move failable work outside of constructors for SkGlyphCache and SkScalerContextGDI. If we fail, try…

src/ports/SkFontHost_win.cpp

 
 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkAdvancedTypefaceMetrics.h"
 #include "SkBase64.h"
@@ skipping 487 matching lines @@
     }
     *srcRBPtr = srcRB;
     // offset to the start of the image
     return (const char*)fBits + (fHeight - glyph.fHeight) * srcRB;
 }
 
 //////////////////////////////////////////////////////////////////////////////
 
 class SkScalerContext_Windows : public SkScalerContext {
 public:
-    SkScalerContext_Windows(SkTypeface*, const SkDescriptor* desc);
+    // we take ownership of the HDC
+    SkScalerContext_Windows(SkTypeface*, const SkDescriptor* desc, HDC);
     virtual ~SkScalerContext_Windows();
 
 protected:
     virtual unsigned generateGlyphCount() SK_OVERRIDE;
     virtual uint16_t generateCharToGlyph(SkUnichar uni) SK_OVERRIDE;
     virtual void generateAdvance(SkGlyph* glyph) SK_OVERRIDE;
     virtual void generateMetrics(SkGlyph* glyph) SK_OVERRIDE;
     virtual void generateImage(const SkGlyph& glyph) SK_OVERRIDE;
     virtual void generatePath(const SkGlyph& glyph, SkPath* path) SK_OVERRIDE;
     virtual void generateFontMetrics(SkPaint::FontMetrics* mX,
@@ skipping 46 matching lines @@
         default:
             if (rec.fFlags & SkScalerContext::kGenA8FromLCD_Flag) {
                 return CLEARTYPE_QUALITY;
             } else {
                 return ANTIALIASED_QUALITY;
             }
     }
 }
 
 SkScalerContext_Windows::SkScalerContext_Windows(SkTypeface* rawTypeface,
-                                                 const SkDescriptor* desc)
+                                                 const SkDescriptor* desc,
+                                                 HDC ddc)
         : SkScalerContext(rawTypeface, desc)
-        , fDDC(0)
+        , fDDC(ddc)
         , fFont(0)
         , fSavefont(0)
         , fSC(0)
         , fGlyphCount(-1)
 {
+    SkASSERT(fDDC);
     LogFontTypeface* typeface = reinterpret_cast<LogFontTypeface*>(rawTypeface);
 
-    fDDC = ::CreateCompatibleDC(NULL);
     SetGraphicsMode(fDDC, GM_ADVANCED);
     SetBkMode(fDDC, TRANSPARENT);
 
     // Scaling by the DPI is inconsistent with how Skia draws elsewhere
     //SkScalar height = -(fRec.fTextSize * GetDeviceCaps(ddc, LOGPIXELSY) / 72);
     LOGFONT lf = typeface->fLogFont;
     lf.lfHeight = -gCanonicalTextSize;
     lf.lfQuality = compute_quality(fRec);
     fFont = CreateFontIndirect(&lf);

[bungeman-skia, 2013/07/08 19:36:49]

This line also creates a handle, we should also be checking that (we just don't
currently have an assert for it, so we won't be seeing it).

 
     // if we're rotated, or want fractional widths, create a hires font
     fHiResFont = 0;
     if (needHiResMetrics(fRec.fPost2x2)) {
         lf.lfHeight = -HIRES_TEXTSIZE;
         fHiResFont = CreateFontIndirect(&lf);
 
         fMat22Identity.eM11 = fMat22Identity.eM22 = SkFixedToFIXED(SK_Fixed1);
         fMat22Identity.eM12 = fMat22Identity.eM21 = SkFixedToFIXED(0);
 
@@ skipping 75 matching lines @@
             call_ensure_accessible(lf);
             //if the following fails, we'll just draw at gCanonicalTextSize.
             GetTextMetrics(fDDC, &fTM);
         }
     }
 
     fOffscreen.init(fFont, xform);
 }
 
 SkScalerContext_Windows::~SkScalerContext_Windows() {
-    if (fDDC) {
-        ::SelectObject(fDDC, fSavefont);
-        ::DeleteDC(fDDC);
-    }
+    ::SelectObject(fDDC, fSavefont);
+    ::DeleteDC(fDDC);
+
     if (fFont) {
         ::DeleteObject(fFont);
     }
     if (fHiResFont) {
         ::DeleteObject(fHiResFont);
     }
     if (fSC) {
         ::ScriptFreeCache(&fSC);
     }
 }
@@ skipping 954 matching lines @@
     }
 
     SelectObject(hdc, savefont);
     DeleteObject(font);
     DeleteDC(hdc);
 
     return stream;
 }
 
 SkScalerContext* LogFontTypeface::onCreateScalerContext(const SkDescriptor* desc) const {
-    return SkNEW_ARGS(SkScalerContext_Windows, (const_cast<LogFontTypeface*>(this), desc));
+    HDC hdc = ::CreateCompatibleDC(NULL);
+    if (!hdc) {
+        return NULL;
+    }
+    return SkNEW_ARGS(SkScalerContext_Windows, (const_cast<LogFontTypeface*>(this), desc, hdc));
 }
 
 /** Return the closest matching typeface given either an existing family
  (specified by a typeface in that family) or by a familyName, and a
  requested style.
  1) If familyFace is null, use familyName.
  2) If familyName is null, use familyFace.
  3) If both are null, return the default font that best matches style
  This MUST not return NULL.
  */
@@ skipping 239 matching lines @@
         return this->createFromStream(stream);
     }
 
 private:
     SkTDArray<ENUMLOGFONTEX> fLogFontArray;
 };
 
 SkFontMgr* SkFontMgr::Factory() {
     return SkNEW(SkFontMgrGDI);
 }