#!python
# -*- mode: python; Encoding: utf-8; coding: utf-8 -*-
# Last updated: <2019/11/11 01:57:24 +0900>
"""
wxPython with pycairo.

python - Drawing with cairo in wxpython - Stack Overflow
https://stackoverflow.com/questions/23661347/drawing-with-cairo-in-wxpython

Windows10 x64 + Python 2.7.17 32bit + wxPython 4.0.7.post1
"""

import wx
import wx.lib.wxcairo
import cairo
import random
import math
import time


random_seed = 42


def make_texture(tw, th):
    surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, tw, th)
    cr = cairo.Context(surface)

    # fill BG
    cr.set_source_rgb(0, 0, 0)
    cr.rectangle(0, 0, tw, th)
    cr.fill()

    random.seed(random_seed)

    # fill rectangles
    for i in range(96):
        w = int(random.uniform(tw * 0.02, tw * 0.25))
        h = int(random.uniform(th * 0.02, th * 0.25))
        x = random.randint(0 - w, tw - 1)
        y = random.randint(0 - h, th - 1)

        r = random.uniform(0.0, 1.0)
        g = random.uniform(0.0, 1.0)
        b = random.uniform(0.0, 1.0)
        a = random.uniform(0.0, 1.0)

        cr.set_source_rgba(r, g, b, a)
        cr.rectangle(x, y, w, h)
        cr.fill()

    return surface


class MyDrawingArea(wx.Panel):

    def __init__(self, parent):
        super(MyDrawingArea, self).__init__(parent, wx.ID_ANY, size=(512, 512))
        self.w, self.h = 512, 512
        self.SetBackgroundColour([64, 64, 64])
        self.SetDoubleBuffered(True)
        self.Bind(wx.EVT_PAINT, self.on_paint)

    def on_paint(self, e):
        dc = wx.PaintDC(self)
        cr = wx.lib.wxcairo.ContextFromDC(dc)
        # w, h = self.Size.GetWidth(), self.Size.GetHeight()
        self.surface = make_texture(self.w, self.h)
        cr.set_source_surface(self.surface, 0, 0)
        cr.paint()


class MyFrame(wx.Frame):

    def __init__(self, title):
        super(MyFrame, self).__init__(None, title=title, size=(720, 600))

        self.panel = wx.Panel(self)

        self.btn1 = wx.Button(self.panel, wx.ID_ANY, "Generate")
        self.btn1.Bind(wx.EVT_BUTTON, self.on_click_generate)

        self.btn2 = wx.Button(self.panel, wx.ID_ANY, "Redraw")
        self.btn2.Bind(wx.EVT_BUTTON, self.on_click_redraw)

        self.darea = MyDrawingArea(self.panel)

        self.vbox = wx.BoxSizer(wx.VERTICAL)
        self.vbox.Add(self.btn1, 2)
        self.vbox.Add(self.btn2, 1)

        self.hbox = wx.BoxSizer(wx.HORIZONTAL)
        self.hbox.Add(self.darea, 4, wx.EXPAND | wx.ALL, 8)
        self.hbox.Add(self.vbox, 1)
        self.panel.SetSizer(self.hbox)

    def on_click_generate(self, event):
        global random_seed
        random_seed = math.floor(time.time() * 100)
        self.darea.Refresh()

    def on_click_redraw(self, event):
        self.darea.Refresh()


def main():
    app = wx.App(False)
    frm = MyFrame("wxPython with pycairo")
    frm.Show()
    app.MainLoop()


if __name__ == '__main__':
    main()