xref: /aosp_15_r20/frameworks/base/data/fonts/script/font_builder.py (revision d57664e9bc4670b3ecf6748a746a57c557b6bc9e) 
1#!/usr/bin/env python
2
3#
4# Copyright (C) 2024 The Android Open Source Project
5#
6# Licensed under the Apache License, Version 2.0 (the "License");
7# you may not use this file except in compliance with the License.
8# You may obtain a copy of the License at
9#
10#      http://www.apache.org/licenses/LICENSE-2.0
11#
12# Unless required by applicable law or agreed to in writing, software
13# distributed under the License is distributed on an "AS IS" BASIS,
14# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15# See the License for the specific language governing permissions and
16# limitations under the License.
17#
18
19"""Build Font instance with validating JSON contents."""
20
21import dataclasses
22
23from custom_json import _load_json_with_comment
24from validators import check_enum_or_none
25from validators import check_float
26from validators import check_int_or_none
27from validators import check_str
28from validators import check_str_or_none
29from validators import check_tag
30from validators import check_weight_or_none
31
32
33@dataclasses.dataclass
34class Font:
35  file: str
36  weight: int | None
37  style: str | None
38  index: int | None
39  supported_axes: str | None
40  post_script_name: str | None
41  axes: dict[str | float]
42
43
44_FONT_KEYS = set([
45    "file",
46    "weight",
47    "style",
48    "index",
49    "supportedAxes",
50    "postScriptName",
51    "axes",
52])
53
54
55def _check_axes(axes) -> dict[str | float] | None:
56  """Sanitize the variation axes."""
57  if axes is None:
58    return None
59  assert isinstance(axes, dict), "axes must be dict"
60
61  sanitized = {}
62  for key in axes.keys():
63    sanitized[check_tag(key)] = check_float(axes, key)
64
65  return sanitized
66
67
68def _parse_font(obj, for_sanitization_test=False) -> Font:
69  """Convert given dict object to Font instance."""
70  unknown_keys = obj.keys() - _FONT_KEYS
71  assert not unknown_keys, "Unknown keys found: %s" % unknown_keys
72  font = Font(
73      file=check_str(obj, "file"),
74      weight=check_weight_or_none(obj, "weight"),
75      style=check_enum_or_none(obj, "style", ["normal", "italic"]),
76      index=check_int_or_none(obj, "index"),
77      supported_axes=check_enum_or_none(
78          obj, "supportedAxes", ["wght", "wght,ital"]
79      ),
80      post_script_name=check_str_or_none(obj, "postScriptName"),
81      axes=_check_axes(obj.get("axes")),
82  )
83
84  if not for_sanitization_test:
85    assert font.file, "file must be specified"
86    if not font.supported_axes:
87      assert font.weight, (
88          "If supported_axes is not specified, weight should be specified: %s"
89          % obj
90      )
91      assert font.style, (
92          "If supported_axes is not specified, style should be specified: %s"
93          % obj
94      )
95
96  return font
97
98
99def parse_fonts(objs) -> Font:
100  assert isinstance(objs, list), "fonts must be list: %s" % (objs)
101  assert objs, "At least one font should be added."
102  return [_parse_font(obj) for obj in objs]
103
104
105def parse_font_from_json_for_sanitization_test(json_str: str) -> Font:
106  """For testing purposes."""
107  return _parse_font(
108      _load_json_with_comment(json_str), for_sanitization_test=False
109  )
110
111
112def parse_fonts_from_json_for_validation_test(json_str: str) -> [Font]:
113  """For testing purposes."""
114  return parse_fonts(_load_json_with_comment(json_str))
115