Grammar Fixes

Fixed grammar horrors in ranger.pod and ranger.conf
Improved resize handling

5 files changed, 39 insertions, 36 deletions

diff --git a/doc/ranger.pod b/doc/ranger.pod
index fbe20012..a45ab2e4 100644
--- a/doc/ranger.pod
+++ b/doc/ranger.pod
@@ -222,7 +222,7 @@ C<iterm2_font_width> and C<iterm2_font_height> to the desired values.
 
 =head3 terminology
 
-This only works in terminology. It can render vectors graphics, but works only locally.
+This only works in terminology. It can render vector graphics, but works only locally.
 To enable this feature, set the option C<preview_images_method> to terminology.
 
 =head3 urxvt
@@ -243,18 +243,14 @@ To enable this feature, set the option C<preview_images_method> to urxvt-full.
 
 =head3 kitty
 
-This only works on Kitty.
-It requires PIL or pillow at the moment to work. A nasty bug that can
-corrupt the terminal window when scrolling quicly many images, that can
-be solved by with the C<redraw_window> command.
+This only works on Kitty. It requires PIL (or pillow) to work.
 
-To enable this feature, set the option C<preview_images_method> to kitty
+To enable this feature, set the option C<preview_images_method> to kitty.
 
 =head3 kitty-network
 
 The same as kitty, but uses a streaming method to allow previews remotely,
-for example in an ssh session. However the system is slighly more computationally taxing
-and the quality of the preview is reduced for bandwidth considerations.
+for example in an ssh session. However the system is more computationally taxing.
 
 =head2 SELECTION
 
diff --git a/ranger/config/rc.conf b/ranger/config/rc.conf
index cf27cbb5..7adbc239 100644
--- a/ranger/config/rc.conf
+++ b/ranger/config/rc.conf
@@ -88,7 +88,7 @@ set preview_images false
 #
 # * terminology:
 #   Previews images in full color in the terminology terminal emulator.
-#   Supports a wide variety of formats, even vector graphics like svg
+#   Supports a wide variety of formats, even vector graphics like svg.
 #
 # * urxvt:
 #   Preview images in full color using urxvt image backgrounds. This
@@ -99,17 +99,15 @@ set preview_images false
 #   whole terminal window.
 #
 # * kitty:
-#   Preview images in full color using kitty image protocol
-#   (https://github.com/kovidgoyal/kitty/blob/master/graphics-protocol.asciidoc),
+#   Preview images in full color using kitty image protocol.
 #   Requires python PIL or pillow library.
-#   In experimental stage: tmux support is untested, and a scrolling too fast a folder with many images may glitch ranger;
-#   Future improvements to kitty will ameliorate this issue, for now call the command 'redraw_window' to get rid of the garbage.
+#   Tmux support is untested.
 #
 # * kitty-network
-#   Similar to base kitty, bit instead of local storage it uses kitty's protocol special feature to
-#   stream the whole image over standard input. More error prone, and more intensive since it scales down images,
-#   producing also worse quality previews.
-#   However it makes possible to see previews froma ranger instance over the network,
+#   Similar to base kitty, but instead of local storage it streams the whole image
+#   over standard input. More error prone,
+#   and more intensive since it base64 encodes entire images.
+#   However it makes possible to see previews from ranger over the network,
 #   so it makes sense to enable this on remote machines.
 #   Note that has been untested over an actual network.
 set preview_images_method w3m
diff --git a/ranger/container/settings.py b/ranger/container/settings.py
index dcadf8bf..b360cf20 100644
--- a/ranger/container/settings.py
+++ b/ranger/container/settings.py
@@ -100,7 +100,7 @@ ALLOWED_VALUES = {
     'confirm_on_delete': ['multiple', 'always', 'never'],
     'line_numbers': ['false', 'absolute', 'relative'],
     'one_indexed': [False, True],
-    'preview_images_method': ['w3m', 'iterm2', 'urxvt',
+    'preview_images_method': ['w3m', 'iterm2', 'terminology', 'urxvt',
                               'urxvt-full', 'kitty', 'kitty-network'],
     'vcs_backend_bzr': ['disabled', 'local', 'enabled'],
     'vcs_backend_git': ['enabled', 'disabled', 'local'],
diff --git a/ranger/core/fm.py b/ranger/core/fm.py
index 226b1461..5f4e141d 100644
--- a/ranger/core/fm.py
+++ b/ranger/core/fm.py
@@ -239,7 +239,7 @@ class FM(Actions,  # pylint: disable=too-many-instance-attributes
         elif self.settings.preview_images_method == "kitty":
             return KittyImageDisplayer()
         elif self.settings.preview_images_method == "kitty-network":
-            return KittyImageDisplayer(stream=True, resize_height=480)
+            return KittyImageDisplayer(stream=True)
         return ImageDisplayer()
 
     def _get_thisfile(self):
diff --git a/ranger/ext/img_display.py b/ranger/ext/img_display.py
index 09d3429c..f444e0f9 100644
--- a/ranger/ext/img_display.py
+++ b/ranger/ext/img_display.py
@@ -11,6 +11,7 @@ implementations, which are currently w3m, iTerm2 and urxvt.
 
 from __future__ import (absolute_import, division, print_function)
 
+import math
 import base64
 import curses
 import errno
@@ -42,9 +43,9 @@ W3MIMGDISPLAY_PATHS = [
 
 
 @contextmanager
-def temporarly_moved_cursor(to_y, to_x):
+def temporarily_moved_cursor(to_y, to_x):
     """Common boilerplate code to move the cursor to a drawing area. Use it as:
-        with temporarly_moved_cursor(dest_y, dest_x):
+        with temporarily_moved_cursor(dest_y, dest_x):
             your_func_here()"""
     curses.putp(curses.tigetstr("sc"))
     move_cur(to_y, to_x)
@@ -236,7 +237,7 @@ class ITerm2ImageDisplayer(ImageDisplayer, FileManagerAware):
     """
 
     def draw(self, path, start_x, start_y, width, height):
-        with temporarly_moved_cursor(start_y, start_x):
+        with temporarily_moved_cursor(start_y, start_x):
             sys.stdout.write(self._generate_iterm2_input(path, width, height))
 
     def clear(self, start_x, start_y, width, height):
@@ -346,7 +347,7 @@ class TerminologyImageDisplayer(ImageDisplayer, FileManagerAware):
         self.close_protocol = "\000"
 
     def draw(self, path, start_x, start_y, width, height):
-        with temporarly_moved_cursor(start_y, start_x):
+        with temporarily_moved_cursor(start_y, start_x):
             # Write intent
             sys.stdout.write("%s}ic#%d;%d;%s%s" % (
                 self.display_protocol,
@@ -479,13 +480,12 @@ class KittyImageDisplayer(ImageDisplayer):
     protocol_start = b'\033_G'
     protocol_end = b'\033\\'
 
-    def __init__(self, stream=False, resize_height=720):
+    def __init__(self, stream=False):
         self.image_id = 0
         self.temp_paths = []
         # parameter deciding if we're going to send the picture data
         # in the command body, or save it to a temporary file
         self.stream = stream
-        self.max_height = resize_height
 
         if "screen" in os.environ['TERM']:
             # TODO: probably need to modify the preamble
@@ -527,7 +527,7 @@ class KittyImageDisplayer(ImageDisplayer):
             # to spawn other processes, so it _should_ be faster
             import PIL.Image
             self.backend = PIL.Image
-            self.filter = PIL.Image.BILINEAR
+            self.filter = PIL.Image.LANCZOS
         except ImportError:
             sys.stderr.write("PIL not Found")
             # TODO: implement a wrapper class for Imagemagick process to
@@ -543,24 +543,23 @@ class KittyImageDisplayer(ImageDisplayer):
 
         assert self.backend is not None  # sanity check if we actually have a backend
         image = self.backend.open(path)
-        aspect = image.width / image.height
-        # first let's reduce the size of the image
-        if image.height > self.max_height:
-            image = image.resize((int(self.max_height * aspect), self.max_height), self.filter)
-
         # since kitty streches the image to fill the view box
         # we need to resize the box to not get distortion
-        mismatch_ratio = aspect / (width * 0.5 / height)
+        mismatch_ratio = (image.width / image.height) / (width * 0.5 / height)
         if mismatch_ratio > 1.05:
             new_h = height / mismatch_ratio
-            start_y += int((height - new_h) / 2)
+            start_y += int((height - new_h) // 2)
             height = int(new_h)
         elif mismatch_ratio < 0.95:
             new_w = width * mismatch_ratio
-            start_x += int((width - new_w) / 2)
+            start_x += int((width - new_w) // 2)
             width = int(new_w)
 
+        # resize image to a smaller size. Ideally this should be
+        # image = self._resize_max_area(image, (480*960), self.filter)
+
         if self.stream:
+            image = self._resize_max_area(image, (480 * 960), self.filter)
             # encode the whole image as base64
             # TODO: implement z compression
             # to possibly increase resolution in sent image
@@ -581,13 +580,14 @@ class KittyImageDisplayer(ImageDisplayer):
             # f: size of a pixel fragment (100 just mean that the file is png encoded,
             #       the only format except raw RGB(A) bitmap that kitty understand)
             # c, r: size in cells of the viewbox
-            cmds.update({'t': 't', 'f': 100, 'c': width, 'r': height})
+            cmds.update({'t': 't', 'f': 100,
+                         'c': width, 'r': height})
             with NamedTemporaryFile(prefix='rgr_thumb_', suffix='.png', delete=False) as tmpf:
                 image.save(tmpf, format='png', compress_level=0)
                 self.temp_paths.append(tmpf.name)
                 payload = base64.standard_b64encode(tmpf.name.encode(self.fsenc))
 
-        with temporarly_moved_cursor(start_y, start_x):
+        with temporarily_moved_cursor(start_y, start_x):
             for cmd_str in self._format_cmd_str(cmds, payload=payload):
                 sys.stdout.buffer.write(cmd_str)
         # catch kitty answer before the escape codes corrupt the console
@@ -627,6 +627,15 @@ class KittyImageDisplayer(ImageDisplayer):
         else:
             yield self.protocol_start + central_blk + b';' + self.protocol_end
 
+    @staticmethod
+    def _resize_max_area(image, max_area, img_filter):
+        aspect = image.width / image.height
+        area = image.width * image.height
+        if area > max_area:
+            image = image.resize((int(math.sqrt(area * aspect)),
+                                  int(math.sqrt(area / aspect))), img_filter)
+        return image
+
     def quit(self):
         # clear all remaining images, then check if all files went through or are orphaned
         while self.image_id >= 1: