popovers: Add Copied! tooltip when `copy code` button is clicked.

`copy code` button now show a `Copied!` tooltip when clicked.
It implements a similar function used on `saved as draft` notice.

We need to modify the copy_code_button template to limit
data-tippy-trigger to not include click; otherwise, repeated clicks to
copy code will incorrectly also display the "Copy code" tooltip
alternating with "Copied".

Fixes part of #21036.

web/src/rendered_markdown.js

@@ -13,6 +13,7 @@ import * as realm_playground from "./realm_playground";
 import * as rtl from "./rtl";
 import * as stream_data from "./stream_data";
 import * as timerender from "./timerender";
+import {show_copied_confirmation} from "./tippyjs";
 import * as user_groups from "./user_groups";
 import {user_settings} from "./user_settings";
 
@@ -227,11 +228,14 @@ export const update_elements = ($content) => {
         }
         const $copy_button = $(copy_code_button());
         $pre.prepend($copy_button);
-        new ClipboardJS($copy_button[0], {
+        const clipboard = new ClipboardJS($copy_button[0], {
             text(copy_element) {
                 return $(copy_element).siblings("code").text();
             },
         });
+        clipboard.on("success", () => {
+            show_copied_confirmation($copy_button[0]);
+        });
     });
 
     // Display emoji (including realm emoji) as text if

web/src/tippyjs.js

@@ -624,3 +624,22 @@ export function initialize() {
         appendTo: () => document.body,
     });
 }
+
+export function show_copied_confirmation($copy_button) {
+    // Display a tooltip to notify the user the message or code was copied.
+    const instance = tippy($copy_button, {
+        placement: "top",
+        appendTo: () => document.body,
+        onUntrigger() {
+            remove_instance();
+        },
+    });
+    instance.setContent($t({defaultMessage: "Copied!"}));
+    instance.show();
+    function remove_instance() {
+        if (!instance.state.isDestroyed) {
+            instance.destroy();
+        }
+    }
+    setTimeout(remove_instance, 1000);
+}

web/templates/copy_code_button.hbs

@@ -1,3 +1,3 @@
-<button class="btn pull-left copy_button_base copy_codeblock" data-tippy-content="{{t 'Copy code' }}" aria-label="{{t 'Copy code' }}">
+<button class="btn pull-left copy_button_base copy_codeblock" data-tippy-content="{{t 'Copy code' }}" data-tippy-trigger="mouseenter" aria-label="{{t 'Copy code' }}">
     {{> copy_to_clipboard_svg }}
 </button>

web/tests/rendered_markdown.test.js

@@ -13,11 +13,15 @@ class Clipboard {
     constructor(...args) {
         clipboard_args = args;
     }
+    on(success, show_copied_confirmation) {
+        show_copied_confirmation();
+    }
 }
 
 mock_cjs("clipboard", Clipboard);
 
 const realm_playground = mock_esm("../src/realm_playground");
+const tippyjs = mock_esm("../src/tippyjs");
 user_settings.emojiset = "apple";
 
 const rm = zrequire("rendered_markdown");
@@ -428,6 +432,8 @@ run_test("code playground none", ({override, mock_template}) => {
         return undefined;
     });
 
+    override(tippyjs, "show_copied_confirmation", () => {});
+
     const {prepends, $copy_code, $view_code} = test_code_playground(mock_template, false);
     assert.deepEqual(prepends, [$copy_code]);
     assert_clipboard_setup();
@@ -442,6 +448,8 @@ run_test("code playground single", ({override, mock_template}) => {
         return [{name: "Some Javascript Playground"}];
     });
 
+    override(tippyjs, "show_copied_confirmation", () => {});
+
     const {prepends, $copy_code, $view_code} = test_code_playground(mock_template, true);
     assert.deepEqual(prepends, [$view_code, $copy_code]);
     assert_clipboard_setup();
@@ -460,6 +468,8 @@ run_test("code playground multiple", ({override, mock_template}) => {
         return ["whatever", "whatever"];
     });
 
+    override(tippyjs, "show_copied_confirmation", () => {});
+
     const {prepends, $copy_code, $view_code} = test_code_playground(mock_template, true);
     assert.deepEqual(prepends, [$view_code, $copy_code]);
     assert_clipboard_setup();