feat: add plasma-face-unlock

src/agent/lockcontroller.h

@@ -0,0 +1,62 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+//
+// The lock screen.
+//
+// When the screen locks, this waits for somebody to come back: a key, the
+// mouse, the lid opening, the machine waking from sleep. Then it scans, and
+// when the face matches it asks logind to unlock the session, which is the
+// same request `loginctl unlock-session` makes and which Plasma's screen
+// locker has always honoured.
+//
+// Why not a PAM module in the lock screen, like fingerprints? Plasma runs its
+// fingerprint stack in parallel with the password, but only starts it once per
+// lock, gives up for good the first time it fails, and labels it "scan your
+// fingerprint". Doing it from here means scanning again every time somebody
+// sits back down, no wrong label, and a bubble that knows what is going on.
+// It does not lower the bar either: any program running as this user can
+// already unlock this user's session through logind. Face data and the
+// decision stay with the daemon, which runs as root.
+
+#pragma once
+
+#include <QElapsedTimer>
+#include <QObject>
+#include <QPointer>
+#include <QTimer>
+
+class BubbleController;
+class DaemonRequest;
+class UserConfig;
+
+class LockController : public QObject
+{
+    Q_OBJECT
+public:
+    LockController(BubbleController *bubble, UserConfig *config, QObject *parent = nullptr);
+
+    bool locked() const
+    {
+        return m_locked;
+    }
+
+private Q_SLOTS:
+    void onActiveChanged(bool active);
+    void onPrepareForSleep(bool sleeping);
+
+private:
+    void arm();
+    void onResume();
+    void startScan(const QString &why);
+    void onScanFinished(const QJsonObject &result);
+    void unlock();
+    void warmUp();
+
+    BubbleController *m_bubble;
+    UserConfig *m_config;
+    bool m_locked = false;
+    bool m_stopped = false;
+    QElapsedTimer m_lockedFor;
+    QPointer<DaemonRequest> m_scan;
+    QTimer m_armTimer;
+    int m_idleId = -1;
+};