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