Unifying NativeMetafile class interface (as much as possible) for Linux, Mac, Win

printing/emf_win.cc

 // Copyright (c) 2010 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 "printing/emf_win.h"
 
 #include "base/file_path.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "base/scoped_ptr.h"
@@ skipping 32 matching lines @@
     ExtEscape(dc, escape, size, reinterpret_cast<LPCSTR>(bits),
               sizeof(supported), reinterpret_cast<LPSTR>(&supported));
   }
   return !!supported;
 }
 
 Emf::Emf() : emf_(NULL), hdc_(NULL) {
 }
 
 Emf::~Emf() {
-  CloseEmf();
+  Close();
   DCHECK(!emf_ && !hdc_);
 }
 
 bool Emf::Init(const void* src_buffer, uint32 src_buffer_size) {
   DCHECK(!emf_ && !hdc_);
   emf_ = SetEnhMetaFileBits(src_buffer_size,
                             reinterpret_cast<const BYTE*>(src_buffer));
   return emf_ != NULL;
 }

[vandebo (ex-Chrome), 2011/03/12 01:21:06]

I don't remember if I specifically said to reorder the methods in the
implementation file.  If I did, sorry, we should leave this in the same order so
that svn blame will continue to work.

[dpapad, 2011/03/14 18:02:38]

Done.

 
+uint32 Emf::GetDataSize() const {
+  DCHECK(emf_ && !hdc_);
+  return GetEnhMetaFileBits(emf_, 0, NULL);
+}
+
+bool Emf::GetData(void* buffer, uint32 size) const {
+  DCHECK(emf_ && !hdc_);
+  DCHECK(buffer && size);
+  uint32 size2 =
+      GetEnhMetaFileBits(emf_, size, reinterpret_cast<BYTE*>(buffer));
+  DCHECK(size2 == size);
+  return size2 == size && size2 != 0;
+}
+
+bool Emf::FinishPage() {
+  DCHECK(hdc_);
+  if (!hdc_)
+    return false;
+  PageBreakRecord record(PageBreakRecord::END_PAGE);
+  return !!GdiComment(hdc_, sizeof(record),
+                      reinterpret_cast<const BYTE *>(&record));
+}
+
+void Emf::Close() {
+  DCHECK(!hdc_);
+  if (emf_) {
+    DeleteEnhMetaFile(emf_);
+    emf_ = NULL;
+  }
+}
+
+bool Emf::SaveTo(const FilePath& file_path) const {
+  HANDLE file = CreateFile(file_path.value().c_str(), GENERIC_WRITE,
+                           FILE_SHARE_READ | FILE_SHARE_WRITE, NULL,
+                           CREATE_ALWAYS, 0, NULL);
+  if (file == INVALID_HANDLE_VALUE)
+    return false;
+
+  bool success = false;
+  std::vector<uint8> buffer;
+  if (GetData(&buffer)) {
+    DWORD written = 0;
+    if (WriteFile(file, &*buffer.begin(), static_cast<DWORD>(buffer.size()),
+                  &written, NULL) &&
+        written == buffer.size()) {
+      success = true;
+    }
+  }
+  CloseHandle(file);
+  return success;
+}
+
+gfx::Rect Emf::GetPageBounds(unsigned int page_number) const {
+  DCHECK(emf_ && !hdc_);
+  ENHMETAHEADER header;
+  if (GetEnhMetaFileHeader(emf_, sizeof(header), &header) != sizeof(header)) {
+    NOTREACHED();
+    return gfx::Rect();
+  }
+  if (header.rclBounds.left == 0 &&
+      header.rclBounds.top == 0 &&
+      header.rclBounds.right == -1 &&
+      header.rclBounds.bottom == -1) {
+    // A freshly created EMF buffer that has no drawing operation has invalid
+    // bounds. Instead of having an (0,0) size, it has a (-1,-1) size. Detect
+    // this special case and returns an empty Rect instead of an invalid one.
+    return gfx::Rect();
+  }
+  return gfx::Rect(header.rclBounds.left,
+                   header.rclBounds.top,
+                   header.rclBounds.right - header.rclBounds.left,
+                   header.rclBounds.bottom - header.rclBounds.top);
+}
+
+bool Emf::StartPage() {
+  DCHECK(hdc_);
+  if (!hdc_)
+    return false;
+  PageBreakRecord record(PageBreakRecord::START_PAGE);
+  return !!GdiComment(hdc_, sizeof(record),
+                      reinterpret_cast<const BYTE *>(&record));
+}
+
 bool Emf::CreateDc(HDC sibling, const RECT* rect) {
   DCHECK(!emf_ && !hdc_);
   hdc_ = CreateEnhMetaFile(sibling, NULL, rect, NULL);
   DCHECK(hdc_);
   return hdc_ != NULL;
 }
 
-bool Emf::CreateFileBackedDc(HDC sibling, const RECT* rect,
+bool Emf::CreateFileBackedDc(HDC sibling,
+                             const RECT* rect,
                              const FilePath& path) {
   DCHECK(!emf_ && !hdc_);
   DCHECK(!path.empty());
   hdc_ = CreateEnhMetaFile(sibling, path.value().c_str(), rect, NULL);
   DCHECK(hdc_);
   return hdc_ != NULL;
 }
 
 bool Emf::CreateFromFile(const FilePath& metafile_path) {
   DCHECK(!emf_ && !hdc_);
   emf_ = GetEnhMetaFile(metafile_path.value().c_str());
   DCHECK(emf_);
   return emf_ != NULL;
 }
 
 
 bool Emf::CloseDc() {

[vandebo (ex-Chrome), 2011/03/12 01:21:06]

CloseDC should be Close(), not CloseEmf -- CloseEmf destroys the emf data.

[dpapad, 2011/03/14 18:02:38]

Done.

   DCHECK(!emf_ && hdc_);
   emf_ = CloseEnhMetaFile(hdc_);
   DCHECK(emf_);
   hdc_ = NULL;
   return emf_ != NULL;
 }
 
-void Emf::CloseEmf() {
-  DCHECK(!hdc_);
-  if (emf_) {
-    DeleteEnhMetaFile(emf_);
-    emf_ = NULL;
-  }
-}
-
 bool Emf::Playback(HDC hdc, const RECT* rect) const {
   DCHECK(emf_ && !hdc_);
   RECT bounds;
   if (!rect) {
     // Get the natural bounds of the EMF buffer.
-    bounds = GetBounds().ToRECT();
+    bounds = GetPageBounds(1).ToRECT();
     rect = &bounds;
   }
   return PlayEnhMetaFile(hdc, emf_, rect) != 0;
 }
 
 bool Emf::SafePlayback(HDC context) const {
   DCHECK(emf_ && !hdc_);
   XFORM base_matrix;
   if (!GetWorldTransform(context, &base_matrix)) {
     NOTREACHED();
     return false;
   }
   return EnumEnhMetaFile(context,
                          emf_,
                          &Emf::SafePlaybackProc,
                          reinterpret_cast<void*>(&base_matrix),
-                         &GetBounds().ToRECT()) != 0;
-}
-
-gfx::Rect Emf::GetBounds() const {
-  DCHECK(emf_ && !hdc_);
-  ENHMETAHEADER header;
-  if (GetEnhMetaFileHeader(emf_, sizeof(header), &header) != sizeof(header)) {
-    NOTREACHED();
-    return gfx::Rect();
-  }
-  if (header.rclBounds.left == 0 &&
-      header.rclBounds.top == 0 &&
-      header.rclBounds.right == -1 &&
-      header.rclBounds.bottom == -1) {
-    // A freshly created EMF buffer that has no drawing operation has invalid
-    // bounds. Instead of having an (0,0) size, it has a (-1,-1) size. Detect
-    // this special case and returns an empty Rect instead of an invalid one.
-    return gfx::Rect();
-  }
-  return gfx::Rect(header.rclBounds.left,
-                   header.rclBounds.top,
-                   header.rclBounds.right - header.rclBounds.left,
-                   header.rclBounds.bottom - header.rclBounds.top);
-}
-
-uint32 Emf::GetDataSize() const {
-  DCHECK(emf_ && !hdc_);
-  return GetEnhMetaFileBits(emf_, 0, NULL);
-}
-
-bool Emf::GetData(void* buffer, uint32 size) const {
-  DCHECK(emf_ && !hdc_);
-  DCHECK(buffer && size);
-  uint32 size2 =
-      GetEnhMetaFileBits(emf_, size, reinterpret_cast<BYTE*>(buffer));
-  DCHECK(size2 == size);
-  return size2 == size && size2 != 0;
+                         &GetPageBounds(1).ToRECT()) != 0;
 }
 
 bool Emf::GetData(std::vector<uint8>* buffer) const {
   uint32 size = GetDataSize();
   if (!size)
     return false;
 
   buffer->resize(size);
   if (!GetData(&buffer->front(), size))
     return false;
   return true;
 }
 
-bool Emf::SaveTo(const std::wstring& filename) const {
-  HANDLE file = CreateFile(filename.c_str(), GENERIC_WRITE,
-                           FILE_SHARE_READ | FILE_SHARE_WRITE, NULL,
-                           CREATE_ALWAYS, 0, NULL);
-  if (file == INVALID_HANDLE_VALUE)
-    return false;
-
-  bool success = false;
-  std::vector<uint8> buffer;
-  if (GetData(&buffer)) {
-    DWORD written = 0;
-    if (WriteFile(file, &*buffer.begin(), static_cast<DWORD>(buffer.size()),
-                  &written, NULL) &&
-        written == buffer.size()) {
-      success = true;
-    }
-  }
-  CloseHandle(file);
-  return success;
-}
-
 int CALLBACK Emf::SafePlaybackProc(HDC hdc,
                                    HANDLETABLE* handle_table,
                                    const ENHMETARECORD* record,
                                    int objects_count,
                                    LPARAM param) {
   const XFORM* base_matrix = reinterpret_cast<const XFORM*>(param);
   EnumerationContext context;
   context.handle_table = handle_table;
   context.objects_count = objects_count;
   context.hdc = hdc;
@@ skipping 195 matching lines @@
       break;
     }
     default: {
       res = Play();
       break;
     }
   }
   return res;
 }
 
-bool Emf::StartPage() {
-  DCHECK(hdc_);
-  if (!hdc_)
-    return false;
-  PageBreakRecord record(PageBreakRecord::START_PAGE);
-  return !!GdiComment(hdc_, sizeof(record),
-                      reinterpret_cast<const BYTE *>(&record));
-}
-
-bool Emf::EndPage() {
-  DCHECK(hdc_);
-  if (!hdc_)
-    return false;
-  PageBreakRecord record(PageBreakRecord::END_PAGE);
-  return !!GdiComment(hdc_, sizeof(record),
-                      reinterpret_cast<const BYTE *>(&record));
-}
-
-
 Emf::Enumerator::Enumerator(const Emf& emf, HDC context, const RECT* rect) {
   context_.handle_table = NULL;
   context_.objects_count = 0;
   context_.hdc = NULL;
   items_.clear();
   if (!EnumEnhMetaFile(context,
                        emf.emf(),
                        &Emf::Enumerator::EnhMetaFileProc,
                        reinterpret_cast<void*>(this),
                        rect)) {
@@ skipping 26 matching lines @@
   } else {
     DCHECK_EQ(emf.context_.handle_table, handle_table);
     DCHECK_EQ(emf.context_.objects_count, objects_count);
     DCHECK_EQ(emf.context_.hdc, hdc);
   }
   emf.items_.push_back(Record(&emf.context_, record));
   return 1;
 }
 
 }  // namespace printing