;;; input.el --- Configure behaviour of input devices. -*- lexical-binding: t; -*-

;; Time-stamp: <2020-01-28T10:24:44+0100>

;;; Commentary:
;; * Setup mouse & keyboard behaviour.
;; * Setup basic keybindings.

;;; Code:

(use-package emacs
  :ensure nil

  :custom
  (mouse-wheel-scroll-amount '(1 ((shift) . 1))) ; Scroll 1 line at a time.
  ;; Paste text where the cursor is, not where the mouse is.
  (mouse-yank-at-point t)
  ;; Reduce scroll lag significantly. <https://emacs.stackexchange.com/a/28746>
  (auto-window-vscroll nil)

  :config
  (delete-selection-mode t)          ; Delete selection when you start to write.

  ;; kill-region (cut) and kill-ring-save (copy) act on the current line if no
  ;; text is visually selected.
  ;; <https://www.emacswiki.org/emacs/WholeLineOrRegion>
  (put 'kill-ring-save 'interactive-form
       '(interactive
         (if (use-region-p)
             (list (region-beginning) (region-end))
           (list (line-beginning-position) (line-beginning-position 2)))))
  (put 'kill-region 'interactive-form
       '(interactive
         (if (use-region-p)
             (list (region-beginning) (region-end))
           (list (line-beginning-position) (line-beginning-position 2)))))
  )

(use-package bind-key
  :functions (my/delete-word my/backward-delete-word)

  :config
  (defun my/delete-word (arg)
    "Delete characters forward until encountering the end of a word.
With argument, do this that many times."
    (interactive "p")
    (if (use-region-p)
        (delete-region (region-beginning) (region-end))
      (delete-region (point) (progn (forward-word arg) (point)))))

  (defun my/backward-delete-word (arg)
    "Delete characters backward until encountering the end of a word.
With argument, do this that many times."
    (interactive "p")
    (my/delete-word (- arg)))

  (bind-keys
   ;; Reduce whitespace around cursor to 0 or 1, according to context.
   ("C-S-<delete>"  . fixup-whitespace)
   ;; Scroll without moving the cursor.
   ("M-<down>"      . scroll-up-line)
   ("M-<up>"        . scroll-down-line)
   ;; Delete words without storing them in the kill buffer.
   ("C-<delete>"    . my/delete-word)
   ("C-<backspace>" . my/backward-delete-word)
   ("C-q"           . delete-frame)
   ;; Insert next character with control characters. Like C-V in the shell.
   ("C-S-v"         . quoted-insert)
   )
  )

; Multiple cursors.
(use-package multiple-cursors
  :init
  (global-unset-key (kbd "M-<down-mouse-1>"))

  :bind
  ("C-x M-m"     . mc/edit-lines)
  ("M-<mouse-1>" . mc/add-cursor-on-click)
  )

;; Edit multiple regions in the same way simultaneously.
(use-package iedit
  :bind
  ("C-;" . iedit-mode)
  )

;; Display available keybindings.
(use-package which-key
  :config
  (which-key-mode)
  )

;; Navigate between windows with alt+arrows.
(use-package windmove
  :config
  (windmove-default-keybindings '(meta shift))

  :bind                                 ; Needed for Emacs-over-SSH. 🤷
  ([(meta shift left)] . windmove-left)
  ([(meta shift right)] . windmove-right)
  ([(meta shift up)] . windmove-up)
  ([(meta shift down)] . windmove-down)
  )

(provide 'basics/input)
;;; input.el ends here