Slice images based on their height in SHR, not their zoom level

* lisp/net/shr.el (shr-sliced-image-height): New option...
(shr-put-image): ... use it.  Compute the number of slices in relation
to the image height; this way, each slice is roughly the height of a
line of ordinary text.

* test/lisp/net/shr-tests.el (shr-test/zoom-image): Update test, since
zooming no longer necessarily triggers slicing.

* doc/misc/eww.texi (Advanced): Document 'shr-sliced-image-proportion'.

* etc/NEWS: Announce this change.

1 files changed, 9 insertions, 0 deletions

diff --git a/doc/misc/eww.texi b/doc/misc/eww.texi
index eec6b3c3299..e0c6b7d610b 100644
--- a/doc/misc/eww.texi
+++ b/doc/misc/eww.texi
@@ -373,6 +373,15 @@ customizing @code{shr-blocked-images}.
 @code{shr-inhibit-images}.  If this variable is @code{nil}, display
 the ``ALT'' text of images instead.
 
+@vindex shr-sliced-image-height
+  To make scrolling up/down past images more intuititve, EWW splits
+large images into several rows.  This way, you can scroll individually
+past each slice, instead of jumping past the entire image.  EWW slices
+images that take up more than @code{shr-sliced-image-height} of the
+height of the window they are displayed in.  For example, a value of 0.7
+means that images are allowed to take up 70% of the height of the window
+before being sliced.
+
 @vindex shr-color-visible-distance-min
 @vindex shr-color-visible-luminance-min
 @cindex Contrast