Add copy button to code blocks in documentation (#9830)

* Add copy button to code blocks for improved documentation usability

* Add copy button to code blocks for improved documentation usability

* Add copy button to code blocks for improved documentation usability

* Make "Copy" button smaller

---------

Co-authored-by: Bruno Alla <alla.brunoo@gmail.com>

docs_theme/css/copy-button.css

@@ -0,0 +1,30 @@
+.copy-block-button {
+  position: absolute;
+  top: 6px;
+  right: 6px;
+  z-index: 10;
+  white-space: nowrap; /* Prevent text wrap */
+}
+
+/* Ensure the PRE container provides positioning context */
+pre {
+  position: relative;
+  padding-top: 35px; /* Room for the button */
+  overflow-x: auto;   /* Allow horizontal scrolling */
+}
+
+/* Code block scrollable */
+pre code {
+  display: block;
+  overflow-x: auto;
+}
+
+/* 
+  The MkDocs/DRF theme injects a <span> inside buttons and applies
+  a text color that overrides btn-inverse defaults.
+  This override is intentionally scoped and limited to color only.
+*/
+.copy-block-button,
+.copy-block-button span {
+  color: #ffffff !important;
+}

docs_theme/js/copy-button.js

@@ -0,0 +1,24 @@
+document.addEventListener("DOMContentLoaded", function () {
+  document.querySelectorAll("pre > code").forEach(function (codeBlock) {
+    const button = document.createElement("button");
+    button.className = "copy-block-button btn btn-inverse btn-mini";
+    button.type = "button";
+    button.textContent = "Copy";
+
+    button.addEventListener("click", function () {
+      navigator.clipboard.writeText(codeBlock.textContent)
+        .then(() => {
+          button.textContent = "Copied!";
+          setTimeout(() => button.textContent = "Copy", 1200);
+        })
+        .catch(() => {
+          button.textContent = "Failed";
+          setTimeout(() => button.textContent = "Copy", 1200);
+        });
+    });
+
+    const pre = codeBlock.parentNode;
+    pre.style.position = "relative";
+    pre.appendChild(button);
+  });
+});

docs_theme/main.html

@@ -16,6 +16,9 @@
   <link href="{{ 'css/bootstrap.css'|url }}" rel="stylesheet">
   <link href="{{ 'css/bootstrap-responsive.css'|url }}" rel="stylesheet">
   <link href="{{ 'css/default.css'|url }}" rel="stylesheet">
+  {% for path in config.extra_css %}
+    <link href="{{ path|url }}" rel="stylesheet">
+  {% endfor %}
 
 
   <script type="text/javascript">

mkdocs.yml

@@ -86,3 +86,9 @@ nav:
      - 'Kickstarter Announcement': 'community/kickstarter-announcement.md'
      - 'Mozilla Grant': 'community/mozilla-grant.md'
      - 'Jobs': 'community/jobs.md'
+
+extra_css:
+  - css/copy-button.css
+
+extra_javascript:
+  - js/copy-button.js