Consolidate how ImageDocument sets image styling

third_party/WebKit/Source/core/html/ImageDocument.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2010 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 380 matching lines @@
           // page is currently being scaled.
           scale = frame()->host()->visualViewport().scale();
         } else {
           // The checker pattern is initialized based on how large the image is
           // relative to the viewport.
           int viewportWidth = frame()->host()->visualViewport().size().width();
           scale = viewportWidth / static_cast<double>(calculateDivWidth());
         }
 
         newCheckerSize = round(std::max(1.0, newCheckerSize / scale));
+      } else if (!imageFitsInWindow()) {
+        // In desktop mode, the user can click on the image to zoom in or out.
+        DCHECK_EQ(m_shrinkToFitMode, Desktop);
+        imageStyle.append(m_shouldShrinkImage ? "cursor: zoom-in; "

[pdr., 2016/11/21 23:26:47]

I see we're using "m_imageElement->setInlineStyleProperty(CSSPropertyCursor,
CSSValueZoomOut);" to do this elsewhere. Is the style code in this function
overwriting that? I wonder if we should just have this function be in charge of
managing the image style (i.e., have the other callers of
m_imageElement->setInlineStyleProperty call updateImageStyle())?

[gone, 2016/11/21 23:43:26]

Yeah, on desktop this is called during ::imageLoaded(), after the cursor is
initially set via setInlineStyleProperty(), effectively erasing it.  This
function isn't called anywhere else after initialization, though, and I'm not
sure if it's cheaper overall to edit the whole style tag than to just
remove/change the single style property explicitly when we know it needs to be
updated.  It might make sense to just pull out the cursor-setting code
specifically, then have everything call that.  WDYT?

+                                              : "cursor: zoom-out; ");
       }
 
       // The only thing that can differ between updates is the checker size.
       if (newCheckerSize == m_checkerSize)
         return;
       m_checkerSize = newCheckerSize;
 
       imageStyle.append("background-position: 0px 0px, ");
       imageStyle.append(AtomicString::number(m_checkerSize));
       imageStyle.append("px ");
@@ skipping 176 matching lines @@
 }
 
 bool ImageEventListener::operator==(const EventListener& listener) const {
   if (const ImageEventListener* imageEventListener =
           ImageEventListener::cast(&listener))
     return m_doc == imageEventListener->m_doc;
   return false;
 }
 
 }  // namespace blink