From 136a47bf1018defd7947465dfde211782ef5fadb Mon Sep 17 00:00:00 2001
From: Ethan Dalool <git@voussoir.net>
Date: Thu, 11 Jun 2020 18:20:20 -0700
Subject: [PATCH] Add support for spinner groups, all buttons spin when one
 clicked.

---
 frontends/etiquette_flask/static/js/common.js | 97 ++++++++++++++++---
 1 file changed, 85 insertions(+), 12 deletions(-)

diff --git a/frontends/etiquette_flask/static/js/common.js b/frontends/etiquette_flask/static/js/common.js
index 68603ff..ef21a31 100644
--- a/frontends/etiquette_flask/static/js/common.js
+++ b/frontends/etiquette_flask/static/js/common.js
@@ -262,13 +262,55 @@ function init_button_with_confirm()
     });
 }
 
-var spinner_button_index = 0;
+common.spinner_button_index = 0;
+common.button_spinner_groups = {};
+// When a group member is closing, it will call the closer on all other members
+// in the group. Of course, this would recurse forever without some kind of
+// flagging, so this dict will hold group_id:true if a close is in progress,
+// and be empty otherwise.
+common.spinner_group_closing = {};
+
+common.add_to_spinner_group =
+function add_to_spinner_group(group_id, button)
+{
+    if (!(group_id in common.button_spinner_groups))
+    {
+        common.button_spinner_groups[group_id] = [];
+    }
+    common.button_spinner_groups[group_id].push(button);
+}
+
+common.close_grouped_spinners =
+function close_grouped_spinners(group_id)
+{
+    if (group_id && !(common.spinner_group_closing[group_id]))
+    {
+        common.spinner_group_closing[group_id] = true;
+        common.button_spinner_groups[group_id].forEach(function(button)
+        {
+            window[button.dataset.spinnerCloser]();
+        });
+        delete common.spinner_group_closing[group_id];
+    }
+}
+
+common.open_grouped_spinners =
+function open_grouped_spinners(group_id)
+{
+    common.button_spinner_groups[group_id].forEach(function(button)
+    {
+        window[button.dataset.spinnerOpener]();
+    });
+}
+
 common.init_button_with_spinner =
 function init_button_with_spinner()
 {
     /*
     To create a button that has a spinner, and cannot be clicked again while
     the action is running, assign it the class "button_with_spinner".
+    When you're ready for the spinner to disappear, call
+    window[button.dataset.spinnerCloser]().
 
     Required:
         data-onclick: The string that would normally be the button's onclick.
@@ -277,7 +319,17 @@ function init_button_with_spinner()
         data-spinner-id: If you want to use your own element as the spinner,
             give its ID here. Otherwise a new one will be created.
 
+        data-spinner-delay: The number of milliseconds to wait before the
+            spinner appears. For tasks that you expect to run very quickly,
+            this helps prevent a pointlessly short spinner.
+
         data-holder-class: CSS class for the new span that holds the menu.
+
+        data-spinner-group: An opaque string. All button_with_spinner that have
+            the same group will go into spinner mode when any of them is
+            clicked. Useful if you want to have two copies of a button on the
+            page, or two buttons which do opposite things and you only want one
+            to run at a time.
     */
     var buttons = Array.from(document.getElementsByClassName("button_with_spinner"));
     buttons.forEach(function(button)
@@ -305,26 +357,47 @@ function init_button_with_spinner()
             holder.appendChild(spinner_element);
         }
 
+        if (button.dataset.spinnerGroup)
+        {
+            common.add_to_spinner_group(button.dataset.spinnerGroup, button);
+        }
+
         var spin = new spinner.Spinner(spinner_element);
         var spin_delay = parseFloat(button.dataset.spinnerDelay) || 0;
 
+        button.dataset.spinnerOpener = "spinner_opener_" + common.spinner_button_index;
+        window[button.dataset.spinnerOpener] = function spinner_opener()
+        {
+            spin.show(spin_delay);
+            button.disabled = true;
+        }
+        // It is expected that the function referenced by data-onclick will call
+        // window[button.dataset.spinnerCloser]() when appropriate, since from
+        // our perspective we cannot be sure when to close the spinner.
+        button.dataset.spinnerCloser = "spinner_closer_" + common.spinner_button_index;
+        window[button.dataset.spinnerCloser] = function spinner_closer()
+        {
+            common.close_grouped_spinners(button.dataset.spinnerGroup);
+            spin.hide();
+            button.disabled = false;
+        }
+
         var wrapped_onclick = Function(button.dataset.onclick);
         button.onclick = function()
         {
-            spin.show(spin_delay);
-            button.disabled = true;
-            wrapped_onclick();
+            if (button.dataset.spinnerGroup)
+            {
+                common.open_grouped_spinners(button.dataset.spinnerGroup);
+            }
+            else
+            {
+                window[button.dataset.spinnerOpener]();
+            }
+            return wrapped_onclick();
         }
         delete button.dataset.onclick;
 
-        var closer_id = "spinner_closer_" + spinner_button_index;
-        spinner_button_index += 1;
-        window[closer_id] = function spinner_closer()
-        {
-            spin.hide();
-            button.disabled = false;
-        }
-        button.dataset.spinnerCloser = closer_id;
+        common.spinner_button_index += 1;
     });
 }