The Tor Browser: widget/qt/nsScreenManagerQt.cpp@97036ab72558

Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

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

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

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

     5 #include <QGuiApplication>

     6 #include <QScreen>

     8 #include "nsScreenManagerQt.h"

     9 #include "nsScreenQt.h"

    11 nsScreenManagerQt::nsScreenManagerQt()

    12 {

    13     mInitialized = false;

    14     desktop = 0;

    15     screens = 0;

    16 }

    18 nsScreenManagerQt::~nsScreenManagerQt()

    19 {

    20     delete [] screens;

    21 }

    23 // addref, release, QI

    24 NS_IMPL_ISUPPORTS(nsScreenManagerQt, nsIScreenManager)

    26 void nsScreenManagerQt::init()

    27 {

    28     if (mInitialized)

    29         return;

    31     nScreens = QGuiApplication::screens().size();

    32     screens = new nsCOMPtr<nsIScreen>[nScreens];

    34     for (int i = 0; i < nScreens; ++i)

    35         screens[i] = new nsScreenQt(i);

    36     mInitialized = true;

    37 }

    39 //

    40 // ScreenForRect

    41 //

    42 // Returns the screen that contains the rectangle. If the rect overlaps

    43 // multiple screens, it picks the screen with the greatest area of intersection.

    44 //

    45 // The coordinates are in pixels (not twips) and in screen coordinates.

    46 //

    47 NS_IMETHODIMP

    48 nsScreenManagerQt::ScreenForRect(int32_t inLeft, int32_t inTop,

    49                                  int32_t inWidth, int32_t inHeight,

    50                                  nsIScreen **outScreen)

    51 {

    52     if (!mInitialized)

    53         init();

    55     QRect r(inLeft, inTop, inWidth, inHeight);

    56     int best = 0;

    57     int area = 0;

    58     for (int i = 0; i < nScreens; ++i) {

    59         const QRect& rect = QGuiApplication::screens()[i]->geometry();

    60         QRect intersection = r&rect;

    61         int a = intersection.width()*intersection.height();

    62         if (a > area) {

    63             best = i;

    64             area = a;

    65         }

    66     }

    68     NS_IF_ADDREF(*outScreen = screens[best]);

    69     return NS_OK;

    70 }

    72 //

    73 // GetPrimaryScreen

    74 //

    75 // The screen with the menubar/taskbar. This shouldn't be needed very

    76 // often.

    77 //

    78 NS_IMETHODIMP

    79 nsScreenManagerQt::GetPrimaryScreen(nsIScreen **aPrimaryScreen)

    80 {

    81     if (!desktop)

    82         init();

    84     NS_IF_ADDREF(*aPrimaryScreen = screens[0]);

    85     return NS_OK;

    86 }

    88 //

    89 // GetNumberOfScreens

    90 //

    91 // Returns how many physical screens are available.

    92 //

    93 NS_IMETHODIMP

    94 nsScreenManagerQt::GetNumberOfScreens(uint32_t *aNumberOfScreens)

    95 {

    96     if (!desktop)

    97         init();

    99     *aNumberOfScreens = nScreens;

   100     return NS_OK;

   101 }

   103 NS_IMETHODIMP

   104 nsScreenManagerQt::GetSystemDefaultScale(float *aDefaultScale)

   105 {

   106     *aDefaultScale = 1.0f;

   107     return NS_OK;

   108 }

   110 NS_IMETHODIMP

   111 nsScreenManagerQt::ScreenForNativeWidget(void *aWidget, nsIScreen **outScreen)

   112 {

   113     // I don't know how to go from GtkWindow to nsIScreen, especially

   114     // given xinerama and stuff, so let's just do this

   115     QRect rect(0, 0, 1, 1);

   116     return ScreenForRect(rect.x(), rect.y(), rect.width(), rect.height(), outScreen);

   117 }

The Tor Browser / file revision

widget/qt/nsScreenManagerQt.cpp@97036ab72558

widget/qt/nsScreenManagerQt.cpp