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 <vector>
+
 #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
+// 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;
+
+// Return a sorted vector of zoom factors. The vector will consist of preset
+// values along with a custom value (if the custom value is not already
+// represented.)
+CONTENT_EXPORT std::vector<double> PresetZoomFactors(double custom_factor);
+
+// Return a sorted vector of zoom levels. The vector will consist of preset
+// values along with a custom value (if the custom value is not already
+// represented.)
+CONTENT_EXPORT std::vector<double> PresetZoomLevels(double custom_level);
+
+// Test if two zoom values (either zoom factors or zoom levels) should be
+// considered equal.
+CONTENT_EXPORT bool ZoomValuesEqual(double value_a, double value_b);
+
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_COMMON_PAGE_ZOOM_H_