[kde5] RpOverlayIconPlugin: New plugin (and forwarder) for overlay icons.

Currently returns "security-medium" for all URLs.

TODO:
- The JSON file is not currently used. Should use kcoreaddons_add_plugin()
  in CMake to make use of it.
- Consolidate common code in the plugin forwarders into a templated class.
  (Or don't; it's not *that* much duplicated code...)
- Actually check the RomData subclass for overlay icons.

debian/rom-properties-kde5.install

@@ -1,3 +1,4 @@
 usr/lib/*/qt5/plugins/rom-properties-kde5.so
 usr/lib/*/qt5/plugins/kf5/kfilemetadata/kfilemetadata_rom-properties-kde5.so
+usr/lib/*/qt5/plugins/kf5/overlayicon/overlayiconplugin_rom-properties-kde5.so
 usr/share/kservices5/rom-properties-kde5.desktop

src/kde/kde5/CMakeLists.txt

@@ -73,6 +73,7 @@ IF(ECM_MODULE_PATH AND ECM_KDE_MODULE_DIR)
 
 		# TODO: Can we get the subdirectory from KFileMetaData?
 		SET(KFMD_PLUGIN_INSTALL_DIR "${PLUGIN_INSTALL_DIR}/kf5/kfilemetadata")
+		SET(KFOV_PLUGIN_INSTALL_DIR "${PLUGIN_INSTALL_DIR}/kf5/overlayicon")
 	ELSE()
 		# Qt5 not found.
 		SET(BUILD_KDE5 OFF CACHE "" INTERNAL FORCE)
@@ -91,11 +92,13 @@ STRING(REGEX REPLACE "([^;]+)" "../\\1" rom-properties-kde5_UIS  "${rom-properti
 SET(rom-properties-kde5_SRCS
 	${rom-properties-kde5_SRCS}
 	RpExtractorPlugin.cpp
+	RpOverlayIconPlugin.cpp
 	RomPropertiesDialogPluginFactoryKDE5.cpp
 	)
 SET(rom-properties-kde5_H
 	${rom-properties-kde5_H}
 	RpExtractorPlugin.hpp
+	RpOverlayIconPlugin.hpp
 	)
 
 IF(COMMAND QT5_WRAP_UI)
@@ -152,12 +155,30 @@ IF(BUILD_KDE5)
 	TARGET_COMPILE_DEFINITIONS(kfilemetadata_rom-properties-kde5
 		PRIVATE PLUGIN_INSTALL_DIR=\"${PLUGIN_INSTALL_DIR}\"
 		)
-
 	# Link in libdl if it's required for dlopen().
 	IF(CMAKE_DL_LIBS)
 		TARGET_LINK_LIBRARIES(kfilemetadata_rom-properties-kde5 ${CMAKE_DL_LIBS})
 	ENDIF(CMAKE_DL_LIBS)
 
+	# RpOverlayIconPluginForwarder
+	# TODO: Use kcoreaddons_add_plugin() for the JSON?
+	# https://github.com/owncloud/client/blob/master/shell_integration/dolphin/CMakeLists.txt
+	# TODO: Better name.
+	ADD_LIBRARY(overlayiconplugin_rom-properties-kde5 MODULE
+		RpOverlayIconPluginForwarder.cpp
+		RpOverlayIconPluginForwarder.hpp
+		)
+	SET_TARGET_PROPERTIES(overlayiconplugin_rom-properties-kde5 PROPERTIES PREFIX "")
+	DO_SPLIT_DEBUG(overlayiconplugin_rom-properties-kde5)
+	TARGET_LINK_LIBRARIES(overlayiconplugin_rom-properties-kde5 KF5::KIOCore KF5::KIOWidgets)
+	TARGET_COMPILE_DEFINITIONS(overlayiconplugin_rom-properties-kde5
+		PRIVATE PLUGIN_INSTALL_DIR=\"${PLUGIN_INSTALL_DIR}\"
+		)
+	# Link in libdl if it's required for dlopen().
+	IF(CMAKE_DL_LIBS)
+		TARGET_LINK_LIBRARIES(overlayiconplugin_rom-properties-kde5 ${CMAKE_DL_LIBS})
+	ENDIF(CMAKE_DL_LIBS)
+
 	# FIXME: Workaround for gcc-5.4.0 LTO bug.
 	# Disabling LTO for the KDE5 build if using gcc-5.4.0 or earlier,
 	# and decryption is enabled. (It crashes when compiling the moc
@@ -187,6 +208,10 @@ IF(BUILD_KDE5)
 		LIBRARY DESTINATION "${KFMD_PLUGIN_INSTALL_DIR}"
 		COMPONENT "plugin"
 		)
+	INSTALL(TARGETS overlayiconplugin_rom-properties-kde5
+		LIBRARY DESTINATION "${KFOV_PLUGIN_INSTALL_DIR}"
+		COMPONENT "plugin"
+		)
 	INSTALL(FILES "${CMAKE_CURRENT_SOURCE_DIR}/rom-properties-kde5.desktop"
 		DESTINATION "${SERVICES_INSTALL_DIR}"
 		COMPONENT "plugin"
@@ -211,5 +236,13 @@ IF(BUILD_KDE5)
 				COMPONENT "debug"
 				)
 		ENDIF(DEBUG_FILENAME)
+
+		GET_TARGET_PROPERTY(DEBUG_FILENAME overlayiconplugin_rom-properties-kde5 PDB)
+		IF(DEBUG_FILENAME)
+			INSTALL(FILES "${DEBUG_FILENAME}"
+				DESTINATION "lib/debug/${CMAKE_INSTALL_PREFIX}/${KFOV_PLUGIN_INSTALL_DIR}"
+				COMPONENT "debug"
+				)
+		ENDIF(DEBUG_FILENAME)
 	ENDIF(INSTALL_DEBUG)
 ENDIF(BUILD_KDE5)

src/kde/kde5/RpOverlayIconPlugin.cpp

@@ -0,0 +1,91 @@
+/***************************************************************************
+ * ROM Properties Page shell extension. (KDE)                              *
+ * RpOverlayIconPlugin.cpp: KOverlayIconPlugin.                            *
+ *                                                                         *
+ * Qt's plugin system prevents a single shared library from exporting      *
+ * multiple plugins, so this file acts as a KOverlayIconPlugin,            *
+ * and then forwards the request to the main library.                      *
+ *                                                                         *
+ * Copyright (c) 2018 by David Korth.                                      *
+ *                                                                         *
+ * This program is free software; you can redistribute it and/or modify it *
+ * under the terms of the GNU General Public License as published by the   *
+ * Free Software Foundation; either version 2 of the License, or (at your  *
+ * option) any later version.                                              *
+ *                                                                         *
+ * This program is distributed in the hope that it will be useful, but     *
+ * WITHOUT ANY WARRANTY; without even the implied warranty of              *
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the           *
+ * GNU General Public License for more details.                            *
+ *                                                                         *
+ * You should have received a copy of the GNU General Public License       *
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.   *
+ ***************************************************************************/
+
+#include "RpOverlayIconPlugin.hpp"
+
+// librpbase
+#include "librpbase/RomData.hpp"
+#include "librpbase/file/RpFile.hpp"
+using LibRpBase::RomData;
+using LibRpBase::IRpFile;
+using LibRpBase::RpFile;
+
+// libromdata
+#include "libromdata/RomDataFactory.hpp"
+using LibRomData::RomDataFactory;
+
+// C includes. (C++ namespace)
+#include <cassert>
+
+// C++ includes.
+#include <memory>
+#include <string>
+#include <vector>
+using std::string;
+using std::unique_ptr;
+using std::vector;
+
+// Qt includes.
+#include <QtCore/QDateTime>
+
+// KDE includes.
+#include <kfilemetadata/extractorplugin.h>
+#include <kfilemetadata/properties.h>
+using KFileMetaData::ExtractorPlugin;
+using KFileMetaData::ExtractionResult;
+using namespace KFileMetaData::Property;
+
+#if QT_VERSION >= QT_VERSION_CHECK(5,0,0)
+
+#include <kfileitem.h>
+
+namespace RomPropertiesKDE {
+
+/**
+ * Factory method.
+ * NOTE: Unlike the ThumbCreator version, this one is specific to
+ * rom-properties, and is called by a forwarder library.
+ */
+extern "C" {
+	Q_DECL_EXPORT RpOverlayIconPlugin *PFN_CREATEOVERLAYICONPLUGINKDE_FN(QObject *parent)
+	{
+		return new RpOverlayIconPlugin(parent);
+	}
+}
+
+RpOverlayIconPlugin::RpOverlayIconPlugin(QObject *parent)
+	: super(parent)
+{ }
+
+QStringList RpOverlayIconPlugin::getOverlays(const QUrl &item)
+{
+	// TODO: Check the RomData object.
+	QStringList sl;
+	sl += QLatin1String("security-medium");
+	return sl;
+}
+
+}
+
+#endif /* QT_VERSION >= QT_VERSION_CHECK(5,0,0) */

src/kde/kde5/RpOverlayIconPlugin.hpp

@@ -0,0 +1,69 @@
+/***************************************************************************
+ * ROM Properties Page shell extension. (KDE)                              *
+ * RpOverlayIconPlugin.hpp: KOverlayIconPlugin.                            *
+ *                                                                         *
+ * Qt's plugin system prevents a single shared library from exporting      *
+ * multiple plugins, so this file acts as a KOverlayIconPlugin,            *
+ * and then forwards the request to the main library.                      *
+ *                                                                         *
+ * Copyright (c) 2018 by David Korth.                                      *
+ *                                                                         *
+ * This program is free software; you can redistribute it and/or modify it *
+ * under the terms of the GNU General Public License as published by the   *
+ * Free Software Foundation; either version 2 of the License, or (at your  *
+ * option) any later version.                                              *
+ *                                                                         *
+ * This program is distributed in the hope that it will be useful, but     *
+ * WITHOUT ANY WARRANTY; without even the implied warranty of              *
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the           *
+ * GNU General Public License for more details.                            *
+ *                                                                         *
+ * You should have received a copy of the GNU General Public License       *
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.   *
+ ***************************************************************************/
+
+#ifndef __ROMPROPERTIES_KDE_RPOVERLAYICONPLUGIN_HPP__
+#define __ROMPROPERTIES_KDE_RPOVERLAYICONPLUGIN_HPP__
+
+// FIXME: Test on KDE4.
+#include <QtCore/qglobal.h>
+
+#if QT_VERSION >= QT_VERSION_CHECK(5,0,0)
+
+#include <KOverlayIconPlugin>
+
+namespace RomPropertiesKDE {
+
+class RpOverlayIconPlugin : public KOverlayIconPlugin
+{
+	Q_OBJECT
+	//Q_INTERFACES(KOverlayIconPlugin)
+
+	public:
+		explicit RpOverlayIconPlugin(QObject *parent = nullptr);
+
+	private:
+		typedef KOverlayIconPlugin super;
+		Q_DISABLE_COPY(RpOverlayIconPlugin);
+
+	public:
+		QStringList getOverlays(const QUrl &item) final;
+};
+
+// Exported function pointer to create a new RpExtractorPlugin.
+typedef RpOverlayIconPlugin* (*pfn_createOverlayIconPluginKDE_t)(QObject *parent);
+#if QT_VERSION >= QT_VERSION_CHECK(6,0,0)
+# error Qt6 is not supported.
+#elif QT_VERSION >= QT_VERSION_CHECK(5,0,0)
+# define PFN_CREATEOVERLAYICONPLUGINKDE_FN createOverlayIconPluginKDE5
+# define PFN_CREATEOVERLAYICONPLUGINKDE_NAME "createOverlayIconPluginKDE5"
+#else /* QT_VERSION < QT_VERSION_CHECK(5,0,0) */
+# define PFN_CREATEOVERLAYICONPLUGINKDE_FN createOverlayIconPluginKDE4
+# define PFN_CREATEOVERLAYICONPLUGINKDE_NAME "createOverlayIconPluginKDE4"
+#endif
+
+}
+
+#endif /* QT_VERSION >= QT_VERSION_CHECK(5,0,0) */
+
+#endif /* __ROMPROPERTIES_KDE_RPOVERLAYICONPLUGIN_HPP__ */

src/kde/kde5/RpOverlayIconPluginForwarder.cpp

@@ -0,0 +1,119 @@
+/***************************************************************************
+ * ROM Properties Page shell extension. (KDE)                              *
+ * RpOverlayIconPluginForwarder.cpp: KOverlayIconPlugin forwarder.         *
+ *                                                                         *
+ * Qt's plugin system prevents a single shared library from exporting      *
+ * multiple plugins, so this file acts as a KOverlayIconPlugin,            *
+ * and then forwards the request to the main library.                      *
+ *                                                                         *
+ * Copyright (c) 2018 by David Korth.                                      *
+ *                                                                         *
+ * This program is free software; you can redistribute it and/or modify it *
+ * under the terms of the GNU General Public License as published by the   *
+ * Free Software Foundation; either version 2 of the License, or (at your  *
+ * option) any later version.                                              *
+ *                                                                         *
+ * This program is distributed in the hope that it will be useful, but     *
+ * WITHOUT ANY WARRANTY; without even the implied warranty of              *
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the           *
+ * GNU General Public License for more details.                            *
+ *                                                                         *
+ * You should have received a copy of the GNU General Public License       *
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.   *
+ ***************************************************************************/
+
+#include "RpOverlayIconPluginForwarder.hpp"
+#include "RpOverlayIconPlugin.hpp"
+
+// C includes.
+#include <dlfcn.h>
+
+// KDE includes.
+#include <KOverlayIconPlugin>
+
+#if QT_VERSION >= QT_VERSION_CHECK(5,0,0)
+
+#include <kfileitem.h>
+
+namespace RomPropertiesKDE {
+
+RpOverlayIconPluginForwarder::RpOverlayIconPluginForwarder(QObject *parent)
+	: super(parent)
+	, hRpKdeSo(nullptr)
+	, fwd_plugin(nullptr)
+{
+#ifndef PLUGIN_INSTALL_DIR
+# error PLUGIN_INSTALL_DIR is not set.
+#endif
+	// FIXME: Check the .desktop file?
+	QString pluginPath(QString::fromUtf8(PLUGIN_INSTALL_DIR));
+	pluginPath += QLatin1String("/rom-properties-kde5.so");
+
+	// Attempt to load the plugin.
+	hRpKdeSo = dlopen(pluginPath.toUtf8().constData(), RTLD_LOCAL|RTLD_LAZY);
+	if (!hRpKdeSo) {
+		// Unable to open the plugin.
+		// NOTE: We can't use mismatched plugins here.
+		return;
+	}
+
+	// Load the symbol.
+	pfn_createOverlayIconPluginKDE_t pfn = reinterpret_cast<pfn_createOverlayIconPluginKDE_t>(
+		dlsym(hRpKdeSo, PFN_CREATEOVERLAYICONPLUGINKDE_NAME));
+	if (!pfn) {
+		// Symbol not found.
+		dlclose(hRpKdeSo);
+		hRpKdeSo = nullptr;
+		return;
+	}
+
+	// Create an RpOverlayIconPlugin object.
+	fwd_plugin = pfn(this);
+	if (!fwd_plugin) {
+		// Unable to create an RpOverlayIconPlugin object.
+		dlclose(hRpKdeSo);
+		hRpKdeSo = nullptr;
+		return;
+	}
+
+	// Make sure we know if the OverlayPlugin gets deleted.
+	// This *shouldn't* happen, but it's possible that our parent
+	// object enumerates child objects and does weird things.
+	connect(fwd_plugin, SIGNAL(destroyed(QObject*)),
+		this, SLOT(fwd_plugin_destroyed(QObject*)));
+}
+
+RpOverlayIconPluginForwarder::~RpOverlayIconPluginForwarder()
+{
+	delete fwd_plugin;
+
+	// FIXME: What does dlclose(nullptr) do?
+	if (hRpKdeSo) {
+		dlclose(hRpKdeSo);
+	}
+}
+
+QStringList RpOverlayIconPluginForwarder::getOverlays(const QUrl &item)
+{
+	if (fwd_plugin) {
+		return fwd_plugin->getOverlays(item);
+	}
+	return QStringList();
+}
+
+/**
+ * fwd_plugin was destroyed.
+ * @param obj
+ */
+void RpOverlayIconPluginForwarder::fwd_plugin_destroyed(QObject *obj)
+{
+	if (obj == fwd_plugin) {
+		// Object matches.
+		// NULL it out so we don't have problems later.
+		fwd_plugin = nullptr;
+	}
+}
+
+}
+
+#endif /* QT_VERSION >= QT_VERSION_CHECK(5,0,0) */

src/kde/kde5/RpOverlayIconPluginForwarder.hpp

@@ -0,0 +1,74 @@
+/***************************************************************************
+ * ROM Properties Page shell extension. (KDE)                              *
+ * RpOverlayIconPluginForwarder.hpp: KOverlayIconPlugin forwarder.         *
+ *                                                                         *
+ * Qt's plugin system prevents a single shared library from exporting      *
+ * multiple plugins, so this file acts as a KOverlayIconPlugin,            *
+ * and then forwards the request to the main library.                      *
+ *                                                                         *
+ * Copyright (c) 2018 by David Korth.                                      *
+ *                                                                         *
+ * This program is free software; you can redistribute it and/or modify it *
+ * under the terms of the GNU General Public License as published by the   *
+ * Free Software Foundation; either version 2 of the License, or (at your  *
+ * option) any later version.                                              *
+ *                                                                         *
+ * This program is distributed in the hope that it will be useful, but     *
+ * WITHOUT ANY WARRANTY; without even the implied warranty of              *
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the           *
+ * GNU General Public License for more details.                            *
+ *                                                                         *
+ * You should have received a copy of the GNU General Public License       *
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.   *
+ ***************************************************************************/
+
+#ifndef __ROMPROPERTIES_KDE_OVERLAYICONPLUGINFORWARDER_HPP__
+#define __ROMPROPERTIES_KDE_OVERLAYICONPLUGINFORWARDER_HPP__
+
+// FIXME: Test on KDE4.
+#include <QtCore/qglobal.h>
+
+#if QT_VERSION >= QT_VERSION_CHECK(5,0,0)
+
+#include <KOverlayIconPlugin>
+
+namespace RomPropertiesKDE {
+
+class RpOverlayIconPluginForwarder : public KOverlayIconPlugin
+{
+	Q_OBJECT
+	// NOTE: KDE doesn't have a standard IID for KOverlayIconPlugin...
+	Q_PLUGIN_METADATA(IID "com.gerbilsoft.rom-properties.KOverlayIconPlugin" FILE "RpOverlayIconPluginForwarder.json")
+	//Q_INTERFACES(KOverlayIconPlugin)
+
+	public:
+		explicit RpOverlayIconPluginForwarder(QObject *parent = nullptr);
+		virtual ~RpOverlayIconPluginForwarder();
+
+	private:
+		typedef KOverlayIconPlugin super;
+		Q_DISABLE_COPY(RpOverlayIconPluginForwarder);
+
+	public:
+		QStringList getOverlays(const QUrl &item) final;
+
+	private:
+		// rom-properties-kde5.so handle.
+		void *hRpKdeSo;
+
+		// Actual OverlayPlugin.
+		KOverlayIconPlugin *fwd_plugin;
+
+	private slots:
+		/**
+		 * fwd_plugin was destroyed.
+		 * @param obj
+		 */
+		void fwd_plugin_destroyed(QObject *obj = nullptr);
+};
+
+}
+
+#endif /* QT_VERSION >= QT_VERSION_CHECK(5,0,0) */
+
+#endif /* __ROMPROPERTIES_KDE_OVERLAYICONPLUGINFORWARDER_HPP__ */

src/kde/kde5/RpOverlayIconPluginForwarder.json

@@ -0,0 +1,8 @@
+{
+    "KPlugin": {
+        "Description": "Overlay icon for rom-properties",
+        "ServiceTypes": [
+            "KOverlayIconPlugin"
+        ]
+    }
+}