/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is mozilla.org code.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1998
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Travis Bogard <travis@netscape.com>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
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 * the provisions above, a recipient may use your version of this file under
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 *
 * ***** END LICENSE BLOCK ***** */

#include "nscore.h"
#include "nsScreen.h"
#include "nsPIDOMWindow.h"
#include "nsIScriptGlobalObject.h"
#include "nsIDocShell.h"
#include "nsIDeviceContext.h"
#include "nsPresContext.h"
#include "nsCOMPtr.h"
#include "nsIDocumentViewer.h"
#include "nsDOMClassInfo.h"
#include "nsIInterfaceRequestorUtils.h"

//
//  Screen class implementation
//
nsScreen::nsScreen(nsIDocShell* aDocShell)
  : mDocShell(aDocShell)
{
}

nsScreen::~nsScreen()
{
}


// QueryInterface implementation for nsScreen
NS_INTERFACE_MAP_BEGIN(nsScreen)
  NS_INTERFACE_MAP_ENTRY(nsISupports)
  NS_INTERFACE_MAP_ENTRY(nsIDOMScreen)
  NS_DOM_INTERFACE_MAP_ENTRY_CLASSINFO(Screen)
NS_INTERFACE_MAP_END


NS_IMPL_ADDREF(nsScreen)
NS_IMPL_RELEASE(nsScreen)


NS_IMETHODIMP
nsScreen::SetDocShell(nsIDocShell* aDocShell)
{
   mDocShell = aDocShell; // Weak Reference
   return NS_OK;
}

NS_IMETHODIMP
nsScreen::GetTop(PRInt32* aTop)
{
  nsRect rect;
  nsresult rv = GetRect(rect);

  *aTop = rect.y;

  return rv;
}


NS_IMETHODIMP
nsScreen::GetLeft(PRInt32* aLeft)
{
  nsRect rect;
  nsresult rv = GetRect(rect);

  *aLeft = rect.x;

  return rv;
}


NS_IMETHODIMP
nsScreen::GetWidth(PRInt32* aWidth)
{
  nsRect rect;
  nsresult rv = GetRect(rect);

  *aWidth = rect.width;

  return rv;
}

NS_IMETHODIMP
nsScreen::GetHeight(PRInt32* aHeight)
{
  nsRect rect;
  nsresult rv = GetRect(rect);

  *aHeight = rect.height;

  return rv;
}

NS_IMETHODIMP
nsScreen::GetPixelDepth(PRInt32* aPixelDepth)
{
  nsIDeviceContext* context = GetDeviceContext();

  if (!context) {
    *aPixelDepth = -1;

    return NS_ERROR_FAILURE;
  }

  PRUint32 depth;
  context->GetDepth(depth);

  *aPixelDepth = depth;

  return NS_OK;
}

NS_IMETHODIMP
nsScreen::GetColorDepth(PRInt32* aColorDepth)
{
  return GetPixelDepth(aColorDepth);
}

NS_IMETHODIMP
nsScreen::GetAvailWidth(PRInt32* aAvailWidth)
{
  nsRect rect;
  nsresult rv = GetAvailRect(rect);

  *aAvailWidth = rect.width;

  return rv;
}

NS_IMETHODIMP
nsScreen::GetAvailHeight(PRInt32* aAvailHeight)
{
  nsRect rect;
  nsresult rv = GetAvailRect(rect);

  *aAvailHeight = rect.height;

  return rv;
}

NS_IMETHODIMP
nsScreen::GetAvailLeft(PRInt32* aAvailLeft)
{
  nsRect rect;
  nsresult rv = GetAvailRect(rect);

  *aAvailLeft = rect.x;

  return rv;
}

NS_IMETHODIMP
nsScreen::GetAvailTop(PRInt32* aAvailTop)
{
  nsRect rect;
  nsresult rv = GetAvailRect(rect);

  *aAvailTop = rect.y;

  return rv;
}

nsIDeviceContext*
nsScreen::GetDeviceContext()
{
  if(!mDocShell)
    return nsnull;

  // Now make sure our size is up to date.  That will mean that the device
  // context does the right thing on multi-monitor systems when we return it to
  // the caller.  It will also make sure that our prescontext has been created,
  // if we're supposed to have one.
  nsCOMPtr<nsPIDOMWindow> win = do_GetInterface(mDocShell);
  if (!win) {
    // No reason to go on
    return nsnull;
  }

  win->EnsureSizeUpToDate();
  
  nsCOMPtr<nsIContentViewer> contentViewer;
  mDocShell->GetContentViewer(getter_AddRefs(contentViewer));

  nsCOMPtr<nsIDocumentViewer> docViewer(do_QueryInterface(contentViewer));
  if(!docViewer)
    return nsnull;

  nsCOMPtr<nsPresContext> presContext;
  docViewer->GetPresContext(getter_AddRefs(presContext));

  nsIDeviceContext* context = nsnull;
  if(presContext)
    context = presContext->DeviceContext();

  return context;
}

nsresult
nsScreen::GetRect(nsRect& aRect)
{
  nsIDeviceContext *context = GetDeviceContext();

  if (!context) {
    return NS_ERROR_FAILURE;
  }

  context->GetRect(aRect);

  float devUnits;
  devUnits = context->DevUnitsToAppUnits();

  aRect.x = NSToIntRound(float(aRect.x) / devUnits);
  aRect.y = NSToIntRound(float(aRect.y) / devUnits);

  context->GetDeviceSurfaceDimensions(aRect.width, aRect.height);

  aRect.height = NSToIntRound(float(aRect.height) / devUnits);
  aRect.width = NSToIntRound(float(aRect.width) / devUnits);

  return NS_OK;
}

nsresult
nsScreen::GetAvailRect(nsRect& aRect)
{
  nsIDeviceContext *context = GetDeviceContext();

  if (!context) {
    return NS_ERROR_FAILURE;
  }

  context->GetClientRect(aRect);

  float devUnits;
  devUnits = context->DevUnitsToAppUnits();

  aRect.x = NSToIntRound(float(aRect.x) / devUnits);
  aRect.y = NSToIntRound(float(aRect.y) / devUnits);
  aRect.height = NSToIntRound(float(aRect.height) / devUnits);
  aRect.width = NSToIntRound(float(aRect.width) / devUnits);

  return NS_OK;
}
