code.delx.au - gnu-emacs-elpa/blob - darkroom.el

   1 (defvar darkroom-margins 0.15
   2   "Margins to use in darkroom-mode.
   3
   4 It's value can be:
   5
   6 - a floating point value betweeen 0 and 1, specifies percentage of
   7   window width in columns to use as a margin.
   8
   9 - a cons cell (LEFT RIGHT) specifying the left and right margins
  10   in columns.
  11
  12 - a function that returns a cons cell interpreted like the
  13   previous option.
  14
  15 Value is effective when `darkroom-minor-mode' is toggled, when
  16 changing window or by calling `darkroom-set-margins'")
  17
  18 (defvar darkroom-turns-on-visual-line-mode t
  19   "If non-nil pair `visual-line-mode' with
  20   `darkroom-minor-mode'")
  21 (defvar darkroom-fringes-outside-margins t
  22   "If non-nil use fringes outside margins for `darkroom-minor-mode'")
  23
  24 (defun darkroom-margins ()
  25   (cond ((functionp darkroom-margins)
  26          (funcall darkroom-margins))
  27         ((consp darkroom-margins)
  28          darkroom-margins)
  29         ((and (floatp darkroom-margins)
  30               (< darkroom-margins 1))
  31          (let ((delta (darkroom-float-to-columns darkroom-margins)))
  32            (cons delta delta)))))
  33
  34 (defun darkroom-float-to-columns (f)
  35   (ceiling (* (let ((edges (window-edges)))
  36                 (- (nth 2 edges) (nth 0 edges)))
  37               f)))
  38
  39 (defun darkroom-set-margins (&optional margins)
  40   "Adjust margins to `darkroom-margins' or optional MARGINS."
  41   (let ((margins
  42          (or margins
  43              (darkroom-margins))))
  44     (when margins
  45       (set-window-margins (selected-window) (car margins) (cdr margins)))))
  46
  47 (defun darkroom-increase-margins ()
  48   (interactive)
  49   (when (floatp darkroom-margins)
  50     (setq darkroom-margins (+ 0.05 darkroom-margins))
  51     (darkroom-set-margins)))
  52
  53 (defun darkroom-decrease-margins ()
  54   (interactive)
  55   (when (floatp darkroom-margins)
  56     (setq darkroom-margins (- darkroom-margins 0.05))
  57     (darkroom-set-margins)))
  58
  59 (defun darkroom-fill-paragraph-maybe (really)
  60   (interactive "P")
  61   (cond (visual-line-mode
  62          (if (not really)
  63              (message "not filling paragraph")
  64            (call-interactively 'fill-paragraph)
  65            (message "filled paragraph even in visual-line-mode")))
  66         (t
  67          (call-interactively 'fill-paragraph))))
  68
  69 (defvar darkroom-minor-mode-map (let ((map (make-sparse-keymap)))
  70                                   (define-key map (kbd "C-M-+") 'darkroom-increase-margins)
  71                                   (define-key map (kbd "C-M--") 'darkroom-decrease-margins)
  72                                   (define-key map (kbd "M-q") 'darkroom-fill-paragraph-maybe)
  73                                   map))
  74
  75 (defvar darkroom-saved-mode-line-format nil)
  76 (defvar darkroom-saved-visual-mode nil)
  77 (define-minor-mode darkroom-minor-mode
  78   "A minor mode that emulates the darkroom editor."
  79   nil
  80   " dark"
  81   nil
  82   (cond (darkroom-minor-mode
  83          (setq darkroom-saved-mode-line-format mode-line-format
  84                mode-line-format nil
  85                darkroom-saved-header-line-format header-line-format
  86                header-line-format "")
  87          (setq fringes-outside-margins darkroom-fringes-outside-margins)
  88          (add-hook 'window-configuration-change-hook 'darkroom-set-margins nil t)
  89          (darkroom-set-margins)
  90          ;; a hack shoulnd't be needed but apparently is
  91          (set-window-buffer (selected-window) (current-buffer))
  92          (when darkroom-turns-on-visual-line-mode
  93            (visual-line-mode 1)))
  94         (t
  95          (setq mode-line-format darkroom-saved-mode-line-format
  96                header-line-format darkroom-saved-header-line-format)
  97          (when darkroom-turns-on-visual-line-mode
  98            (visual-line-mode -1))
  99          (remove-hook 'window-configuration-change-hook 'darkroom-set-margins t)
 100          (set-window-margins (selected-window) 0 0))))
 101
 102
 103
 104
 105 (provide 'darkroom)