標準入力読んで画面にコメント流すやつ、 OSX でも動くかもしれない版。

nsd.py

'''Niconico Style Display

requirements:
    PyQt5
    pyobjc-framework-Cocoa (pyobjc-cocoa?, osx only)
'''

import multiprocessing
import sys
import threading
import time

from PyQt5 import QtCore
from PyQt5 import QtGui
from PyQt5 import QtWidgets


class OutlinedLabel(QtWidgets.QLabel):
    def paintEvent(self, *args, **kwargs):
        # TODO: text containing newline characters
        painter = QtGui.QPainter(self)
        path = QtGui.QPainterPath()
        pen = QtGui.QPen()
        font = self.font()

        # XXX: really?
        y = (font.pixelSize() + self.height()) / 2

        pen.setWidth(1)
        pen.setColor(QtCore.Qt.black)
        painter.setFont(font)
        painter.setPen(pen)
        painter.setRenderHints(
            QtGui.QPainter.Antialiasing | QtGui.QPainter.TextAntialiasing)

        path.addText(0, y, font, self.text())
        painter.fillPath(path, QtCore.Qt.white)
        painter.drawPath(path)


class Comment(QtWidgets.QMainWindow):
    font = 'Sans Serif'
    font_size = 24
    fps = 60
    duration = 10

    def __init__(self, app, message):
        super(Comment, self).__init__()

        self.setWindowFlags(self.windowFlags() |
                            QtCore.Qt.FramelessWindowHint |
                            QtCore.Qt.BypassWindowManagerHint |
                            QtCore.Qt.WindowStaysOnTopHint)
        self.setAttribute(QtCore.Qt.WA_TranslucentBackground)
        self.setFocusPolicy(QtCore.Qt.NoFocus)

        self.app = app

        self.label = OutlinedLabel()
        font = QtGui.QFont(self.font, self.font_size, QtGui.QFont.Bold)
        self.label.setFont(font)
        palette = QtGui.QPalette()
        palette.setColor(palette.Foreground, QtCore.Qt.white)
        self.label.setPalette(palette)
        self.label.setText(message)

        self.setCentralWidget(self.label)

    def start(self, y):
        desktop = QtWidgets.QDesktopWidget()
        resolution = desktop.screenGeometry()
        self.x = resolution.width()
        self.y = y

        self.move(self.x, self.y)

        self.show()
        self.label.show()

        self.step = (self.x + self.size().width()) / (self.duration * self.fps)

        self.timer = QtCore.QTimer()
        self.timer.timeout.connect(self.move_next)
        self.timer.start(16)

    def move_next(self):
        self.x -= self.step
        self.move(self.x, self.y)

        if self.x < -self.size().width():
            self.timer.stop()
            self.hide()
            self.destroy()

            self.app.exit()


def _hideMacDockIcon():
    if sys.platform != 'darwin':
        return

    import AppKit
    info = AppKit.NSBundle.mainBundle().infoDictionary()
    info["LSBackgroundOnly"] = "1"


def _main(message):
    import random

    _hideMacDockIcon()

    app = QtWidgets.QApplication(sys.argv)

    desktop = QtWidgets.QDesktopWidget()
    resolution = desktop.screenGeometry()

    comment = Comment(app, message)
    comment.start(random.randint(100, resolution.height()-200))

    sys.exit(app.exec_())


def _child_waiter():
    # wait for chailds (needs on osx only?)
    while True:
        multiprocessing.active_children()
        time.sleep(3)


def main():
    MAX_NUM_COMMENTS = 50

    threading.Thread(target=_child_waiter, daemon=True).start()

    for i, line in enumerate(sys.stdin, 1):
        line = line.rstrip('\r\n')
        # XXX: because moving many windows on same process is too slow on PyQt,
        #      spawn process for each windows.
        p = multiprocessing.Process(name=i, target=_main, args=(line, ))
        p.start()

        active_comments = multiprocessing.active_children()

        if len(active_comments) > MAX_NUM_COMMENTS:
            active_comments.sort(key=lambda c: c.name)
            active_comments[0].terminate()

if __name__ == '__main__':
    main()