calibre/src/pyj/utils.pyj

# vim:fileencoding=utf-8
# License: GPL v3 Copyright: 2015, Kovid Goyal <kovid at kovidgoyal.net>
from __python__ import hash_literals

from encodings import hexlify

def debounce(func, wait, immediate=False):
    # Returns a function, that, as long as it continues to be invoked, will not
    # be triggered. The function will be called after it stops being called for
    # wait milliseconds. If `immediate` is True, trigger the function on the
    # leading edge, instead of the trailing.
    timeout = None
    return def debounce_inner():  # noqa: unused-local
        nonlocal timeout
        context, args = this, arguments
        def later():
            nonlocal timeout
            timeout = None
            if not immediate:
                func.apply(context, args)
        call_now = immediate and not timeout
        window.clearTimeout(timeout)
        timeout = window.setTimeout(later, wait)
        if call_now:
            func.apply(context, args)

def parse_url_params(url=None, allow_multiple=False):
    url = url or window.location.href
    qs = url.indexOf('?')
    ans = {}
    if qs < 0:
        return ans
    q = url.slice(qs + 1, ((url.indexOf('#') + 1) or (url.length + 1)))
    if not q:
        return ans
    pairs = q.replace(/\+/g, " ").split("&")
    for pair in pairs:
        key, val = pair.partition('=')[::2]
        key, val = decodeURIComponent(key), decodeURIComponent(val)
        if allow_multiple:
            if ans[key] is undefined:
                ans[key] = []
            ans[key].append(val)
        else:
            ans[key] = val
    return ans

_roman = list(zip(
[1000,900,500,400,100,90,50,40,10,9,5,4,1],
["M","CM","D","CD","C","XC","L","XL","X","IX","V","IV","I"]
))

def roman(num):
    if num <= 0 or num >= 4000 or int(num) is not num:
        return num + ''
    result = []
    for d, r in _roman:
        while num >= d:
            result.append(r)
            num -= d
    return result.join('')

def fmt_sidx(val, fmt='{:.2f}', use_roman=True):
    if val is undefined or val is None or val is '':
        return '1'
    if int(val) is float(val):
        if use_roman:
            return roman(val)
        return int(val) + ''
    return fmt.format(float(val))

def rating_to_stars(value, allow_half_stars=False, star='★', half='½'):
    r = max(0, min(int(value or 0), 10))
    if allow_half_stars:
        ans = star.repeat(r // 2)
        if r % 2:
            ans += half
    else:
        ans = star.repeat(int(r/2.0))
    return ans

def human_readable(size, sep=' '):
    divisor, suffix = 1, "B"
    for i, candidate in enumerate(('B', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB')):
        if size < (1 << ((i + 1) * 10)):
            divisor, suffix = (1 << (i * 10)), candidate
            break
    size = (float(size)/divisor) + ''
    pos = size.find(".")
    if pos > -1:
        size = size[:pos + 2]
    if size.endswith('.0'):
        size = size[:-2]
    return size + sep + suffix

def document_height():
    html = document.documentElement
    return max(document.body.scrollHeight, document.body.offsetHeight, html.clientHeight, html.scrollHeight, html.offsetHeight)

def document_width():
    html = document.documentElement
    return max(document.body.scrollWidth, document.body.offsetWidth, html.clientWidth, html.scrollWidth, html.offsetWidth)

_data_ns = None

def data_ns(name):
    nonlocal _data_ns
    if _data_ns is None:
        rand = Uint8Array(12)
        window.crypto.getRandomValues(rand)
        _data_ns = 'data-' + hexlify(rand) + '-'
    return _data_ns + name

def get_elem_data(elem, name, defval):
    ans = elem.getAttribute(data_ns(name))
    if ans is None:
        return defval ? None
    return JSON.parse(ans)

def set_elem_data(elem, name, val):
    elem.setAttribute(data_ns(name), JSON.stringify(val))

def viewport_to_document(x, y, doc):
    # Convert x, y from the viewport (window) co-ordinate system to the
    # document (body) co-ordinate system
    doc = doc or window.document
    topdoc = window.document
    while doc is not topdoc:
        # We are in a frame
        frame = doc.defaultView.frameElement
        rect = frame.getBoundingClientRect()
        x += rect.left
        y += rect.top
        doc = frame.ownerDocument
    win = doc.defaultView
    wx, wy = win.pageXOffset, win.pageYOffset
    x += wx
    y += wy
    return x, y

def username_key(username):
    return ('u' if username else 'n') + username

def html_escape(text):
    repl = { '&': "&amp;", '"': "&quot;", '<': "&lt;", '>': "&gt;" }
    return String.prototype.replace.call(text, /[&"<>]/g, def (c): return repl[c];)

def uniq(vals):
    # Remove all duplicates from vals, while preserving order
    ans = v'[]'
    seen = {}
    for x in vals:
        if not seen[x]:
            seen[x] = True
            ans.push(x)
    return ans

if __name__ is '__main__':
    from pythonize import strings
    strings()
    print(rating_to_stars(3, True))
    print(fmt_sidx(10), fmt_sidx(1.2))
    print(list(map(human_readable, [1, 1024.0, 1025, 1024*1024*2.3])))