Merge pull request #129 from Stateford/bug-fixes

Refactor thread handling and improve memory management; add configura…

Author: Stateford

.claude/settings.local.json

@@ -0,0 +1,13 @@
+{
+  "permissions": {
+    "allow": [
+      "Bash(wc:*)",
+      "Bash(cmake:*)",
+      "Bash(ctest:*)",
+      "Bash(\"build/tests/Release/display-lock-unittests.exe\")",
+      "Bash(\"display-lock-unittests.exe\")",
+      "Bash(\"./display-lock-unittests.exe\")",
+      "Bash(xxd:*)"
+    ]
+  }
+}

CLAUDE.md

@@ -0,0 +1,64 @@
+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Project Overview
+
+Display-Lock is a lightweight Windows application that locks the cursor to a selected window. Written primarily in C using the Win32 API, it's designed for gamers and multi-monitor users who need to keep their cursor confined to a specific window.
+
+## Build Commands
+
+```bash
+# Configure and build (Release)
+cmake -B build -DCMAKE_BUILD_TYPE=Release
+cmake --build build --config Release
+
+# Configure and build (Debug)
+cmake -B build -DCMAKE_BUILD_TYPE=Debug
+cmake --build build --config Debug
+
+# Run tests (requires Conan for GTest dependency)
+pip install conan==1.59.0
+ctest --test-dir build -C Release
+```
+
+The build requires Visual Studio 2022 (MSVC) on Windows. Conan package manager is used to fetch Google Test for unit testing.
+
+## Architecture
+
+**Component Library (`src/components/`)**: Core functionality as a static library (`display_lock_components`)
+- `win.c` - Cursor locking logic and window manipulation
+- `settings.c` - Binary config file persistence (`.DLOCK` format in `%APPDATA%/DisplayLock/`)
+- `applications.c` - Application whitelist management and monitoring thread
+- `notify.c` - System tray icon and notifications
+- `update.c` - Version checking via HTTP
+- `menu.c` - Menu UI handling
+
+**Main Application (`src/`)**: Win32 dialog-based UI
+- `main.c` - Entry point, window class registration, message loop
+- `ui.c` - Tab view rendering (Window Select, Settings, Applications)
+- `procedures/` - Dialog procedure handlers
+
+**Key Data Structures (`include/common.h`)**:
+- `SETTINGS` - User preferences (minimize on start, fullscreen, borderless, etc.)
+- `WINDOWLIST` - Array of up to 35 windows for selection
+- `APPLICATION_LIST` - Whitelisted applications for automatic cursor locking
+
+**Threading Model**: Cursor locking and application monitoring run in dedicated threads, synchronized via mutex (`DLockApplicationMutex`).
+
+## Testing
+
+Tests use Google Test (fetched via Conan). Test files are in `tests/` with test resources copied to the build directory.
+
+```bash
+# Run a single test
+ctest --test-dir build -C Release -R SettingsTest
+```
+
+## Contributing Guidelines
+
+- Work on `develop` branch for features, `master` for hotfixes
+- Avoid external dependencies (keep it lightweight)
+- Do not manually change version numbers or build scripts
+- Update CHANGELOG.md with changes
+- All builds and tests must pass before merge

include/applications.h

@@ -20,7 +20,7 @@ BOOL createApplicationDirectory(wchar_t *outPath);
 BOOL createApplicationSettings(const wchar_t *appPath, APPLICATION_SETTINGS *application);
 
 BOOL startApplicationThread(HANDLE *thread, int (*callback)(void *parameters), void *args);
-void closeApplicationThread(HANDLE thread, BOOL *status);
+void closeApplicationThread(HANDLE *thread, volatile BOOL *status);
 DWORD getPidFromName(const wchar_t *name);
 
 BOOL CALLBACK EnumWindowsProcPID(HWND hwnd, LPARAM lParam);

include/common.h

@@ -25,6 +25,12 @@
 #define APPLICATION_VIEW 2
 
 #define APPLICATION_MUTEX_NAME L"DLockApplicationMutex"
+
+// Magic number constants
+#define MAX_WINDOW_COUNT 35
+#define MAX_TITLE_LENGTH 500
+#define MAX_CLASS_NAME 500
+
 // custom messages
 
 #define NOTIFY_MSG (WM_USER + 0x1)
@@ -86,7 +92,7 @@ struct MAIN_WINDOW_CONTROLS
 
 struct WINDOW
 {
-    char title[500];
+    char title[MAX_TITLE_LENGTH];
     int x;
     int y;
     RECT size;
@@ -97,7 +103,7 @@ struct WINDOW
 struct WINDOWLIST
 {
     int count;
-    WINDOW windows[35];
+    WINDOW windows[MAX_WINDOW_COUNT];
 };
 
 struct WINDOW_VIEW_CONTROLS
@@ -125,7 +131,7 @@ struct SETTINGS_VIEW_CONTROLS
 
 struct MENU
 {
-    void (*closeThread)(HANDLE thread, BOOL *status);
+    void (*closeThread)(HANDLE *thread, volatile BOOL *status);
     void (*updateComboBox)(HWND control, WINDOWLIST *windows, void (*callback)(WINDOWLIST *));
     BOOL (*startThread)
     (HANDLE *thread, int (*callback)(void *parameters), void *args);
@@ -145,7 +151,7 @@ struct SETTINGS
 struct ARGS
 {
     SETTINGS *settings;
-    BOOL *clipRunning;
+    volatile BOOL *clipRunning;
     WINDOW selectedWindow;
     HWND hWnd;
     MAIN_WINDOW_CONTROLS controls;
@@ -154,7 +160,8 @@ struct ARGS
 struct APPLICATION_ARGS
 {
     APPLICATION_LIST *applicationList;
-    BOOL *clipRunning;
+    volatile BOOL *clipRunning;
+    HANDLE mutex;
 };
 
 union VERSION

include/menu.h

@@ -23,4 +23,4 @@
 void initMenuObj(MENU *menu);
 void updateComboBox(HWND control, WINDOWLIST *windows, void (*callback)(WINDOWLIST *));
 BOOL startThread(HANDLE *thread, int (*callback)(void *parameters), void *args);
-void closeThread(HANDLE thread, BOOL *status);
+void closeThread(HANDLE *thread, volatile BOOL *status);

src/components/applications.c

@@ -30,15 +30,42 @@ BOOL readApplicationList(APPLICATION_LIST *applicationList, const wchar_t *path)
         return FALSE;
     }
 
-    fread(&applicationList->count, sizeof(int), 1, file);
-    applicationList->applications = (APPLICATION_SETTINGS *)malloc(sizeof(APPLICATION_SETTINGS) * applicationList->count);
-    for (int i = 0; i < applicationList->count; i++)
+    if (fread(&applicationList->count, sizeof(int), 1, file) != 1)
     {
-        fread(&applicationList->applications[i], sizeof(APPLICATION_SETTINGS), 1, file);
+        applicationList->count = 0;
+        applicationList->applications = NULL;
+        fclose(file);
+        return FALSE;
+    }
+
+    if (applicationList->count > 0)
+    {
+        applicationList->applications = (APPLICATION_SETTINGS *)malloc(sizeof(APPLICATION_SETTINGS) * applicationList->count);
+        if (applicationList->applications == NULL)
+        {
+            applicationList->count = 0;
+            fclose(file);
+            return FALSE;
+        }
+
+        for (int i = 0; i < applicationList->count; i++)
+        {
+            if (fread(&applicationList->applications[i], sizeof(APPLICATION_SETTINGS), 1, file) != 1)
+            {
+                free(applicationList->applications);
+                applicationList->applications = NULL;
+                applicationList->count = 0;
+                fclose(file);
+                return FALSE;
+            }
+        }
+    }
+    else
+    {
+        applicationList->applications = NULL;
     }
 
     fclose(file);
-    _fcloseall();
 
     return TRUE;
 }
@@ -64,7 +91,6 @@ BOOL writeApplicationList(APPLICATION_LIST *applicationList, const wchar_t *path
     }
 
     fclose(file);
-    _fcloseall();
 
     return TRUE;
 }
@@ -76,6 +102,8 @@ BOOL addApplication(APPLICATION_LIST *applicationList, APPLICATION_SETTINGS appl
     {
         applicationList->count = 1;
         applicationList->applications = (APPLICATION_SETTINGS *)malloc(sizeof(APPLICATION_SETTINGS));
+        if (applicationList->applications == NULL)
+            return FALSE;
         applicationList->applications[0] = application;
     }
     else
@@ -87,8 +115,11 @@ BOOL addApplication(APPLICATION_LIST *applicationList, APPLICATION_SETTINGS appl
                 return FALSE;
         }
 
+        APPLICATION_SETTINGS *temp = (APPLICATION_SETTINGS *)realloc(applicationList->applications, sizeof(APPLICATION_SETTINGS) * (applicationList->count + 1));
+        if (temp == NULL)
+            return FALSE;
+        applicationList->applications = temp;
         applicationList->count++;
-        applicationList->applications = (APPLICATION_SETTINGS *)realloc(applicationList->applications, sizeof(APPLICATION_SETTINGS) * applicationList->count);
         applicationList->applications[applicationList->count - 1] = application;
     }
 
@@ -119,7 +150,10 @@ BOOL removeApplication(APPLICATION_LIST *applicationList, int index)
         }
 
         applicationList->count--;
-        applicationList->applications = (APPLICATION_SETTINGS *)realloc(applicationList->applications, sizeof(APPLICATION_SETTINGS) * applicationList->count);
+        APPLICATION_SETTINGS *temp = (APPLICATION_SETTINGS *)realloc(applicationList->applications, sizeof(APPLICATION_SETTINGS) * applicationList->count);
+        if (temp != NULL)
+            applicationList->applications = temp;
+        // If realloc fails, keep the old pointer (memory is still valid, just larger than needed)
     }
 
     return TRUE;
@@ -153,7 +187,7 @@ BOOL createApplicationDirectory(wchar_t *outPath)
     if (!SUCCEEDED(SHGetKnownFolderPath(&FOLDERID_RoamingAppData, 0, NULL, &path)))
         return FALSE;
 
-    wcscpy(outPath, path);
+    wcscpy_s(outPath, MAX_PATH, path);
 
     // create directory
     PathAppend(outPath, TEXT("DisplayLock"));
@@ -173,8 +207,8 @@ BOOL createApplicationSettings(const wchar_t *appPath, APPLICATION_SETTINGS *app
     if (basename == appPath)
         return FALSE;
 
-    wcscpy(application->application_path, appPath);
-    wcscpy(application->application_name, basename);
+    wcscpy_s(application->application_path, MAX_PATH, appPath);
+    wcscpy_s(application->application_name, MAX_PATH, basename);
     application->borderless = FALSE;
     application->fullscreen = FALSE;
     application->enabled = TRUE;
@@ -185,7 +219,7 @@ BOOL createApplicationSettings(const wchar_t *appPath, APPLICATION_SETTINGS *app
 BOOL startApplicationThread(HANDLE *thread, int (*callback)(void *parameters), void *args)
 {
     // TODO: check better error checking
-    *thread = (HANDLE)_beginthreadex(NULL, 0, callback, args, 0, NULL);
+    *thread = (HANDLE)(uintptr_t)_beginthreadex(NULL, 0, callback, args, 0, NULL);
 
     if (*thread == NULL)
         return FALSE;
@@ -194,15 +228,15 @@ BOOL startApplicationThread(HANDLE *thread, int (*callback)(void *parameters), v
 }
 
 // safely closes the thread
-void closeApplicationThread(HANDLE thread, BOOL *status)
+void closeApplicationThread(HANDLE *thread, volatile BOOL *status)
 {
     // check to see if thread is running
-    if (thread != NULL)
+    if (*thread != NULL)
     {
         *status = FALSE;
-        WaitForSingleObject(thread, INFINITE);
-        CloseHandle(thread);
-        thread = NULL;
+        WaitForSingleObject(*thread, INFINITE);
+        CloseHandle(*thread);
+        *thread = NULL;
     }
 }
 
@@ -251,62 +285,61 @@ int CALLBACK cursorLockApplications(void *parameters)
 
     while (*(args->clipRunning))
     {
-        HANDLE mutex = CreateMutex(NULL, FALSE, APPLICATION_MUTEX_NAME);
-        WaitForSingleObject(mutex, INFINITE);
+        WaitForSingleObject(args->mutex, INFINITE);
 
         for (int i = 0; i < args->applicationList->count; i++)
         {
             APPLICATION_SETTINGS application = args->applicationList->applications[i];
 
             if (application.enabled)
             {
-                EnumWindowsProcPIDArgs args;
-                args.pid = getPidFromName(application.application_name);
-                args.hwnd = NULL;
+                EnumWindowsProcPIDArgs enumArgs;
+                enumArgs.pid = getPidFromName(application.application_name);
+                enumArgs.hwnd = NULL;
 
-                if (args.pid != 0)
-                    EnumWindows(EnumWindowsProcPID, (LPARAM)&args);
+                if (enumArgs.pid != 0)
+                    EnumWindows(EnumWindowsProcPID, (LPARAM)&enumArgs);
 
-                if (args.hwnd != NULL)
+                if (enumArgs.hwnd != NULL)
                 {
                     RECT rect;
-                    GetWindowRect(args.hwnd, &rect);
+                    GetWindowRect(enumArgs.hwnd, &rect);
 
                     if (application.borderless)
                     {
-                        const long long borderlessStyle = GetWindowLongPtr(args.hwnd, GWL_STYLE);
-                        const long long borderlessStyleEx = GetWindowLongPtr(args.hwnd, GWL_EXSTYLE);
+                        const long long borderlessStyle = GetWindowLongPtr(enumArgs.hwnd, GWL_STYLE);
+                        const long long borderlessStyleEx = GetWindowLongPtr(enumArgs.hwnd, GWL_EXSTYLE);
 
                         const long long mask = WS_OVERLAPPED | WS_THICKFRAME | WS_SYSMENU | WS_CAPTION;
                         const long long exMask = WS_EX_WINDOWEDGE;
 
                         if ((borderlessStyle & mask) != 0)
-                            SetWindowLongPtr(args.hwnd, GWL_STYLE, borderlessStyle & ~mask);
+                            SetWindowLongPtr(enumArgs.hwnd, GWL_STYLE, borderlessStyle & ~mask);
 
                         if ((borderlessStyleEx & exMask) != 0)
-                            SetWindowLongPtr(args.hwnd, GWL_EXSTYLE, borderlessStyleEx & ~exMask);
+                            SetWindowLongPtr(enumArgs.hwnd, GWL_EXSTYLE, borderlessStyleEx & ~exMask);
                     }
                     else if (application.fullscreen)
                     {
-                        RECT rect = {0};
-                        GetClientRect(args.hwnd, &rect);
-                        ClientToScreen(args.hwnd, (LPPOINT)&rect.left);
-                        ClientToScreen(args.hwnd, (LPPOINT)&rect.right);
+                        RECT fsRect = {0};
+                        GetClientRect(enumArgs.hwnd, &fsRect);
+                        ClientToScreen(enumArgs.hwnd, (LPPOINT)&fsRect.left);
+                        ClientToScreen(enumArgs.hwnd, (LPPOINT)&fsRect.right);
 
-                        if (rect.left != 0 || rect.top != 0 || rect.right != GetSystemMetrics(SM_CXSCREEN) || rect.bottom != GetSystemMetrics(SM_CYSCREEN))
-                            SetWindowPos(args.hwnd, NULL, 0, 0, GetSystemMetrics(SM_CXSCREEN), GetSystemMetrics(SM_CYSCREEN), 0);
+                        if (fsRect.left != 0 || fsRect.top != 0 || fsRect.right != GetSystemMetrics(SM_CXSCREEN) || fsRect.bottom != GetSystemMetrics(SM_CYSCREEN))
+                            SetWindowPos(enumArgs.hwnd, NULL, 0, 0, GetSystemMetrics(SM_CXSCREEN), GetSystemMetrics(SM_CYSCREEN), 0);
                     }
 
                     // TODO: lock cursor
                     HWND active = GetForegroundWindow();
 
-                    if (args.hwnd == active)
+                    if (enumArgs.hwnd == active)
                     {
                         GetCursorPos(&cursorPosition);
                         RECT windowRect = {0};
-                        GetClientRect(args.hwnd, &windowRect);
-                        ClientToScreen(args.hwnd, (LPPOINT)&windowRect.left);
-                        ClientToScreen(args.hwnd, (LPPOINT)&windowRect.right);
+                        GetClientRect(enumArgs.hwnd, &windowRect);
+                        ClientToScreen(enumArgs.hwnd, (LPPOINT)&windowRect.left);
+                        ClientToScreen(enumArgs.hwnd, (LPPOINT)&windowRect.right);
 
                         if ((cursorPosition.y <= windowRect.bottom && cursorPosition.y >= windowRect.top) && (cursorPosition.x >= windowRect.left && cursorPosition.x <= windowRect.right))
                             ClipCursor(&windowRect);
@@ -315,11 +348,10 @@ int CALLBACK cursorLockApplications(void *parameters)
                     }
                 }
             }
-            Sleep(1);
         }
 
-        ReleaseMutex(mutex);
-        CloseHandle(mutex);
+        ReleaseMutex(args->mutex);
+        Sleep(1);
     }
 
     ClipCursor(NULL);