lock: fix red screen issues with multiple monitors (#5100)

* lock: use uint64_t for iMonitorID

* lock: move activateLock to onNewSessionLock

* lock: add red screen fade

* lock: damage when fading the red screen and delay for screencopy

* lock: remove redundant scheduleFrameForMonitor

2 files changed, 27 insertions, 5 deletions

diff --git a/src/managers/SessionLockManager.cpp b/src/managers/SessionLockManager.cpp
index 82606a8a..1e366034 100644
--- a/src/managers/SessionLockManager.cpp
+++ b/src/managers/SessionLockManager.cpp
@@ -15,8 +15,6 @@ static void handleSurfaceMap(void* owner, void* data) {
 
     if (PMONITOR)
         g_pHyprRenderer->damageMonitor(PMONITOR);
-
-    g_pSessionLockManager->activateLock(); // activate lock here to prevent the red screen from flashing before that
 }
 
 static void handleSurfaceCommit(void* owner, void* data) {
@@ -97,6 +95,8 @@ void CSessionLockManager::onNewSessionLock(wlr_session_lock_v1* pWlrLock) {
 
             m_sSessionLock.active = false;
 
+            m_sSessionLock.mMonitorsWithoutMappedSurfaceTimers.clear();
+
             g_pCompositor->m_sSeat.exclusiveClient = nullptr;
             g_pInputManager->refocus();
 
@@ -126,13 +126,15 @@ void CSessionLockManager::onNewSessionLock(wlr_session_lock_v1* pWlrLock) {
         pWlrLock, "wlr_session_lock_v1");
 
     wlr_session_lock_v1_send_locked(pWlrLock);
+
+    g_pSessionLockManager->activateLock();
 }
 
 bool CSessionLockManager::isSessionLocked() {
     return m_sSessionLock.active;
 }
 
-SSessionLockSurface* CSessionLockManager::getSessionLockSurfaceForMonitor(const int& id) {
+SSessionLockSurface* CSessionLockManager::getSessionLockSurfaceForMonitor(uint64_t id) {
     for (auto& sls : m_sSessionLock.vSessionLockSurfaces) {
         if (sls->iMonitorID == id) {
             if (sls->mapped)
@@ -145,6 +147,20 @@ SSessionLockSurface* CSessionLockManager::getSessionLockSurfaceForMonitor(const
     return nullptr;
 }
 
+// We don't want the red screen to flash.
+// This violates the protocol a bit, but tries to handle the missing sync between a lock surface beeing created and the red screen beeing drawn.
+float CSessionLockManager::getRedScreenAlphaForMonitor(uint64_t id) {
+    const auto& NOMAPPEDSURFACETIMER = m_sSessionLock.mMonitorsWithoutMappedSurfaceTimers.find(id);
+
+    if (NOMAPPEDSURFACETIMER == m_sSessionLock.mMonitorsWithoutMappedSurfaceTimers.end()) {
+        m_sSessionLock.mMonitorsWithoutMappedSurfaceTimers.emplace(id, CTimer());
+        m_sSessionLock.mMonitorsWithoutMappedSurfaceTimers[id].reset();
+        return 0.f;
+    }
+
+    return std::clamp(NOMAPPEDSURFACETIMER->second.getSeconds() - /* delay for screencopy */ 0.5f, 0.f, 1.f);
+}
+
 bool CSessionLockManager::isSurfaceSessionLock(wlr_surface* pSurface) {
     for (auto& sls : m_sSessionLock.vSessionLockSurfaces) {
         if (sls->pWlrLockSurface->surface == pSurface)
diff --git a/src/managers/SessionLockManager.hpp b/src/managers/SessionLockManager.hpp
index 51232867..c2c539db 100644
--- a/src/managers/SessionLockManager.hpp
+++ b/src/managers/SessionLockManager.hpp
@@ -1,10 +1,13 @@
 #pragma once
 
 #include "../defines.hpp"
+#include "../helpers/Timer.hpp"
+#include <cstdint>
+#include <unordered_map>
 
 struct SSessionLockSurface {
     wlr_session_lock_surface_v1* pWlrLockSurface = nullptr;
-    int                          iMonitorID      = -1;
+    uint64_t                     iMonitorID      = -1;
 
     bool                         mapped = false;
 
@@ -18,6 +21,7 @@ struct SSessionLock {
     wlr_session_lock_v1*                              pWlrLock = nullptr;
 
     std::vector<std::unique_ptr<SSessionLockSurface>> vSessionLockSurfaces;
+    std::unordered_map<uint64_t, CTimer>              mMonitorsWithoutMappedSurfaceTimers;
 
     DYNLISTENER(newSurface);
     DYNLISTENER(unlock);
@@ -30,7 +34,9 @@ class CSessionLockManager {
     ~CSessionLockManager() = default;
 
     void                 onNewSessionLock(wlr_session_lock_v1*);
-    SSessionLockSurface* getSessionLockSurfaceForMonitor(const int&);
+    SSessionLockSurface* getSessionLockSurfaceForMonitor(uint64_t);
+
+    float                getRedScreenAlphaForMonitor(uint64_t);
 
     bool                 isSessionLocked();
     bool                 isSurfaceSessionLock(wlr_surface*);