sublimeRunner starts ST3 and removes its window title bar

sublimeRunner.cpp

#include <windows.h>
#include <shlwapi.h>
#include <strsafe.h>

#pragma optimize("gsy", on)
#pragma comment(linker, "/ENTRY:start")
#pragma comment(linker, "/NODEFAULTLIB:no")

void reuseRunningInstance(HWND hST) {
	int argc;
	LPWSTR* argv = CommandLineToArgvW(GetCommandLine(), &argc);
	
	COPYDATASTRUCT cds;
	TCHAR fullpath[MAX_PATH+1];	fullpath[0] = '/';
	auto heap = GetProcessHeap();

	for (int i = 1; i < argc; i++) {
		GetFullPathName(argv[i], MAX_PATH, &fullpath[1], NULL);

		for (int j = 1; j <= MAX_PATH; j++) {
			auto ch = fullpath[j];
			if (!ch)
				break;
			if (ch == '\\') {
				fullpath[j] = '/';
			} else if (ch == ':') {
				StringCchCopy(&fullpath[j], MAX_PATH+1-j, &fullpath[j+1]);
				j--;
			}
		}
		auto fullpathptr = fullpath[1] == '/' ? &fullpath[1] : &fullpath[0];
		auto n = WideCharToMultiByte(CP_UTF8, 0, fullpathptr, -1, NULL, 0, NULL, NULL);
		
		cds.dwData = 0x59;
		cds.cbData = 3 * sizeof(DWORD) + n;
		cds.lpData = HeapAlloc(heap, 0, cds.cbData);
		
		typedef struct { DWORD a; DWORD b; DWORD len; BYTE data; } DATA;
		DATA* dataptr = cds.lpData;
		dataptr->a = 7;
		dataptr->b = 1;
		dataptr->len = n-1;
		WideCharToMultiByte(CP_UTF8, 0, fullpathptr, -1, &dataptr->data, n, NULL, NULL);

		SendMessage(FindWindowA("com.sublimetext.three.timer_window", NULL), WM_COPYDATA, hST, &cds);

		HeapFree(heap, 0, dataptr);
	}

	LocalFree(argv);
}

LPCTSTR findParamsPtr() {
	TCHAR* cmdline = GetCommandLine();

	// find params by skipping the executable file name
	TCHAR skipTo = *cmdline == '"' ? '"' : ' ';
	TCHAR current;
	while (current = *(++cmdline)) {
		if (current == skipTo) {
			++cmdline;
			break;
		}
	}
	return cmdline;
}

void removeWindowFrame() {
	for (int i = 0; i < 200; i++) {
		Sleep(10);

		auto hST = FindWindowA("PX_WINDOW_CLASS", NULL);
		if (!hST) {
			MSG msg;
			if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)) {
				TranslateMessage(&msg);
				DispatchMessage(&msg);
			}
			continue;
		}

		auto style = GetWindowLong(hST, GWL_STYLE);
		SetWindowLong(hST, GWL_STYLE, style & ~(WS_CAPTION | WS_THICKFRAME));

		WINDOWPLACEMENT wp;
		if (GetWindowPlacement(hST, &wp)) {
			wp.rcNormalPosition.bottom++; SetWindowPlacement(hST, &wp);
			wp.rcNormalPosition.bottom--; SetWindowPlacement(hST, &wp);
		}
		ExitProcess(0);
	}
}

void start() {
	auto hST = FindWindowA("PX_WINDOW_CLASS", NULL);
	if (hST) {
		reuseRunningInstance(hST);
		ExitProcess(0);
	}

	ShellExecuteW(0, NULL, L"sublime_text", findParamsPtr(), NULL, SW_SHOWDEFAULT);
	removeWindowFrame();

	ExitProcess(1);
}