ClaudeCode-Roblox-Studio-MCP/inject_bg.py

"""
Background injection into Roblox Studio using SendMessage/PostMessage.
Works even when Studio is minimized or behind other windows.
Finds the command bar child control and sends text directly to it.
"""
import ctypes, ctypes.wintypes, subprocess, time, sys, os

user32 = ctypes.windll.user32
WM_SETTEXT = 0x000C
WM_KEYDOWN = 0x0100
WM_KEYUP = 0x0101
WM_CHAR = 0x0102
EM_GETLINECOUNT = 0x00BA
EM_LINELENGTH = 0x00C1

def find_studio():
    target = [None]
    def cb(hwnd, _):
        l = user32.GetWindowTextLengthW(hwnd)
        if l > 0:
            buf = ctypes.create_unicode_buffer(l + 1)
            user32.GetWindowTextW(hwnd, buf, l + 1)
            if "Roblox Studio" in buf.value:
                target[0] = hwnd
                return False
        return True
    WNDENUMPROC = ctypes.WINFUNCTYPE(ctypes.c_bool, ctypes.wintypes.HWND, ctypes.wintypes.LPARAM)
    user32.EnumWindows(WNDENUMPROC(cb), 0)
    return target[0]

def find_command_bar(parent_hwnd):
    """Find the command bar edit control inside Studio."""
    result = [None]
    WNDENUMPROC = ctypes.WINFUNCTYPE(ctypes.c_bool, ctypes.wintypes.HWND, ctypes.wintypes.LPARAM)

    def enum_children(hwnd, _):
        # Check class name - Roblox command bar is typically an edit control
        buf = ctypes.create_unicode_buffer(256)
        user32.GetClassNameW(hwnd, buf, 256)
        class_name = buf.value

        # Get control text
        l = user32.GetWindowTextLengthW(hwnd)
        if l > 0:
            tbuf = ctypes.create_unicode_buffer(l + 1)
            user32.GetWindowTextW(hwnd, tbuf, l + 1)

        # Look for edit controls or text input controls
        # Roblox Studio uses WPF which hosts Win32 controls
        rect = ctypes.wintypes.RECT()
        user32.GetWindowRect(hwnd, ctypes.byref(rect))
        h = rect.bottom - rect.top

        # Command bar is a thin single-line edit at the bottom
        if class_name in ("Edit", "TextBox", "WindowsForms10.Edit", "WpfTextEdit"):
            if h > 10 and h < 60:
                result[0] = hwnd
                return False

        # Recurse into children
        user32.EnumChildWindows(hwnd, WNDENUMPROC(enum_children), 0)
        return True

    user32.EnumChildWindows(parent_hwnd, WNDENUMPROC(enum_children), 0)
    return result[0]

def find_all_children(parent_hwnd):
    """List all child windows for debugging."""
    children = []
    WNDENUMPROC = ctypes.WINFUNCTYPE(ctypes.c_bool, ctypes.wintypes.HWND, ctypes.wintypes.LPARAM)

    def enum_children(hwnd, _):
        buf = ctypes.create_unicode_buffer(256)
        user32.GetClassNameW(hwnd, buf, 256)
        class_name = buf.value

        l = user32.GetWindowTextLengthW(hwnd)
        text = ""
        if l > 0:
            tbuf = ctypes.create_unicode_buffer(l + 1)
            user32.GetWindowTextW(hwnd, tbuf, l + 1)
            text = tbuf.value

        rect = ctypes.wintypes.RECT()
        user32.GetWindowRect(hwnd, ctypes.byref(rect))
        w = rect.right - rect.left
        h = rect.bottom - rect.top

        visible = user32.IsWindowVisible(hwnd)
        enabled = user32.IsWindowEnabled(hwnd)

        children.append({
            'hwnd': hwnd,
            'class': class_name,
            'text': text[:50],
            'size': f"{w}x{h}",
            'pos': f"({rect.left},{rect.top})",
            'visible': visible,
            'enabled': enabled
        })
        return True

    user32.EnumChildWindows(parent_hwnd, WNDENUMPROC(enum_children), 0)
    return children

def inject_background(code, target_hwnd):
    """Inject Lua code into a specific child control using SendMessage."""
    # Put code on clipboard
    tmp = os.path.join(os.environ["TEMP"], "rbx.lua")
    with open(tmp, "w", encoding="utf-8") as f:
        f.write(code)
    subprocess.run(["powershell", "-Command", f"Get-Content '{tmp}' -Raw | Set-Clipboard"],
                   capture_output=True, timeout=10)
    time.sleep(0.2)

    # Send Ctrl+A (select all) then Ctrl+V (paste) then Enter via PostMessage
    # PostMessage works on background windows
    VK_CONTROL = 0x11
    VK_A = 0x41
    VK_V = 0x56
    VK_RETURN = 0x0D

    # Select all: Ctrl+A
    user32.PostMessageW(target_hwnd, WM_KEYDOWN, VK_CONTROL, 0)
    user32.PostMessageW(target_hwnd, WM_KEYDOWN, VK_A, 0)
    time.sleep(0.02)
    user32.PostMessageW(target_hwnd, WM_KEYUP, VK_A, 0)
    user32.PostMessageW(target_hwnd, WM_KEYUP, VK_CONTROL, 0)
    time.sleep(0.05)

    # Paste: Ctrl+V
    user32.PostMessageW(target_hwnd, WM_KEYDOWN, VK_CONTROL, 0)
    user32.PostMessageW(target_hwnd, WM_KEYDOWN, VK_V, 0)
    time.sleep(0.02)
    user32.PostMessageW(target_hwnd, WM_KEYUP, VK_V, 0)
    user32.PostMessageW(target_hwnd, WM_KEYUP, VK_CONTROL, 0)
    time.sleep(0.5)

    # Execute: Enter
    user32.PostMessageW(target_hwnd, WM_KEYDOWN, VK_RETURN, 0)
    time.sleep(0.02)
    user32.PostMessageW(target_hwnd, WM_KEYUP, VK_RETURN, 0)
    time.sleep(2)

# ═══════════════════════════════════════
# MAIN
# ═══════════════════════════════════════
hwnd = find_studio()
if not hwnd:
    print("ERROR: Roblox Studio not found!")
    sys.exit(1)

print(f"Studio window: {hwnd}")

# List all child windows to find command bar
print("\nSearching for command bar control...")
children = find_all_children(hwnd)

# Filter for likely candidates: visible, enabled, small height (thin bar), near bottom
print(f"Found {len(children)} child windows")

# Get main window rect
main_rect = ctypes.wintypes.RECT()
user32.GetWindowRect(hwnd, ctypes.byref(main_rect))
main_bottom = main_rect.bottom
main_top = main_rect.top

# Find candidates near bottom of window, visible, reasonable size
candidates = []
for c in children:
    if not c['visible']:
        continue
    try:
        h = int(c['size'].split('x')[1])
        w = int(c['size'].split('x')[0])
    except:
        continue
    if h < 5 or h > 80:
        continue
    if w < 100:
        continue
    # Parse position
    pos = c['pos'].strip('()')
    try:
        y = int(pos.split(',')[1])
    except:
        continue
    # Check if near bottom of main window
    if y > main_bottom - 100:
        candidates.append(c)
        print(f"  CANDIDATE: hwnd={c['hwnd']} class={c['class']} text='{c['text']}' size={c['size']} pos={c['pos']}")

if not candidates:
    print("\nNo command bar candidates found. Listing ALL visible children near bottom:")
    for c in children:
        if not c['visible']:
            continue
        pos = c['pos'].strip('()')
        try:
            y = int(pos.split(',')[1])
        except:
            continue
        if y > main_bottom - 150:
            print(f"  hwnd={c['hwnd']} class={c['class']} text='{c['text']}' size={c['size']} pos={c['pos']}")

# Try to test each candidate with a simple print
test_code = 'print("BG_INJECT_OK")'
print(f"\nTesting candidates with: {test_code}")

for c in candidates:
    target = c['hwnd']
    print(f"\n  Trying hwnd={target} class={c['class']}...")
    inject_background(test_code, target)
    print(f"  Sent to {target}. Check Studio Output for 'BG_INJECT_OK'")