1 files changed, 106 insertions, 0 deletions
diff --git a/dom/base/nsViewportInfo.h b/dom/base/nsViewportInfo.h
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+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsViewportInfo_h___
+#define nsViewportInfo_h___
+
+#include <stdint.h>
+#include "mozilla/Attributes.h"
+#include "Units.h"
+
+/**
+ * Default values for the nsViewportInfo class.
+ */
+static const mozilla::LayoutDeviceToScreenScale kViewportMinScale(0.1f);
+static const mozilla::LayoutDeviceToScreenScale kViewportMaxScale(10.0f);
+static const mozilla::CSSIntSize kViewportMinSize(200, 40);
+static const mozilla::CSSIntSize kViewportMaxSize(10000, 10000);
+
+/**
+ * Information retrieved from the <meta name="viewport"> tag. See
+ * nsIDocument::GetViewportInfo for more information on this functionality.
+ */
+class MOZ_STACK_CLASS nsViewportInfo
+{
+  public:
+    nsViewportInfo(const mozilla::ScreenIntSize& aDisplaySize,
+                   const mozilla::CSSToScreenScale& aDefaultZoom,
+                   bool aAllowZoom) :
+      mDefaultZoomValid(true),
+      mDefaultZoom(aDefaultZoom),
+      mAutoSize(true),
+      mAllowZoom(aAllowZoom)
+    {
+        mSize = mozilla::ScreenSize(aDisplaySize) / mDefaultZoom;
+        mozilla::CSSToLayoutDeviceScale pixelRatio(1.0f);
+        mMinZoom = pixelRatio * kViewportMinScale;
+        mMaxZoom = pixelRatio * kViewportMaxScale;
+        ConstrainViewportValues();
+    }
+
+    nsViewportInfo(const mozilla::CSSToScreenScale& aDefaultZoom,
+                   const mozilla::CSSToScreenScale& aMinZoom,
+                   const mozilla::CSSToScreenScale& aMaxZoom,
+                   const mozilla::CSSSize& aSize,
+                   bool aAutoSize,
+                   bool aAllowZoom) :
+                     mDefaultZoomValid(true),
+                     mDefaultZoom(aDefaultZoom),
+                     mMinZoom(aMinZoom),
+                     mMaxZoom(aMaxZoom),
+                     mSize(aSize),
+                     mAutoSize(aAutoSize),
+                     mAllowZoom(aAllowZoom)
+    {
+      ConstrainViewportValues();
+    }
+
+    bool IsDefaultZoomValid() const { return mDefaultZoomValid; }
+    mozilla::CSSToScreenScale GetDefaultZoom() const { return mDefaultZoom; }
+    mozilla::CSSToScreenScale GetMinZoom() const { return mMinZoom; }
+    mozilla::CSSToScreenScale GetMaxZoom() const { return mMaxZoom; }
+
+    mozilla::CSSSize GetSize() const { return mSize; }
+
+    bool IsAutoSizeEnabled() const { return mAutoSize; }
+    bool IsZoomAllowed() const { return mAllowZoom; }
+
+  private:
+
+    /**
+     * Constrain the viewport calculations from the
+     * nsIDocument::GetViewportInfo() function in order to always return
+     * sane minimum/maximum values.
+     */
+    void ConstrainViewportValues();
+
+    // If the default zoom was specified and was between the min and max
+    // zoom values.
+    bool mDefaultZoomValid;
+
+    // Default zoom indicates the level at which the display is 'zoomed in'
+    // initially for the user, upon loading of the page.
+    mozilla::CSSToScreenScale mDefaultZoom;
+
+    // The minimum zoom level permitted by the page.
+    mozilla::CSSToScreenScale mMinZoom;
+
+    // The maximum zoom level permitted by the page.
+    mozilla::CSSToScreenScale mMaxZoom;
+
+    // The size of the viewport, specified by the <meta name="viewport"> tag.
+    mozilla::CSSSize mSize;
+
+    // Whether or not we should automatically size the viewport to the device's
+    // width. This is true if the document has been optimized for mobile, and
+    // the width property of a specified <meta name="viewport"> tag is either
+    // not specified, or is set to the special value 'device-width'.
+    bool mAutoSize;
+
+    // Whether or not the user can zoom in and out on the page. Default is true.
+    bool mAllowZoom;
+};
+
+#endif
+