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diff --git a/devdocs/elisp/abstract-display-example.html b/devdocs/elisp/abstract-display-example.html deleted file mode 100644 index 4e9c36ea..00000000 --- a/devdocs/elisp/abstract-display-example.html +++ /dev/null @@ -1,96 +0,0 @@ - <h4 class="subsection">Abstract Display Example</h4> <p>Here is a simple example using functions of the ewoc package to implement a <em>color components</em> display, an area in a buffer that represents a vector of three integers (itself representing a 24-bit RGB value) in various ways. </p> <div class="example"> <pre class="example">(setq colorcomp-ewoc nil - colorcomp-data nil - colorcomp-mode-map nil - colorcomp-labels ["Red" "Green" "Blue"]) - -(defun colorcomp-pp (data) - (if data - (let ((comp (aref colorcomp-data data))) - (insert (aref colorcomp-labels data) "\t: #x" - (format "%02X" comp) " " - (make-string (ash comp -2) ?#) "\n")) - (let ((cstr (format "#%02X%02X%02X" - (aref colorcomp-data 0) - (aref colorcomp-data 1) - (aref colorcomp-data 2))) - (samp " (sample text) ")) - (insert "Color\t: " - (propertize samp 'face - `(foreground-color . ,cstr)) - (propertize samp 'face - `(background-color . ,cstr)) - "\n")))) - -(defun colorcomp (color) - "Allow fiddling with COLOR in a new buffer. -The buffer is in Color Components mode." - (interactive "sColor (name or #RGB or #RRGGBB): ") - (when (string= "" color) - (setq color "green")) - (unless (color-values color) - (error "No such color: %S" color)) - (switch-to-buffer - (generate-new-buffer (format "originally: %s" color))) - (kill-all-local-variables) - (setq major-mode 'colorcomp-mode - mode-name "Color Components") - (use-local-map colorcomp-mode-map) - (erase-buffer) - (buffer-disable-undo) - (let ((data (apply 'vector (mapcar (lambda (n) (ash n -8)) - (color-values color)))) - (ewoc (ewoc-create 'colorcomp-pp - "\nColor Components\n\n" - (substitute-command-keys - "\n\\{colorcomp-mode-map}")))) - (set (make-local-variable 'colorcomp-data) data) - (set (make-local-variable 'colorcomp-ewoc) ewoc) - (ewoc-enter-last ewoc 0) - (ewoc-enter-last ewoc 1) - (ewoc-enter-last ewoc 2) - (ewoc-enter-last ewoc nil))) -</pre> -</div> <p>This example can be extended to be a color selection widget (in other words, the “controller” part of the “model–view–controller” design paradigm) by defining commands to modify <code>colorcomp-data</code> and to finish the selection process, and a keymap to tie it all together conveniently. </p> <div class="example"> <pre class="example">(defun colorcomp-mod (index limit delta) - (let ((cur (aref colorcomp-data index))) - (unless (= limit cur) - (aset colorcomp-data index (+ cur delta))) - (ewoc-invalidate - colorcomp-ewoc - (ewoc-nth colorcomp-ewoc index) - (ewoc-nth colorcomp-ewoc -1)))) - -(defun colorcomp-R-more () (interactive) (colorcomp-mod 0 255 1)) -(defun colorcomp-G-more () (interactive) (colorcomp-mod 1 255 1)) -(defun colorcomp-B-more () (interactive) (colorcomp-mod 2 255 1)) -(defun colorcomp-R-less () (interactive) (colorcomp-mod 0 0 -1)) -(defun colorcomp-G-less () (interactive) (colorcomp-mod 1 0 -1)) -(defun colorcomp-B-less () (interactive) (colorcomp-mod 2 0 -1)) - -(defun colorcomp-copy-as-kill-and-exit () - "Copy the color components into the kill ring and kill the buffer. -The string is formatted #RRGGBB (hash followed by six hex digits)." - (interactive) - (kill-new (format "#%02X%02X%02X" - (aref colorcomp-data 0) - (aref colorcomp-data 1) - (aref colorcomp-data 2))) - (kill-buffer nil)) - -(setq colorcomp-mode-map - (let ((m (make-sparse-keymap))) - (suppress-keymap m) - (define-key m "i" 'colorcomp-R-less) - (define-key m "o" 'colorcomp-R-more) - (define-key m "k" 'colorcomp-G-less) - (define-key m "l" 'colorcomp-G-more) - (define-key m "," 'colorcomp-B-less) - (define-key m "." 'colorcomp-B-more) - (define-key m " " 'colorcomp-copy-as-kill-and-exit) - m)) -</pre> -</div> <p>Note that we never modify the data in each node, which is fixed when the ewoc is created to be either <code>nil</code> or an index into the vector <code>colorcomp-data</code>, the actual color components. </p><div class="_attribution"> - <p class="_attribution-p"> - Copyright © 1990-1996, 1998-2022 Free Software Foundation, Inc. <br>Licensed under the GNU GPL license.<br> - <a href="https://www.gnu.org/software/emacs/manual/html_node/elisp/Abstract-Display-Example.html" class="_attribution-link">https://www.gnu.org/software/emacs/manual/html_node/elisp/Abstract-Display-Example.html</a> - </p> -</div> |