Skip to content

Expand

Demo

Quick Start

expand.py
from terminaltexteffects.effects.effect_expand import Expand

effect = Expand("YourTextHere")
with effect.terminal_output() as terminal:
    for frame in effect:
        terminal.print(frame)

Characters expand from the center.

Classes:

Name Description
Expand

Characters expand from the center.
ExpandConfig

Configuration for the Expand effect.
ExpandIterator

Iterates over the effect.

Expand

Bases: BaseEffect[ExpandConfig]

Characters expand from the center.

Attributes:

Name Type Description
effect_config ExpandConfig

Configuration for the effect.
terminal_config TerminalConfig

Configuration for the terminal.
Source code in terminaltexteffects/effects/effect_expand.py 
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
class Expand(BaseEffect[ExpandConfig]):
    """Characters expand from the center.

    Attributes:
        effect_config (ExpandConfig): Configuration for the effect.
        terminal_config (TerminalConfig): Configuration for the terminal.

    """

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

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

ExpandConfig dataclass

Bases: BaseConfig

Configuration for the Expand effect.

Attributes:

Name Type Description
movement_speed float

Movement speed of the characters.
expand_easing EasingFunction

Easing function to use for character movement.
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

Tuple of the number of gradient steps to use. More steps will create a smoother and longer gradient animation. Valid values are n > 0.
final_gradient_direction Direction

Direction of the final gradient.
Source code in terminaltexteffects/effects/effect_expand.py 
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
@dataclass
class ExpandConfig(BaseConfig):
    """Configuration for the Expand effect.

    Attributes:
        movement_speed (float): Movement speed of the characters.
        expand_easing (easing.EasingFunction): Easing function to use for character movement.
        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): Tuple of the number of gradient steps to use. More steps will
            create a smoother and longer gradient animation. Valid values are n > 0.
        final_gradient_direction (Gradient.Direction): Direction of the final gradient.

    """

    parser_spec = argutils.ParserSpec(
        name="expand",
        help="Expands the text from a single point.",
        description="expand | Expands the text from a single point.",
        epilog=(
            f"{argutils.EASING_EPILOG}"
            "Example: terminaltexteffects expand --final-gradient-stops 8A008A 00D1FF FFFFFF --final-gradient-steps 12 "
            "--final-gradient-direction vertical --movement-speed 0.35 --expand-easing IN_OUT_QUART"
        ),
    )
    expand_easing: easing.EasingFunction = argutils.ArgSpec(
        name="--expand-easing",
        default=easing.in_out_quart,
        type=argutils.Ease.type_parser,
        help="Easing function to use for character movement.",
    )  # pyright: ignore[reportAssignmentType]
    "easing.EasingFunction : Easing function to use for character movement."

    movement_speed: float = argutils.ArgSpec(
        name="--movement-speed",
        type=argutils.PositiveFloat.type_parser,
        default=0.35,
        metavar=argutils.PositiveFloat.METAVAR,
        help="Movement speed of the characters. ",
    )  # pyright: ignore[reportAssignmentType]
    "float : Movement speed of the characters. "

    final_gradient_stops: tuple[Color, ...] = FinalGradientStopsArg(
        default=(Color("#8A008A"), Color("#00D1FF"), Color("#FFFFFF")),
    )  # 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 = FinalGradientStepsArg(
        default=12,
    )  # 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 = FinalGradientDirectionArg(
        default=Gradient.Direction.VERTICAL,
    )  # pyright: ignore[reportAssignmentType]
    "Gradient.Direction : Direction of the final gradient."

expand_easing = argutils.ArgSpec(name='--expand-easing', default=(easing.in_out_quart), type=(argutils.Ease.type_parser), help='Easing function to use for character movement.') class-attribute instance-attribute

easing.EasingFunction : Easing function to use for character movement.

final_gradient_direction = FinalGradientDirectionArg(default=(Gradient.Direction.VERTICAL)) class-attribute instance-attribute

Gradient.Direction : Direction of the final gradient.

final_gradient_steps = FinalGradientStepsArg(default=12) 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 = FinalGradientStopsArg(default=(Color('#8A008A'), Color('#00D1FF'), Color('#FFFFFF'))) 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.

movement_speed = argutils.ArgSpec(name='--movement-speed', type=(argutils.PositiveFloat.type_parser), default=0.35, metavar=(argutils.PositiveFloat.METAVAR), help='Movement speed of the characters. ') class-attribute instance-attribute

float : Movement speed of the characters.

ExpandIterator

Bases: BaseEffectIterator[ExpandConfig]

Iterates over the Expand effect.

Source code in terminaltexteffects/effects/effect_expand.py 
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
153
154
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
class ExpandIterator(BaseEffectIterator[ExpandConfig]):
    """Iterates over the Expand effect."""

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

        Args:
            effect (Expand): The effect to use for the iterator.

        """
        super().__init__(effect)
        self.pending_chars: list[EffectCharacter] = []
        self.character_final_color_map: dict[EffectCharacter, ColorPair] = {}
        self.build()

    def build(self) -> None:
        """Build the Expand 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():
            if self.terminal.config.existing_color_handling == "dynamic":
                self.character_final_color_map[character] = ColorPair(
                    fg=character.animation.input_fg_color,
                    bg=character.animation.input_bg_color,
                )
            else:
                self.character_final_color_map[character] = ColorPair(
                    fg=final_gradient_mapping[character.input_coord],
                )
        for character in self.terminal.get_characters():
            character.motion.set_coordinate(self.terminal.canvas.center)
            input_coord_path = character.motion.new_path(
                speed=self.config.movement_speed,
                ease=self.config.expand_easing,
            )
            input_coord_path.new_waypoint(character.input_coord)
            self.terminal.set_character_visibility(character, is_visible=True)
            self.active_characters.add(character)
            character.event_handler.register_event(
                EventHandler.Event.PATH_ACTIVATED,
                input_coord_path,
                EventHandler.Action.SET_LAYER,
                1,
            )
            character.event_handler.register_event(
                EventHandler.Event.PATH_COMPLETE,
                input_coord_path,
                EventHandler.Action.SET_LAYER,
                0,
            )
            character.motion.activate_path(input_coord_path)
            gradient_scn = character.animation.new_scene(sync=Scene.SyncMetric.DISTANCE)
            if self.terminal.config.existing_color_handling == "dynamic":
                fg_gradient = (
                    Gradient(final_gradient.spectrum[0], character.animation.input_fg_color, steps=10)
                    if character.animation.input_fg_color
                    else None
                )
                bg_gradient = (
                    Gradient(final_gradient.spectrum[0], character.animation.input_bg_color, steps=10)
                    if character.animation.input_bg_color
                    else None
                )
                if fg_gradient or bg_gradient:
                    gradient_scn.apply_gradient_to_symbols(
                        character.input_symbol,
                        1,
                        fg_gradient=fg_gradient,
                        bg_gradient=bg_gradient,
                    )
                else:
                    gradient_scn.add_frame(
                        character.input_symbol,
                        1,
                        colors=ColorPair(),
                    )
            else:
                gradient = Gradient(
                    final_gradient.spectrum[0],
                    cast("Color", self.character_final_color_map[character].fg_color),
                    steps=10,
                )
                gradient_scn.apply_gradient_to_symbols(
                    character.input_symbol,
                    5,
                    fg_gradient=gradient,
                )
            character.animation.activate_scene(gradient_scn)

    def __next__(self) -> str:
        """Return the next frame in the animation."""
        if self.active_characters:
            self.update()
            return self.frame
        raise StopIteration

__init__(effect)

Initialize the Expand effect iterator.

Parameters:

Name Type Description Default
effect Expand

The effect to use for the iterator.

 required
Source code in terminaltexteffects/effects/effect_expand.py 
103
104
105
106
107
108
109
110
111
112
113
114
115
116
def __init__(
    self,
    effect: Expand,
) -> None:
    """Initialize the Expand effect iterator.

    Args:
        effect (Expand): The effect to use for the iterator.

    """
    super().__init__(effect)
    self.pending_chars: list[EffectCharacter] = []
    self.character_final_color_map: dict[EffectCharacter, ColorPair] = {}
    self.build()

__next__()

Return the next frame in the animation.

Source code in terminaltexteffects/effects/effect_expand.py 
198
199
200
201
202
203
def __next__(self) -> str:
    """Return the next frame in the animation."""
    if self.active_characters:
        self.update()
        return self.frame
    raise StopIteration

build()

Build the Expand effect.

Source code in terminaltexteffects/effects/effect_expand.py 
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
153
154
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
def build(self) -> None:
    """Build the Expand 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():
        if self.terminal.config.existing_color_handling == "dynamic":
            self.character_final_color_map[character] = ColorPair(
                fg=character.animation.input_fg_color,
                bg=character.animation.input_bg_color,
            )
        else:
            self.character_final_color_map[character] = ColorPair(
                fg=final_gradient_mapping[character.input_coord],
            )
    for character in self.terminal.get_characters():
        character.motion.set_coordinate(self.terminal.canvas.center)
        input_coord_path = character.motion.new_path(
            speed=self.config.movement_speed,
            ease=self.config.expand_easing,
        )
        input_coord_path.new_waypoint(character.input_coord)
        self.terminal.set_character_visibility(character, is_visible=True)
        self.active_characters.add(character)
        character.event_handler.register_event(
            EventHandler.Event.PATH_ACTIVATED,
            input_coord_path,
            EventHandler.Action.SET_LAYER,
            1,
        )
        character.event_handler.register_event(
            EventHandler.Event.PATH_COMPLETE,
            input_coord_path,
            EventHandler.Action.SET_LAYER,
            0,
        )
        character.motion.activate_path(input_coord_path)
        gradient_scn = character.animation.new_scene(sync=Scene.SyncMetric.DISTANCE)
        if self.terminal.config.existing_color_handling == "dynamic":
            fg_gradient = (
                Gradient(final_gradient.spectrum[0], character.animation.input_fg_color, steps=10)
                if character.animation.input_fg_color
                else None
            )
            bg_gradient = (
                Gradient(final_gradient.spectrum[0], character.animation.input_bg_color, steps=10)
                if character.animation.input_bg_color
                else None
            )
            if fg_gradient or bg_gradient:
                gradient_scn.apply_gradient_to_symbols(
                    character.input_symbol,
                    1,
                    fg_gradient=fg_gradient,
                    bg_gradient=bg_gradient,
                )
            else:
                gradient_scn.add_frame(
                    character.input_symbol,
                    1,
                    colors=ColorPair(),
                )
        else:
            gradient = Gradient(
                final_gradient.spectrum[0],
                cast("Color", self.character_final_color_map[character].fg_color),
                steps=10,
            )
            gradient_scn.apply_gradient_to_symbols(
                character.input_symbol,
                5,
                fg_gradient=gradient,
            )
        character.animation.activate_scene(gradient_scn)

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_expand.py 
26
27
28
29
30
31
32
33
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 "expand", Expand, ExpandConfig