Differential D11064 Diff 28844 kcms/fonts/previewimageprovider.cpp

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kcms/fonts/previewimageprovider.cpp

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1		/*
2		Copyright (c) 2018 Julian Wolff <wolff@julianwolff.de>
3
4		This library is free software; you can redistribute it and/or
5		modify it under the terms of the GNU Library General Public
6		License as published by the Free Software Foundation; either
7		version 2 of the License, or (at your option) any later version.
8
9		This library is distributed in the hope that it will be useful,
10		but WITHOUT ANY WARRANTY; without even the implied warranty of
11		MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12		Library General Public License for more details.
13
14		You should have received a copy of the GNU Library General Public License
15		along with this library; see the file COPYING.LIB. If not, write to
16		the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
17		Boston, MA 02110-1301, USA.
18		*/
19
20		#include <QApplication>
21		#include <QPainter>
22		#include <QPalette>
23
24		#include "kxftconfig.h"
25		#include "previewimageprovider.h"
26		#include "previewrenderengine.h"
27
28		QImage combineImages(const QList<QImage>& images, const QColor& bgnd, int spacing=0)
29		{
30		int width = 0;
31		int height = 0;
32		QImage::Format format = QImage::Format_Invalid;
33		int devicePixelRatio = 1;
34		for(const auto& image : images) {
35		if(width < image.width()) {
36		width = image.width();
	broulikUnsubmitted Done avoid splitting twice, I suggest storing const auto sections = id.splitRef(QLatin1Char('_')); Also do a bounds check broulik: avoid splitting twice, I suggest storing ``` const auto sections = id.splitRef(QLatin1Char…
37		}
38		height += image.height() + spacing;
39		format = image.format();
40		devicePixelRatio = image.devicePixelRatio();
41		}
42		height -= spacing;
43
44		// To correctly align the image pixels on a high dpi display,
45		// the image dimensions need to be a multiple of devicePixelRatio
46		width = (width + devicePixelRatio - 1) / devicePixelRatio * devicePixelRatio;
47		height = (height + devicePixelRatio - 1) / devicePixelRatio * devicePixelRatio;
48
49		QImage combinedImage(width, height, format);
50		combinedImage.setDevicePixelRatio(devicePixelRatio);
51		combinedImage.fill(bgnd);
52
53		int offset = 0;
54		QPainter p(&combinedImage);
55		for(const auto& image : images) {
56		p.drawImage(0, offset, image);
57		offset += (image.height() + spacing) / devicePixelRatio;
58		}
59
60		return combinedImage;
61		}
62
63		PreviewImageProvider::PreviewImageProvider(const QFont& font)
64		: QQuickImageProvider(QQuickImageProvider::Image)
65		, m_font(font)
66		{
67		}
	broulikUnsubmitted Done Your image does not take into account `devicePixelRatio` which makes it blurred on my high dpi screen. I'm not sure how to exactly fix that, perhaps `@2x` works for the image provider, or you can manually implement this, to test run QT_SCREEN_SCALE_FACTORS=2 kcmshell5 kcm_fonts broulik: Your image does not take into account `devicePixelRatio` which makes it blurred on my high dpi…
68
69		QImage PreviewImageProvider::requestImage(const QString &id, QSize *size, const QSize &requestedSize)
70		{
71		int subPixelIndex = 0;
72		int hintingIndex = 0;
73
74		const auto idpart = id.splitRef(QLatin1Char('.'))[0];
75		const auto sections = idpart.split(QLatin1Char('_'));
76
77		if (sections.size() >= 2) {
78		subPixelIndex = sections[0].toInt();
79		hintingIndex = sections[1].toInt();
80		}
81
82		KXftConfig xft;
83
84
85		KXftConfig::AntiAliasing::State oldAntialiasing = xft.getAntiAliasing();
86		double oldStart,oldEnd;
87		xft.getExcludeRange(oldStart, oldEnd);
88		KXftConfig::SubPixel::Type oldSubPixelType;
89		xft.getSubPixelType(oldSubPixelType);
90		KXftConfig::Hint::Style oldHintStyle;
91		xft.getHintStyle(oldHintStyle);
92
93
94		xft.setAntiAliasing(KXftConfig::AntiAliasing::Enabled);
95		xft.setExcludeRange(0, 0);
96
97		KXftConfig::SubPixel::Type subPixelType = (KXftConfig::SubPixel::Type)subPixelIndex;
98		xft.setSubPixelType(subPixelType);
99
100		KXftConfig::Hint::Style hintStyle = (KXftConfig::Hint::Style)hintingIndex;
101		xft.setHintStyle(hintStyle);
102
103		xft.apply();
104
105
106		QColor text(QApplication::palette().color(QPalette::Text));
107		QColor bgnd(QApplication::palette().color(QPalette::Window));
108
109		PreviewRenderEngine eng(true);
110		QList<QImage> lines;
111
112		lines << eng.drawAutoSize(m_font, text, bgnd, eng.getDefaultPreviewString());
113
114		QImage img = combineImages(lines, bgnd, lines[0].height()*.25);
115
116
117		xft.setAntiAliasing(oldAntialiasing);
118		xft.setExcludeRange(oldStart, oldEnd);
119		xft.setSubPixelType(oldSubPixelType);
120		xft.setHintStyle(oldHintStyle);
121
122		*size = img.size();
123
124		return img;
125		}