[elpa] externals/topspace 186ea6091a 148/181: Internal optimizations and refactoring

[ELPA Syncer]

branch: externals/topspace
commit 186ea6091a8696adc24b2afa314d919fcf225ca5
Author: Trevor Pogue <poguete@mcmaster.ca>
Commit: Trevor Pogue <poguete@mcmaster.ca>

    Internal optimizations and refactoring
    
    - Remove uneeded `topspace--count-lines` call in
      `topspace--filter-args-scroll-down`
    - Make `topspace--count-lines` more accurate by not adding extra 1 to value
    - Increase test coverage
    - Make tests run in workflow only when a src file is changed
    - Add supported Emacs versions badge to readme
---
 .github/workflows/test.yml |  2 ++
 .gitignore                 |  1 +
 README.md                  |  6 +++--
 test/topspace-test.el      | 18 ++++++++++-----
 topspace.el                | 57 +++++++++++++++++++++++++---------------------
 5 files changed, 50 insertions(+), 34 deletions(-)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index c26fa0c799..8549e60eb4 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -1,6 +1,8 @@
 name: Test
 
 on: [ push, pull_request ]
+  paths:
+    - '*.el'
 jobs:
   test:
     runs-on: ubuntu-latest
diff --git a/.gitignore b/.gitignore
index 3c603c71e4..668e2ffa75 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,6 +5,7 @@
 Eldev
 .eldev
 topspace.log
+\#*\#
 coverage/
 cask-run
 test/director/
\ No newline at end of file
diff --git a/README.md b/README.md
index 8d340bfe6c..ddddfb7044 100644
--- a/README.md
+++ b/README.md
@@ -5,9 +5,11 @@
 
 <p align="center">
    <a 
href="https://github.com/trevorpogue/topspace/actions/workflows/test.yml/";><img 
src="https://github.com/trevorpogue/topspace/actions/workflows/test.yml/badge.svg";
 height="20"/></a>
-  <a href='https://coveralls.io/github/trevorpogue/topspace?branch=main'><img 
src='https://coveralls.io/repos/github/trevorpogue/topspace/badge.svg?branch=main&&;'
 alt='Coverage Status' /></a>
+  <a href='https://coveralls.io/github/trevorpogue/topspace?branch=main'><img 
src='https://coveralls.io/repos/github/trevorpogue/topspace/badge.svg?branch=main&0'
 alt='Coverage Status' /></a>
+     <a 
href="https://github.com/trevorpogue/topspace/blob/main/.github/workflows/test.yml";><img
 
src="https://img.shields.io/badge/Supports-Emacs_25.1--28.1-blueviolet.svg?style=flat-square&logo=GNU%20Emacs&logoColor=whit";
 height="20"/></a>
   <a href="http://melpa.org/#/topspace";><img 
src="http://melpa.org/packages/topspace-badge.svg"; height="20"/></a>
   <a href="http://stable.melpa.org/#/topspace";><img 
src="http://stable.melpa.org/packages/topspace-badge.svg"; height="20"/></a>
+
 </p>
 
 <p align="center"><img 
src="https://user-images.githubusercontent.com/12535207/164986647-cdb35afa-de45-4e6f-ac16-fad765f9969e.gif"/></p>
@@ -22,7 +24,7 @@
 TopSpace is an Emacs minor mode that allows you to scroll down and recenter 
top lines by automatically drawing an upper margin/padding above the top line
 as you scroll down or recenter top text.
 
-TopSpace is:
+### Features
 
 * **Easier on the eyes**: Recenter or scroll down top text to a more 
comfortable eye level for reading, especially when in full-screen or on a large 
monitor.
 * **Easy to use**: No new keybindings are required, keep using all your 
previous scrolling & recentering commands, except now you can also scroll above 
the top lines. It also integrates seamlessly with  [centered-cursor-mode][1] to 
keep the cursor centered all the way to the top line.
diff --git a/test/topspace-test.el b/test/topspace-test.el
index 486a0fd4e6..22d3a98dea 100644
--- a/test/topspace-test.el
+++ b/test/topspace-test.el
@@ -8,6 +8,7 @@
 
 (setq topspace--log-target '(file . "~/topspace/topspace.log"))
 (setq topspace--start-time (float-time))
+(setq topspace--scroll-down-scale-factor 0)
 
 (defun topspace--log (message)
   "Log MESSAGE."
@@ -48,8 +49,7 @@
  (before-all
   (topspace--cmds (set-frame-size (selected-frame) 90 24))
   (switch-to-buffer (find-file-noselect "./topspace.el" t))
-  (global-topspace-mode)
-  )
+  (global-topspace-mode))
 
  (before-each (switch-to-buffer "topspace.el"))
 
@@ -159,13 +159,13 @@ in case topspace-autocenter-buffers changed return value"
       (previous-line)
       (previous-line)
       (expect (round (topspace-height)) :to-equal 2)
-      (setq smooth-scrolling-mode nil)
-      ))
+      (setq smooth-scrolling-mode nil)))
 
  (describe
   "topspace-default-empty-line-indicator"
   (it "can return a string with an indicator in left-fringe"
       (setq indicate-empty-lines t)
+      (add-to-list 'fringe-indicator-alist '(up . up-arrow))
       (let ((bitmap (catch 'tag (dolist (x fringe-indicator-alist)
                                   (when (eq (car x) 'empty-line)
                                     (throw 'tag (cdr x)))))))
@@ -187,11 +187,17 @@ in case topspace-autocenter-buffers changed return value"
   ;;               :to-equal
   ;;               (line-number-at-pos (point-max)))))
 
+  (it "can count lines if start is larger than end"
+      (set-window-start (selected-window) 100)
+      (expect (round (topspace--count-lines (point-max) (point-min)))
+              :to-equal
+              (line-number-at-pos (point-max)))
+      (set-window-start (selected-window) 1))
+
   (it "can count lines if window-absolute-pixel-position returns nil"
       (expect (round (topspace--count-lines (point-min) (point-max)))
               :to-equal
-              (line-number-at-pos (point-max))
-              )))
+              (line-number-at-pos (point-max)))))
 
  (describe
   "topspace--correct-height"
diff --git a/topspace.el b/topspace.el
index 8039fb700c..47f1531cb5 100644
--- a/topspace.el
+++ b/topspace.el
@@ -27,7 +27,7 @@
 ;; by automatically drawing an upper margin/padding above the top line
 ;; as you scroll down or recenter top text.
 
-;; TopSpace is:
+;; Features:
 
 ;; - Easier on the eyes: Recenter or scroll down top text to a more
 ;;   comfortable eye level for reading, especially when in full-screen
@@ -103,6 +103,12 @@ This flag signals to wait until then to display top 
space.")
 
 (defvar topspace--advice-added nil "Keep track if `advice-add` done already.")
 
+(defvar topspace--scroll-down-scale-factor 1
+  "For eliminating an error when testing in non-interactive batch mode.
+An error occurs in this mode any time `scroll-down' is passed a
+non-zero value, which halts tests and makes testing many topspace features
+impossible.  So this variable is set to zero when testing in this mode.")
+
 
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;; Customization
 
@@ -223,16 +229,8 @@ TOTAL-LINES is used in the same way as in `scroll-down'."
     (setq total-lines (or total-lines (- (topspace--window-height)
                                          next-screen-context-lines)))
     (setq topspace--total-lines-scrolling total-lines)
-    (setq total-lines (topspace--scroll total-lines))
-    (let ((window-start-visual-line))
-      (when (and
-             (> total-lines 1)
-             (< (line-number-at-pos (window-start)) (topspace--window-height)))
-        ;; only count lines here otherwise it will take too much compute time
-        (setq window-start-visual-line (topspace--count-lines 1 
(window-start)))
-        (when (> total-lines window-start-visual-line)
-          (setq total-lines window-start-visual-line)))
-      (list (round total-lines))))))
+    (list (* topspace--scroll-down-scale-factor
+             (topspace--scroll total-lines))))))
 
 (defun topspace--filter-args-scroll-up (&optional total-lines)
   "Run before `scroll-up' for scrolling above the top line.
@@ -364,16 +362,18 @@ which must be accounted for in the calling functions."
 
 (defun topspace--count-pixel-height (start end)
   "Return total pixels between points START and END as if they're both 
visible."
-  (setq end (min end (point-max)))
-  (setq start (max start (point-min)))
   (let ((result 0))
     (save-excursion
+      (goto-char end)
+      (beginning-of-visual-line)
+      (setq end (point))
       (goto-char start)
+      (beginning-of-visual-line)
       (while (< (point) end)
         (setq result (+ result (* (vertical-motion 1) (line-pixel-height))))))
     result))
 
-(defun topspace--count-slow (start end)
+(defun topspace--count-lines-slow (start end)
   "Return screen lines between points START and END.
 Like `topspace--count-lines' but is a slower backup alternative."
   (/ (topspace--count-pixel-height start end) (float (default-line-height))))
@@ -384,22 +384,27 @@ Like `count-screen-lines' except `count-screen-lines' will
 return unexpected value when END is in column 0. This fixes that issue.
 This function also tries to first count the lines using a potentially faster
 technique involving `window-absolute-pixel-position'.
-If that doesn't work it uses `topspace--count-slow'."
-  (let ((old-end end) (old-start start))
+If that doesn't work it uses `topspace--count-lines-slow'."
+  (setq end (min end (point-max)))
+  (setq start (max start (point-min)))
+  (let ((old-end) (old-start) (swap)
+        (line-height (float (default-line-height))))
+    (when (> start end) (setq swap end) (setq end start) (setq start swap))
+    (setq old-end end) (setq old-start start)
     (setq end (min end (- (window-end) 1)))
     (setq start (max start (window-start)))
     (let ((end-y (window-absolute-pixel-position end))
           (start-y (window-absolute-pixel-position start)))
-      (cond
-       ((and end-y start-y)
-        ;; first try counting lines by getting the pixel difference
-        ;; between end and start and dividing by `default-line-height'
-        (+ (/ (- (cdr end-y) (cdr start-y)) (float (default-line-height)))
-           (if (> old-end end) (topspace--count-slow end old-end) 0)
-           (if (< old-start start) (topspace--count-slow old-start start) 0)))
-       (t ;; if the pixel method above doesn't work do this slower method
-        ;; (it won't work if either START or END are not visible in window)
-        (topspace--count-slow start old-end))))))
+      (+
+       (if (> old-end end) (topspace--count-lines-slow end old-end) 0)
+       (if (< old-start start) (topspace--count-lines-slow old-start start) 0)
+       (condition-case nil
+           ;; first try counting lines by getting the pixel difference
+           ;; between end and start and dividing by `default-line-height'
+           (/ (- (cdr end-y) (cdr start-y)) line-height)
+         ;; if the pixel method above doesn't work do this slower method
+         ;; (it won't work if either START or END are not visible in window)
+         (error (topspace--count-lines-slow start end)))))))
 
 
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;; Overlay drawing