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/* -*- Mode: C++; tab-width: 20; 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 "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)
{
MOZ_ASSERT(aRecorder);
MOZ_ASSERT(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()) {
gfxCriticalNote
<< "Failed to create a recording DrawTarget for PrintTarget";
return nullptr;
}
return dt.forget();
}
} // namespace gfx
} // namespace mozilla
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