Function: evil-visual-highlight-block

evil-visual-highlight-block is a byte-compiled function defined in evil-states.el.

Signature

(evil-visual-highlight-block BEG END &optional OVERLAYS)

Documentation

Highlight rectangular region from BEG to END.

Do this by putting an overlay on each line within the rectangle. Each overlay extends across all the columns of the rectangle. Reuse overlays where possible to prevent flicker.

Source Code

;; Defined in ~/.emacs.d/elpa/evil-20251108.138/evil-states.el
(defun evil-visual-highlight-block (beg end &optional overlays)
  "Highlight rectangular region from BEG to END.
Do this by putting an overlay on each line within the rectangle.
Each overlay extends across all the columns of the rectangle.
Reuse overlays where possible to prevent flicker."
  (let* ((point (point))
         (overlays (or overlays 'evil-visual-block-overlays))
         (old (symbol-value overlays))
         beg-col end-col new nlines overlay window-beg window-end)
    (save-excursion
      ;; calculate the rectangular region represented by BEG and END,
      ;; but put BEG in the upper-left corner and END in the
      ;; lower-right if not already there
      (setq beg-col (evil-column beg)
            end-col (evil-column end))
      (when (>= beg-col end-col)
        (if (= beg-col end-col)
            (setq end-col (1+ end-col))
          (evil-swap beg-col end-col))
        (setq beg (progn (goto-char beg) (evil-move-to-column beg-col))
              end (progn (goto-char end) (evil-move-to-column end-col 1))))
      ;; maybe extend end column to EOL
      (and (memq this-command '(next-line previous-line evil-use-register))
           (eq temporary-goal-column most-positive-fixnum)
           (setq end-col most-positive-fixnum))
      ;; force a redisplay so we can do reliable window
      ;; BEG/END calculations
      (sit-for 0)
      (setq window-beg (max (window-start) beg)
            window-end (min (window-end) (1+ end))
            nlines (count-lines window-beg
                                (min window-end (point-max))))
      ;; iterate over those lines of the rectangle which are
      ;; visible in the currently selected window
      (goto-char window-beg)
      (dotimes (_ nlines)
        (let (before after row-beg row-end)
          ;; beginning of row
          (evil-move-to-column beg-col)
          (when (< (current-column) beg-col)
            ;; prepend overlay with virtual spaces if unable to
            ;; move directly to the first column
            (setq before
                  (propertize
                   (make-string
                    (- beg-col (current-column)) ?\s)
                   'face
                   (or (get-text-property (1- (point)) 'face)
                       'default))))
          (setq row-beg (point))
          ;; end of row
          (evil-move-to-column end-col)
          (when (and (not (eolp))
                     (< (current-column) end-col))
            ;; append overlay with virtual spaces if unable to
            ;; move directly to the last column
            (setq after
                  (propertize
                   (make-string
                    (if (= (point) row-beg)
                        (- end-col beg-col)
                      (- end-col (current-column)))
                    ?\s) 'face 'region))
            ;; place cursor on one of the virtual spaces
            (if (= point row-beg)
                (put-text-property
                 0 (min (length after) 1)
                 'cursor t after)
              (put-text-property
               (max 0 (1- (length after))) (length after)
               'cursor t after)))
          (setq row-end (min (point) (line-end-position)))
          ;; trim old leading overlays
          (while (and old
                      (setq overlay (car old))
                      (< (overlay-start overlay) row-beg)
                      (/= (overlay-end overlay) row-end))
            (delete-overlay overlay)
            (setq old (cdr old)))
          ;; reuse an overlay if possible, otherwise create one
          (cond
           ((and old (setq overlay (car old))
                 (or (= (overlay-start overlay) row-beg)
                     (= (overlay-end overlay) row-end)))
            (move-overlay overlay row-beg row-end)
            (overlay-put overlay 'before-string before)
            (overlay-put overlay 'after-string after)
            (setq new (cons overlay new)
                  old (cdr old)))
           (t
            (setq overlay (make-overlay row-beg row-end))
            (overlay-put overlay 'before-string before)
            (overlay-put overlay 'after-string after)
            (setq new (cons overlay new)))))
        (forward-line 1))
      ;; display overlays
      (dolist (overlay new)
        (overlay-put overlay 'face 'region)
        (overlay-put overlay 'priority 99))
      ;; trim old overlays
      (dolist (overlay old)
        (delete-overlay overlay))
      (set overlays (nreverse new)))))