The Tor Browser: gfx/thebes/gfxWindowsNativeDrawing.h@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 /* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-

     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 #ifndef _GFXWINDOWSNATIVEDRAWING_H_

     7 #define _GFXWINDOWSNATIVEDRAWING_H_

     9 #include <windows.h>

    11 #include "gfxContext.h"

    12 #include "gfxWindowsSurface.h"

    14 class gfxWindowsNativeDrawing {

    15 public:

    17     /* Flags for notifying this class what kind of operations the native

    18      * drawing supports

    19      */

    21     enum {

    22         /* Whether the native drawing can draw to a surface of content COLOR_ALPHA */

    23         CAN_DRAW_TO_COLOR_ALPHA    = 1 << 0,

    24         CANNOT_DRAW_TO_COLOR_ALPHA = 0 << 0,

    26         /* Whether the native drawing can be scaled using SetWorldTransform */

    27         CAN_AXIS_ALIGNED_SCALE     = 1 << 1,

    28         CANNOT_AXIS_ALIGNED_SCALE  = 0 << 1,

    30         /* Whether the native drawing can be both scaled and rotated arbitrarily using SetWorldTransform */

    31         CAN_COMPLEX_TRANSFORM      = 1 << 2,

    32         CANNOT_COMPLEX_TRANSFORM   = 0 << 2,

    34         /* If we have to do transforms with cairo, should we use nearest-neighbour filtering? */

    35         DO_NEAREST_NEIGHBOR_FILTERING = 1 << 3,

    36         DO_BILINEAR_FILTERING         = 0 << 3

    37     };

    39     /* Create native win32 drawing for a rectangle bounded by

    40      * nativeRect.

    41      *

    42      * Typical usage looks like:

    43      *

    44      *   gfxWindowsNativeDrawing nativeDraw(ctx, destGfxRect, capabilities);

    45      *   do {

    46      *     HDC dc = nativeDraw.BeginNativeDrawing();

    47      *     if (!dc)

    48      *       return NS_ERROR_FAILURE;

    49      *

    50      *     RECT winRect;

    51      *     nativeDraw.TransformToNativeRect(rect, winRect);

    52      *

    53      *       ... call win32 operations on HDC to draw to winRect ...

    54      *

    55      *     nativeDraw.EndNativeDrawing();

    56      *   } while (nativeDraw.ShouldRenderAgain());

    57      *   nativeDraw.PaintToContext();

    58      */

    59     gfxWindowsNativeDrawing(gfxContext *ctx,

    60                             const gfxRect& nativeRect,

    61                             uint32_t nativeDrawFlags = CANNOT_DRAW_TO_COLOR_ALPHA |

    62                                                        CANNOT_AXIS_ALIGNED_SCALE |

    63                                                        CANNOT_COMPLEX_TRANSFORM |

    64                                                        DO_BILINEAR_FILTERING);

    66     /* Returns a HDC which may be used for native drawing.  This HDC is valid

    67      * until EndNativeDrawing is called; if it is used for drawing after that time,

    68      * the result is undefined. */

    69     HDC BeginNativeDrawing();

    71     /* Transform the native rect into something valid for rendering

    72      * to the HDC.  This may or may not change RECT, depending on

    73      * whether SetWorldTransform is used or not. */

    74     void TransformToNativeRect(const gfxRect& r, RECT& rout);

    76     /* Marks the end of native drawing */

    77     void EndNativeDrawing();

    79     /* Returns true if the native drawing should be executed again */

    80     bool ShouldRenderAgain();

    82     /* Returns true if double pass alpha extraction is taking place. */

    83     bool IsDoublePass();

    85     /* Places the result to the context, if necessary */

    86     void PaintToContext();

    88 private:

    90     nsRefPtr<gfxContext> mContext;

    91     gfxRect mNativeRect;

    92     uint32_t mNativeDrawFlags;

    94     // what state the rendering is in

    95     uint8_t mRenderState;

    97     gfxPoint mDeviceOffset;

    98     nsRefPtr<gfxPattern> mBlackPattern, mWhitePattern;

   100     enum TransformType {

   101         TRANSLATION_ONLY,

   102         AXIS_ALIGNED_SCALE,

   103         COMPLEX

   104     };

   106     TransformType mTransformType;

   107     gfxPoint mTranslation;

   108     gfxSize mScale;

   109     XFORM mWorldTransform;

   111     // saved state

   112     nsRefPtr<gfxWindowsSurface> mWinSurface, mBlackSurface, mWhiteSurface;

   113     HDC mDC;

   114     XFORM mOldWorldTransform;

   115     POINT mOrigViewportOrigin;

   116     gfxIntSize mTempSurfaceSize;

   117 };

   119 #endif

The Tor Browser / file revision

gfx/thebes/gfxWindowsNativeDrawing.h@97036ab72558

gfx/thebes/gfxWindowsNativeDrawing.h