Bug 1156742 Part 19: Implement GetFontFileData for ScaledFontWin. r=bas

gfx/2d/AutoHelpersWin.h

@@ -0,0 +1,86 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+* This Source Code Form is subject to the terms of the Mozilla Public
+* License, v. 2.0. If a copy of the MPL was not distributed with this
+* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_gfx_AutoHelpersWin_h
+#define mozilla_gfx_AutoHelpersWin_h
+
+#include <windows.h>
+
+namespace mozilla {
+namespace gfx {
+
+// Get the global device context, and auto-release it on destruction.
+class AutoDC
+{
+public:
+  AutoDC() {
+    mDC = ::GetDC(nullptr);
+  }
+
+  ~AutoDC() {
+    ::ReleaseDC(nullptr, mDC);
+  }
+
+  HDC GetDC() {
+    return mDC;
+  }
+
+private:
+  HDC mDC;
+};
+
+// Select a font into the given DC, and auto-restore.
+class AutoSelectFont
+{
+public:
+  AutoSelectFont(HDC aDC, LOGFONTW *aLogFont)
+    : mOwnsFont(false)
+  {
+    mFont = ::CreateFontIndirectW(aLogFont);
+    if (mFont) {
+      mOwnsFont = true;
+      mDC = aDC;
+      mOldFont = (HFONT)::SelectObject(aDC, mFont);
+    } else {
+      mOldFont = nullptr;
+    }
+  }
+
+  AutoSelectFont(HDC aDC, HFONT aFont)
+    : mOwnsFont(false)
+  {
+    mDC = aDC;
+    mFont = aFont;
+    mOldFont = (HFONT)::SelectObject(aDC, aFont);
+  }
+
+  ~AutoSelectFont() {
+    if (mOldFont) {
+      ::SelectObject(mDC, mOldFont);
+      if (mOwnsFont) {
+        ::DeleteObject(mFont);
+      }
+    }
+  }
+
+  bool IsValid() const {
+    return mFont != nullptr;
+  }
+
+  HFONT GetFont() const {
+    return mFont;
+  }
+
+private:
+  HDC mDC;
+  HFONT mFont;
+  HFONT mOldFont;
+  bool mOwnsFont;
+};
+
+} // gfx
+} // mozilla
+
+#endif // mozilla_gfx_AutoHelpersWin_h

gfx/2d/RecordedEvent.cpp

@@ -1404,6 +1404,12 @@ RecordedScaledFontCreation::PlayEvent(Translator *aTranslator) const
 void
 RecordedScaledFontCreation::RecordToStream(std::ostream &aStream) const
 {
+  if (!mGetFontFileDataSucceeded) {
+    gfxWarning()
+      << "Unable to record ScaledFont creation as no data was retrieved.";
+    return;
+  }
+
   WriteElement(aStream, mRefPtr);
   WriteElement(aStream, mIndex);
   WriteElement(aStream, mGlyphSize);

gfx/2d/RecordedEvent.h

@@ -947,7 +947,7 @@ public:
   RecordedScaledFontCreation(ReferencePtr aRefPtr, ScaledFont *aScaledFont)
     : RecordedEvent(SCALEDFONTCREATION), mRefPtr(aRefPtr), mData(nullptr)
   {
-    aScaledFont->GetFontFileData(&FontDataProc, this);
+    mGetFontFileDataSucceeded = aScaledFont->GetFontFileData(&FontDataProc, this);
   }
 
   ~RecordedScaledFontCreation();
@@ -970,6 +970,7 @@ private:
   uint32_t mSize;
   Float mGlyphSize;
   uint32_t mIndex;
+  bool mGetFontFileDataSucceeded = false;
 
   MOZ_IMPLICIT RecordedScaledFontCreation(std::istream &aStream);
 };

gfx/2d/ScaledFontWin.cpp

@@ -6,6 +6,7 @@
 #include "ScaledFontWin.h"
 #include "ScaledFontBase.h"
 
+#include "AutoHelpersWin.h"
 #include "Logging.h"
 #include "SFNTData.h"
 
@@ -77,6 +78,55 @@ ScaledFontWin::ScaledFontWin(uint8_t* aFontData, uint32_t aFontDataLength,
 
 }
 
+bool
+ScaledFontWin::GetFontFileData(FontFileDataOutput aDataCallback, void *aBaton)
+{
+  AutoDC dc;
+  AutoSelectFont font(dc.GetDC(), &mLogFont);
+
+  // Check for a font collection first.
+  uint32_t table = 0x66637474; // 'ttcf'
+  uint32_t tableSize = ::GetFontData(dc.GetDC(), table, 0, nullptr, 0);
+  if (tableSize == GDI_ERROR) {
+    // Try as if just a single font.
+    table = 0;
+    tableSize = ::GetFontData(dc.GetDC(), table, 0, nullptr, 0);
+    if (tableSize == GDI_ERROR) {
+      return false;
+    }
+  }
+
+  UniquePtr<uint8_t[]> fontData(new uint8_t[tableSize]);
+
+  uint32_t sizeGot =
+    ::GetFontData(dc.GetDC(), table, 0, fontData.get(), tableSize);
+  if (sizeGot != tableSize) {
+    return false;
+  }
+
+  // If it's a font collection then attempt to get the index.
+  uint32_t index = 0;
+  if (table != 0) {
+    UniquePtr<SFNTData> sfntData = SFNTData::Create(fontData.get(),
+                                                    tableSize);
+    if (!sfntData) {
+      gfxWarning() << "Failed to create SFNTData for GetFontFileData.";
+      return false;
+    }
+
+    // We cast here because for VS2015 char16_t != wchar_t, even though they are
+    // both 16 bit.
+    if (!sfntData->GetIndexForU16Name(
+          reinterpret_cast<char16_t*>(mLogFont.lfFaceName), &index)) {
+      gfxWarning() << "Failed to get index for face name.";
+      return false;
+    }
+  }
+
+  aDataCallback(fontData.get(), tableSize, index, mSize, aBaton);
+  return true;
+}
+
 #ifdef USE_SKIA
 SkTypeface* ScaledFontWin::GetSkTypeface()
 {

gfx/2d/ScaledFontWin.h

@@ -24,6 +24,9 @@ public:
                 Float aGlyphSize);
 
   virtual FontType GetType() const { return FontType::GDI; }
+
+  bool GetFontFileData(FontFileDataOutput aDataCallback, void *aBaton) override;
+
 #ifdef USE_SKIA
   virtual SkTypeface* GetSkTypeface();
 #endif