Add the ability to use tabs inside the paste box and choose between Tabs/Spaces à la GitHub

static/js/paste_create.js

@@ -36,6 +36,93 @@ document.addEventListener('DOMContentLoaded', function () {
     expirySelect.addEventListener('change', () =>
         localStorage.setItem('preferred_expiry', expirySelect.value));
 
+    // ── Indent controls (Tabs / Spaces + size) ───────────────────────────────
+    const indentType = document.getElementById('indent_type');
+    const indentSize = document.getElementById('indent_size');
+
+    // Restore saved preferences
+    const savedIndentType = localStorage.getItem('preferred_indent_type');
+    const savedIndentSize = localStorage.getItem('preferred_indent_size');
+    if (savedIndentType) indentType.value = savedIndentType;
+    if (savedIndentSize) indentSize.value = savedIndentSize;
+
+    // Hide size selector when Tabs is chosen (tabs have no width setting in the input)
+    function syncIndentUI() {
+        indentSize.style.display = indentType.value === 'tabs' ? 'none' : '';
+    }
+    syncIndentUI();
+
+    indentType.addEventListener('change', () => {
+        localStorage.setItem('preferred_indent_type', indentType.value);
+        syncIndentUI();
+    });
+    indentSize.addEventListener('change', () =>
+        localStorage.setItem('preferred_indent_size', indentSize.value));
+
+    // ── Tab key handler ──────────────────────────────────────────────────────
+    textarea.addEventListener('keydown', function (e) {
+        if (e.key !== 'Tab') return;
+        e.preventDefault();
+
+        const useTab  = indentType.value === 'tabs';
+        const indent  = useTab ? '\t' : ' '.repeat(parseInt(indentSize.value, 10));
+
+        const start = this.selectionStart;
+        const end   = this.selectionEnd;
+        const value = this.value;
+
+        if (start === end) {
+            // No selection — insert indent at cursor
+            this.value = value.slice(0, start) + indent + value.slice(end);
+            this.selectionStart = this.selectionEnd = start + indent.length;
+        } else {
+            // Multi-line selection — indent / unindent each line
+            const lineStart = value.lastIndexOf('\n', start - 1) + 1;
+            const selectedText = value.slice(lineStart, end);
+            const lines = selectedText.split('\n');
+
+            let newText;
+            if (e.shiftKey) {
+                // Unindent: remove one level of indent from the start of each line
+                newText = lines.map(line => {
+                    if (useTab) return line.startsWith('\t') ? line.slice(1) : line;
+                    const spaces = parseInt(indentSize.value, 10);
+                    return line.startsWith(' '.repeat(spaces))
+                        ? line.slice(spaces)
+                        : line.replace(/^ +/, m => m.slice(Math.min(m.length, spaces)));
+                }).join('\n');
+            } else {
+                // Indent: prepend indent to each line
+                newText = lines.map(line => indent + line).join('\n');
+            }
+
+            const removed = selectedText.length - newText.length; // negative when indenting
+            this.value = value.slice(0, lineStart) + newText + value.slice(end);
+            this.selectionStart = lineStart;
+            this.selectionEnd   = lineStart + newText.length;
+        }
+    });
+
+    // ── Enter key: auto-indent to match previous line ────────────────────────
+    textarea.addEventListener('keydown', function (e) {
+        if (e.key !== 'Enter') return;
+        e.preventDefault();
+
+        const start = this.selectionStart;
+        const value = this.value;
+
+        // Find the beginning of the current line
+        const lineStart = value.lastIndexOf('\n', start - 1) + 1;
+        const currentLine = value.slice(lineStart, start);
+
+        // Grab the leading whitespace (spaces or tabs) of the current line
+        const leadingWhitespace = currentLine.match(/^(\s*)/)[1];
+
+        const insert = '\n' + leadingWhitespace;
+        this.value = value.slice(0, start) + insert + value.slice(this.selectionEnd);
+        this.selectionStart = this.selectionEnd = start + insert.length;
+    });
+
     // ── Ctrl/Cmd+S shortcut ──────────────────────────────────────────────────
     document.addEventListener('keydown', e => {
         if ((e.ctrlKey || e.metaKey) && e.key === 's') {

templates/index.html

@@ -6,6 +6,15 @@
 {% block nav_actions %}
 <input type="text" id="title" placeholder="Title (optional)" class="nav-input" maxlength="100" autocomplete="off">
 <select id="language" class="nav-select"></select>
+<select id="indent_type" class="nav-select">
+    <option value="spaces">Spaces</option>
+    <option value="tabs">Tabs</option>
+</select>
+<select id="indent_size" class="nav-select">
+    <option value="2">2</option>
+    <option value="4">4</option>
+    <option value="8">8</option>
+</select>
 <select id="expires_in" class="nav-select">
     {% for opt in cfg.pastes.allow_expiry_options %}
     <option value="{{ opt }}" {% if opt == cfg.pastes.default_expiry %}selected{% endif %}>