widget/WindowSurfaceX11SHM.cpp
author Nicholas Nethercote <nnethercote@mozilla.com>
Wed, 25 Oct 2017 10:22:38 +1100
changeset 387909 3d0093f961eec929caa370444cd0f7fcbfbc82bc
parent 304992 586815d86b50e44a1cc48c734c4da6efcd8ae8ff
child 448947 6f3709b3878117466168c40affa7bca0b60cf75b
permissions -rw-r--r--
Bug 1410794 - Change some |string| occurrences in nsIPrefBranch.idl to |ACString|. r=erahm. This makes the code nicer. In particular, it removes many getter_Copies() calls. The patch also converts a lot of nsCStrings to nsAutoCString, which will avoid heap allocation in the common case. The patch also renames PREF_CopyCharPref() as PREF_GetCStringPref(), because it's actually getting a string, not a char, and that matches the existing GetCString() and GetDefaultCString() methods. Correspondingly, it also renames PREF_SetCharPref() as PREF_SetCStringPref(). The |aPrefName| arguments in nsIPrefBranch.idl remain as |string| because they almost always involve passing in C string literals, and passing "foo" is much nicer than passing NS_LITERAL_CSTRING("foo"). It's worth noting that early versions of this patch used |AUTF8String| instead of |ACString|. But it turns out that libpref stores prefs internally as Latin1. And |ACString| is compatible with Latin1 but |AUTF8String| isn't, because non-ASCII Latin1 strings are not valid UTF-8!

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "WindowSurfaceX11SHM.h"

namespace mozilla {
namespace widget {

WindowSurfaceX11SHM::WindowSurfaceX11SHM(Display* aDisplay, Drawable aWindow,
                                         Visual* aVisual, unsigned int aDepth)
{
  mFrontImage = new nsShmImage(aDisplay, aWindow, aVisual, aDepth);
  mBackImage = new nsShmImage(aDisplay, aWindow, aVisual, aDepth);
}

already_AddRefed<gfx::DrawTarget>
WindowSurfaceX11SHM::Lock(const LayoutDeviceIntRegion& aRegion)
{
  mBackImage.swap(mFrontImage);
  return mBackImage->CreateDrawTarget(aRegion);
}

void
WindowSurfaceX11SHM::Commit(const LayoutDeviceIntRegion& aInvalidRegion)
{
  mBackImage->Put(aInvalidRegion);
}

} // namespace widget
} // namespace mozilla