Pillow/Tests/test_imagefont.py

# -*- coding: utf-8 -*-
from .helper import unittest, PillowTestCase

from PIL import Image, ImageDraw, ImageFont, features
from io import BytesIO
import os
import sys
import copy
import re
import shutil
import distutils.version

FONT_PATH = "Tests/fonts/FreeMono.ttf"
FONT_SIZE = 20

TEST_TEXT = "hey you\nyou are awesome\nthis looks awkward"

HAS_FREETYPE = features.check('freetype2')
HAS_RAQM = features.check('raqm')


class SimplePatcher(object):
    def __init__(self, parent_obj, attr_name, value):
        self._parent_obj = parent_obj
        self._attr_name = attr_name
        self._saved = None
        self._is_saved = False
        self._value = value

    def __enter__(self):
        # Patch the attr on the object
        if hasattr(self._parent_obj, self._attr_name):
            self._saved = getattr(self._parent_obj, self._attr_name)
            setattr(self._parent_obj, self._attr_name, self._value)
            self._is_saved = True
        else:
            setattr(self._parent_obj, self._attr_name, self._value)
            self._is_saved = False

    def __exit__(self, type, value, traceback):
        # Restore the original value
        if self._is_saved:
            setattr(self._parent_obj, self._attr_name, self._saved)
        else:
            delattr(self._parent_obj, self._attr_name)


@unittest.skipUnless(HAS_FREETYPE, "ImageFont not available")
class TestImageFont(PillowTestCase):
    LAYOUT_ENGINE = ImageFont.LAYOUT_BASIC

    # Freetype has different metrics depending on the version.
    # (and, other things, but first things first)
    METRICS = {
                ('>=2.3', '<2.4'): {
                    'multiline': 30,
                    'textsize': 12,
                    'getters': (13, 16)},
                ('>=2.7',): {
                    'multiline': 6.2,
                    'textsize': 2.5,
                    'getters': (12, 16)},
                'Default': {
                    'multiline': 0.5,
                    'textsize': 0.5,
                    'getters': (12, 16)},
                }

    def setUp(self):
        freetype = distutils.version.StrictVersion(ImageFont.core.freetype2_version)

        self.metrics = self.METRICS['Default']
        for conditions, metrics in self.METRICS.items():
            if not isinstance(conditions, tuple):
                continue

            for condition in conditions:
                version = re.sub('[<=>]', '', condition)
                if (condition.startswith('>=') and freetype >= version) or \
                   (condition.startswith('<') and freetype < version):
                    # Condition was met
                    continue

                # Condition failed
                break
            else:
                # All conditions were met
                self.metrics = metrics

    def get_font(self):
        return ImageFont.truetype(FONT_PATH, FONT_SIZE,
                                  layout_engine=self.LAYOUT_ENGINE)

    def test_sanity(self):
        self.assertRegex(ImageFont.core.freetype2_version, r"\d+\.\d+\.\d+$")

    def test_font_properties(self):
        ttf = self.get_font()
        self.assertEqual(ttf.path, FONT_PATH)
        self.assertEqual(ttf.size, FONT_SIZE)

        ttf_copy = ttf.font_variant()
        self.assertEqual(ttf_copy.path, FONT_PATH)
        self.assertEqual(ttf_copy.size, FONT_SIZE)

        ttf_copy = ttf.font_variant(size=FONT_SIZE+1)
        self.assertEqual(ttf_copy.size, FONT_SIZE+1)

        second_font_path = "Tests/fonts/DejaVuSans.ttf"
        ttf_copy = ttf.font_variant(font=second_font_path)
        self.assertEqual(ttf_copy.path, second_font_path)

    def test_font_with_name(self):
        self.get_font()
        self._render(FONT_PATH)

    def _font_as_bytes(self):
        with open(FONT_PATH, 'rb') as f:
            font_bytes = BytesIO(f.read())
        return font_bytes

    def test_font_with_filelike(self):
        ImageFont.truetype(self._font_as_bytes(), FONT_SIZE,
                           layout_engine=self.LAYOUT_ENGINE)
        self._render(self._font_as_bytes())
        # Usage note:  making two fonts from the same buffer fails.
        # shared_bytes = self._font_as_bytes()
        # self._render(shared_bytes)
        # self.assertRaises(Exception, _render, shared_bytes)

    def test_font_with_open_file(self):
        with open(FONT_PATH, 'rb') as f:
            self._render(f)

    def test_non_unicode_path(self):
        try:
            tempfile = self.tempfile("temp_"+chr(128)+".ttf")
        except UnicodeEncodeError:
            self.skipTest("Unicode path could not be created")
        shutil.copy(FONT_PATH, tempfile)

        ImageFont.truetype(tempfile, FONT_SIZE)

    def test_unavailable_layout_engine(self):
        have_raqm = ImageFont.core.HAVE_RAQM
        ImageFont.core.HAVE_RAQM = False

        try:
            ttf = ImageFont.truetype(FONT_PATH, FONT_SIZE,
                                     layout_engine=ImageFont.LAYOUT_RAQM)
        finally:
            ImageFont.core.HAVE_RAQM = have_raqm

        self.assertEqual(ttf.layout_engine, ImageFont.LAYOUT_BASIC)

    def _render(self, font):
        txt = "Hello World!"
        ttf = ImageFont.truetype(font, FONT_SIZE,
                                 layout_engine=self.LAYOUT_ENGINE)
        ttf.getsize(txt)

        img = Image.new("RGB", (256, 64), "white")
        d = ImageDraw.Draw(img)
        d.text((10, 10), txt, font=ttf, fill='black')

        return img

    def test_render_equal(self):
        img_path = self._render(FONT_PATH)
        with open(FONT_PATH, 'rb') as f:
            font_filelike = BytesIO(f.read())
        img_filelike = self._render(font_filelike)

        self.assert_image_equal(img_path, img_filelike)

    def test_textsize_equal(self):
        im = Image.new(mode='RGB', size=(300, 100))
        draw = ImageDraw.Draw(im)
        ttf = self.get_font()

        txt = "Hello World!"
        size = draw.textsize(txt, ttf)
        draw.text((10, 10), txt, font=ttf)
        draw.rectangle((10, 10, 10 + size[0], 10 + size[1]))

        target = 'Tests/images/rectangle_surrounding_text.png'
        target_img = Image.open(target)

        # Epsilon ~.5 fails with FreeType 2.7
        self.assert_image_similar(im, target_img, self.metrics['textsize'])

    def test_render_multiline(self):
        im = Image.new(mode='RGB', size=(300, 100))
        draw = ImageDraw.Draw(im)
        ttf = self.get_font()
        line_spacing = draw.textsize('A', font=ttf)[1] + 4
        lines = TEST_TEXT.split("\n")
        y = 0
        for line in lines:
            draw.text((0, y), line, font=ttf)
            y += line_spacing

        target = 'Tests/images/multiline_text.png'
        target_img = Image.open(target)

        # some versions of freetype have different horizontal spacing.
        # setting a tight epsilon, I'm showing the original test failure
        # at epsilon = ~38.
        self.assert_image_similar(im, target_img, self.metrics['multiline'])

    def test_render_multiline_text(self):
        ttf = self.get_font()

        # Test that text() correctly connects to multiline_text()
        # and that align defaults to left
        im = Image.new(mode='RGB', size=(300, 100))
        draw = ImageDraw.Draw(im)
        draw.text((0, 0), TEST_TEXT, font=ttf)

        target = 'Tests/images/multiline_text.png'
        target_img = Image.open(target)

        # Epsilon ~.5 fails with FreeType 2.7
        self.assert_image_similar(im, target_img, self.metrics['multiline'])

        # Test that text() can pass on additional arguments
        # to multiline_text()
        draw.text((0, 0), TEST_TEXT, fill=None, font=ttf, anchor=None,
                  spacing=4, align="left")
        draw.text((0, 0), TEST_TEXT, None, ttf, None, 4, "left")

        # Test align center and right
        for align, ext in {"center": "_center",
                           "right": "_right"}.items():
            im = Image.new(mode='RGB', size=(300, 100))
            draw = ImageDraw.Draw(im)
            draw.multiline_text((0, 0), TEST_TEXT, font=ttf, align=align)

            target = 'Tests/images/multiline_text'+ext+'.png'
            target_img = Image.open(target)

            # Epsilon ~.5 fails with FreeType 2.7
            self.assert_image_similar(im, target_img,
                                      self.metrics['multiline'])

    def test_unknown_align(self):
        im = Image.new(mode='RGB', size=(300, 100))
        draw = ImageDraw.Draw(im)
        ttf = self.get_font()

        # Act/Assert
        self.assertRaises(
            ValueError,
            draw.multiline_text, (0, 0), TEST_TEXT, font=ttf, align="unknown")

    def test_draw_align(self):
        im = Image.new('RGB', (300, 100), 'white')
        draw = ImageDraw.Draw(im)
        ttf = self.get_font()
        line = "some text"
        draw.text((100, 40), line, (0, 0, 0), font=ttf, align='left')

    def test_multiline_size(self):
        ttf = self.get_font()
        im = Image.new(mode='RGB', size=(300, 100))
        draw = ImageDraw.Draw(im)

        # Test that textsize() correctly connects to multiline_textsize()
        self.assertEqual(draw.textsize(TEST_TEXT, font=ttf),
                         draw.multiline_textsize(TEST_TEXT, font=ttf))

        # Test that multiline_textsize corresponds to ImageFont.textsize()
        # for single line text
        self.assertEqual(ttf.getsize('A'),
                         draw.multiline_textsize('A', font=ttf))

        # Test that textsize() can pass on additional arguments
        # to multiline_textsize()
        draw.textsize(TEST_TEXT, font=ttf, spacing=4)
        draw.textsize(TEST_TEXT, ttf, 4)

    def test_multiline_width(self):
        ttf = self.get_font()
        im = Image.new(mode='RGB', size=(300, 100))
        draw = ImageDraw.Draw(im)

        self.assertEqual(draw.textsize("longest line", font=ttf)[0],
                         draw.multiline_textsize("longest line\nline",
                                                 font=ttf)[0])

    def test_multiline_spacing(self):
        ttf = self.get_font()

        im = Image.new(mode='RGB', size=(300, 100))
        draw = ImageDraw.Draw(im)
        draw.multiline_text((0, 0), TEST_TEXT, font=ttf, spacing=10)

        target = 'Tests/images/multiline_text_spacing.png'
        target_img = Image.open(target)

        # Epsilon ~.5 fails with FreeType 2.7
        self.assert_image_similar(im, target_img, self.metrics['multiline'])

    def test_rotated_transposed_font(self):
        img_grey = Image.new("L", (100, 100))
        draw = ImageDraw.Draw(img_grey)
        word = "testing"
        font = self.get_font()

        orientation = Image.ROTATE_90
        transposed_font = ImageFont.TransposedFont(
            font, orientation=orientation)

        # Original font
        draw.font = font
        box_size_a = draw.textsize(word)

        # Rotated font
        draw.font = transposed_font
        box_size_b = draw.textsize(word)

        # Check (w,h) of box a is (h,w) of box b
        self.assertEqual(box_size_a[0], box_size_b[1])
        self.assertEqual(box_size_a[1], box_size_b[0])

    def test_unrotated_transposed_font(self):
        img_grey = Image.new("L", (100, 100))
        draw = ImageDraw.Draw(img_grey)
        word = "testing"
        font = self.get_font()

        orientation = None
        transposed_font = ImageFont.TransposedFont(
            font, orientation=orientation)

        # Original font
        draw.font = font
        box_size_a = draw.textsize(word)

        # Rotated font
        draw.font = transposed_font
        box_size_b = draw.textsize(word)

        # Check boxes a and b are same size
        self.assertEqual(box_size_a, box_size_b)

    def test_rotated_transposed_font_get_mask(self):
        # Arrange
        text = "mask this"
        font = self.get_font()
        orientation = Image.ROTATE_90
        transposed_font = ImageFont.TransposedFont(
            font, orientation=orientation)

        # Act
        mask = transposed_font.getmask(text)

        # Assert
        self.assertEqual(mask.size, (13, 108))

    def test_unrotated_transposed_font_get_mask(self):
        # Arrange
        text = "mask this"
        font = self.get_font()
        orientation = None
        transposed_font = ImageFont.TransposedFont(
            font, orientation=orientation)

        # Act
        mask = transposed_font.getmask(text)

        # Assert
        self.assertEqual(mask.size, (108, 13))

    def test_free_type_font_get_name(self):
        # Arrange
        font = self.get_font()

        # Act
        name = font.getname()

        # Assert
        self.assertEqual(('FreeMono', 'Regular'), name)

    def test_free_type_font_get_metrics(self):
        # Arrange
        font = self.get_font()

        # Act
        ascent, descent = font.getmetrics()

        # Assert
        self.assertIsInstance(ascent, int)
        self.assertIsInstance(descent, int)
        self.assertEqual((ascent, descent), (16, 4))  # too exact check?

    def test_free_type_font_get_offset(self):
        # Arrange
        font = self.get_font()
        text = "offset this"

        # Act
        offset = font.getoffset(text)

        # Assert
        self.assertEqual(offset, (0, 3))

    def test_free_type_font_get_mask(self):
        # Arrange
        font = self.get_font()
        text = "mask this"

        # Act
        mask = font.getmask(text)

        # Assert
        self.assertEqual(mask.size, (108, 13))

    def test_load_path_not_found(self):
        # Arrange
        filename = "somefilenamethatdoesntexist.ttf"

        # Act/Assert
        self.assertRaises(IOError, ImageFont.load_path, filename)
        self.assertRaises(IOError, ImageFont.truetype, filename)

    def test_default_font(self):
        # Arrange
        txt = 'This is a "better than nothing" default font.'
        im = Image.new(mode='RGB', size=(300, 100))
        draw = ImageDraw.Draw(im)

        target = 'Tests/images/default_font.png'
        target_img = Image.open(target)

        # Act
        default_font = ImageFont.load_default()
        draw.text((10, 10), txt, font=default_font)

        # Assert
        self.assert_image_equal(im, target_img)

    def test_getsize_empty(self):
        # issue #2614
        font = self.get_font()
        # should not crash.
        self.assertEqual((0, 0), font.getsize(''))

    def test_render_empty(self):
        # issue 2666
        font = self.get_font()
        im = Image.new(mode='RGB', size=(300, 100))
        target = im.copy()
        draw = ImageDraw.Draw(im)
        # should not crash here.
        draw.text((10, 10), '', font=font)
        self.assert_image_equal(im, target)

    def test_unicode_pilfont(self):
        # should not segfault, should return UnicodeDecodeError
        # issue #2826
        font = ImageFont.load_default()
        with self.assertRaises(UnicodeEncodeError):
            font.getsize(u"’")

    def _test_fake_loading_font(self, path_to_fake, fontname):
        # Make a copy of FreeTypeFont so we can patch the original
        free_type_font = copy.deepcopy(ImageFont.FreeTypeFont)
        with SimplePatcher(ImageFont, '_FreeTypeFont', free_type_font):
            def loadable_font(filepath, size, index, encoding,
                              *args, **kwargs):
                if filepath == path_to_fake:
                    return ImageFont._FreeTypeFont(FONT_PATH, size, index,
                                                   encoding, *args, **kwargs)
                return ImageFont._FreeTypeFont(filepath, size, index,
                                               encoding, *args, **kwargs)
            with SimplePatcher(ImageFont, 'FreeTypeFont', loadable_font):
                font = ImageFont.truetype(fontname)
                # Make sure it's loaded
                name = font.getname()
                self.assertEqual(('FreeMono', 'Regular'), name)

    @unittest.skipIf(sys.platform.startswith('win32'),
                     "requires Unix or macOS")
    def test_find_linux_font(self):
        # A lot of mocking here - this is more for hitting code and
        # catching syntax like errors
        font_directory = '/usr/local/share/fonts'
        with SimplePatcher(sys, 'platform', 'linux'):
            patched_env = copy.deepcopy(os.environ)
            patched_env['XDG_DATA_DIRS'] = '/usr/share/:/usr/local/share/'
            with SimplePatcher(os, 'environ', patched_env):
                def fake_walker(path):
                    if path == font_directory:
                        return [(path, [], [
                            'Arial.ttf', 'Single.otf', 'Duplicate.otf',
                            'Duplicate.ttf'], )]
                    return [(path, [], ['some_random_font.ttf'], )]
                with SimplePatcher(os, 'walk', fake_walker):
                    # Test that the font loads both with and without the
                    # extension
                    self._test_fake_loading_font(
                        font_directory+'/Arial.ttf', 'Arial.ttf')
                    self._test_fake_loading_font(
                        font_directory+'/Arial.ttf', 'Arial')

                    # Test that non-ttf fonts can be found without the
                    # extension
                    self._test_fake_loading_font(
                        font_directory+'/Single.otf', 'Single')

                    # Test that ttf fonts are preferred if the extension is
                    # not specified
                    self._test_fake_loading_font(
                        font_directory+'/Duplicate.ttf', 'Duplicate')

    @unittest.skipIf(sys.platform.startswith('win32'),
                     "requires Unix or macOS")
    def test_find_macos_font(self):
        # Like the linux test, more cover hitting code rather than testing
        # correctness.
        font_directory = '/System/Library/Fonts'
        with SimplePatcher(sys, 'platform', 'darwin'):
            def fake_walker(path):
                if path == font_directory:
                    return [(path, [],
                            ['Arial.ttf', 'Single.otf',
                             'Duplicate.otf', 'Duplicate.ttf'], )]
                return [(path, [], ['some_random_font.ttf'], )]
            with SimplePatcher(os, 'walk', fake_walker):
                self._test_fake_loading_font(
                    font_directory+'/Arial.ttf', 'Arial.ttf')
                self._test_fake_loading_font(
                    font_directory+'/Arial.ttf', 'Arial')
                self._test_fake_loading_font(
                    font_directory+'/Single.otf', 'Single')
                self._test_fake_loading_font(
                    font_directory+'/Duplicate.ttf', 'Duplicate')

    def test_imagefont_getters(self):
        # Arrange
        t = self.get_font()

        # Act / Assert
        self.assertEqual(t.getmetrics(), (16, 4))
        self.assertEqual(t.font.ascent, 16)
        self.assertEqual(t.font.descent, 4)
        self.assertEqual(t.font.height, 20)
        self.assertEqual(t.font.x_ppem, 20)
        self.assertEqual(t.font.y_ppem, 20)
        self.assertEqual(t.font.glyphs, 4177)
        self.assertEqual(t.getsize('A'), (12, 16))
        self.assertEqual(t.getsize('AB'), (24, 16))
        self.assertEqual(t.getsize('M'), self.metrics['getters'])
        self.assertEqual(t.getsize('y'), (12, 20))
        self.assertEqual(t.getsize('a'), (12, 16))
        self.assertEqual(t.getsize_multiline('A'), (12, 16))
        self.assertEqual(t.getsize_multiline('AB'), (24, 16))
        self.assertEqual(t.getsize_multiline('a'), (12, 16))
        self.assertEqual(t.getsize_multiline('ABC\n'), (36, 36))
        self.assertEqual(t.getsize_multiline('ABC\nA'), (36, 36))
        self.assertEqual(t.getsize_multiline('ABC\nAaaa'), (48, 36))

    def test_complex_font_settings(self):
        # Arrange
        t = self.get_font()
        # Act / Assert
        if t.layout_engine == ImageFont.LAYOUT_BASIC:
            self.assertRaises(KeyError, t.getmask, 'абвг', direction='rtl')
            self.assertRaises(KeyError, t.getmask, 'абвг', features=['-kern'])
            self.assertRaises(KeyError, t.getmask, 'абвг', language='sr')


@unittest.skipUnless(HAS_RAQM, "Raqm not Available")
class TestImageFont_RaqmLayout(TestImageFont):
    LAYOUT_ENGINE = ImageFont.LAYOUT_RAQM