Skip to content

Highlight

Demo

Quick Start

highlight.py
from terminaltexteffects import Gradient
from terminaltexteffects.effects.effect_highlight import Highlight

effect = Highlight("YourTextHere")

with effect.terminal_output() as terminal:
    effect.effect_config.final_gradient_direction = Gradient.Direction.HORIZONTAL
    for frame in effect:
        terminal.print(frame)

Runs a specular highlight across the text.

Classes:

Name Description
Highlight

Runs a specular highlight across the text.
HighlightConfig

Configuration for the Highlight effect.
HighlightIterator

Effect iterator for the Highlight effect.

Highlight

Bases: BaseEffect[HighlightConfig]

Run a specular highlight across the text.

Source code in terminaltexteffects/effects/effect_highlight.py 
232
233
234
235
236
237
238
239
240
241
class Highlight(BaseEffect[HighlightConfig]):
    """Run a specular highlight across the text."""

    @property
    def _config_cls(self) -> type[HighlightConfig]:
        return HighlightConfig

    @property
    def _iterator_cls(self) -> type[HighlightIterator]:
        return HighlightIterator

HighlightConfig dataclass

Bases: BaseConfig

Configuration for the Highlight effect.

Attributes:

Name Type Description
highlight_brightness float

Brightness of the highlight color. Values less than 1 will darken the highlight color, while values greater than 1 will brighten the highlight color.
highlight_direction typing.Literal['column_left_to_right','row_top_to_bottom','row_bottom_to_top', diagonal_top_left_to_bottom_right', 'diagonal_bottom_left_to_top_right', 'diagonal_top_right_to_bottom_left', 'diagonal_bottom_right_to_top_left',]

Direction the highlight will travel.
highlight_width int

Width of the highlight. n >= 1
final_gradient_stops tuple[Color, ...]

Tuple of colors for the final color gradient. If only one color is provided, the characters will be displayed in that color.
final_gradient_steps tuple[int, ...] | int

Int or Tuple of ints for the number of gradient steps to use. More steps will create a smoother and longer gradient animation.
final_gradient_direction Direction

Direction of the final gradient.
Source code in terminaltexteffects/effects/effect_highlight.py 
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
@dataclass
class HighlightConfig(BaseConfig):
    """Configuration for the Highlight effect.

    Attributes:
        highlight_brightness (float): Brightness of the highlight color. Values less than 1 will darken the highlight
            color, while values greater than 1 will brighten the highlight color.
        highlight_direction (typing.Literal['column_left_to_right','row_top_to_bottom','row_bottom_to_top', diagonal_top_left_to_bottom_right', 'diagonal_bottom_left_to_top_right', 'diagonal_top_right_to_bottom_left', 'diagonal_bottom_right_to_top_left',]): Direction the highlight will travel.
        highlight_width (int): Width of the highlight. n >= 1
        final_gradient_stops (tuple[Color, ...]): Tuple of colors for the final color gradient. If only one color is
            provided, the characters will be displayed in that color.
        final_gradient_steps (tuple[int, ...] | int): Int or Tuple of ints for the number of gradient steps to use.
            More steps will create a smoother and longer gradient animation.
        final_gradient_direction (Gradient.Direction): Direction of the final gradient.

    """  # noqa: E501 # long type hint for highlight_direction required for mkdocs to associate the name: description pair

    parser_spec: ParserSpec = ParserSpec(
        name="highlight",
        help="Run a specular highlight across the text.",
        description="highlight | Run a specular highlight across the text.",
        epilog=(
            "Example: terminaltexteffects highlight --highlight-brightness 1.5 --highlight-direction "
            "diagonal_bottom_left_to_top_right --highlight-width 8 --final-gradient-stops 8A008A 00D1FF FFFFFF "
            "--final-gradient-steps 12 --final-gradient-direction vertical"
        ),
    )

    highlight_brightness: float = ArgSpec(
        name="--highlight-brightness",
        type=argutils.PositiveFloat.type_parser,
        default=1.75,
        metavar=argutils.PositiveFloat.METAVAR,
        help="Brightness of the highlight color. Values less than 1 will darken the highlight color, while values "
        "greater than 1 will brighten the highlight color.",
    )  # pyright: ignore[reportAssignmentType]
    (
        "float : Brightness of the highlight color. Values less than 1 will darken the highlight color, while "
        "values greater than 1 will brighten the highlight color."
    )

    highlight_direction: typing.Literal[
        "column_left_to_right",
        "row_top_to_bottom",
        "row_bottom_to_top",
        "diagonal_top_left_to_bottom_right",
        "diagonal_bottom_left_to_top_right",
        "diagonal_top_right_to_bottom_left",
        "diagonal_bottom_right_to_top_left",
        "outside_to_center",
        "center_to_outside",
    ] = ArgSpec(
        name="--highlight-direction",
        default="diagonal_bottom_left_to_top_right",
        choices=[
            "column_left_to_right",
            "column_right_to_left",
            "row_top_to_bottom",
            "row_bottom_to_top",
            "diagonal_top_left_to_bottom_right",
            "diagonal_bottom_left_to_top_right",
            "diagonal_top_right_to_bottom_left",
            "diagonal_bottom_right_to_top_left",
            "outside_to_center",
            "center_to_outside",
        ],
        help="Direction the highlight will travel.",
    )  # pyright: ignore[reportAssignmentType]
    (
        "typing.Literal['column_left_to_right','row_top_to_bottom','row_bottom_to_top',"
        "'diagonal_top_left_to_bottom_right','diagonal_bottom_left_to_top_right',"
        "'diagonal_top_right_to_bottom_left','diagonal_bottom_right_to_top_left',] : Direction the "
        "highlight will travel."
    )

    highlight_width: int = ArgSpec(
        name="--highlight-width",
        type=argutils.PositiveInt.type_parser,
        default=8,
        metavar=argutils.PositiveInt.METAVAR,
        help="Width of the highlight. n >= 1",
    )  # pyright: ignore[reportAssignmentType]
    "int : Width of the highlight. n >= 1"

    final_gradient_stops: tuple[Color, ...] = ArgSpec(
        name="--final-gradient-stops",
        type=argutils.ColorArg.type_parser,
        nargs="+",
        action=argutils.TupleAction,
        default=(Color("#8A008A"), Color("#00D1FF"), Color("#FFFFFF")),
        metavar=argutils.ColorArg.METAVAR,
        help="Space separated, unquoted, list of colors for the character gradient (applied across the canvas). If "
        "only one color is provided, the characters will be displayed in that color.",
    )  # pyright: ignore[reportAssignmentType]
    (
        "tuple[Color, ...] : Tuple of colors for the final color gradient. If only one color is provided, the "
        "characters will be displayed in that color."
    )

    final_gradient_steps: tuple[int, ...] | int = ArgSpec(
        name="--final-gradient-steps",
        type=argutils.PositiveInt.type_parser,
        nargs="+",
        action=argutils.TupleAction,
        default=12,
        metavar=argutils.PositiveInt.METAVAR,
        help="Space separated, unquoted, list of the number of gradient steps to use. More steps will create a "
        "smoother and longer gradient animation.",
    )  # pyright: ignore[reportAssignmentType]
    (
        "tuple[int, ...] | int : Int or Tuple of ints for the number of gradient steps to use. More steps will "
        "create a smoother and longer gradient animation."
    )

    final_gradient_direction: Gradient.Direction = ArgSpec(
        name="--final-gradient-direction",
        type=argutils.GradientDirection.type_parser,
        default=Gradient.Direction.VERTICAL,
        metavar=argutils.GradientDirection.METAVAR,
        help="Direction of the final gradient.",
    )  # pyright: ignore[reportAssignmentType]
    "Gradient.Direction : Direction of the final gradient."

final_gradient_direction = ArgSpec(name='--final-gradient-direction', type=(argutils.GradientDirection.type_parser), default=(Gradient.Direction.VERTICAL), metavar=(argutils.GradientDirection.METAVAR), help='Direction of the final gradient.') class-attribute instance-attribute

Gradient.Direction : Direction of the final gradient.

final_gradient_steps = ArgSpec(name='--final-gradient-steps', type=(argutils.PositiveInt.type_parser), nargs='+', action=(argutils.TupleAction), default=12, metavar=(argutils.PositiveInt.METAVAR), help='Space separated, unquoted, list of the number of gradient steps to use. More steps will create a smoother and longer gradient animation.') class-attribute instance-attribute

tuple[int, ...] | int : Int or Tuple of ints for the number of gradient steps to use. More steps will create a smoother and longer gradient animation.

final_gradient_stops = ArgSpec(name='--final-gradient-stops', type=(argutils.ColorArg.type_parser), nargs='+', action=(argutils.TupleAction), default=(Color('#8A008A'), Color('#00D1FF'), Color('#FFFFFF')), metavar=(argutils.ColorArg.METAVAR), help='Space separated, unquoted, list of colors for the character gradient (applied across the canvas). If only one color is provided, the characters will be displayed in that color.') class-attribute instance-attribute

tuple[Color, ...] : Tuple of colors for the final color gradient. If only one color is provided, the characters will be displayed in that color.

highlight_brightness = ArgSpec(name='--highlight-brightness', type=(argutils.PositiveFloat.type_parser), default=1.75, metavar=(argutils.PositiveFloat.METAVAR), help='Brightness of the highlight color. Values less than 1 will darken the highlight color, while values greater than 1 will brighten the highlight color.') class-attribute instance-attribute

float : Brightness of the highlight color. Values less than 1 will darken the highlight color, while values greater than 1 will brighten the highlight color.

highlight_direction = ArgSpec(name='--highlight-direction', default='diagonal_bottom_left_to_top_right', choices=['column_left_to_right', 'column_right_to_left', 'row_top_to_bottom', 'row_bottom_to_top', 'diagonal_top_left_to_bottom_right', 'diagonal_bottom_left_to_top_right', 'diagonal_top_right_to_bottom_left', 'diagonal_bottom_right_to_top_left', 'outside_to_center', 'center_to_outside'], help='Direction the highlight will travel.') class-attribute instance-attribute

typing.Literal['column_left_to_right','row_top_to_bottom','row_bottom_to_top','diagonal_top_left_to_bottom_right','diagonal_bottom_left_to_top_right','diagonal_top_right_to_bottom_left','diagonal_bottom_right_to_top_left',] : Direction the highlight will travel.

highlight_width = ArgSpec(name='--highlight-width', type=(argutils.PositiveInt.type_parser), default=8, metavar=(argutils.PositiveInt.METAVAR), help='Width of the highlight. n >= 1') class-attribute instance-attribute

int : Width of the highlight. n >= 1

HighlightIterator

Bases: BaseEffectIterator[HighlightConfig]

Effect iterator for the Highlight effect.

Source code in terminaltexteffects/effects/effect_highlight.py 
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
class HighlightIterator(BaseEffectIterator[HighlightConfig]):
    """Effect iterator for the Highlight effect."""

    def __init__(self, effect: Highlight) -> None:
        """Initialize the Highlight effect iterator.

        Args:
            effect (Highlight): The Highlight effect to iterate over.

        """
        super().__init__(effect)
        self.character_final_color_map: dict[EffectCharacter, Color] = {}
        self.pending_characters: list[list[EffectCharacter]] = []
        self.easer = easing.eased_step_function(easing.in_out_circ, 0.01)
        self.groups_activated = 0
        self.sort_map = {
            "column_left_to_right": self.terminal.CharacterGroup.COLUMN_LEFT_TO_RIGHT,
            "column_right_to_left": self.terminal.CharacterGroup.COLUMN_RIGHT_TO_LEFT,
            "row_top_to_bottom": self.terminal.CharacterGroup.ROW_TOP_TO_BOTTOM,
            "row_bottom_to_top": self.terminal.CharacterGroup.ROW_BOTTOM_TO_TOP,
            "diagonal_top_left_to_bottom_right": self.terminal.CharacterGroup.DIAGONAL_TOP_LEFT_TO_BOTTOM_RIGHT,
            "diagonal_bottom_left_to_top_right": self.terminal.CharacterGroup.DIAGONAL_BOTTOM_LEFT_TO_TOP_RIGHT,
            "diagonal_top_right_to_bottom_left": self.terminal.CharacterGroup.DIAGONAL_TOP_RIGHT_TO_BOTTOM_LEFT,
            "diagonal_bottom_right_to_top_left": self.terminal.CharacterGroup.DIAGONAL_BOTTOM_RIGHT_TO_TOP_LEFT,
            "center_to_outside": self.terminal.CharacterGroup.CENTER_TO_OUTSIDE_DIAMONDS,
            "outside_to_center": self.terminal.CharacterGroup.OUTSIDE_TO_CENTER_DIAMONDS,
        }
        self.pending_characters = self.terminal.get_characters_grouped(self.sort_map[self.config.highlight_direction])
        self.total_groups = len(self.pending_characters)
        self.build()

    def build(self) -> None:
        """Build the effect."""
        final_gradient = Gradient(*self.config.final_gradient_stops, steps=self.config.final_gradient_steps)
        final_gradient_mapping = final_gradient.build_coordinate_color_mapping(
            self.terminal.canvas.text_bottom,
            self.terminal.canvas.text_top,
            self.terminal.canvas.text_left,
            self.terminal.canvas.text_right,
            self.config.final_gradient_direction,
        )
        for character in self.terminal.get_characters():
            base_color = final_gradient_mapping[character.input_coord]
            self.character_final_color_map[character] = base_color
            highlight_color = Animation.adjust_color_brightness(base_color, self.config.highlight_brightness)
            highlight_gradient = Gradient(
                base_color,
                highlight_color,
                highlight_color,
                base_color,
                steps=(3, self.config.highlight_width, 3),
            )
            character.animation.set_appearance(character.input_symbol, ColorPair(fg=base_color))
            specular_highlight_scn = character.animation.new_scene(scene_id="highlight")
            for color in highlight_gradient:
                specular_highlight_scn.add_frame(character.input_symbol, 2, colors=ColorPair(fg=color))
            self.terminal.set_character_visibility(character, is_visible=True)
            self.active_characters.add(character)

    def __next__(self) -> str:
        """Return the next frame in the animation."""
        if self.active_characters or self.pending_characters:
            _, eased_percentage = self.easer()
            while (self.groups_activated / self.total_groups) < eased_percentage:
                if self.pending_characters:
                    next_group = self.pending_characters.pop(0)
                    for character in next_group:
                        character.animation.activate_scene("highlight")
                        self.active_characters.add(character)
                    self.groups_activated += 1

            self.update()
            return self.frame

        raise StopIteration

__init__(effect)

Initialize the Highlight effect iterator.

Parameters:

Name Type Description Default
effect Highlight

The Highlight effect to iterate over.

 required
Source code in terminaltexteffects/effects/effect_highlight.py 
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
def __init__(self, effect: Highlight) -> None:
    """Initialize the Highlight effect iterator.

    Args:
        effect (Highlight): The Highlight effect to iterate over.

    """
    super().__init__(effect)
    self.character_final_color_map: dict[EffectCharacter, Color] = {}
    self.pending_characters: list[list[EffectCharacter]] = []
    self.easer = easing.eased_step_function(easing.in_out_circ, 0.01)
    self.groups_activated = 0
    self.sort_map = {
        "column_left_to_right": self.terminal.CharacterGroup.COLUMN_LEFT_TO_RIGHT,
        "column_right_to_left": self.terminal.CharacterGroup.COLUMN_RIGHT_TO_LEFT,
        "row_top_to_bottom": self.terminal.CharacterGroup.ROW_TOP_TO_BOTTOM,
        "row_bottom_to_top": self.terminal.CharacterGroup.ROW_BOTTOM_TO_TOP,
        "diagonal_top_left_to_bottom_right": self.terminal.CharacterGroup.DIAGONAL_TOP_LEFT_TO_BOTTOM_RIGHT,
        "diagonal_bottom_left_to_top_right": self.terminal.CharacterGroup.DIAGONAL_BOTTOM_LEFT_TO_TOP_RIGHT,
        "diagonal_top_right_to_bottom_left": self.terminal.CharacterGroup.DIAGONAL_TOP_RIGHT_TO_BOTTOM_LEFT,
        "diagonal_bottom_right_to_top_left": self.terminal.CharacterGroup.DIAGONAL_BOTTOM_RIGHT_TO_TOP_LEFT,
        "center_to_outside": self.terminal.CharacterGroup.CENTER_TO_OUTSIDE_DIAMONDS,
        "outside_to_center": self.terminal.CharacterGroup.OUTSIDE_TO_CENTER_DIAMONDS,
    }
    self.pending_characters = self.terminal.get_characters_grouped(self.sort_map[self.config.highlight_direction])
    self.total_groups = len(self.pending_characters)
    self.build()

__next__()

Return the next frame in the animation.

Source code in terminaltexteffects/effects/effect_highlight.py 
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
def __next__(self) -> str:
    """Return the next frame in the animation."""
    if self.active_characters or self.pending_characters:
        _, eased_percentage = self.easer()
        while (self.groups_activated / self.total_groups) < eased_percentage:
            if self.pending_characters:
                next_group = self.pending_characters.pop(0)
                for character in next_group:
                    character.animation.activate_scene("highlight")
                    self.active_characters.add(character)
                self.groups_activated += 1

        self.update()
        return self.frame

    raise StopIteration

build()

Build the effect.

Source code in terminaltexteffects/effects/effect_highlight.py 
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
def build(self) -> None:
    """Build the effect."""
    final_gradient = Gradient(*self.config.final_gradient_stops, steps=self.config.final_gradient_steps)
    final_gradient_mapping = final_gradient.build_coordinate_color_mapping(
        self.terminal.canvas.text_bottom,
        self.terminal.canvas.text_top,
        self.terminal.canvas.text_left,
        self.terminal.canvas.text_right,
        self.config.final_gradient_direction,
    )
    for character in self.terminal.get_characters():
        base_color = final_gradient_mapping[character.input_coord]
        self.character_final_color_map[character] = base_color
        highlight_color = Animation.adjust_color_brightness(base_color, self.config.highlight_brightness)
        highlight_gradient = Gradient(
            base_color,
            highlight_color,
            highlight_color,
            base_color,
            steps=(3, self.config.highlight_width, 3),
        )
        character.animation.set_appearance(character.input_symbol, ColorPair(fg=base_color))
        specular_highlight_scn = character.animation.new_scene(scene_id="highlight")
        for color in highlight_gradient:
            specular_highlight_scn.add_frame(character.input_symbol, 2, colors=ColorPair(fg=color))
        self.terminal.set_character_visibility(character, is_visible=True)
        self.active_characters.add(character)

get_effect_resources()

Get the command, effect class, and configuration class for the effect.

Returns:

Type Description
tuple[str, type[BaseEffect], type[BaseConfig]]

tuple[str, type[BaseEffect], type[BaseConfig]]: The command name, effect class, and configuration class.
Source code in terminaltexteffects/effects/effect_highlight.py 
21
22
23
24
25
26
27
28
def get_effect_resources() -> tuple[str, type[BaseEffect], type[BaseConfig]]:
    """Get the command, effect class, and configuration class for the effect.

    Returns:
        tuple[str, type[BaseEffect], type[BaseConfig]]: The command name, effect class, and configuration class.

    """
    return "highlight", Highlight, HighlightConfig