Add support for Windows UWP apps (#80)

Co-authored-by: Sindre Sorhus <[email protected]>

lib/windows.js

@@ -14,6 +14,7 @@ const Rect = struct({
 	bottom: 'long'
 });
 const RectPointer = ref.refType(Rect);
+const VoidPointer = ref.refType(ref.types.void);
 
 // Required by QueryFullProcessImageName
 // https://msdn.microsoft.com/en-us/library/windows/desktop/ms684880(v=vs.85).aspx
@@ -31,7 +32,10 @@ const user32 = new ffi.Library('User32.dll', {
 	GetWindowThreadProcessId: ['uint32', ['pointer', 'uint32 *']],
 	// Get window bounds function
 	// https://docs.microsoft.com/en-us/windows/desktop/api/winuser/nf-winuser-getwindowrect
-	GetWindowRect: ['bool', ['pointer', RectPointer]]
+	GetWindowRect: ['bool', ['pointer', RectPointer]],
+	// Iterate through child windows
+	// https://docs.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-enumchildwindows
+	EnumChildWindows: ['bool', ['pointer', VoidPointer, 'int32']]
 });
 
 const SIZE_T = 'uint64';
@@ -68,6 +72,74 @@ const kernel32 = new ffi.Library('kernel32', {
 	QueryFullProcessImageNameW: ['int', ['pointer', 'uint32', 'pointer', 'pointer']]
 });
 
+// Check parent window for SubWindows and find the unique process inside of it.
+function getSubWindowRealProcessPath(activeWindowHandle, processPath) {
+	let newProcessPath;
+
+	const windowProcess = ffi.Callback('bool', ['pointer', 'int32'], hwnd => {
+		// Return the Process ID & Process Handle from the Active Window Handle
+		const [, processHandle] = getProcessIdAndHandle(hwnd);
+
+		if (ref.isNull(processHandle)) {
+			return false; // Failed to get process handle
+		}
+
+		const processPathChild = getProcessPath(processHandle);
+
+		if (processPathChild !== processPath) {
+			newProcessPath = processPathChild;
+			return false;
+		}
+
+		return true;
+	});
+
+	user32.EnumChildWindows(activeWindowHandle, windowProcess, 0);
+
+	if (newProcessPath !== undefined && newProcessPath !== processPath) {
+		return newProcessPath;
+	}
+
+	return processPath;
+}
+
+function getProcessPath(processHandle) {
+	if (ref.isNull(processHandle)) {
+		return undefined;
+	}
+
+	// Set the path length to more than the Windows extended-length MAX_PATH length
+	// The maximum path of 32,767 characters is approximate, because the "\\?\" prefix may be expanded to a longer string by the system at run time, and this expansion applies to the total length.
+	const pathLengthBytes = 66000;
+	// Path length in "characters"
+	const pathCharacterCount = Math.floor(pathLengthBytes / 2);
+	// Allocate a buffer to store the path of the process
+	const processFileNameBuffer = Buffer.alloc(pathLengthBytes);
+	// Create a buffer containing the allocated size for the path, as a buffer as it must be writable
+	const processFileNameSizeBuffer = ref.alloc('uint32', pathCharacterCount);
+	// Write process file path to buffer
+	kernel32.QueryFullProcessImageNameW(processHandle, 0, processFileNameBuffer, processFileNameSizeBuffer);
+	// Remove null characters from buffer
+	const processFileNameBufferClean = ref.reinterpretUntilZeros(processFileNameBuffer, wchar.size);
+	// Get process file path as a string
+	const processPath = wchar.toString(processFileNameBufferClean);
+
+	return processPath;
+}
+
+function getProcessIdAndHandle(windowHandle) {
+	// Allocate a buffer to store the process ID
+	const processIdBuffer = ref.alloc('uint32');
+	// Write the process ID creating the window to the buffer (it returns the thread ID, but it's not used here)
+	user32.GetWindowThreadProcessId(windowHandle, processIdBuffer);
+	// Get the process ID as a number from the buffer
+	const processId = ref.get(processIdBuffer);
+	// Get a "handle" of the process
+	const processHandle = kernel32.OpenProcess(PROCESS_QUERY_LIMITED_INFORMATION, false, processId);
+
+	return [processId, processHandle];
+}
+
 function windows() {
 	// Windows C++ APIs' functions are declared with capitals, so this rule has to be turned off
 
@@ -93,35 +165,23 @@ function windows() {
 	// The text as a JavaScript string
 	const windowTitle = wchar.toString(windowTextBufferClean);
 
-	// Allocate a buffer to store the process ID
-	const processIdBuffer = ref.alloc('uint32');
-	// Write the process ID creating the window to the buffer (it returns the thread ID, but it's not used here)
-	user32.GetWindowThreadProcessId(activeWindowHandle, processIdBuffer);
-	// Get the process ID as a number from the buffer
-	const processId = ref.get(processIdBuffer);
-	// Get a "handle" of the process
-	const processHandle = kernel32.OpenProcess(PROCESS_QUERY_LIMITED_INFORMATION, false, processId);
+	// Return the Process ID & Process Handle from the Active Window Handle
+	const [processId, processHandle] = getProcessIdAndHandle(activeWindowHandle);
 
 	if (ref.isNull(processHandle)) {
 		return undefined; // Failed to get process handle
 	}
 
-	// Set the path length to more than the Windows extended-length MAX_PATH length
-	const pathLengthBytes = 66000;
-	// Path length in "characters"
-	const pathLengthChars = Math.floor(pathLengthBytes / 2);
-	// Allocate a buffer to store the path of the process
-	const processFileNameBuffer = Buffer.alloc(pathLengthBytes);
-	// Create a buffer containing the allocated size for the path, as a buffer as it must be writable
-	const processFileNameSizeBuffer = ref.alloc('uint32', pathLengthChars);
-	// Write process file path to buffer
-	kernel32.QueryFullProcessImageNameW(processHandle, 0, processFileNameBuffer, processFileNameSizeBuffer);
-	// Remove null characters from buffer
-	const processFileNameBufferClean = ref.reinterpretUntilZeros(processFileNameBuffer, wchar.size);
-	// Get process file path as a string
-	const processPath = wchar.toString(processFileNameBufferClean);
+	// Return the Process Path & Process Name from a Process Handle
+	let processPath = getProcessPath(processHandle);
 	// Get process file name from path
-	const processName = path.basename(processPath);
+	let processName = path.basename(processPath);
+
+	// ApplicationFrameHost & Universal Windows Platform Support
+	if (processName === 'ApplicationFrameHost.exe') {
+		processPath = getSubWindowRealProcessPath(activeWindowHandle, processPath);
+		processName = path.basename(processPath);
+	}
 
 	// Get process memory counters
 	const memoryCounters = new ProcessMemoryCounters();