Change Log of pulsar (pulsar.el)

The newest release is at the top. For further details, please consult the manual: https://protesilaos.com/emacs/pulsar.

Version 0.5.0 on 2022-08-19

Added convenience functions/commands to pulse a line using one of the provided faces. These can be used interactively or via Lisp (e.g. be assigned to a hook). They are:
- pulsar-pulse-line-red
- pulsar-pulse-line-green
- pulsar-pulse-line-yellow
- pulsar-pulse-line-blue
- pulsar-pulse-line-magenta
- pulsar-pulse-line-cyan
Deprecated pulsar-pulse-on-window-change due to complications it created in some edge cases. Part of this effort was to fix a bug that pertained to a duplicate pulse when the pulsar commands were invoked via M-x. The duplication had the effect of potentially overriding the color of the pulse such as if, say, pulsar-pulse-line-red was invoked while the pulsar-face was blue.
Restored several command symbols to the default value of pulsar-pulse-functions. Those were disabled to support the use option pulsar-pulse-on-window-change, but as that is now removed we revert to the old and more predictable way of handling things.
Introduced conditionality that checks for real-this-command. This is necessary for commands that have to fudge this-command to provide their functionality. Such is the case with the evil-scroll-up and evil-scroll-down commands which are internally reported as previous-line and next-line, respectively. I discovered this problem while trying to support Duy Nguyen attempts that making pulsar work with evil.

Thanks to Duy Nguyen for reporting the issue on the mailing list and then to Tom Dalziel who explained why evil does things the way it does (it is a good reason):
Documented how to use pulsar with the next-error-hook. By default, the n and p keys in Emacs' compilation buffers (e.g. the results of a grep search) produce a highlight for the locus of the given match. Due to how the code is implemented, we cannot use Pulsar's standard mechanism to trigger a pulse after the match is highlighted (i.e. by adding the commands to pulsar-pulse-functions. Instead, the user must add this to their configuration:
```
  (add-hook 'next-error-hook #'pulsar-pulse-line)
```
Made other miscellaneous changes to tweak the code base and the manual.

Version 0.4.0 on 2022-07-19

Added the user option pulsar-pulse-on-window-change. This covers all commands or functions that affect the current window, so there is no need to include them individually in the pulsar-pulse-functions. Users who prefer to trigger a pulse only after select functions (e.g. only after other-window) are advised to set this user option to nil and update the pulsar-pulse-functions accordingly. Thanks to Ivan Popovych for the patch (commit b1a78dd).
Changed the default value of pulsar-pulse-functions to omit all those commands which are already covered by the aforementioned. In the interest of continuity, the old value is kept in the source code, with the relevant symbols commented out.
Named the mailing list email address as the Maintainer: of Pulsar. The package headers help the user find our primary sources and/or communication channels. This change conforms with work being done upstream in package.el by Philip Kaludercic. I was informed about it here: https://lists.sr.ht/~protesilaos/general-issues/%3C875ykl84yi.fsf%40posteo.net%3E.
Updated the documentation, where necessary and made other minor tweaks to the code.

Version 0.3.0 on 2022-04-08

Changed the source repository from GitLab to SourceHut: https://git.sr.ht/~protesilaos/pulsar. Use the mailing list to start a discussion, report a bug, send a patch, etc.: https://lists.sr.ht/~protesilaos/pulsar. The GitLab URL will serve as a mirror from now on (a GitHub mirror is still available and will remain that way).
Refined how Pulsar behaves in the case of the last line. Basically, when the last line cannot be highlighted we want to pulse the one right above. Thanks to JD Smith for fine-tuning this behaviour in merge request 1 over at the GitLab mirror: https://gitlab.com/protesilaos/pulsar/-/merge_requests/1 (exempt from the requirement to assign copyright to the Free Software Foundation as it is below the threshold).
Ensured that the Pulsar effect are limited to the current window when the buffer is displayed in multiple windows. This avoids the common problem of simultaneous highlights in multiple locations, which confuse rather than inform the user of where the point is. Thanks to Aymeric Agon-Rambosson for the contribution in merge request 2 over at the GitLab mirror: https://gitlab.com/protesilaos/pulsar/-/merge_requests/2. Aymeric has assigned copyright to the Free Software Foundation.
Wrote a buffer-local and a global minor mode that sets up Pulsar. This supersedes the old design which had a built-in assumption that the "pulse line" effect should always be global. Now the user has more flexibility. They may also disable Pulsar on demand. Note that pulsar still only triggers its effect for entries in the user option pulsar-pulse-functions. Thanks to Rudolf Adamkovič for the feedback in issue 9 over at the GitLab mirror: https://gitlab.com/protesilaos/pulsar/-/issues/9.
Implement the pulsar-highlight-dwim command. It is like the pulsar-highlight-line except it also understands regions, be they regular or rectangular. Thanks to Mark Barton for the feedback in issue 13 over at the GitLab mirror: https://gitlab.com/protesilaos/pulsar/-/issues/13.
Clarified some technical points in various doc strings and the manual, such as what is the pulsar-delay and the pulsar-iterations. Thanks to Rudolf Adamkovič for the feedback in issue 12 over at the GitLab mirror: https://gitlab.com/protesilaos/pulsar/-/issues/12.

Version 0.2.0 on 2022-03-16

Fixed an inconsistency that was present when Emacs was running in a server-client model where the highlight would never pulse but instead remain fixed in place until another command was invoked. By default, the pulse effect should now work for that use-case. Thanks to Mark Barton, Petter Storvik, and user kb for their feedback in issue 1: https://gitlab.com/protesilaos/pulsar/-/issues/1.
Implemented the pulsar-highlight-line command and abstracted the relevant code. Unlike pulsar-pulse-line, it never pulses the current line. Instead it keeps the highlight in place until another command is invoked. Thanks to Mark Barton for proposing this in issue 1.
Introduced the user option pulsar-pulse which determines whether pulsar should use a pulse effect (notwithstanding the aforementioned new command). When its value is non-nil (the default) pulsing takes place. Thanks to Petter Storvik for suggesting this approach in issue 1.
Added the user option pulsar-iterations which controls how smooth or abrupt the pulse effect is. This complements the existing variable pulsar-delay. Both apply only when pulsar-pulse is non-nil.
Wrote the pulsar-generic face and made it the default value of the pulsar-face user option. This is consistent with the original design of a theme-agnostic presentation, though now it ensures that the :extend attribute is used to stretch the highlight to the edge of the window (without it and depending on the theme, the highlight would only reach the last character on the line).
Updated the manual to reflect those changes.

Version 0.1.0 on 2022-03-14

Initial release of the package. Please read the manual.

The core idea for this package was implemented in the prot-pulse.el file that is part of my dotfiles (now deprecated). I was using it at least since December 2020.