The Tor Browser: widget/gtk/nsScreenGtk.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 "nsScreenGtk.h"

     8 #include <gdk/gdk.h>

     9 #ifdef MOZ_X11

    10 #include <gdk/gdkx.h>

    11 #include <X11/Xatom.h>

    12 #endif

    13 #include <gtk/gtk.h>

    15 nsScreenGtk :: nsScreenGtk (  )

    16   : mScreenNum(0),

    17     mRect(0, 0, 0, 0),

    18     mAvailRect(0, 0, 0, 0)

    19 {

    20 }

    23 nsScreenGtk :: ~nsScreenGtk()

    24 {

    25 }

    28 NS_IMETHODIMP

    29 nsScreenGtk :: GetRect(int32_t *outLeft, int32_t *outTop, int32_t *outWidth, int32_t *outHeight)

    30 {

    31   *outLeft = mRect.x;

    32   *outTop = mRect.y;

    33   *outWidth = mRect.width;

    34   *outHeight = mRect.height;

    36   return NS_OK;

    38 } // GetRect

    41 NS_IMETHODIMP

    42 nsScreenGtk :: GetAvailRect(int32_t *outLeft, int32_t *outTop, int32_t *outWidth, int32_t *outHeight)

    43 {

    44   *outLeft = mAvailRect.x;

    45   *outTop = mAvailRect.y;

    46   *outWidth = mAvailRect.width;

    47   *outHeight = mAvailRect.height;

    49   return NS_OK;

    51 } // GetAvailRect

    54 NS_IMETHODIMP

    55 nsScreenGtk :: GetPixelDepth(int32_t *aPixelDepth)

    56 {

    57   GdkVisual * visual = gdk_screen_get_system_visual(gdk_screen_get_default());

    58   *aPixelDepth = gdk_visual_get_depth(visual);

    60   return NS_OK;

    62 } // GetPixelDepth

    65 NS_IMETHODIMP

    66 nsScreenGtk :: GetColorDepth(int32_t *aColorDepth)

    67 {

    68   return GetPixelDepth ( aColorDepth );

    70 } // GetColorDepth

    73 void

    74 nsScreenGtk :: Init (GdkWindow *aRootWindow)

    75 {

    76   // We listen for configure events on the root window to pick up

    77   // changes to this rect.  We could listen for "size_changed" signals

    78   // on the default screen to do this, except that doesn't work with

    79   // versions of GDK predating the GdkScreen object.  See bug 256646.

    80   mAvailRect = mRect = nsIntRect(0, 0, gdk_screen_width(), gdk_screen_height());

    82 #ifdef MOZ_X11

    83   // We need to account for the taskbar, etc in the available rect.

    84   // See http://freedesktop.org/Standards/wm-spec/index.html#id2767771

    86   // XXX do we care about _NET_WM_STRUT_PARTIAL?  That will

    87   // add much more complexity to the code here (our screen

    88   // could have a non-rectangular shape), but should

    89   // lead to greater accuracy.

    91   long *workareas;

    92   GdkAtom type_returned;

    93   int format_returned;

    94   int length_returned;

    96   GdkAtom cardinal_atom = gdk_x11_xatom_to_atom(XA_CARDINAL);

    98   gdk_error_trap_push();

   100   // gdk_property_get uses (length + 3) / 4, hence G_MAXLONG - 3 here.

   101   if (!gdk_property_get(aRootWindow,

   102                         gdk_atom_intern ("_NET_WORKAREA", FALSE),

   103                         cardinal_atom,

   104                         0, G_MAXLONG - 3, FALSE,

   105                         &type_returned,

   106                         &format_returned,

   107                         &length_returned,

   108                         (guchar **) &workareas)) {

   109     // This window manager doesn't support the freedesktop standard.

   110     // Nothing we can do about it, so assume full screen size.

   111     return;

   112   }

   114   // Flush the X queue to catch errors now.

   115   gdk_flush();

   117   if (!gdk_error_trap_pop() &&

   118       type_returned == cardinal_atom &&

   119       length_returned && (length_returned % 4) == 0 &&

   120       format_returned == 32) {

   121     int num_items = length_returned / sizeof(long);

   123     for (int i = 0; i < num_items; i += 4) {

   124       nsIntRect workarea(workareas[i],     workareas[i + 1],

   125                          workareas[i + 2], workareas[i + 3]);

   126       if (!mRect.Contains(workarea)) {

   127         // Note that we hit this when processing screen size changes,

   128         // since we'll get the configure event before the toolbars have

   129         // been moved.  We'll end up cleaning this up when we get the

   130         // change notification to the _NET_WORKAREA property.  However,

   131         // we still want to listen to both, so we'll handle changes

   132         // properly for desktop environments that don't set the

   133         // _NET_WORKAREA property.

   134         NS_WARNING("Invalid bounds");

   135         continue;

   136       }

   138       mAvailRect.IntersectRect(mAvailRect, workarea);

   139     }

   140   }

   141   g_free (workareas);

   142 #endif

   143 }

   145 #ifdef MOZ_X11

   146 void

   147 nsScreenGtk :: Init (XineramaScreenInfo *aScreenInfo)

   148 {

   149   nsIntRect xineRect(aScreenInfo->x_org, aScreenInfo->y_org,

   150                      aScreenInfo->width, aScreenInfo->height);

   152   mScreenNum = aScreenInfo->screen_number;

   154   mAvailRect = mRect = xineRect;

   155 }

   156 #endif

The Tor Browser / file revision

widget/gtk/nsScreenGtk.cpp@ac0c01689b40

widget/gtk/nsScreenGtk.cpp