service/tray!: redesign menus / dbusmenu and add native menu support

Reworks dbusmenu menus to be displayable with a system context menu.

Breaks the entire DBusMenu api.

src/core/generation.cpp

@@ -8,12 +8,17 @@
 #include <qfileinfo.h>
 #include <qfilesystemwatcher.h>
 #include <qhash.h>
+#include <qicon.h>
+#include <qiconengine.h>
 #include <qlogging.h>
 #include <qloggingcategory.h>
 #include <qobject.h>
+#include <qpixmap.h>
 #include <qqmlcontext.h>
 #include <qqmlengine.h>
 #include <qqmlincubator.h>
+#include <qquickimageprovider.h>
+#include <qsize.h>
 #include <qtmetamacros.h>
 
 #include "iconimageprovider.hpp"
@@ -308,6 +313,90 @@ EngineGeneration* EngineGeneration::currentGeneration() {
 	} else return nullptr;
 }
 
+// QMenu re-calls pixmap() every time the mouse moves so its important to cache it.
+class PixmapCacheIconEngine: public QIconEngine {
+	void paint(
+	    QPainter* /*unused*/,
+	    const QRect& /*unused*/,
+	    QIcon::Mode /*unused*/,
+	    QIcon::State /*unused*/
+	) override {
+		qFatal(
+		) << "Unexpected icon paint request bypassed pixmap method. Please report this as a bug.";
+	}
+
+	QPixmap pixmap(const QSize& size, QIcon::Mode /*unused*/, QIcon::State /*unused*/) override {
+		if (this->lastPixmap.isNull() || size != this->lastSize) {
+			this->lastPixmap = this->createPixmap(size);
+			this->lastSize = size;
+		}
+
+		return this->lastPixmap;
+	}
+
+	virtual QPixmap createPixmap(const QSize& size) = 0;
+
+private:
+	QSize lastSize;
+	QPixmap lastPixmap;
+};
+
+class ImageProviderIconEngine: public PixmapCacheIconEngine {
+public:
+	explicit ImageProviderIconEngine(QQuickImageProvider* provider, QString id)
+	    : provider(provider)
+	    , id(std::move(id)) {}
+
+	QPixmap createPixmap(const QSize& size) override {
+		if (this->provider->imageType() == QQmlImageProviderBase::Pixmap) {
+			return this->provider->requestPixmap(this->id, nullptr, size);
+		} else if (this->provider->imageType() == QQmlImageProviderBase::Image) {
+			auto image = this->provider->requestImage(this->id, nullptr, size);
+			return QPixmap::fromImage(image);
+		} else {
+			qFatal() << "Unexpected ImageProviderIconEngine image type" << this->provider->imageType();
+			return QPixmap(); // never reached, satisfies lint
+		}
+	}
+
+	[[nodiscard]] QIconEngine* clone() const override {
+		return new ImageProviderIconEngine(this->provider, this->id);
+	}
+
+private:
+	QQuickImageProvider* provider;
+	QString id;
+};
+
+QIcon EngineGeneration::iconByUrl(const QUrl& url) const {
+	if (url.isEmpty()) return QIcon();
+
+	auto scheme = url.scheme();
+	if (scheme == "image") {
+		auto providerName = url.authority();
+		auto path = url.path();
+		if (!path.isEmpty()) path = path.sliced(1);
+
+		auto* provider = qobject_cast<QQuickImageProvider*>(this->engine->imageProvider(providerName));
+
+		if (provider == nullptr) {
+			qWarning() << "iconByUrl failed: no provider found for" << url;
+			return QIcon();
+		}
+
+		if (provider->imageType() == QQmlImageProviderBase::Pixmap
+		    || provider->imageType() == QQmlImageProviderBase::Image)
+		{
+			return QIcon(new ImageProviderIconEngine(provider, path));
+		}
+
+	} else {
+		qWarning() << "iconByUrl failed: unsupported scheme" << scheme << "in path" << url;
+	}
+
+	return QIcon();
+}
+
 EngineGeneration* EngineGeneration::findEngineGeneration(QQmlEngine* engine) {
 	return g_generations.value(engine);
 }