cppn-abstract-utils.py

from pyxll import xl_app, async_call
import win32gui, win32ui
import tempfile
import os


def get_image_size(image):
    """Return the size of an image in pixels as (width, height)."""
    # Get the size of the input image in pixels (Excel sizes are in points,
    # or 1/72th of an inch.
    xl = xl_app()
    dc = win32gui.GetDC(xl.Hwnd)
    pixels_per_inch_x = win32ui.GetDeviceCaps(dc, win32con.LOGPIXELSX)
    pixels_per_inch_y = win32ui.GetDeviceCaps(dc, win32con.LOGPIXELSY)
    size_x = int(image.Width * pixels_per_inch_x / 72)
    size_y = int(image.Height * pixels_per_inch_y / 72)

    return size_x, size_y


def create_temporary_file(suffix=None):
    """Create a named temporary file that is deleted automatically."""
    # Rather than delete the file when it's closed we delete it when the
    # windows message loop next runs. This gives Excel enough time to
    # load the image before the file disappears.
    file = tempfile.NamedTemporaryFile(suffix=suffix, delete=False)

    def try_delete(filename):
        try:
            os.unlink(filename)
        except PermissionError:
            # retry if Excel is still accessing it
            async_call(os.unlink, filename)

    # Make sure the file gets deleted after the function is complete
    async_call(try_delete, file.name)

    return file