Ticket #2757: cairo_replayscroll2.py

#!/usr/bin/env python
# This file is part of Xpra.
# Copyright (C) 2020 Antoine Martin <antoine@xpra.org>
# Xpra is released under the terms of the GNU GPL v2, or, at your option, any
# later version. See the file COPYING for details.

import sys
import cairo

import gi
gi.require_version("Gtk", "3.0")
gi.require_version("Gdk", "3.0")
from gi.repository import Gtk, Gdk, GLib


class ImageWindow(Gtk.Window):

    def __init__(self, title="Original"):
        super().__init__()

        self.image = None

        self.darea = Gtk.DrawingArea()
        self.darea.connect("draw", self.on_draw)
        self.darea.set_size_request(1024, 1024)
        self.add(self.darea)

        self.set_title(title)
        self.set_position(Gtk.WindowPosition.CENTER)
        self.connect("delete-event", Gtk.main_quit)
        self.show_all()

    def clear(self, w, h):
        self.image = cairo.ImageSurface(cairo.FORMAT_ARGB32, w, h)
        cr = cairo.Context(self.image)
        cr.set_operator(cairo.OPERATOR_CLEAR)
        cr.set_source_rgba(1, 1, 1, 1)
        cr.rectangle(0, 0, w, h)
        cr.fill()
        self.image.flush()
        self.redraw()
        print("clear")

    def load_image(self, filename):
        self.last = self.image
        self.image = cairo.ImageSurface.create_from_png(filename)
        self.resize(self.image.get_width(), self.image.get_height())
        self.darea.queue_draw()

    def redraw(self):
        self.darea.queue_draw()

    def on_draw(self, wid, cr):
        if self.image:
            cr.set_source_surface(self.image, 0, 0)
            cr.paint()


def load_scrolls(filename):
    with open(filename, "rb") as f:
        data = f.read()
    scrolls = []
    for line in data.decode().splitlines():
        scroll = [int(x.strip()) for x in line.split(",")]
        scrolls.append(scroll)
    return scrolls

def apply_scroll(original, scrolled, filename):
    scrolls = load_scrolls(filename)
    src = original.image
    w, h = src.get_width(), src.get_height()
    scrolled.clear(w, h)

    def copy():
        print("copy")
        cr = cairo.Context(scrolled.image)
        cr.set_operator(cairo.OPERATOR_SOURCE)
        cr.set_source_surface(original.image, 0, 0)
        cr.paint()
        scrolled.redraw()

    GLib.timeout_add(5000, paint_scrolls, original, scrolled, scrolls)

def paint_scrolls(original, scrolled, scrolls):
    if not scrolls:
        return False
    scroll = scrolls.pop(0)
    sx,sy,sw,sh,xdelta,ydelta = scroll
    print("paint scroll: %s" % (scroll))

    #show source rect:
    cr = cairo.Context(original.image)
    color = 1, 0, 0, 1
    cr.set_line_width(1)
    cr.set_source_rgba(*color)
    cr.rectangle(sx, sy, sw, sh)
    cr.stroke()
    original.redraw()

    x = sx+xdelta
    y = sy+ydelta

    def show_dst():
        print("show_dst()")
        cr = cairo.Context(scrolled.image)
        color = 0, 1, 0, 1
        cr.set_line_width(1)
        cr.set_source_rgba(*color)
        cr.rectangle(x, y, sw, sh)
        cr.stroke()
        scrolled.redraw()
    GLib.timeout_add(1000, show_dst)

    def copy_scroll():
        print("copy_scroll()")
        cr = cairo.Context(scrolled.image)
        cr.set_operator(cairo.OPERATOR_SOURCE)
        cr.set_source_surface(original.image, xdelta, ydelta)
        x = sx+xdelta
        y = sy+ydelta
        cr.rectangle(x, y, sw, sh)
        cr.fill()
        if True:
            color = 0, 0, 1, 1
            cr.set_line_width(1)
            cr.set_source_rgba(*color)
            cr.rectangle(x, y, sw, sh)
            cr.stroke()
        scrolled.redraw()
    GLib.timeout_add(2000, copy_scroll)
    return bool(scrolls)


def main():
    original = ImageWindow("Original")
    original.move(0, 0)
    scrolled = ImageWindow("Scrolled")
    scrolled.move(1024, 0)
    i1 = sys.argv[1]
    original.load_image(i1)
    scrolled.load_image(i1)
    def update_image():
        for x in sys.argv[1:]:
            if x.endswith(".png"):
                original.load_image(x)
            else:
                apply_scroll(original, scrolled, x)
    GLib.timeout_add(1000, update_image)
    Gtk.main()

if __name__ == "__main__":    
    main()