Rendering text to a canvas in a frame-less document.

third_party/WebKit/Source/modules/canvas2d/CanvasRenderingContext2D.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2007 Alp Toker <alp@atoker.com>
  * Copyright (C) 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008 Dirk Schulze <krit@webkit.org>
  * Copyright (C) 2010 Torch Mobile (Beijing) Co. Ltd. All rights reserved.
  * Copyright (C) 2012, 2013 Intel Corporation. All rights reserved.
  * Copyright (C) 2013 Adobe Systems Incorporated. All rights reserved.
  *
@@ skipping 356 matching lines @@
     return state().hasFilter(canvas(), canvas()->size(), this);
 }
 
 SkImageFilter* CanvasRenderingContext2D::stateGetFilter()
 {
     return state().getFilter(canvas(), canvas()->size(), this);
 }
 
 void CanvasRenderingContext2D::snapshotStateForFilter()
 {
-    // The style resolution required for fonts is not available in frame-less documents.
-    if (!canvas()->document().frame())
-        return;
-
     modifiableState().setFontForFilter(accessFont());
 }
 
 SkCanvas* CanvasRenderingContext2D::drawingCanvas() const
 {
     if (isContextLost())
         return nullptr;
     return canvas()->drawingCanvas();
 }
 
@@ skipping 45 matching lines @@
 
         serializedFont.append(' ');
         serializedFont.append(family);
     }
 
     return serializedFont.toString();
 }
 
 void CanvasRenderingContext2D::setFont(const String& newFont)
 {
-    // The style resolution required for rendering text is not available in frame-less documents.
-    if (!canvas()->document().frame())
-        return;
-
     canvas()->document().updateStyleAndLayoutTreeForNode(canvas());
 
     // The following early exit is dependent on the cache not being empty
     // because an empty cache may indicate that a style change has occured
     // which would require that the font be re-resolved. This check has to
     // come after the layout tree update to flush pending style changes.
     if (newFont == state().unparsedFont() && state().hasRealizedFont() && m_fontsResolvedUsingCurrentStyle.size() > 0)
         return;
 
     CanvasFontCache* canvasFontCache = canvas()->document().canvasFontCache();
@@ skipping 260 matching lines @@
 void CanvasRenderingContext2D::strokeText(const String& text, double x, double y, double maxWidth)
 {
     trackDrawCall(StrokeText);
     drawTextInternal(text, x, y, CanvasRenderingContext2DState::StrokePaintType, &maxWidth);
 }
 
 TextMetrics* CanvasRenderingContext2D::measureText(const String& text)
 {
     TextMetrics* metrics = TextMetrics::create();
 
-    // The style resolution required for rendering text is not available in frame-less documents.
-    if (!canvas()->document().frame())
-        return metrics;
-
     canvas()->document().updateStyleAndLayoutTreeForNode(canvas());
     const Font& font = accessFont();
 
     TextDirection direction;
     if (state().getDirection() == CanvasRenderingContext2DState::DirectionInherit)
         direction = determineDirectionality(text);
     else
         direction = toTextDirection(state().getDirection(), canvas());
     TextRun textRun(text, 0, 0, TextRun::AllowTrailingExpansion | TextRun::ForbidLeadingExpansion, direction, false);
     textRun.setNormalizeSpace(true);
@@ skipping 21 matching lines @@
     metrics->setEmHeightDescent(0);
 
     metrics->setHangingBaseline(0.8f * ascent - baselineY);
     metrics->setAlphabeticBaseline(-baselineY);
     metrics->setIdeographicBaseline(-descent - baselineY);
     return metrics;
 }
 
 void CanvasRenderingContext2D::drawTextInternal(const String& text, double x, double y, CanvasRenderingContext2DState::PaintType paintType, double* maxWidth)
 {
-    // The style resolution required for rendering text is not available in frame-less documents.
-    if (!canvas()->document().frame())
-        return;
-
     // accessFont needs the style to be up to date, but updating style can cause script to run,
     // (e.g. due to autofocus) which can free the canvas (set size to 0, for example), so update
     // style before grabbing the drawingCanvas.
     canvas()->document().updateStyleAndLayoutTreeForNode(canvas());
 
     SkCanvas* c = drawingCanvas();
     if (!c)
         return;
 
     if (!std::isfinite(x) || !std::isfinite(y))
@@ skipping 308 matching lines @@
     return true;
 }
 
 void CanvasRenderingContext2D::resetUsageTracking()
 {
     UsageCounters newCounters;
     m_usageCounters = newCounters;
 }
 
 } // namespace blink