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	# ignore-this-changeset Differential Revision: https://phabricator.services.mozilla.com/D95434
		
			
				
	
	
		
			111 lines
		
	
	
	
		
			3.9 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			111 lines
		
	
	
	
		
			3.9 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
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 * This Source Code Form is subject to the terms of the Mozilla Public
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 * License, v. 2.0. If a copy of the MPL was not distributed with this
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 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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#include "PrintTargetRecording.h"
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#include "cairo.h"
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#include "mozilla/gfx/2D.h"
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#include "mozilla/gfx/Logging.h"
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namespace mozilla {
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namespace gfx {
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PrintTargetRecording::PrintTargetRecording(cairo_surface_t* aCairoSurface,
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                                           const IntSize& aSize)
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    : PrintTarget(aCairoSurface, aSize) {}
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/* static */
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already_AddRefed<PrintTargetRecording> PrintTargetRecording::CreateOrNull(
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    const IntSize& aSize) {
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  if (!Factory::CheckSurfaceSize(aSize)) {
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    return nullptr;
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  }
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  // Perhaps surprisingly, this surface is never actually drawn to.  This class
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  // creates a DrawTargetRecording using CreateRecordingDrawTarget, and
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  // that needs another DrawTarget to be passed to it.  You might expect the
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  // type of the DrawTarget that is passed to matter because it would seem
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  // logical to encoded its type in the recording, and on replaying the
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  // recording a DrawTarget of the same type would be created.  However, the
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  // passed DrawTarget's type doesn't seem to be encoded any more accurately
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  // than just "BackendType::CAIRO".  Even if it were, the code that replays the
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  // recording is PrintTranslator::TranslateRecording which (indirectly) calls
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  // MakePrintTarget on the type of nsIDeviceContextSpecProxy that is created
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  // for the platform that we're running on, and the type of DrawTarget that
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  // that returns is hardcoded.
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  //
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  // The only reason that we use cairo_recording_surface_create here is:
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  //
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  //   * It's pretty much the only cairo_*_surface_create methods that's both
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  //     available on all platforms and doesn't require allocating a
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  //     potentially large surface.
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  //
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  //   * Since we need a DrawTarget to pass to CreateRecordingDrawTarget we
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  //     might as well leverage our base class's machinery to create a
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  //     DrawTarget (it's as good a way as any other that will work), and to do
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  //     that we need a cairo_surface_t.
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  //
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  // So the fact that this is a "recording" PrintTarget and the function that
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  // we call here is cairo_recording_surface_create is simply a coincidence. We
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  // could use any cairo_*_surface_create method and this class would still
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  // work.
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  //
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  cairo_surface_t* surface =
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      cairo_recording_surface_create(CAIRO_CONTENT_COLOR_ALPHA, nullptr);
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  if (cairo_surface_status(surface)) {
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    return nullptr;
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  }
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  // The new object takes ownership of our surface reference.
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  RefPtr<PrintTargetRecording> target =
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      new PrintTargetRecording(surface, aSize);
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  return target.forget();
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}
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already_AddRefed<DrawTarget> PrintTargetRecording::MakeDrawTarget(
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    const IntSize& aSize, DrawEventRecorder* aRecorder) {
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  MOZ_ASSERT(aRecorder, "A DrawEventRecorder is required");
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  if (!aRecorder) {
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    return nullptr;
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  }
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  RefPtr<DrawTarget> dt = PrintTarget::MakeDrawTarget(aSize, nullptr);
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  if (dt) {
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    dt = CreateRecordingDrawTarget(aRecorder, dt);
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    if (!dt || !dt->IsValid()) {
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      return nullptr;
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    }
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  }
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  return dt.forget();
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}
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already_AddRefed<DrawTarget> PrintTargetRecording::CreateRecordingDrawTarget(
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    DrawEventRecorder* aRecorder, DrawTarget* aDrawTarget) {
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  MOZ_ASSERT(aRecorder);
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  MOZ_ASSERT(aDrawTarget);
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  RefPtr<DrawTarget> dt;
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  if (aRecorder) {
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    // It doesn't really matter what we pass as the DrawTarget here.
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    dt = gfx::Factory::CreateRecordingDrawTarget(aRecorder, aDrawTarget,
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                                                 aDrawTarget->GetRect());
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  }
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  if (!dt || !dt->IsValid()) {
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    gfxCriticalNote
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        << "Failed to create a recording DrawTarget for PrintTarget";
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    return nullptr;
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  }
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  return dt.forget();
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}
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}  // namespace gfx
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}  // namespace mozilla
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