Add public shareable link for galleries

photo21/static/copy-button.js

@@ -0,0 +1,24 @@
+document.querySelectorAll('[data-clipboard-text]').forEach(function(btn) {
+    btn.addEventListener('click', function() {
+        var text = btn.dataset.clipboardText;
+        if (navigator.clipboard) {
+            navigator.clipboard.writeText(text);
+        } else {
+            var ta = document.createElement('textarea');
+            ta.value = text;
+            ta.style.position = 'fixed';
+            ta.style.opacity = '0';
+            document.body.appendChild(ta);
+            ta.select();
+            document.execCommand('copy');
+            document.body.removeChild(ta);
+        }
+        var original = btn.textContent;
+        btn.textContent = '✓ Copied!';
+        btn.disabled = true;
+        setTimeout(function() {
+            btn.textContent = original;
+            btn.disabled = false;
+        }, 2000);
+    });
+});