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Diffstat (limited to 'modules/ui-theme.el')
| -rw-r--r-- | modules/ui-theme.el | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/modules/ui-theme.el b/modules/ui-theme.el new file mode 100644 index 00000000..609acab3 --- /dev/null +++ b/modules/ui-theme.el @@ -0,0 +1,110 @@ +;;; ui-theme.el --- UI Theme Configuration and Persistence -*- lexical-binding: t; -*- +;; Craig Jennings <c@cjennings.net> +;; +;;; Commentary: + +;; Add custom theme files to "themes" subdirectory. +;; Load other preferred themes via use-package. +;; cj/switch-theme function unloads previous themes then applies the chosen theme. +;; Persist themes between sessions using a file to store the theme name. +;; The persist file can live in a sync'd dir, so theme choice may persist across machines. + +;;; Code: + +;; ----------------------------------- Themes ---------------------------------- +;; theme choices and settings + +;; downloaded custom themes go in themes subdirectory +(setq custom-safe-themes t) ;; trust all custom themes +(add-to-list 'custom-theme-load-path + (concat user-emacs-directory "themes")) + +(use-package ef-themes) +(use-package github-dark-vscode-theme) +(use-package madhat2r-theme) +(use-package adwaita-dark-theme) + +;; ------------------------------- Switch Themes ------------------------------- +;; loads themes in completing read, then persists via the functions below + +(defun cj/switch-themes () + "Function to switch themes and save chosen theme name for persistence. +Unloads any other applied themes before applying the chosen theme." + (interactive) + (let ((chosentheme "")) + (setq chosentheme + (completing-read "Load custom theme: " + (mapcar 'symbol-name + (custom-available-themes)))) + (mapcar #'disable-theme custom-enabled-themes) + (load-theme (intern chosentheme) t)) + (cj/save-theme-to-file)) +(global-set-key (kbd "M-L") 'cj/switch-themes) + +;; ----------------------------- Theme Persistence ----------------------------- +;; persistence utility functions used by switch themes. + +(defvar theme-file (concat sync-dir "emacs-theme.persist") + "The location of the file to persist the theme name.") + +(defvar fallback-theme-name "wombat" + "The name of the theme to fallback on. +This is used then there's no file, or the theme name doesn't match +any of the installed themes. If theme name is 'nil', there will be +no theme.") + +(defun cj/read-file-contents (filename) + "Read FILENAME and return its content as a string. +If FILENAME isn't readable, return nil." + (if (file-readable-p filename) + (with-temp-buffer + (insert-file-contents filename) + (buffer-string)) + 'nil)) + +(defun cj/write-file-contents (content filename) + "Write CONTENT to FILENAME. +If FILENAME isn't writeable, return nil. If successful, return t." + (if (file-writable-p filename) + (progn + (with-temp-buffer + (insert content) + (write-file filename)) + 't) + 'nil)) + +(defun cj/get-active-theme-name () + "Return the name of the active UI theme as a string." + (symbol-name (car custom-enabled-themes))) + +(defun cj/save-theme-to-file () + "Save the string representing the current theme to the theme-file." + (if (equal (cj/write-file-contents (cj/get-active-theme-name) theme-file) 'nil) + (message "Cannot save theme: %s is unwriteable" theme-file) + (message "%s theme saved to %s" (cj/get-active-theme-name) theme-file))) + +(defun cj/load-fallback-theme (msg) + "Display MSG and load ui-theme fallback-theme-name. +Used to handle errors with loading persisted theme." + (message (concat msg (format " Loading fallback theme %s" fallback-theme-name))) + (load-theme fallback-theme-name t)) + +(defun cj/load-theme-from-file () + "Apply the thame name contained in theme-file as the active UI theme. +If the theme is nil, it disables all current themes. If an error occurs +loading the file name, the fallback-theme-name is applied and saved." + (let ((theme-name (cj/read-file-contents theme-file))) + ;; if theme-name is nil, unload all themes + (if (string= theme-name "nil") + (mapcar #'disable-theme custom-enabled-themes) + ;; apply theme name or if error, load fallback theme + (progn + (condition-case err + (load-theme (intern theme-name) t) + (error + (cj/load-fallback-theme (concat "Error loading " theme-name ".")))))))) + +(cj/load-theme-from-file) + +(provide 'ui-theme) +;;; ui-theme.el ends here. |