from contextlib import nullcontext

from .backend_cairo import FigureCanvasCairo

from .backend_gtk3 import GLib, Gtk, FigureCanvasGTK3, _BackendGTK3

class FigureCanvasGTK3Cairo(FigureCanvasCairo, FigureCanvasGTK3):

def on_draw_event(self, widget, ctx):

if self._idle_draw_id:

GLib.source_remove(self._idle_draw_id)

self._idle_draw_id = 0

self.draw()

with (self.toolbar._wait_cursor_for_draw_cm() if self.toolbar

else nullcontext()):

allocation = self.get_allocation()

# Render the background before scaling, as the allocated size here is in

# logical pixels.

Gtk.render_background(

self.get_style_context(), ctx,

0, 0, allocation.width, allocation.height)

scale = self.device_pixel_ratio

# Scale physical drawing to logical size.

ctx.scale(1 / scale, 1 / scale)

self._renderer.set_context(ctx)

# Set renderer to physical size so it renders in full resolution.

self._renderer.width = allocation.width * scale

self._renderer.height = allocation.height * scale

self._renderer.dpi = self.figure.dpi

self.figure.draw(self._renderer)

@_BackendGTK3.export

class _BackendGTK3Cairo(_BackendGTK3):

FigureCanvas = FigureCanvasGTK3Cairo