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mr-linch/capture_darwin.py

Last active August 14, 2025 23:18
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Revisions

  1. mr-linch revised this gist Jan 12, 2024. No changes.
  2. mr-linch revised this gist Jan 12, 2024. No changes.
  3. mr-linch created this gist Jan 7, 2024.
    103 changes: 103 additions & 0 deletions capture_darwin.py
    View file
    Original file line number Diff line number Diff line change
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    import Quartz as QZ
    import Quartz.CoreGraphics as CG
    import AppKit as AK

    import numpy as np
    import numpy.typing as npt

    import typing as t

    Matcher = t.Callable[[dict[str, t.Any]], bool]


    def _find_window(matcher: Matcher) -> list[dict]:
    """Find the window id of the window with the given name."""

    window_list = QZ.CGWindowListCopyWindowInfo(
    QZ.kCGWindowListOptionAll, QZ.kCGNullWindowID
    )

    result = []

    for window in window_list:
    if matcher(window):
    result.append(window)

    return result


    def new_name_matcher(name: str) -> Matcher:
    def matcher(window: dict[str, t.Any]) -> bool:
    return window.get("kCGWindowName") == name

    return matcher


    def capture(name: str):
    windows = _find_window(new_name_matcher(name))

    if len(windows) == 0:
    raise ValueError(f"Could not find window with name: {name}")
    elif len(windows) > 1:
    raise ValueError(f"Found multiple windows with name: {name}")

    window = windows[0]

    return _cg_capture_region_as_image(
    window_id=window["kCGWindowNumber"],
    )


    def _cg_capture_region_as_image(
    region: tuple[int, int, int, int] | None = None,
    window_id: int | None = None,
    ) -> npt.NDArray[np.uint8]:
    """Capture a region of the screen using CoreGraphics."""

    if window_id is not None and region is not None:
    raise ValueError("Only one of region or window_id must be specified")

    image: CG.CGImage | None = None

    if region is not None:
    cg_region = None

    if region is None:
    cg_region = CG.CGRectInfinite
    else:
    cg_region = CG.CGRectMake(*region)

    image = CG.CGWindowListCreateImage(
    cg_region,
    CG.kCGWindowListOptionOnScreenOnly,
    CG.kCGNullWindowID,
    CG.kCGWindowImageDefault,
    )
    elif window_id is not None:
    image = CG.CGWindowListCreateImage(
    CG.CGRectNull,
    CG.kCGWindowListOptionIncludingWindow,
    window_id,
    CG.kCGWindowImageBoundsIgnoreFraming | CG.kCGWindowImageNominalResolution,
    )
    else:
    raise ValueError("Either region or window_id must be specified")

    if image is None:
    raise ValueError("Could not capture image")

    bpr = CG.CGImageGetBytesPerRow(image)
    width = CG.CGImageGetWidth(image)
    height = CG.CGImageGetHeight(image)

    cg_dataprovider = CG.CGImageGetDataProvider(image)
    cg_data = CG.CGDataProviderCopyData(cg_dataprovider)

    np_raw_data = np.frombuffer(cg_data, dtype=np.uint8)

    return np.lib.stride_tricks.as_strided(
    np_raw_data,
    shape=(height, width, 3),
    strides=(bpr, 4, 1),
    writeable=True,
    )