import numpy as np

from .. import cbook, transforms

from . import backend_agg, backend_gtk3

from .backend_gtk3 import GLib, Gtk, _BackendGTK3

import cairo # Presence of cairo is already checked by _backend_gtk.

class FigureCanvasGTK3Agg(backend_agg.FigureCanvasAgg,

backend_gtk3.FigureCanvasGTK3):

def __init__(self, figure):

super().__init__(figure=figure)

self._bbox_queue = []

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()

scale = self.device_pixel_ratio

allocation = self.get_allocation()

w = allocation.width * scale

h = allocation.height * scale

if not len(self._bbox_queue):

Gtk.render_background(

self.get_style_context(), ctx,

allocation.x, allocation.y,

allocation.width, allocation.height)

bbox_queue = [transforms.Bbox([[0, 0], [w, h]])]

else:

bbox_queue = self._bbox_queue

for bbox in bbox_queue:

x = int(bbox.x0)

y = h - int(bbox.y1)

width = int(bbox.x1) - int(bbox.x0)

height = int(bbox.y1) - int(bbox.y0)

buf = cbook._unmultiplied_rgba8888_to_premultiplied_argb32(

np.asarray(self.copy_from_bbox(bbox)))

image = cairo.ImageSurface.create_for_data(

buf.ravel().data, cairo.FORMAT_ARGB32, width, height)

image.set_device_scale(scale, scale)

ctx.set_source_surface(image, x / scale, y / scale)

ctx.paint()

if len(self._bbox_queue):

self._bbox_queue = []

return False

def blit(self, bbox=None):

# If bbox is None, blit the entire canvas to gtk. Otherwise

# blit only the area defined by the bbox.

if bbox is None:

bbox = self.figure.bbox

scale = self.device_pixel_ratio

allocation = self.get_allocation()

x = int(bbox.x0 / scale)

y = allocation.height - int(bbox.y1 / scale)

width = (int(bbox.x1) - int(bbox.x0)) // scale

height = (int(bbox.y1) - int(bbox.y0)) // scale

self._bbox_queue.append(bbox)

self.queue_draw_area(x, y, width, height)

@_BackendGTK3.export

class _BackendGTK3Agg(_BackendGTK3):

FigureCanvas = FigureCanvasGTK3Agg