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author | Glenn Morris <rgm@gnu.org> | 2020-12-18 08:55:06 -0800 |
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committer | Glenn Morris <rgm@gnu.org> | 2020-12-18 08:55:06 -0800 |
commit | 8d2d8d7f53055d93ed2d8a435533c9a6a6303725 (patch) | |
tree | de620148368bc681a6d21912b4d39543a96e7e1a /etc | |
parent | fdaaf886b71fc41d0d6d717af55e4927ed4cd2c1 (diff) | |
parent | 48b9c47805fc304441017f6ee4c114212cdb0496 (diff) | |
download | emacs-8d2d8d7f53055d93ed2d8a435533c9a6a6303725.tar.gz |
Merge from origin/emacs-27
48b9c47805 Minor fixes in authors.el and in tarball-making instructions
d7a4ceaa1e ; Add a new item to TODO
64fe805b19 Improve documentation of 'query-replace'
7cacf5da47 Update to Org 9.4.3
# Conflicts:
# admin/authors.el
Diffstat (limited to 'etc')
-rw-r--r-- | etc/TODO | 36 |
1 files changed, 36 insertions, 0 deletions
@@ -536,6 +536,42 @@ This should go with point, so that motion commands can also move through tall images. This value would be to point as window-vscroll is to window-start. +** Make redisplay smarter about which parts to redraw +Currently, redisplay has only 2 levels of redrawing: either it +redisplays only the selected window on the selected frame, or it +redisplays all the windows on all the frames. This doesn't scale well +when the number of visible frames is large. + +Currently, two variables are used to make the decision what to +redisplay: update_mode_lines and windows_or_buffers_changed. These +are set by various functions called from Lisp, and if redisplay finds +one of them to be non-zero, it considers all the windows on all the +frames for redisplay. + +The idea is to make the decision which parts need to be redrawn more +fine-grained. Instead of simple boolean variables, we could have a +bitmapped variable which records the kinds of changes done by Lisp +since the previous redisplay cycle. Then the decision what exactly +needs to be redrawn could be made based on the bits that are set. + +For example, one reason to consider all frames is that some scrolling +command sets the update_mode_lines variable non-zero. This is done +because the frame title, which doesn't belong to any window, needs to +be reconsidered when the selected window is scrolled. But considering +the frame title doesn't have to redisplay all the other windows on the +frame, doesn't need to recompute the menu items and the tool-bar +buttons, and doesn't need to consider frames other than the selected +one. Being selective about what parts of the Emacs display need to be +reconsidered and redrawn given the changes since the last redisplay +will go along way towards making redisplay more scalable. + +One way of making this change is to go through all the places that set +update_mode_lines and windows_or_buffers_changed, figure out which +portions of the Emacs display could be affected by each change, and +then implement the bitmap which will record each of these affected +display portions. The logic in redisplay_internal will then need to +be restructured so as to support this fine-grained redisplay. + ** Address internationalization of symbols names Essentially as if they were documentation, e.g. in command names and Custom. |