Don't crash on monitor remove

gBar no longer crashes when it's monitor is removed and is instead
evacuated onto another monitor or the next monitor added. We don't
change any monitor indices etc., which results in some glitchy results

src/Wayland.cpp

@@ -8,7 +8,7 @@
 namespace Wayland
 {
     // There's probably a better way to avoid the LUTs
-    static std::unordered_map<uint32_t, Monitor> monitors;
+    static std::unordered_map<std::string, Monitor> monitors;
     static std::unordered_map<zext_workspace_group_handle_v1*, WorkspaceGroup> workspaceGroups;
     static std::unordered_map<zext_workspace_handle_v1*, Workspace> workspaces;
 
@@ -27,11 +27,18 @@ namespace Wayland
 
     // Workspace Callbacks
     static void OnWorkspaceName(void*, zext_workspace_handle_v1* workspace, const char* name)
+    {
+        try
         {
             workspaces[workspace].id = std::stoul(name);
             LOG("Workspace ID: " << workspaces[workspace].id);
             registeredWorkspaceInfo = true;
         }
+        catch (const std::invalid_argument&)
+        {
+            LOG("Wayland: Invalid WS name: " << name);
+        }
+    }
     static void OnWorkspaceGeometry(void*, zext_workspace_handle_v1*, wl_array*) {}
     static void OnWorkspaceState(void*, zext_workspace_handle_v1* ws, wl_array* arrState)
     {
@@ -67,6 +74,13 @@ namespace Wayland
         workspaces.erase(ws);
 
         LOG("Wayland: Removed workspace!");
+        if (group.lastActiveWorkspace == ws)
+        {
+            if (group.workspaces.size())
+                group.lastActiveWorkspace = group.workspaces[0];
+            else
+                group.lastActiveWorkspace = nullptr;
+        }
     }
     zext_workspace_handle_v1_listener workspaceListener = {OnWorkspaceName, OnWorkspaceGeometry, OnWorkspaceState, OnWorkspaceRemove};
 
@@ -74,7 +88,7 @@ namespace Wayland
     static void OnWSGroupOutputEnter(void*, zext_workspace_group_handle_v1* group, wl_output* output)
     {
         auto monitor = std::find_if(monitors.begin(), monitors.end(),
-                                    [&](const std::pair<uint32_t, Monitor>& mon)
+                                    [&](const std::pair<std::string, Monitor>& mon)
                                     {
                                         return mon.second.output == output;
                                     });
@@ -85,7 +99,7 @@ namespace Wayland
     static void OnWSGroupOutputLeave(void*, zext_workspace_group_handle_v1*, wl_output* output)
     {
         auto monitor = std::find_if(monitors.begin(), monitors.end(),
-                                    [&](const std::pair<uint32_t, Monitor>& mon)
+                                    [&](const std::pair<std::string, Monitor>& mon)
                                     {
                                         return mon.second.output == output;
                                     });
@@ -130,10 +144,20 @@ namespace Wayland
     static void OnOutputDone(void*, wl_output*) {}
     static void OnOutputScale(void*, wl_output*, int32_t) {}
     static void OnOutputName(void*, wl_output* output, const char* name)
+    {
+        std::string nameStr = name;
+        auto it = monitors.find(nameStr);
+        if (it == monitors.end())
         {
             LOG("Wayland: Registering monitor " << name << " at ID " << curID);
             registeredMonitors = true;
-        monitors.try_emplace(curID++, Monitor{name, output, nullptr});
+            Monitor mon = {nameStr, output, nullptr, curID++};
+            monitors.try_emplace(nameStr, mon);
+        }
+        else
+        {
+            LOG("Wayland: Recovering monitor " << name << " at ID " << curID);
+        }
     }
     static void OnOutputDescription(void*, wl_output*, const char*) {}
     wl_output_listener outputListener = {OnOutputGeometry, OnOutputMode, OnOutputDone, OnOutputScale, OnOutputName, OnOutputDescription};
@@ -198,7 +222,7 @@ namespace Wayland
             auto workspaceIt = std::find_if(workspaces.begin(), workspaces.end(),
                                             [&](const std::pair<zext_workspace_handle_v1*, Workspace>& ws)
                                             {
-                                                return ws.second.id == monitor.first + 1;
+                                                return ws.second.id == monitor.second.ID + 1;
                                             });
             if (workspaceIt != workspaces.end())
             {
@@ -240,7 +264,7 @@ namespace Wayland
             wl_display_disconnect(display);
     }
 
-    const std::unordered_map<uint32_t, Monitor>& GetMonitors()
+    const std::unordered_map<std::string, Monitor>& GetMonitors()
     {
         return monitors;
     }

src/Wayland.h

@@ -11,6 +11,7 @@ namespace Wayland
         std::string name;
         wl_output* output;
         zext_workspace_group_handle_v1* workspaceGroup;
+        uint32_t ID;
     };
 
     struct Workspace
@@ -28,7 +29,7 @@ namespace Wayland
     void Init();
     void PollEvents();
 
-    const std::unordered_map<uint32_t, Monitor>& GetMonitors();
+    const std::unordered_map<std::string, Monitor>& GetMonitors();
     const std::unordered_map<zext_workspace_group_handle_v1*, WorkspaceGroup>& GetWorkspaceGroups();
     const std::unordered_map<zext_workspace_handle_v1*, Workspace>& GetWorkspaces();
 

src/Window.cpp

@@ -39,6 +39,18 @@ void Window::Init(const std::string& overideConfigLocation)
     {
         m_Monitor = gdk_display_get_primary_monitor(defaultDisplay);
     }
+
+    // Register monitor added/removed callbacks
+    auto monAdded = [](GdkDisplay* display, GdkMonitor* mon, void* window)
+    {
+        ((Window*)window)->MonitorAdded(display, mon);
+    };
+    g_signal_connect(defaultDisplay, "monitor-added", G_CALLBACK(+monAdded), this);
+    auto monRemoved = [](GdkDisplay* display, GdkMonitor* mon, void* window)
+    {
+        ((Window*)window)->MonitorRemoved(display, mon);
+    };
+    g_signal_connect(defaultDisplay, "monitor-removed", G_CALLBACK(+monRemoved), this);
 }
 
 void Window::Run()
@@ -158,3 +170,31 @@ int Window::GetHeight() const
     gdk_monitor_get_geometry(m_Monitor, &rect);
     return rect.height;
 }
+
+void Window::MonitorAdded(GdkDisplay* display, GdkMonitor* mon)
+{
+    LOG("Window: Monitor added: " << mon);
+    if (!m_Monitor)
+    {
+        LOG("Window: Activating window");
+        gtk_layer_set_monitor(m_Window, mon);
+        m_Monitor = mon;
+        gtk_widget_show_all((GtkWidget*)m_Window);
+    }
+}
+
+void Window::MonitorRemoved(GdkDisplay* display, GdkMonitor* mon)
+{
+    LOG("Window: Monitor removed: " << mon);
+    if (mon == m_Monitor)
+    {
+        // Hide the window, so it doesn't get rendered on an invalid monitor
+        gtk_widget_hide((GtkWidget*)m_Window);
+        // Notify gtk layer shell and redisplay window
+        gtk_layer_set_monitor(m_Window, nullptr);
+        m_Monitor = gtk_layer_get_monitor(m_Window);
+        LOG("Window: New Monitor: " << m_Monitor);
+        if (m_Monitor)
+            gtk_widget_show_all((GtkWidget*)m_Window);
+    }
+}

src/Window.h

@@ -41,11 +41,15 @@ public:
 
     int GetWidth() const;
     int GetHeight() const;
+
 private:
     void UpdateMargin();
 
     void LoadCSS(GtkCssProvider* provider);
 
+    void MonitorAdded(GdkDisplay* display, GdkMonitor* monitor);
+    void MonitorRemoved(GdkDisplay* display, GdkMonitor* monitor);
+
     GtkWindow* m_Window = nullptr;
     GtkApplication* m_App = nullptr;
 

src/Workspaces.cpp

@@ -20,12 +20,18 @@ namespace Workspaces
         }
         System::WorkspaceStatus GetStatus(uint32_t workspaceId)
         {
-            const WaylandMonitor& monitor = ::Wayland::GetMonitors().at(lastPolledMonitor);
+            auto& mons = ::Wayland::GetMonitors();
-            if (!monitor.output)
+            auto it = std::find_if(mons.begin(), mons.end(),
+                                   [&](const std::pair<std::string, ::Wayland::Monitor>& mon)
+                                   {
+                                       return mon.second.ID == workspaceId;
+                                   });
+            if (it == mons.end())
             {
                 LOG("Polled monitor doesn't exist!");
                 return System::WorkspaceStatus::Dead;
             }
+            const ::Wayland::Monitor& monitor = it->second;
 
             auto& workspaces = ::Wayland::GetWorkspaces();
             auto workspaceIt = std::find_if(workspaces.begin(), workspaces.end(),
@@ -156,9 +162,10 @@ namespace Workspaces
             std::string workspaces = DispatchIPC("/workspaces");
             while ((parseIdx = workspaces.find("workspace ID ", parseIdx)) != std::string::npos)
             {
-                // Goto (
+                // Advance two spaces
-                size_t begWSNum = workspaces.find('(', parseIdx) + 1;
+                size_t begWSNum = workspaces.find(' ', parseIdx) + 1;
-                size_t endWSNum = workspaces.find(')', begWSNum);
+                begWSNum = workspaces.find(' ', begWSNum) + 1;
+                size_t endWSNum = workspaces.find(' ', begWSNum);
 
                 std::string ws = workspaces.substr(begWSNum, endWSNum - begWSNum);
                 int32_t wsId = std::atoi(ws.c_str());