Files
textual/src/textual/scrollbar.py
2022-09-24 09:20:20 +01:00

332 lines
10 KiB
Python

from __future__ import annotations
from math import ceil
import rich.repr
from rich.color import Color
from rich.console import ConsoleOptions, RenderableType, RenderResult
from rich.segment import Segment, Segments
from rich.style import NULL_STYLE, Style, StyleType
from . import events
from ._types import MessageTarget
from .geometry import Offset
from .message import Message
from .reactive import Reactive
from .renderables.blank import Blank
from .widget import Widget
class ScrollMessage(Message, bubble=False):
pass
@rich.repr.auto
class ScrollUp(ScrollMessage, verbose=True):
"""Message sent when clicking above handle."""
@rich.repr.auto
class ScrollDown(ScrollMessage, verbose=True):
"""Message sent when clicking below handle."""
@rich.repr.auto
class ScrollLeft(ScrollMessage, verbose=True):
"""Message sent when clicking above handle."""
@rich.repr.auto
class ScrollRight(ScrollMessage, verbose=True):
"""Message sent when clicking below handle."""
class ScrollTo(ScrollMessage, verbose=True):
"""Message sent when click and dragging handle."""
def __init__(
self,
sender: MessageTarget,
x: float | None = None,
y: float | None = None,
animate: bool = True,
) -> None:
self.x = x
self.y = y
self.animate = animate
super().__init__(sender)
def __rich_repr__(self) -> rich.repr.Result:
yield "x", self.x, None
yield "y", self.y, None
yield "animate", self.animate, True
class ScrollBarRender:
def __init__(
self,
virtual_size: int = 100,
window_size: int = 0,
position: float = 0,
thickness: int = 1,
vertical: bool = True,
style: StyleType = "bright_magenta on #555555",
) -> None:
self.virtual_size = virtual_size
self.window_size = window_size
self.position = position
self.thickness = thickness
self.vertical = vertical
self.style = style
@classmethod
def render_bar(
cls,
size: int = 25,
virtual_size: float = 50,
window_size: float = 20,
position: float = 0,
thickness: int = 1,
vertical: bool = True,
back_color: Color = Color.parse("#555555"),
bar_color: Color = Color.parse("bright_magenta"),
) -> Segments:
if vertical:
bars = ["", "", "", "", "", "", "", " "]
else:
bars = ["", "", "", "", "", "", "", " "]
back = back_color
bar = bar_color
len_bars = len(bars)
width_thickness = thickness if vertical else 1
_Segment = Segment
_Style = Style
blank = " " * width_thickness
foreground_meta = {"@mouse.up": "release", "@mouse.down": "grab"}
if window_size and size and virtual_size and size != virtual_size:
step_size = virtual_size / size
start = int(position / step_size * len_bars)
end = start + max(len_bars, int(ceil(window_size / step_size * len_bars)))
start_index, start_bar = divmod(max(0, start), len_bars)
end_index, end_bar = divmod(max(0, end), len_bars)
upper = {"@mouse.up": "scroll_up"}
lower = {"@mouse.up": "scroll_down"}
upper_back_segment = Segment(blank, _Style(bgcolor=back, meta=upper))
lower_back_segment = Segment(blank, _Style(bgcolor=back, meta=lower))
segments = [upper_back_segment] * int(size)
segments[end_index:] = [lower_back_segment] * (size - end_index)
segments[start_index:end_index] = [
_Segment(blank, _Style(bgcolor=bar, meta=foreground_meta))
] * (end_index - start_index)
# Apply the smaller bar characters to head and tail of scrollbar for more "granularity"
if start_index < len(segments):
bar_character = bars[len_bars - 1 - start_bar]
if bar_character != " ":
segments[start_index] = _Segment(
bar_character * width_thickness,
_Style(bgcolor=back, color=bar, meta=foreground_meta)
if vertical
else _Style(bgcolor=bar, color=back, meta=foreground_meta),
)
if end_index < len(segments):
bar_character = bars[len_bars - 1 - end_bar]
if bar_character != " ":
segments[end_index] = _Segment(
bar_character * width_thickness,
_Style(bgcolor=bar, color=back, meta=foreground_meta)
if vertical
else _Style(bgcolor=back, color=bar, meta=foreground_meta),
)
else:
style = _Style(bgcolor=back)
segments = [_Segment(blank, style=style)] * int(size)
if vertical:
return Segments(segments, new_lines=True)
else:
return Segments((segments + [_Segment.line()]) * thickness, new_lines=False)
def __rich_console__(
self, console: Console, options: ConsoleOptions
) -> RenderResult:
size = (
(options.height or console.height)
if self.vertical
else (options.max_width or console.width)
)
thickness = (
(options.max_width or console.width)
if self.vertical
else (options.height or console.height)
)
_style = console.get_style(self.style)
bar = self.render_bar(
size=size,
window_size=self.window_size,
virtual_size=self.virtual_size,
position=self.position,
vertical=self.vertical,
thickness=thickness,
back_color=_style.bgcolor or Color.parse("#555555"),
bar_color=_style.color or Color.parse("bright_magenta"),
)
yield bar
@rich.repr.auto
class ScrollBar(Widget):
DEFAULT_CSS = """
ScrollBar {
hover-color: ;
hover-background:;
hover-style: ;
link-color: transparent;
link-background: transparent;
}
"""
def __init__(
self, vertical: bool = True, name: str | None = None, *, thickness: int = 1
) -> None:
self.vertical = vertical
self.thickness = thickness
self.grabbed_position: float = 0
super().__init__(name=name)
self.auto_links = False
window_virtual_size: Reactive[int] = Reactive(100)
window_size: Reactive[int] = Reactive(0)
position: Reactive[int] = Reactive(0)
mouse_over: Reactive[bool] = Reactive(False)
grabbed: Reactive[Offset | None] = Reactive(None)
def __rich_repr__(self) -> rich.repr.Result:
yield from super().__rich_repr__()
yield "window_virtual_size", self.window_virtual_size
yield "window_size", self.window_size
yield "position", self.position
if self.thickness > 1:
yield "thickness", self.thickness
def render(self) -> RenderableType:
styles = self.parent.styles
background = (
styles.scrollbar_background_hover
if self.mouse_over
else styles.scrollbar_background
)
color = (
styles.scrollbar_color_active if self.grabbed else styles.scrollbar_color
)
color = background + color
scrollbar_style = Style.from_color(color.rich_color, background.rich_color)
return ScrollBarRender(
virtual_size=self.window_virtual_size,
window_size=(
self.window_size if self.window_size < self.window_virtual_size else 0
),
position=self.position,
thickness=self.thickness,
vertical=self.vertical,
style=scrollbar_style,
)
def _on_hide(self, event: events.Hide) -> None:
if self.grabbed:
self.release_mouse()
def _on_enter(self, event: events.Enter) -> None:
self.mouse_over = True
def _on_leave(self, event: events.Leave) -> None:
self.mouse_over = False
async def action_scroll_down(self) -> None:
await self.emit(ScrollDown(self) if self.vertical else ScrollRight(self))
async def action_scroll_up(self) -> None:
await self.emit(ScrollUp(self) if self.vertical else ScrollLeft(self))
def action_grab(self) -> None:
self.capture_mouse()
def action_released(self) -> None:
self.capture_mouse(False)
async def _on_mouse_up(self, event: events.MouseUp) -> None:
if self.grabbed:
self.release_mouse()
def _on_mouse_capture(self, event: events.MouseCapture) -> None:
self.grabbed = event.mouse_position
self.grabbed_position = self.position
def _on_mouse_release(self, event: events.MouseRelease) -> None:
self.grabbed = None
async def _on_mouse_move(self, event: events.MouseMove) -> None:
if self.grabbed and self.window_size:
x: float | None = None
y: float | None = None
if self.vertical:
y = round(
self.grabbed_position
+ (
(event.screen_y - self.grabbed.y)
* (self.window_virtual_size / self.window_size)
)
)
else:
x = round(
self.grabbed_position
+ (
(event.screen_x - self.grabbed.x)
* (self.window_virtual_size / self.window_size)
)
)
await self.emit(ScrollTo(self, x=x, y=y))
class ScrollBarCorner(Widget):
"""Widget which fills the gap between horizontal and vertical scrollbars,
should they both be present."""
def __init__(self, name: str | None = None):
super().__init__(name=name)
def render(self) -> RenderableType:
assert self.parent is not None
styles = self.parent.styles
color = styles.scrollbar_corner_color
return Blank(color)
if __name__ == "__main__":
from rich.console import Console
console = Console()
thickness = 2
console.print(f"Bars thickness: {thickness}")
console.print("Vertical bar:")
console.print(ScrollBarRender.render_bar(thickness=thickness))
console.print("Horizontal bar:")
console.print(ScrollBarRender.render_bar(vertical=False, thickness=thickness))