| /* |
| * Copyright 2016 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #include "SkMultiPictureDocumentPriv.h" |
| #include "SkMultiPictureDocumentReader.h" |
| #include "SkPicture.h" |
| #include "SkStream.h" |
| #include "SkPictureRecorder.h" |
| #include "SkNWayCanvas.h" |
| |
| bool SkMultiPictureDocumentReader::init(SkStreamSeekable* stream) { |
| if (!stream) { |
| return false; |
| } |
| stream->seek(0); |
| const size_t size = sizeof(SkMultiPictureDocumentProtocol::kMagic) - 1; |
| char buffer[size]; |
| if (size != stream->read(buffer, size) || |
| 0 != memcmp(SkMultiPictureDocumentProtocol::kMagic, buffer, size)) { |
| stream = nullptr; |
| return false; |
| } |
| bool good = true; |
| uint32_t versionNumber = stream->readU32(); |
| if (versionNumber != SkMultiPictureDocumentProtocol::kVersion) { |
| return false; |
| } |
| uint32_t pageCount = stream->readU32(); |
| fSizes.reset(pageCount); |
| for (uint32_t i = 0; i < pageCount; ++i) { |
| SkSize size; |
| good &= sizeof(size) == stream->read(&size, sizeof(size)); |
| fSizes[i] = size; |
| } |
| fOffset = stream->getPosition(); |
| return good; |
| } |
| |
| namespace { |
| struct PagerCanvas : public SkNWayCanvas { |
| SkPictureRecorder fRecorder; |
| const SkTArray<SkSize>* fSizes; |
| SkTArray<sk_sp<SkPicture>>* fDest; |
| PagerCanvas(SkISize wh, |
| const SkTArray<SkSize>* s, |
| SkTArray<sk_sp<SkPicture>>* d) |
| : SkNWayCanvas(wh.width(), wh.height()), fSizes(s), fDest(d) { |
| this->nextCanvas(); |
| } |
| void nextCanvas() { |
| int i = fDest->count(); |
| if (i < fSizes->count()) { |
| SkRect bounds = SkRect::MakeSize((*fSizes)[i]); |
| this->addCanvas(fRecorder.beginRecording(bounds)); |
| } |
| } |
| void onDrawAnnotation(const SkRect& r, const char* key, SkData* d) override { |
| if (0 == strcmp(key, SkMultiPictureDocumentProtocol::kEndPage)) { |
| this->removeAll(); |
| if (fRecorder.getRecordingCanvas()) { |
| fDest->emplace_back(fRecorder.finishRecordingAsPicture()); |
| } |
| this->nextCanvas(); |
| } else { |
| this->SkNWayCanvas::onDrawAnnotation(r, key, d); |
| } |
| } |
| }; |
| } // namespace |
| |
| sk_sp<SkPicture> SkMultiPictureDocumentReader::readPage(SkStreamSeekable* stream, |
| int pageNumber) const { |
| SkASSERT(pageNumber >= 0); |
| SkASSERT(pageNumber < fSizes.count()); |
| if (0 == fPages.count()) { |
| stream->seek(fOffset); // jump to beginning of skp |
| auto picture = SkPicture::MakeFromStream(stream); |
| SkISize size = SkMultiPictureDocumentProtocol::Join(fSizes).toCeil(); |
| PagerCanvas canvas(size, &fSizes, &this->fPages); |
| // Must call playback(), not drawPicture() to reach |
| // PagerCanvas::onDrawAnnotation(). |
| picture->playback(&canvas); |
| if (fPages.count() != fSizes.count()) { |
| SkDEBUGF(("Malformed SkMultiPictureDocument\n")); |
| } |
| } |
| // Allow for malformed document. |
| return pageNumber < fPages.count() ? fPages[pageNumber] : nullptr; |
| } |