path: root/libraries/iconfix/internal/qiconloader.cpp

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#include "qiconloader_p.h"

#include <QtGui/QIconEnginePlugin>
#include <QtGui/QPixmapCache>
#include <QtGui/QIconEngine>
#include <QtGui/QPalette>
#include <QtCore/QList>
#include <QtCore/QHash>
#include <QtCore/QDir>
#include <QtCore/QSettings>
#include <QtGui/QPainter>
#include <QApplication>
#include <QLatin1Literal>

#include "qhexstring_p.h"

namespace QtXdg
{

Q_GLOBAL_STATIC(QIconLoader, iconLoaderInstance)

/* Theme to use in last resort, if the theme does not have the icon, neither the parents  */

static QString fallbackTheme()
{
	return QString("hicolor");
}

QIconLoader::QIconLoader() : m_themeKey(1), m_supportsSvg(false), m_initialized(false)
{
}

// We lazily initialize the loader to make static icons
// work. Though we do not officially support this.

static inline QString systemThemeName()
{
	return QIcon::themeName();
}

static inline QStringList systemIconSearchPaths()
{
	auto paths = QIcon::themeSearchPaths();
	paths.push_front(":/icons");
	return paths;
}

void QIconLoader::ensureInitialized()
{
	if (!m_initialized)
	{
		m_initialized = true;

		Q_ASSERT(qApp);

		m_systemTheme = QIcon::themeName();

		if (m_systemTheme.isEmpty())
			m_systemTheme = fallbackTheme();
		m_supportsSvg = true;
	}
}

QIconLoader *QIconLoader::instance()
{
	iconLoaderInstance()->ensureInitialized();
	return iconLoaderInstance();
}

// Queries the system theme and invalidates existing
// icons if the theme has changed.
void QIconLoader::updateSystemTheme()
{
	// Only change if this is not explicitly set by the user
	if (m_userTheme.isEmpty())
	{
		QString theme = systemThemeName();
		if (theme.isEmpty())
			theme = fallbackTheme();
		if (theme != m_systemTheme)
		{
			m_systemTheme = theme;
			invalidateKey();
		}
	}
}

void QIconLoader::setThemeName(const QString &themeName)
{
	m_userTheme = themeName;
	invalidateKey();
}

void QIconLoader::setThemeSearchPath(const QStringList &searchPaths)
{
	m_iconDirs = searchPaths;
	themeList.clear();
	invalidateKey();
}

QStringList QIconLoader::themeSearchPaths() const
{
	if (m_iconDirs.isEmpty())
	{
		m_iconDirs = systemIconSearchPaths();
	}
	return m_iconDirs;
}

QIconTheme::QIconTheme(const QString &themeName) : m_valid(false)
{
	QFile themeIndex;

	QStringList iconDirs = systemIconSearchPaths();
	for (int i = 0; i < iconDirs.size(); ++i)
	{
		QDir iconDir(iconDirs[i]);
		QString themeDir = iconDir.path() + QLatin1Char('/') + themeName;
		themeIndex.setFileName(themeDir + QLatin1String("/index.theme"));
		if (themeIndex.exists())
		{
			m_contentDir = themeDir;
			m_valid = true;

			foreach (QString path, iconDirs)
			{
				if (QFileInfo(path).isDir())
					m_contentDirs.append(path + QLatin1Char('/') + themeName);
			}

			break;
		}
	}

	// if there is no index file, abscond.
	if (!themeIndex.exists())
		return;

	// otherwise continue reading index file
	const QSettings indexReader(themeIndex.fileName(), QSettings::IniFormat);
	QStringListIterator keyIterator(indexReader.allKeys());
	while (keyIterator.hasNext())
	{
		const QString key = keyIterator.next();
		if (!key.endsWith(QLatin1String("/Size")))
			continue;

		// Note the QSettings ini-format does not accept
		// slashes in key names, hence we have to cheat
		int size = indexReader.value(key).toInt();
		if (!size)
			continue;

		QString directoryKey = key.left(key.size() - 5);
		QIconDirInfo dirInfo(directoryKey);
		dirInfo.size = size;
		QString type =
			indexReader.value(directoryKey + QLatin1String("/Type")).toString();

		if (type == QLatin1String("Fixed"))
			dirInfo.type = QIconDirInfo::Fixed;
		else if (type == QLatin1String("Scalable"))
			dirInfo.type = QIconDirInfo::Scalable;
		else
			dirInfo.type = QIconDirInfo::Threshold;

		dirInfo.threshold =
			indexReader.value(directoryKey + QLatin1String("/Threshold"), 2)
				.toInt();

		dirInfo.minSize =
			indexReader.value(directoryKey + QLatin1String("/MinSize"), size)
				.toInt();

		dirInfo.maxSize =
			indexReader.value(directoryKey + QLatin1String("/MaxSize"), size)
				.toInt();
		m_keyList.append(dirInfo);
	}

	// Parent themes provide fallbacks for missing icons
	m_parents = indexReader.value(QLatin1String("Icon Theme/Inherits")).toStringList();
	m_parents.removeAll(QString());

	// Ensure a default platform fallback for all themes
	if (m_parents.isEmpty())
	{
		const QString fallback = fallbackTheme();
		if (!fallback.isEmpty())
			m_parents.append(fallback);
	}

	// Ensure that all themes fall back to hicolor
	if (!m_parents.contains(QLatin1String("hicolor")))
		m_parents.append(QLatin1String("hicolor"));
}

QThemeIconEntries QIconLoader::findIconHelper(const QString &themeName, const QString &iconName,
											  QStringList &visited) const
{
	QThemeIconEntries entries;
	Q_ASSERT(!themeName.isEmpty());

	QPixmap pixmap;

	// Used to protect against potential recursions
	visited << themeName;

	QIconTheme theme = themeList.value(themeName);
	if (!theme.isValid())
	{
		theme = QIconTheme(themeName);
		if (!theme.isValid())
			theme = QIconTheme(fallbackTheme());

		themeList.insert(themeName, theme);
	}

	QStringList contentDirs = theme.contentDirs();
	const QVector<QIconDirInfo> subDirs = theme.keyList();

	const QString svgext(QLatin1String(".svg"));
	const QString pngext(QLatin1String(".png"));
	const QString xpmext(QLatin1String(".xpm"));

	// Add all relevant files
	for (int i = 0; i < subDirs.size(); ++i)
	{
		const QIconDirInfo &dirInfo = subDirs.at(i);
		QString subdir = dirInfo.path;

		foreach (QString contentDir, contentDirs)
		{
			QDir currentDir(contentDir + '/' + subdir);

			if (currentDir.exists(iconName + pngext))
			{
				PixmapEntry *iconEntry = new PixmapEntry;
				iconEntry->dir = dirInfo;
				iconEntry->filename = currentDir.filePath(iconName + pngext);
				// Notice we ensure that pixmap entries always come before
				// scalable to preserve search order afterwards
				entries.prepend(iconEntry);
			}
			else if (m_supportsSvg && currentDir.exists(iconName + svgext))
			{
				ScalableEntry *iconEntry = new ScalableEntry;
				iconEntry->dir = dirInfo;
				iconEntry->filename = currentDir.filePath(iconName + svgext);
				entries.append(iconEntry);
				break;
			}
			else if (currentDir.exists(iconName + xpmext))
			{
				PixmapEntry *iconEntry = new PixmapEntry;
				iconEntry->dir = dirInfo;
				iconEntry->filename = currentDir.filePath(iconName + xpmext);
				// Notice we ensure that pixmap entries always come before
				// scalable to preserve search order afterwards
				entries.append(iconEntry);
				break;
			}
		}
	}

	if (entries.isEmpty())
	{
		const QStringList parents = theme.parents();
		// Search recursively through inherited themes
		for (int i = 0; i < parents.size(); ++i)
		{

			const QString parentTheme = parents.at(i).trimmed();

			if (!visited.contains(parentTheme)) // guard against recursion
				entries = findIconHelper(parentTheme, iconName, visited);

			if (!entries.isEmpty()) // success
				break;
		}
	}

/*********************************************************************
Author: Kaitlin Rupert <kaitlin.rupert@intel.com>
Date: Aug 12, 2010
Description: Make it so that the QIcon loader honors /usr/share/pixmaps
			 directory.  This is a valid directory per the Freedesktop.org
			 icon theme specification.
Bug: https://bugreports.qt.nokia.com/browse/QTBUG-12874
 *********************************************************************/
#ifdef Q_OS_LINUX
	/* Freedesktop standard says to look in /usr/share/pixmaps last */
	if (entries.isEmpty())
	{
		const QString pixmaps(QLatin1String("/usr/share/pixmaps"));

		QDir currentDir(pixmaps);
		QIconDirInfo dirInfo(pixmaps);
		if (currentDir.exists(iconName + pngext))
		{
			PixmapEntry *iconEntry = new PixmapEntry;
			iconEntry->dir = dirInfo;
			iconEntry->filename = currentDir.filePath(iconName + pngext);
			// Notice we ensure that pixmap entries always come before
			// scalable to preserve search order afterwards
			entries.prepend(iconEntry);
		}
		else if (m_supportsSvg && currentDir.exists(iconName + svgext))
		{
			ScalableEntry *iconEntry = new ScalableEntry;
			iconEntry->dir = dirInfo;
			iconEntry->filename = currentDir.filePath(iconName + svgext);
			entries.append(iconEntry);
		}
		else if (currentDir.exists(iconName + xpmext))
		{
			PixmapEntry *iconEntry = new PixmapEntry;
			iconEntry->dir = dirInfo;
			iconEntry->filename = currentDir.filePath(iconName + xpmext);
			// Notice we ensure that pixmap entries always come before
			// scalable to preserve search order afterwards
			entries.append(iconEntry);
		}
	}
#endif

	if (entries.isEmpty())
	{
		// Search for unthemed icons in main dir of search paths
		QStringList themeSearchPaths = QIcon::themeSearchPaths();
		foreach (QString contentDir, themeSearchPaths)
		{
			QDir currentDir(contentDir);

			if (currentDir.exists(iconName + pngext))
			{
				PixmapEntry *iconEntry = new PixmapEntry;
				iconEntry->filename = currentDir.filePath(iconName + pngext);
				// Notice we ensure that pixmap entries always come before
				// scalable to preserve search order afterwards
				entries.prepend(iconEntry);
			}
			else if (m_supportsSvg && currentDir.exists(iconName + svgext))
			{
				ScalableEntry *iconEntry = new ScalableEntry;
				iconEntry->filename = currentDir.filePath(iconName + svgext);
				entries.append(iconEntry);
				break;
			}
			else if (currentDir.exists(iconName + xpmext))
			{
				PixmapEntry *iconEntry = new PixmapEntry;
				iconEntry->filename = currentDir.filePath(iconName + xpmext);
				// Notice we ensure that pixmap entries always come before
				// scalable to preserve search order afterwards
				entries.append(iconEntry);
				break;
			}
		}
	}
	return entries;
}

QThemeIconEntries QIconLoader::loadIcon(const QString &name) const
{
	if (!themeName().isEmpty())
	{
		QStringList visited;
		return findIconHelper(themeName(), name, visited);
	}

	return QThemeIconEntries();
}

// -------- Icon Loader Engine -------- //

QIconLoaderEngineFixed::QIconLoaderEngineFixed(const QString &iconName)
	: m_iconName(iconName), m_key(0)
{
}

QIconLoaderEngineFixed::~QIconLoaderEngineFixed()
{
	qDeleteAll(m_entries);
}

QIconLoaderEngineFixed::QIconLoaderEngineFixed(const QIconLoaderEngineFixed &other)
	: QIconEngine(other), m_iconName(other.m_iconName), m_key(0)
{
}

QIconEngine *QIconLoaderEngineFixed::clone() const
{
	return new QIconLoaderEngineFixed(*this);
}

bool QIconLoaderEngineFixed::read(QDataStream &in)
{
	in >> m_iconName;
	return true;
}

bool QIconLoaderEngineFixed::write(QDataStream &out) const
{
	out << m_iconName;
	return true;
}

bool QIconLoaderEngineFixed::hasIcon() const
{
	return !(m_entries.isEmpty());
}

// Lazily load the icon
void QIconLoaderEngineFixed::ensureLoaded()
{
	if (!(QIconLoader::instance()->themeKey() == m_key))
	{

		qDeleteAll(m_entries);

		m_entries = QIconLoader::instance()->loadIcon(m_iconName);
		m_key = QIconLoader::instance()->themeKey();
	}
}

void QIconLoaderEngineFixed::paint(QPainter *painter, const QRect &rect, QIcon::Mode mode,
								   QIcon::State state)
{
	QSize pixmapSize = rect.size();
#if defined(Q_WS_MAC)
	pixmapSize *= qt_mac_get_scalefactor();
#endif
	painter->drawPixmap(rect, pixmap(pixmapSize, mode, state));
}

/*
 * This algorithm is defined by the freedesktop spec:
 * http://standards.freedesktop.org/icon-theme-spec/icon-theme-spec-latest.html
 */
static bool directoryMatchesSize(const QIconDirInfo &dir, int iconsize)
{
	if (dir.type == QIconDirInfo::Fixed)
	{
		return dir.size == iconsize;
	}
	else if (dir.type == QIconDirInfo::Scalable)
	{
		return dir.size <= dir.maxSize && iconsize >= dir.minSize;
	}
	else if (dir.type == QIconDirInfo::Threshold)
	{
		return iconsize >= dir.size - dir.threshold && iconsize <= dir.size + dir.threshold;
	}

	Q_ASSERT(1); // Not a valid value
	return false;
}

/*
 * This algorithm is defined by the freedesktop spec:
 * http://standards.freedesktop.org/icon-theme-spec/icon-theme-spec-latest.html
 */
static int directorySizeDistance(const QIconDirInfo &dir, int iconsize)
{
	if (dir.type == QIconDirInfo::Fixed)
	{
		return qAbs(dir.size - iconsize);
	}
	else if (dir.type == QIconDirInfo::Scalable)
	{
		if (iconsize < dir.minSize)
			return dir.minSize - iconsize;
		else if (iconsize > dir.maxSize)
			return iconsize - dir.maxSize;
		else
			return 0;
	}
	else if (dir.type == QIconDirInfo::Threshold)
	{
		if (iconsize < dir.size - dir.threshold)
			return dir.minSize - iconsize;
		else if (iconsize > dir.size + dir.threshold)
			return iconsize - dir.maxSize;
		else
			return 0;
	}

	Q_ASSERT(1); // Not a valid value
	return INT_MAX;
}

QIconLoaderEngineEntry *QIconLoaderEngineFixed::entryForSize(const QSize &size)
{
	int iconsize = qMin(size.width(), size.height());

	// Note that m_entries are sorted so that png-files
	// come first

	const int numEntries = m_entries.size();

	// Search for exact matches first
	for (int i = 0; i < numEntries; ++i)
	{
		QIconLoaderEngineEntry *entry = m_entries.at(i);
		if (directoryMatchesSize(entry->dir, iconsize))
		{
			return entry;
		}
	}

	// Find the minimum distance icon
	int minimalSize = INT_MAX;
	QIconLoaderEngineEntry *closestMatch = 0;
	for (int i = 0; i < numEntries; ++i)
	{
		QIconLoaderEngineEntry *entry = m_entries.at(i);
		int distance = directorySizeDistance(entry->dir, iconsize);
		if (distance < minimalSize)
		{
			minimalSize = distance;
			closestMatch = entry;
		}
	}
	return closestMatch;
}

/*
 * Returns the actual icon size. For scalable svg's this is equivalent
 * to the requested size. Otherwise the closest match is returned but
 * we can never return a bigger size than the requested size.
 *
 */
QSize QIconLoaderEngineFixed::actualSize(const QSize &size, QIcon::Mode mode,
										 QIcon::State state)
{
	ensureLoaded();

	QIconLoaderEngineEntry *entry = entryForSize(size);
	if (entry)
	{
		const QIconDirInfo &dir = entry->dir;
		if (dir.type == QIconDirInfo::Scalable)
			return size;
		else
		{
			int result = qMin<int>(dir.size, qMin(size.width(), size.height()));
			return QSize(result, result);
		}
	}
	return QIconEngine::actualSize(size, mode, state);
}

QPixmap PixmapEntry::pixmap(const QSize &size, QIcon::Mode mode, QIcon::State state)
{
	Q_UNUSED(state);

	// Ensure that basePixmap is lazily initialized before generating the
	// key, otherwise the cache key is not unique
	if (basePixmap.isNull())
		basePixmap.load(filename);

	QSize actualSize = basePixmap.size();
	if (!actualSize.isNull() &&
		(actualSize.width() > size.width() || actualSize.height() > size.height()))
		actualSize.scale(size, Qt::KeepAspectRatio);

	QString key = QLatin1String("$qt_theme_") % HexString<qint64>(basePixmap.cacheKey()) %
				  HexString<int>(mode) %
				  HexString<qint64>(QGuiApplication::palette().cacheKey()) %
				  HexString<int>(actualSize.width()) % HexString<int>(actualSize.height());

	QPixmap cachedPixmap;
	if (QPixmapCache::find(key, &cachedPixmap))
	{
		return cachedPixmap;
	}
	else
	{
		if (basePixmap.size() != actualSize)
		{
			cachedPixmap = basePixmap.scaled(actualSize, Qt::IgnoreAspectRatio, Qt::SmoothTransformation);
		}
		else
		{
			cachedPixmap = basePixmap;
		}
		QPixmapCache::insert(key, cachedPixmap);
	}
	return cachedPixmap;
}

QPixmap ScalableEntry::pixmap(const QSize &size, QIcon::Mode mode, QIcon::State state)
{
	if (svgIcon.isNull())
	{
		svgIcon = QIcon(filename);
	}

	// Simply reuse svg icon engine
	return svgIcon.pixmap(size, mode, state);
}

QPixmap QIconLoaderEngineFixed::pixmap(const QSize &size, QIcon::Mode mode, QIcon::State state)
{
	ensureLoaded();

	QIconLoaderEngineEntry *entry = entryForSize(size);
	if (entry)
	{
		return entry->pixmap(size, mode, state);
	}

	return QPixmap();
}

QString QIconLoaderEngineFixed::key() const
{
	return QLatin1String("QIconLoaderEngineFixed");
}

void QIconLoaderEngineFixed::virtual_hook(int id, void *data)
{
	ensureLoaded();

	switch (id)
	{
	case QIconEngine::AvailableSizesHook:
	{
		QIconEngine::AvailableSizesArgument &arg =
			*reinterpret_cast<QIconEngine::AvailableSizesArgument *>(data);
		const int N = m_entries.size();
		QList<QSize> sizes;
		sizes.reserve(N);

		// Gets all sizes from the DirectoryInfo entries
		for (int i = 0; i < N; ++i)
		{
			int size = m_entries.at(i)->dir.size;
			sizes.append(QSize(size, size));
		}
		arg.sizes.swap(sizes); // commit
	}
	break;
	case QIconEngine::IconNameHook:
	{
		QString &name = *reinterpret_cast<QString *>(data);
		name = m_iconName;
	}
	break;
	default:
		QIconEngine::virtual_hook(id, data);
	}
}

} // QtXdg