core/desktopentry: add limited desktop entry api

src/core/desktopentry.hpp

@@ -0,0 +1,151 @@
+#pragma once
+
+#include <utility>
+
+#include <qcontainerfwd.h>
+#include <qdir.h>
+#include <qhash.h>
+#include <qobject.h>
+#include <qqmlintegration.h>
+#include <qtmetamacros.h>
+
+#include "model.hpp"
+
+class DesktopAction;
+
+/// A desktop entry. See [DesktopEntries](../desktopentries) for details.
+class DesktopEntry: public QObject {
+	Q_OBJECT;
+	Q_PROPERTY(QString id MEMBER mId CONSTANT);
+	/// Name of the specific application, such as "Firefox".
+	Q_PROPERTY(QString name MEMBER mName CONSTANT);
+	/// Short description of the application, such as "Web Browser". May be empty.
+	Q_PROPERTY(QString genericName MEMBER mGenericName CONSTANT);
+	/// If true, this application should not be displayed in menus and launchers.
+	Q_PROPERTY(bool noDisplay MEMBER mNoDisplay CONSTANT);
+	/// Long description of the application, such as "View websites on the internet". May be empty.
+	Q_PROPERTY(QString comment MEMBER mComment CONSTANT);
+	/// Name of the icon associated with this application. May be empty.
+	Q_PROPERTY(QString icon MEMBER mIcon CONSTANT);
+	/// The raw `Exec` string from the desktop entry. You probably want `execute()`.
+	Q_PROPERTY(QString execString MEMBER mExecString CONSTANT);
+	/// The working directory to execute from.
+	Q_PROPERTY(QString workingDirectory MEMBER mWorkingDirectory CONSTANT);
+	/// If the application should run in a terminal.
+	Q_PROPERTY(bool runInTerminal MEMBER mTerminal CONSTANT);
+	Q_PROPERTY(QVector<QString> categories MEMBER mCategories CONSTANT);
+	Q_PROPERTY(QVector<QString> keywords MEMBER mKeywords CONSTANT);
+	Q_PROPERTY(QVector<DesktopAction*> actions READ actions CONSTANT);
+	QML_ELEMENT;
+	QML_UNCREATABLE("DesktopEntry instances must be retrieved from DesktopEntries");
+
+public:
+	explicit DesktopEntry(QString id, QObject* parent): QObject(parent), mId(std::move(id)) {}
+
+	void parseEntry(const QString& text);
+
+	/// Run the application. Currently ignores `runInTerminal` and field codes.
+	Q_INVOKABLE void execute() const;
+
+	[[nodiscard]] bool isValid() const;
+	[[nodiscard]] bool noDisplay() const;
+	[[nodiscard]] QVector<DesktopAction*> actions() const;
+
+	// currently ignores all field codes.
+	static QVector<QString> parseExecString(const QString& execString);
+	static void doExec(const QString& execString, const QString& workingDirectory);
+
+private:
+	QHash<QString, QString> mEntries;
+	QHash<QString, DesktopAction*> mActions;
+
+	QString mId;
+	QString mName;
+	QString mGenericName;
+	bool mNoDisplay = false;
+	QString mComment;
+	QString mIcon;
+	QString mExecString;
+	QString mWorkingDirectory;
+	bool mTerminal = false;
+	QVector<QString> mCategories;
+	QVector<QString> mKeywords;
+
+	friend class DesktopAction;
+};
+
+/// An action of a [DesktopEntry](../desktopentry).
+class DesktopAction: public QObject {
+	Q_OBJECT;
+	Q_PROPERTY(QString id MEMBER mId CONSTANT);
+	Q_PROPERTY(QString name MEMBER mName CONSTANT);
+	Q_PROPERTY(QString icon MEMBER mIcon CONSTANT);
+	/// The raw `Exec` string from the desktop entry. You probably want `execute()`.
+	Q_PROPERTY(QString execString MEMBER mExecString CONSTANT);
+	QML_ELEMENT;
+	QML_UNCREATABLE("DesktopAction instances must be retrieved from a DesktopEntry");
+
+public:
+	explicit DesktopAction(QString id, DesktopEntry* entry)
+	    : QObject(entry)
+	    , entry(entry)
+	    , mId(std::move(id)) {}
+
+	/// Run the application. Currently ignores `runInTerminal` and field codes.
+	Q_INVOKABLE void execute() const;
+
+private:
+	DesktopEntry* entry;
+	QString mId;
+	QString mName;
+	QString mIcon;
+	QString mExecString;
+	QHash<QString, QString> mEntries;
+
+	friend class DesktopEntry;
+};
+
+class DesktopEntryManager: public QObject {
+	Q_OBJECT;
+
+public:
+	void scanDesktopEntries();
+
+	[[nodiscard]] DesktopEntry* byId(const QString& id);
+
+	[[nodiscard]] ObjectModel<DesktopEntry>* applications();
+
+	static DesktopEntryManager* instance();
+
+private:
+	explicit DesktopEntryManager();
+
+	void populateApplications();
+	void scanPath(const QDir& dir, const QString& prefix = QString());
+
+	QHash<QString, DesktopEntry*> desktopEntries;
+	ObjectModel<DesktopEntry> mApplications {this};
+};
+
+///! Desktop entry index.
+/// Index of desktop entries according to the [desktop entry specification].
+///
+/// Primarily useful for looking up icons and metadata from an id, as there is
+/// currently no mechanism for usage based sorting of entries and other launcher niceties.
+///
+/// [desktop entry specification]: https://specifications.freedesktop.org/desktop-entry-spec/latest/
+class DesktopEntries: public QObject {
+	Q_OBJECT;
+	/// All desktop entries of type Application that are not Hidden or NoDisplay.
+	Q_PROPERTY(ObjectModel<DesktopEntry>* applications READ applications CONSTANT);
+	QML_ELEMENT;
+	QML_SINGLETON;
+
+public:
+	explicit DesktopEntries();
+
+	/// Look up a desktop entry by name. Includes NoDisplay entries. May return null.
+	Q_INVOKABLE [[nodiscard]] static DesktopEntry* byId(const QString& id);
+
+	[[nodiscard]] static ObjectModel<DesktopEntry>* applications();
+};