Scoped labels (#22585)

Add a new "exclusive" option per label. This makes it so that when the
label is named `scope/name`, no other label with the same `scope/`
prefix can be set on an issue.

The scope is determined by the last occurence of `/`, so for example
`scope/alpha/name` and `scope/beta/name` are considered to be in
different scopes and can coexist.

Exclusive scopes are not enforced by any database rules, however they
are enforced when editing labels at the models level, automatically
removing any existing labels in the same scope when either attaching a
new label or replacing all labels.

In menus use a circle instead of checkbox to indicate they function as
radio buttons per scope. Issue filtering by label ensures that only a
single scoped label is selected at a time. Clicking with alt key can be
used to remove a scoped label, both when editing individual issues and
batch editing.

Label rendering refactor for consistency and code simplification:

* Labels now consistently have the same shape, emojis and tooltips
everywhere. This includes the label list and label assignment menus.
* In label list, show description below label same as label menus.
* Don't use exactly black/white text colors to look a bit nicer.
* Simplify text color computation. There is no point computing luminance
in linear color space, as this is a perceptual problem and sRGB is
closer to perceptually linear.
* Increase height of label assignment menus to show more labels. Showing
only 3-4 labels at a time leads to a lot of scrolling.
* Render all labels with a new RenderLabel template helper function.

Label creation and editing in multiline modal menu:

* Change label creation to open a modal menu like label editing.
* Change menu layout to place name, description and colors on separate
lines.
* Don't color cancel button red in label editing modal menu.
* Align text to the left in model menu for better readability and
consistent with settings layout elsewhere.

Custom exclusive scoped label rendering:

* Display scoped label prefix and suffix with slightly darker and
lighter background color respectively, and a slanted edge between them
similar to the `/` symbol.
* In menus exclusive labels are grouped with a divider line.

---------

Co-authored-by: Yarden Shoham <hrsi88@gmail.com>
Co-authored-by: Lauris BH <lauris@nix.lv>

4 files changed, 117 insertions, 51 deletions

diff --git a/web_src/js/features/common-issue.js b/web_src/js/features/common-issue.js
index 4a62089c60..f53dd5081b 100644
--- a/web_src/js/features/common-issue.js
+++ b/web_src/js/features/common-issue.js
@@ -32,7 +32,7 @@ export function initCommonIssue() {
     syncIssueSelectionState();
   });
 
-  $('.issue-action').on('click', async function () {
+  $('.issue-action').on('click', async function (e) {
     let action = this.getAttribute('data-action');
     let elementId = this.getAttribute('data-element-id');
     const url = this.getAttribute('data-url');
@@ -43,6 +43,9 @@ export function initCommonIssue() {
       elementId = '';
       action = 'clear';
     }
+    if (action === 'toggle' && e.altKey) {
+      action = 'toggle-alt';
+    }
     updateIssuesMeta(
       url,
       action,
diff --git a/web_src/js/features/comp/LabelEdit.js b/web_src/js/features/comp/LabelEdit.js
index df294078fa..313d406821 100644
--- a/web_src/js/features/comp/LabelEdit.js
+++ b/web_src/js/features/comp/LabelEdit.js
@@ -1,26 +1,64 @@
 import $ from 'jquery';
 import {initCompColorPicker} from './ColorPicker.js';
 
+function isExclusiveScopeName(name) {
+  return /.*[^/]\/[^/].*/.test(name);
+}
+
+function updateExclusiveLabelEdit(form) {
+  const nameInput = $(`${form} .label-name-input`);
+  const exclusiveField = $(`${form} .label-exclusive-input-field`);
+  const exclusiveCheckbox = $(`${form} .label-exclusive-input`);
+  const exclusiveWarning = $(`${form} .label-exclusive-warning`);
+
+  if (isExclusiveScopeName(nameInput.val())) {
+    exclusiveField.removeClass('muted');
+    if (exclusiveCheckbox.prop('checked') && exclusiveCheckbox.data('exclusive-warn')) {
+      exclusiveWarning.removeClass('gt-hidden');
+    } else {
+      exclusiveWarning.addClass('gt-hidden');
+    }
+  } else {
+    exclusiveField.addClass('muted');
+    exclusiveWarning.addClass('gt-hidden');
+  }
+}
+
 export function initCompLabelEdit(selector) {
   if (!$(selector).length) return;
+  initCompColorPicker();
+
   // Create label
-  const $newLabelPanel = $('.new-label.segment');
   $('.new-label.button').on('click', () => {
-    $newLabelPanel.show();
-  });
-  $('.new-label.segment .cancel').on('click', () => {
-    $newLabelPanel.hide();
+    updateExclusiveLabelEdit('.new-label');
+    $('.new-label.modal').modal({
+      onApprove() {
+        $('.new-label.form').trigger('submit');
+      }
+    }).modal('show');
+    return false;
   });
 
-  initCompColorPicker();
-
+  // Edit label
   $('.edit-label-button').on('click', function () {
     $('.edit-label .color-picker').minicolors('value', $(this).data('color'));
     $('#label-modal-id').val($(this).data('id'));
-    $('.edit-label .new-label-input').val($(this).data('title'));
-    $('.edit-label .new-label-desc-input').val($(this).data('description'));
+
+    const nameInput = $('.edit-label .label-name-input');
+    nameInput.val($(this).data('title'));
+
+    const exclusiveCheckbox = $('.edit-label .label-exclusive-input');
+    exclusiveCheckbox.prop('checked', this.hasAttribute('data-exclusive'));
+    // Warn when label was previously not exclusive and used in issues
+    exclusiveCheckbox.data('exclusive-warn',
+      $(this).data('num-issues') > 0 &&
+      (!this.hasAttribute('data-exclusive') || !isExclusiveScopeName(nameInput.val())));
+    updateExclusiveLabelEdit('.edit-label');
+
+    $('.edit-label .label-desc-input').val($(this).data('description'));
     $('.edit-label .color-picker').val($(this).data('color'));
     $('.edit-label .minicolors-swatch-color').css('background-color', $(this).data('color'));
+
     $('.edit-label.modal').modal({
       onApprove() {
         $('.edit-label.form').trigger('submit');
@@ -28,4 +66,17 @@ export function initCompLabelEdit(selector) {
     }).modal('show');
     return false;
   });
+
+  $('.new-label .label-name-input').on('input', () => {
+    updateExclusiveLabelEdit('.new-label');
+  });
+  $('.new-label .label-exclusive-input').on('change', () => {
+    updateExclusiveLabelEdit('.new-label');
+  });
+  $('.edit-label .label-name-input').on('input', () => {
+    updateExclusiveLabelEdit('.edit-label');
+  });
+  $('.edit-label .label-exclusive-input').on('change', () => {
+    updateExclusiveLabelEdit('.edit-label');
+  });
 }
diff --git a/web_src/js/features/repo-legacy.js b/web_src/js/features/repo-legacy.js
index 07c67ba5da..2cf4963b6a 100644
--- a/web_src/js/features/repo-legacy.js
+++ b/web_src/js/features/repo-legacy.js
@@ -110,35 +110,59 @@ export function initRepoCommentForm() {
       }
 
       hasUpdateAction = $listMenu.data('action') === 'update'; // Update the var
-      if ($(this).hasClass('checked')) {
-        $(this).removeClass('checked');
-        $(this).find('.octicon-check').addClass('invisible');
-        if (hasUpdateAction) {
-          if (!($(this).data('id') in items)) {
-            items[$(this).data('id')] = {
-              'update-url': $listMenu.data('update-url'),
-              action: 'detach',
-              'issue-id': $listMenu.data('issue-id'),
-            };
-          } else {
-            delete items[$(this).data('id')];
+
+      const clickedItem = $(this);
+      const scope = $(this).attr('data-scope');
+      const canRemoveScope = e.altKey;
+
+      $(this).parent().find('.item').each(function () {
+        if (scope) {
+          // Enable only clicked item for scoped labels
+          if ($(this).attr('data-scope') !== scope) {
+            return true;
           }
+          if ($(this).is(clickedItem)) {
+            if (!canRemoveScope && $(this).hasClass('checked')) {
+              return true;
+            }
+          } else if (!$(this).hasClass('checked')) {
+            return true;
+          }
+        } else if (!$(this).is(clickedItem)) {
+          // Toggle for other labels
+          return true;
         }
-      } else {
-        $(this).addClass('checked');
-        $(this).find('.octicon-check').removeClass('invisible');
-        if (hasUpdateAction) {
-          if (!($(this).data('id') in items)) {
-            items[$(this).data('id')] = {
-              'update-url': $listMenu.data('update-url'),
-              action: 'attach',
-              'issue-id': $listMenu.data('issue-id'),
-            };
-          } else {
-            delete items[$(this).data('id')];
+
+        if ($(this).hasClass('checked')) {
+          $(this).removeClass('checked');
+          $(this).find('.octicon-check').addClass('invisible');
+          if (hasUpdateAction) {
+            if (!($(this).data('id') in items)) {
+              items[$(this).data('id')] = {
+                'update-url': $listMenu.data('update-url'),
+                action: 'detach',
+                'issue-id': $listMenu.data('issue-id'),
+              };
+            } else {
+              delete items[$(this).data('id')];
+            }
+          }
+        } else {
+          $(this).addClass('checked');
+          $(this).find('.octicon-check').removeClass('invisible');
+          if (hasUpdateAction) {
+            if (!($(this).data('id') in items)) {
+              items[$(this).data('id')] = {
+                'update-url': $listMenu.data('update-url'),
+                action: 'attach',
+                'issue-id': $listMenu.data('issue-id'),
+              };
+            } else {
+              delete items[$(this).data('id')];
+            }
           }
         }
-      }
+      });
 
       // TODO: Which thing should be done for choosing review requests
       // to make chosen items be shown on time here?
diff --git a/web_src/js/features/repo-projects.js b/web_src/js/features/repo-projects.js
index f6d6c89816..534f517853 100644
--- a/web_src/js/features/repo-projects.js
+++ b/web_src/js/features/repo-projects.js
@@ -1,4 +1,5 @@
 import $ from 'jquery';
+import {useLightTextOnBackground} from '../utils.js';
 
 const {csrfToken} = window.config;
 
@@ -183,26 +184,13 @@ export function initRepoProject() {
 }
 
 function setLabelColor(label, color) {
-  const red = getRelativeColor(parseInt(color.slice(1, 3), 16));
-  const green = getRelativeColor(parseInt(color.slice(3, 5), 16));
-  const blue = getRelativeColor(parseInt(color.slice(5, 7), 16));
-  const luminance = 0.2126 * red + 0.7152 * green + 0.0722 * blue;
-
-  if (luminance > 0.179) {
-    label.removeClass('light-label').addClass('dark-label');
-  } else {
+  if (useLightTextOnBackground(color)) {
     label.removeClass('dark-label').addClass('light-label');
+  } else {
+    label.removeClass('light-label').addClass('dark-label');
   }
 }
 
-/**
- * Inspired by W3C recommendation https://www.w3.org/TR/WCAG20/#relativeluminancedef
- */
-function getRelativeColor(color) {
-  color /= 255;
-  return color <= 0.03928 ? color / 12.92 : ((color + 0.055) / 1.055) ** 2.4;
-}
-
 function rgbToHex(rgb) {
   rgb = rgb.match(/^rgba?\((\d+),\s*(\d+),\s*(\d+).*\)$/);
   return `#${hex(rgb[1])}${hex(rgb[2])}${hex(rgb[3])}`;