/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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/. */

#include "VisualViewport.h"
#include "nsIScrollableFrame.h"
#include "nsIDocShell.h"

using namespace mozilla;
using namespace mozilla::dom;

VisualViewport::VisualViewport(nsPIDOMWindowInner* aWindow)
  : DOMEventTargetHelper(aWindow)
{
}

VisualViewport::VisualViewport(nsIGlobalObject* aGlobal)
  : DOMEventTargetHelper(aGlobal)
{
}

VisualViewport::~VisualViewport()
{
}

/* virtual */
JSObject*
VisualViewport::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
{
  return VisualViewportBinding::Wrap(aCx, this, aGivenProto);
}

/* XXXMC: We are effectively getting the size from the root scrollframe of the content
 * and the scale from our DPP resolution.
 * Since we are only on desktop, by definition have full view size (no "notch" or
 * other mobile "don't touch" areas), we are hard-coding:
 * - VisualViewportOffset = (0,0)
 * - PageLeft/PageTop = 0.0
 * - OffsetLeft/OffsetTop = 0.0
 */
 
CSSSize
VisualViewport::VisualViewportSize() const
{
  CSSSize size = CSSSize(0,0);

  nsIPresShell* presShell = GetPresShell();
  if (presShell) {
    nsIScrollableFrame* sf = presShell->GetRootScrollFrameAsScrollable();
    if (sf) {
      size = CSSRect::FromAppUnits(sf->GetScrollPortRect().Size());
    }
  }
  return size;
}

double
VisualViewport::Width() const
{
  CSSSize size = VisualViewportSize();
  return size.width;
}

double
VisualViewport::Height() const
{
  CSSSize size = VisualViewportSize();
  return size.height;
}

double
VisualViewport::Scale() const
{
  double scale = 1;
  nsIPresShell* presShell = GetPresShell();
  if (presShell) {
    scale = presShell->GetResolution();
  }
  return scale;
}

CSSPoint
VisualViewport::VisualViewportOffset() const
{
  CSSPoint offset = CSSPoint(0,0);
  return offset;
}

CSSPoint
VisualViewport::LayoutViewportOffset() const
{
  CSSPoint offset = CSSPoint(0,0);

  nsIPresShell* presShell = GetPresShell();
  if (presShell) {
    nsIScrollableFrame* sf = presShell->GetRootScrollFrameAsScrollable();
    if (sf) {
      offset = CSSPoint::FromAppUnits(sf->GetScrollPosition());
    }
  }
  return offset;
}

double
VisualViewport::PageLeft() const
{
  return 0.0;
}

double
VisualViewport::PageTop() const
{
  return 0.0;
}

double
VisualViewport::OffsetLeft() const
{
  return 0.0;
}

double
VisualViewport::OffsetTop() const
{
  return 0.0;
}

nsIPresShell*
VisualViewport::GetPresShell() const
{
  nsCOMPtr<nsPIDOMWindowInner> window = GetOwner();
  if (!window) {
    return nullptr;
  }

  nsIDocShell* docShell = window->GetDocShell();
  if (!docShell) {
    return nullptr;
  }

  return docShell->GetPresShell();
}