The Tor Browser: widget/windows/nsScreenWin.cpp@ac0c01689b40

Implement a real Private Browsing Mode condition by changing the API/ABI;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

     1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

     2 /* This Source Code Form is subject to the terms of the Mozilla Public

     3  * License, v. 2.0. If a copy of the MPL was not distributed with this

     4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

     6 #include "nsScreenWin.h"

     7 #include "nsCoord.h"

     8 #include "gfxWindowsPlatform.h"

     9 #include "nsIWidget.h"

    12 nsScreenWin :: nsScreenWin ( HMONITOR inScreen )

    13   : mScreen(inScreen)

    14 {

    15 #ifdef DEBUG

    16   HDC hDCScreen = ::GetDC(nullptr);

    17   NS_ASSERTION(hDCScreen,"GetDC Failure");

    18   NS_ASSERTION ( ::GetDeviceCaps(hDCScreen, TECHNOLOGY) == DT_RASDISPLAY, "Not a display screen");

    19   ::ReleaseDC(nullptr,hDCScreen);

    20 #endif

    22   // nothing else to do. I guess we could cache a bunch of information

    23   // here, but we want to ask the device at runtime in case anything

    24   // has changed.

    25 }

    28 nsScreenWin :: ~nsScreenWin()

    29 {

    30   // nothing to see here.

    31 }

    34 NS_IMETHODIMP

    35 nsScreenWin :: GetRect(int32_t *outLeft, int32_t *outTop, int32_t *outWidth, int32_t *outHeight)

    36 {

    37   BOOL success = FALSE;

    38   if ( mScreen ) {

    39     MONITORINFO info;

    40     info.cbSize = sizeof(MONITORINFO);

    41     success = ::GetMonitorInfoW( mScreen, &info );

    42     if ( success ) {

    43       *outLeft = info.rcMonitor.left;

    44       *outTop = info.rcMonitor.top;

    45       *outWidth = info.rcMonitor.right - info.rcMonitor.left;

    46       *outHeight = info.rcMonitor.bottom - info.rcMonitor.top;

    47     }

    48   }

    49   if (!success) {

    50      HDC hDCScreen = ::GetDC(nullptr);

    51      NS_ASSERTION(hDCScreen,"GetDC Failure");

    53      *outTop = *outLeft = 0;

    54      *outWidth = ::GetDeviceCaps(hDCScreen, HORZRES);

    55      *outHeight = ::GetDeviceCaps(hDCScreen, VERTRES);

    57      ::ReleaseDC(nullptr, hDCScreen);

    58   }

    59   return NS_OK;

    61 } // GetRect

    64 NS_IMETHODIMP

    65 nsScreenWin :: GetAvailRect(int32_t *outLeft, int32_t *outTop, int32_t *outWidth, int32_t *outHeight)

    66 {

    67   BOOL success = FALSE;

    69   if ( mScreen ) {

    70     MONITORINFO info;

    71     info.cbSize = sizeof(MONITORINFO);

    72     success = ::GetMonitorInfoW( mScreen, &info );

    73     if ( success ) {

    74       *outLeft = info.rcWork.left;

    75       *outTop = info.rcWork.top;

    76       *outWidth = info.rcWork.right - info.rcWork.left;

    77       *outHeight = info.rcWork.bottom - info.rcWork.top;

    78     }

    79   }

    80   if (!success) {

    81     RECT workArea;

    82     ::SystemParametersInfo(SPI_GETWORKAREA, 0, &workArea, 0);

    83     *outLeft = workArea.left;

    84     *outTop = workArea.top;

    85     *outWidth = workArea.right - workArea.left;

    86     *outHeight = workArea.bottom - workArea.top;

    87   }

    89   return NS_OK;

    91 } // GetAvailRect

    93 static double

    94 GetDPIScale()

    95 {

    96   double dpiScale= nsIWidget::DefaultScaleOverride();

    97   if (dpiScale <= 0.0) {

    98     dpiScale = gfxWindowsPlatform::GetPlatform()->GetDPIScale();

    99   }

   100   return dpiScale;

   101 }

   103 NS_IMETHODIMP

   104 nsScreenWin::GetRectDisplayPix(int32_t *outLeft,  int32_t *outTop,

   105                                int32_t *outWidth, int32_t *outHeight)

   106 {

   107   int32_t left, top, width, height;

   108   nsresult rv = GetRect(&left, &top, &width, &height);

   109   if (NS_FAILED(rv)) {

   110     return rv;

   111   }

   112   double scaleFactor = 1.0 / GetDPIScale();

   113   *outLeft = NSToIntRound(left * scaleFactor);

   114   *outTop = NSToIntRound(top * scaleFactor);

   115   *outWidth = NSToIntRound(width * scaleFactor);

   116   *outHeight = NSToIntRound(height * scaleFactor);

   117   return NS_OK;

   118 }

   120 NS_IMETHODIMP

   121 nsScreenWin::GetAvailRectDisplayPix(int32_t *outLeft,  int32_t *outTop,

   122                                     int32_t *outWidth, int32_t *outHeight)

   123 {

   124   int32_t left, top, width, height;

   125   nsresult rv = GetAvailRect(&left, &top, &width, &height);

   126   if (NS_FAILED(rv)) {

   127     return rv;

   128   }

   129   double scaleFactor = 1.0 / GetDPIScale();

   130   *outLeft = NSToIntRound(left * scaleFactor);

   131   *outTop = NSToIntRound(top * scaleFactor);

   132   *outWidth = NSToIntRound(width * scaleFactor);

   133   *outHeight = NSToIntRound(height * scaleFactor);

   134   return NS_OK;

   135 }

   138 NS_IMETHODIMP

   139 nsScreenWin :: GetPixelDepth(int32_t *aPixelDepth)

   140 {

   141   //XXX not sure how to get this info for multiple monitors, this might be ok...

   142   HDC hDCScreen = ::GetDC(nullptr);

   143   NS_ASSERTION(hDCScreen,"GetDC Failure");

   145   int32_t depth = ::GetDeviceCaps(hDCScreen, BITSPIXEL);

   146   if (depth == 32) {

   147     // If a device uses 32 bits per pixel, it's still only using 8 bits

   148     // per color component, which is what our callers want to know.

   149     // (Some devices report 32 and some devices report 24.)

   150     depth = 24;

   151   }

   152   *aPixelDepth = depth;

   154   ::ReleaseDC(nullptr, hDCScreen);

   155   return NS_OK;

   157 } // GetPixelDepth

   160 NS_IMETHODIMP

   161 nsScreenWin :: GetColorDepth(int32_t *aColorDepth)

   162 {

   163   return GetPixelDepth(aColorDepth);

   165 } // GetColorDepth

The Tor Browser / file revision

widget/windows/nsScreenWin.cpp@ac0c01689b40

widget/windows/nsScreenWin.cpp