from __future__ import annotations
from typing import TYPE_CHECKING, Collection
from cairo import ANTIALIAS_NONE
from cairo import Context as CairoContext
from gaphas.item import Item
if TYPE_CHECKING:
from gaphas.view import GtkView
[docs]class HandlePainter:
"""Draw handles of items that are marked as selected in the view."""
def __init__(self, view: GtkView) -> None:
assert view
self.view = view
def _draw_handles(
self,
item: Item,
cairo: CairoContext,
opacity: float | None = None,
) -> None:
"""Draw handles for an item.
The handles are drawn in non-antialiased mode for clarity.
"""
view = self.view
model = view.model
assert model
cairo.save()
if not opacity:
opacity = (item is view.selection.focused_item) and 0.7 or 0.4
cairo.set_antialias(ANTIALIAS_NONE)
cairo.set_line_width(1)
get_connection = model.connections.get_connection
for h in item.handles():
if not h.visible:
continue
# connected and not being moved, see HandleTool.on_button_press
if get_connection(h):
r, g, b = 1.0, 0.0, 0.0
elif h.glued:
r, g, b = 1, 0.6, 0
elif h.movable:
r, g, b = 0, 1, 0
else:
r, g, b = 0, 0, 1
vx, vy = cairo.user_to_device(*item.matrix_i2c.transform_point(*h.pos))
cairo.save()
cairo.identity_matrix()
cairo.translate(vx, vy)
cairo.rectangle(-4, -4, 8, 8)
cairo.set_source_rgba(r, g, b, opacity)
cairo.fill_preserve()
cairo.set_source_rgba(r / 4.0, g / 4.0, b / 4.0, opacity * 1.3)
cairo.stroke()
if h.connectable:
cairo.rectangle(-2, -2, 4, 4)
cairo.fill()
cairo.restore()
cairo.restore()
def paint(self, items: Collection[Item], cairo: CairoContext) -> None:
view = self.view
model = view.model
assert model
selection = view.selection
# Order matters here:
for item in model.sort(selection.selected_items):
self._draw_handles(item, cairo)
# Draw nice opaque handles when hovering an item:
hovered = selection.hovered_item
if hovered and hovered not in selection.selected_items:
self._draw_handles(hovered, cairo, opacity=0.25)