/* 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