Start work on image cat utility

__main__.py

@@ -5,5 +5,9 @@
 import sys
 sys.debug_gl = '--debug-kitty-gl' in sys.argv
 
-from kitty.main import main  # noqa
-main()
+if len(sys.argv) > 1 and sys.argv[1] == 'icat':
+    from kitty.icat import main
+    main()
+else:
+    from kitty.main import main
+    main()

kitty/icat.py

@@ -0,0 +1,196 @@
+#!/usr/bin/env python
+# vim:fileencoding=utf-8
+# License: GPL v3 Copyright: 2017, Kovid Goyal <kovid at kovidgoyal.net>
+
+import argparse
+import fcntl
+import mimetypes
+import os
+import struct
+import subprocess
+import sys
+import termios
+import zlib
+from base64 import standard_b64encode
+from collections import namedtuple
+from gettext import gettext as _
+from math import ceil, floor
+
+from kitty.constants import appname
+
+# from kitty.fast_data_types import shm_write, shm_unlink
+
+
+class OpenFailed(ValueError):
+
+    def __init__(self, path, message):
+        ValueError.__init__(
+            self, 'Failed to open: {} with error: {}'.format(path, message)
+        )
+        self.path = path
+
+
+def option_parser():
+    parser = argparse.ArgumentParser(
+        prog=appname + ' icat',
+        description=_('Display images in the terminal')
+    )
+    a = parser.add_argument
+    a(
+        'items',
+        nargs=argparse.REMAINDER,
+        help=_(
+            'Image files or directories. Directories are scanned recursively.'
+        )
+    )
+    return parser
+
+
+Size = namedtuple('Size', 'cols rows width height')
+
+
+def screen_size():
+    if getattr(screen_size, 'ans', None) is None:
+        s = struct.pack('HHHH', 0, 0, 0, 0)
+        x = fcntl.ioctl(1, termios.TIOCGWINSZ, s)
+        screen_size.ans = Size(*struct.unpack('HHHH', x))
+    return screen_size.ans
+
+
+def write_gr_cmd(cmd, payload):
+    sys.stdout.write('\033_G{};{}\033\\'.format(cmd, payload).encode('ascii'))
+    sys.stdout.flush()
+
+
+def add_format_code(cmd, mode, width, height):
+    cmd += ',f=' + {'RGB': '24', 'RGBA': '32', 'PNG': '100'}[mode]
+    if mode != 'PNG':
+        cmd += ',s={},v={}'.format(width, height)
+    return cmd
+
+
+def fit_image(width, height, pwidth, pheight):
+    if height > pheight:
+        corrf = pheight / float(height)
+        width, height = floor(corrf * width), pheight
+    if width > pwidth:
+        corrf = pwidth / float(width)
+        width, height = pwidth, floor(corrf * height)
+    if height > pheight:
+        corrf = pheight / float(height)
+        width, height = floor(corrf * width), pheight
+
+    return int(width), int(height)
+
+
+def set_cursor(cmd, width, height):
+    ss = screen_size()
+    cw = int(ss.width / ss.cols)
+    num_of_cells_needed = int(ceil(width / cw))
+    if num_of_cells_needed > ss.cols:
+        w, h = fit_image(width, height, ss.width, height)
+        ch = int(ss.height / ss.rows)
+        num_of_rows_needed = int(ceil(height / ch))
+        y_off = height % ch
+        cmd += 'c={},r={},Y={}'.format(ss.cols, num_of_rows_needed, y_off)
+    else:
+        x_off = width % cw
+        cmd += 'c={},X={}'.format(num_of_cells_needed, x_off)
+        extra_cells = (ss.cols - num_of_cells_needed) // 2
+        if extra_cells:
+            sys.stdout.write(b' ' * extra_cells)
+    return cmd
+
+
+def write_chunked(data, mode, width, height):
+    data = standard_b64encode(zlib.compress(data))
+    cmd = add_format_code('a=T,o=z', mode, width, height)
+    cmd = set_cursor(cmd, width, height)
+    i = -1
+    while data:
+        i += 1
+        chunk, data = data[:4096], data[4096:]
+        m = 1 if data else 0
+        if i == 0:
+            c = cmd + ',' + 'm={}'.format(m)
+        else:
+            c = 'm={}'.format(m)
+        write_gr_cmd(c, chunk)
+
+
+def show(data, mode, width, height):
+    write_chunked(data, mode, width, height)
+
+
+def convert_svg(path):
+    try:
+        return subprocess.check_output(['rsvg-convert', '-f', 'png', path])
+    except OSError:
+        raise SystemExit(
+            'Could not find the program rsvg-convert, needed to display svg files'
+        )
+
+
+def process(path, mt):
+    if mt == 'image/svg+xml':
+        data = convert_svg(path)
+        width = height = 0
+        mode = 'PNG'
+    else:
+        try:
+            from PIL import Image
+        except ImportError:
+            raise SystemExit(
+                'You need to install the python-pillow package for image support'
+            )
+        try:
+            im = Image.open(path)
+        except Exception as e:
+            raise OpenFailed(path, str(e))
+        if im.mode not in ('RGB', 'RGBA'):
+            im = im.convert('RGBA')
+        data = im.tobytes()
+        width, height = im.size
+        mode = im.mode
+    show(data, mode, width, height)
+    print()  # ensure cursor is on a new line
+
+
+def scan(d):
+    for dirpath, dirnames, filenames in os.walk(d):
+        for f in filenames:
+            mt = mimetypes.guess_type(f)[0]
+            if mt and mt.startswith('image/'):
+                yield os.path.join(dirpath, f), mt
+
+
+def main():
+    if not sys.stdout.isatty():
+        raise SystemExit(
+            'Must be run in a terminal, stdout is currently not a terminal'
+        )
+    if screen_size().width == 0:
+        raise SystemExit(
+            'Terminal does not support reporting screen sizes via the TIOCGWINSZ ioctl'
+        )
+    args = option_parser().parse_args()
+    if not args.items:
+        raise SystemExit('You must specify at least one file to cat')
+    errors = []
+    for item in args.items:
+        try:
+            if os.path.isdir(item):
+                for x, mt in scan(item):
+                    process(item, mt)
+            else:
+                process(
+                    item,
+                    mimetypes.guess_type(item)[0] or 'application/octet-stream'
+                )
+        except OpenFailed as e:
+            errors.append(e)
+    if not errors:
+        return
+    for err in errors:
+        print(err, file=sys.stderr)
+    raise SystemExit(1)