Emf::emf_. The entries become invalid once Emf::CloseEmf() is called.
   std::vector<Record> items_;
 
   EnumerationContext context_;
 
   DISALLOW_COPY_AND_ASSIGN(Enumerator);
 };
 
 }  // namespace printing
 
 #endif  // PRINTING_EMF_WIN_H_