Differential D18883 Diff 51292 thumbnail/pdfcreator.cpp

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thumbnail/pdfcreator.cpp

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1		/*
2		* Copyright (c) 2019 Kai Uwe Broulik <kde@broulik.de>
3		*
4		* This library is free software; you can redistribute it and/or
5		* modify it under the terms of the GNU Lesser General Public
6		* License as published by the Free Software Foundation; either
7		* version 2.1 of the License, or (at your option) version 3, or any
8		* later version accepted by the membership of KDE e.V. (or its
9		* successor approved by the membership of KDE e.V.), which shall
10		* act as a proxy defined in Section 6 of version 3 of the license.
11		*
12		* This library is distributed in the hope that it will be useful,
13		* but WITHOUT ANY WARRANTY; without even the implied warranty of
14		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15		* Lesser General Public License for more details.
16		*
17		* You should have received a copy of the GNU Lesser General Public
18		* License along with this library. If not, see <http://www.gnu.org/licenses/>.
19		*/
20
21		#include "pdfcreator.h"
22
23		#include <QImage>
24		#include <QScopedPointer>
	pinoUnsubmitted Not Done the QFile include is no more needed now pino: the QFile include is no more needed now
25
26		#include <poppler-qt5.h>
27
28		extern "C"
29		{
30		Q_DECL_EXPORT ThumbCreator *new_creator()
31		{
32		return new PdfCreator;
33		}
34		}
35
36		using namespace Poppler;
37
38		PdfCreator::PdfCreator() = default;
39
40		PdfCreator::~PdfCreator() = default;
41
42		bool PdfCreator::create(const QString &path, int width, int height, QImage &image)
43		{
44		QScopedPointer<Document> document;
45		document.reset(Document::load(path));
46
47		if (!document \|\| document->isLocked()) {
	pinoUnsubmitted Not Done please honor the requested width and height pino: please honor the requested width and height
	broulikAuthorUnsubmitted Not Done I can't. The `renderToImage` can only be told a resolution or part of the page to render, to render downscaled into a certain box. The `ThumbnailJob` downscales the image when it exceeds the requested size, so doing any manual downscaling (other than already getting the correct size which we can't) here is superfluous. broulik: I can't. The `renderToImage` can only be told a resolution or part of the page to render, to…
	pinoUnsubmitted Not Done Sure you can: see what okular does, for example, as it requests pixmaps of precise sizes. pino: Sure you can: see what okular does, for example, as it requests pixmaps of precise sizes.
48		return false;
49		}
50
	pinoUnsubmitted Not Done Document::load() takes a QString, so do not encode the filename (which will be encoded twice) pino: Document::load() takes a QString, so do not encode the filename (which will be encoded twice)
51		document->setRenderHint(Poppler::Document::Antialiasing);
52		document->setRenderHint(Poppler::Document::TextAntialiasing);
53
54		QScopedPointer<Page> page;
55		page.reset(document->page(0));
56
57		if (!page) {
58		return false;
59		}
60
61		// Compute a dpi that results in a thumbnail roughly the size we requested
62		const qreal fakeDpiX = width / page->pageSizeF().width() * 72.0;
	dhaumannUnsubmitted Not Done Does this also give nice results with high dpi displays? dhaumann: Does this also give nice results with high dpi displays?
	broulikAuthorUnsubmitted Not Done KIO Thumbnailer doesn't support high dpi at all at this point. broulik: KIO Thumbnailer doesn't support high dpi at all at this point.
63		const qreal fakeDpiY = height / page->pageSizeF().height() * 72.0;
64
65		// Preserve aspect fit
66		const qreal fakeDpi = std::min(fakeDpiX, fakeDpiY);
67
68		image = page->renderToImage(fakeDpi, fakeDpi);
69
70		return !image.isNull();
71		}