How to use cairocffi - 10 common examples

def paint_text(text, w, h, rotate=False, ud=False, multi_fonts=False):
    surface = cairo.ImageSurface(cairo.FORMAT_RGB24, w, h)
    with cairo.Context(surface) as context:
        context.set_source_rgb(1, 1, 1)  # White
        context.paint()
        # this font list works in CentOS 7
        if multi_fonts:
            fonts = ['Century Schoolbook', 'Courier', 'STIX', 'URW Chancery L', 'FreeMono']
            context.select_font_face(np.random.choice(fonts), cairo.FONT_SLANT_NORMAL,
                                     np.random.choice([cairo.FONT_WEIGHT_BOLD, cairo.FONT_WEIGHT_NORMAL]))
        else:
            context.select_font_face('Courier', cairo.FONT_SLANT_NORMAL, cairo.FONT_WEIGHT_BOLD)
        context.set_font_size(25)
        box = context.text_extents(text)
        border_w_h = (4, 4)
        if box[2] > (w - 2 * border_w_h[1]) or box[3] > (h - 2 * border_w_h[0]):
            raise IOError('Could not fit string into image. Max char count is too large for given image width.')

        # teach the RNN translational invariance by
        # fitting text box randomly on canvas, with some room to rotate
        max_shift_x = w - box[2] - border_w_h[0]
        max_shift_y = h - box[3] - border_w_h[1]
        top_left_x = np.random.randint(0, int(max_shift_x))
        if ud:
            top_left_y = np.random.randint(0, int(max_shift_y))
        else:
            top_left_y = h // 2
        context.move_to(top_left_x - int(box[0]), top_left_y - int(box[1]))

def paint_text(self, text, w, h, rotate=False, ud=False, multi_fonts=False):
        surface = cairo.ImageSurface(cairo.FORMAT_RGB24, w, h)
        with cairo.Context(surface) as context:
            context.set_source_rgb(1, 1, 1)  # White
            context.paint()
            # this font list works in CentOS 7
            if multi_fonts:
                fonts = ['Century Schoolbook', 'Courier', 'STIX', 'URW Chancery L', 'FreeMono']
                context.select_font_face(np.random.choice(fonts), cairo.FONT_SLANT_NORMAL,
                                         np.random.choice([cairo.FONT_WEIGHT_BOLD, cairo.FONT_WEIGHT_NORMAL]))
            else:
                context.select_font_face('Courier', cairo.FONT_SLANT_NORMAL, cairo.FONT_WEIGHT_BOLD)
            context.set_font_size(25)
            box = context.text_extents(text)
            border_w_h = (4, 4)
            if box[2] > (w - 2 * border_w_h[1]) or box[3] > (h - 2 * border_w_h[0]):
                raise IOError('Could not fit string into image. Max char count is too large for given image width.')

            # teach the RNN translational invariance by
            # fitting text box randomly on canvas, with some room to rotate
            max_shift_x = w - box[2] - border_w_h[0]
            max_shift_y = h - box[3] - border_w_h[1]
            top_left_x = np.random.randint(0, int(max_shift_x))
            if ud:
                top_left_y = np.random.randint(0, int(max_shift_y))
            else:
                top_left_y = h // 2
            context.move_to(top_left_x - int(box[0]), top_left_y - int(box[1]))

with cairo.Context(surface) as context:
        context.set_source_rgb(1, 1, 1)  # White
        context.paint()
        # this font list works in CentOS 7
        if multi_fonts:
            fonts = [
                'Century Schoolbook', 'Courier', 'STIX',
                'URW Chancery L', 'FreeMono']
            context.select_font_face(
                np.random.choice(fonts),
                cairo.FONT_SLANT_NORMAL,
                np.random.choice([cairo.FONT_WEIGHT_BOLD, cairo.FONT_WEIGHT_NORMAL]))
        else:
            context.select_font_face('Courier',
                                     cairo.FONT_SLANT_NORMAL,
                                     cairo.FONT_WEIGHT_BOLD)
        context.set_font_size(25)
        box = context.text_extents(text)
        border_w_h = (4, 4)
        if box[2] > (w - 2 * border_w_h[1]) or box[3] > (h - 2 * border_w_h[0]):
            raise IOError(('Could not fit string into image.'
                           'Max char count is too large for given image width.'))

        # teach the RNN translational invariance by
        # fitting text box randomly on canvas, with some room to rotate
        max_shift_x = w - box[2] - border_w_h[0]
        max_shift_y = h - box[3] - border_w_h[1]
        top_left_x = np.random.randint(0, int(max_shift_x))
        if ud:
            top_left_y = np.random.randint(0, int(max_shift_y))
        else:
            top_left_y = h // 2

def paint_text(text, w, h, rotate=False, ud=False, multi_fonts=False):
    surface = cairo.ImageSurface(cairo.FORMAT_RGB24, w, h)
    with cairo.Context(surface) as context:
        context.set_source_rgb(1, 1, 1)  # White
        context.paint()
        # this font list works in Centos 7
        if multi_fonts:
            fonts = ['Century Schoolbook', 'Courier', 'STIX', 'URW Chancery L', 'FreeMono']
            context.select_font_face(np.random.choice(fonts), cairo.FONT_SLANT_NORMAL,
                                     np.random.choice([cairo.FONT_WEIGHT_BOLD, cairo.FONT_WEIGHT_NORMAL]))
        else:
            context.select_font_face('Courier', cairo.FONT_SLANT_NORMAL, cairo.FONT_WEIGHT_BOLD)
        context.set_font_size(25)
        box = context.text_extents(text)
        border_w_h = (4, 4)
        if box[2] > (w - 2 * border_w_h[1]) or box[3] > (h - 2 * border_w_h[0]):
            raise IOError('Could not fit string into image. Max char count is too large for given image width.')

        # teach the RNN translational invariance by
        # fitting text box randomly on canvas, with some room to rotate
        max_shift_x = w - box[2] - border_w_h[0]
        max_shift_y = h - box[3] - border_w_h[1]
        top_left_x = np.random.randint(0, int(max_shift_x))
        if ud:
            top_left_y = np.random.randint(0, int(max_shift_y))
        else:
            top_left_y = h // 2
        context.move_to(top_left_x - int(box[0]), top_left_y - int(box[1]))

OUTPUT_DIR = os.path.join(
    os.path.dirname(os.path.abspath(__file__)),
    "test_output"
)


if __name__ == "__main__":
    for test in tests.common.TESTS:
        output = "Running test: %s" % test.name

        if test.description:
            output += " (%s)" % test.description

        print(output)

        surface = cairo.ImageSurface(
            test.surface_format,
            test.width,
            test.height
        )

        cr = cairo.Context(surface)

        cr.set_source_rgba(0.0, 0.0, 0.0, 1.0)
        cr.paint()
        cr.set_source_rgba(1.0, 1.0, 1.0, 1.0)

        try:
            test(cr, test.width, test.height)

        except Exception as e:
            print("Error in test %s: %s" % (test.name, e))

def test():
    cairocffi_context = cairocffi.Context(cairocffi.PDFSurface(None, 10, 20))
    cairocffi_context.scale(2, 3)
    pycairo_context = _UNSAFE_cairocffi_context_to_pycairo(cairocffi_context)
    cairocffi_context2 = _UNSAFE_pycairo_context_to_cairocffi(pycairo_context)
    assert tuple(cairocffi_context.get_matrix()) == (2, 0, 0, 3, 0, 0)
    assert tuple(cairocffi_context2.get_matrix()) == (2, 0, 0, 3, 0, 0)
    assert tuple(pycairo_context.get_matrix()) == (2, 0, 0, 3, 0, 0)
    assert cairocffi_context2._pointer == cairocffi_context._pointer

    file_obj = io.BytesIO()
    # Mostly test that this runs without raising.
    pango_example.write_example_pdf(file_obj)
    assert file_obj.getvalue().startswith(b'%PDF')

def test_document_unit():
    surface = SVGSurface(None, 1, 2)
    assert surface.get_document_unit() == SVG_UNIT_PT

    file_obj = io.BytesIO()
    surface = SVGSurface(file_obj, 1, 2)
    surface.set_document_unit(SVG_UNIT_PX)
    assert surface.get_document_unit() == SVG_UNIT_PX
    surface.finish()
    pdf_bytes = file_obj.getvalue()
    assert b'width="1px"' in pdf_bytes
    assert b'height="2px"' in pdf_bytes

    file_obj = io.BytesIO()
    surface = SVGSurface(file_obj, 1, 2)
    surface.set_document_unit(SVG_UNIT_PC)
    assert surface.get_document_unit() == SVG_UNIT_PC
    surface.finish()

def test_image_bytearray_buffer():
    if '__pypy__' in sys.modules:
        pytest.xfail()
    # Also test buffers through ctypes.c_char.from_buffer,
    # not available on PyPy
    data = bytearray(800)
    surface = ImageSurface.create_for_data(data, cairocffi.FORMAT_ARGB32,
                                           10, 20, stride=40)
    Context(surface).paint_with_alpha(0.5)
    assert data == pixel(b'\x80\x00\x00\x00') * 200

def test_context_mask():
    mask_surface = ImageSurface(cairocffi.FORMAT_ARGB32, 2, 2)
    context = Context(mask_surface)
    context.set_source_rgba(1, 0, .5, 1)
    context.rectangle(0, 0, 1, 1)
    context.fill()
    context.set_source_rgba(1, .5, 1, .5)
    context.rectangle(1, 1, 1, 1)
    context.fill()

    surface = ImageSurface(cairocffi.FORMAT_ARGB32, 4, 4)
    context = Context(surface)
    context.mask(SurfacePattern(mask_surface))
    o = pixel(b'\x00\x00\x00\x00')
    b = pixel(b'\x80\x00\x00\x00')
    B = pixel(b'\xFF\x00\x00\x00')
    assert surface.get_data()[:] == (
        B + o + o + o +

def test_context_fill():
    surface = ImageSurface(cairocffi.FORMAT_A8, 4, 4)
    assert surface.get_data()[:] == b'\x00' * 16
    context = Context(surface)
    context.set_source_rgba(0, 0, 0, .5)
    context.set_line_width(.5)
    context.rectangle(1, 1, 2, 2)
    assert context.fill_extents() == (1, 1, 3, 3)
    assert context.stroke_extents() == (.75, .75, 3.25, 3.25)
    assert context.in_fill(2, 2) is True
    assert context.in_fill(.8, 2) is False
    assert context.in_stroke(2, 2) is False
    assert context.in_stroke(.8, 2) is True
    path = list(context.copy_path())
    assert path
    context.fill_preserve()
    assert list(context.copy_path()) == path
    assert surface.get_data()[:] == (