Page zoom improvements

content/public/common/page_zoom.h

 // Copyright (c) 2009 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.
 
 #ifndef CONTENT_PUBLIC_COMMON_PAGE_ZOOM_H_
 #define CONTENT_PUBLIC_COMMON_PAGE_ZOOM_H_
 #pragma once
 
 #include "base/basictypes.h"
+#include "content/common/content_export.h"
 
 namespace content {
 
 // This enum is the parameter to various text/page zoom commands so we know
 // what the specific zoom command is.
 enum PageZoom {
   PAGE_ZOOM_OUT   = -1,
   PAGE_ZOOM_RESET = 0,
   PAGE_ZOOM_IN    = 1,
 };
 
+// The minimum zoom factor permitted for a page. This is an alternative to

[James Hawkins, 2011/11/14 18:09:05]

What do you mean by 'alternative'?

[csilv, 2011/11/14 23:10:29]

These are the values that we are going to use in Chromium, rather than WebKit's
default values.  The webkit minimum and maximum values are too narrow for
Chromium.  So we're defining our own min/max values and using those in the
appropriate places.

+// WebView::minTextSizeMultiplier.
+CONTENT_EXPORT extern const double kMinimumZoomFactor;
+
+// The maximum zoom factor permitted for a page. This is an alternative to
+// WebView::maxTextSizeMultiplier.
+CONTENT_EXPORT extern const double kMaximumZoomFactor;
+
+// Preset zoom factors that represent common zoom factors within the minimum
+// and maximum values. This array is guaranteed to be in sorted order.
+CONTENT_EXPORT extern const double kPresetZoomFactors[];
+
+// The number of zoom factors contained in the kPresetZoomFactors array.
+CONTENT_EXPORT extern const int kPresetZoomFactorsCount;
+
+// Epsilon for calculating zoom factor/level equality.
+CONTENT_EXPORT extern const double kPageZoomEpsilon;
+
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_COMMON_PAGE_ZOOM_H_