Scoped label display and documentation tweaks (#23430) (#23433)

Backport #23430 by @brechtvl

* Fix scoped label left and right part breaking across lines.
* Remove slanted divider in scoped label display, make it straight.
After using this for a while, this feels more visually noisy than
helpful.
* Reduce contrast between scope and item to reduce probability of
unreadable text on background.
* Change documentation to remove mention of non-exclusive scoped labels.

Co-authored-by: Brecht Van Lommel <brecht@blender.org>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: John Olheiser <john.olheiser@gmail.com>

docs/content/doc/usage/labels.en-us.md

@@ -23,17 +23,15 @@ For repositories, labels can be created by going to `Issues` and clicking on `La
 
 For organizations, you can define organization-wide labels that are shared with all organization repositories, including both already-existing repositories as well as newly created ones. Organization-wide labels can be created in the organization `Settings`.
 
-Labels have a mandatory name, a mandatory color, an optional description, and must either be exclusive or not (see `Scoped labels` below).
+Labels have a mandatory name, a mandatory color, an optional description, and must either be exclusive or not (see `Scoped Labels` below).
 
 When you create a repository, you can ensure certain labels exist by using the `Issue Labels` option. This option lists a number of available label sets that are [configured globally on your instance](../customizing-gitea/#labels). Its contained labels will all be created as well while creating the repository.
 
 ## Scoped Labels
 
-A scoped label is a label that contains `/` in its name (not at either end of the name). For example labels `kind/bug` and `kind/enhancement` both have scope `kind`. Such labels will display the scope with slightly darker color.
+Scoped labels are used to ensure at most a single label with the same scope is assigned to an issue or pull request. For example, if labels `kind/bug` and `kind/enhancement` have the Exclusive option set, an issue can only be classified as a bug or an enhancement.
 
-The scope of a label is determined based on the **last** `/`, so for example the scope of label `scope/subscope/item` is `scope/subscope`.
-
-Scoped labels can be marked as exclusive. This ensures at most a single label with the same scope is assigned to an issue or pull request. For example, if `kind/bug` and `kind/enhancement` are marked exclusive, an issue can only be classified as a bug or an enhancement.
+A scoped label must contain `/` in its name (not at either end of the name). The scope of a label is determined based on the **last** `/`, so for example the scope of label `scope/subscope/item` is `scope/subscope`.
 
 ## Filtering by Label
 

modules/templates/helper.go

@@ -834,7 +834,7 @@ func RenderLabel(ctx context.Context, label *issues_model.Label) string {
 		// Make scope and item background colors slightly darker and lighter respectively.
 		// More contrast needed with higher luminance, empirically tweaked.
 		luminance := (0.299*r + 0.587*g + 0.114*b) / 255
-		contrast := 0.01 + luminance*0.06
+		contrast := 0.01 + luminance*0.03
 		// Ensure we add the same amount of contrast also near 0 and 1.
 		darken := contrast + math.Max(luminance+contrast-1.0, 0.0)
 		lighten := contrast + math.Max(contrast-luminance, 0.0)
@@ -859,12 +859,10 @@ func RenderLabel(ctx context.Context, label *issues_model.Label) string {
 
 	return fmt.Sprintf("<span class='ui label scope-parent' title='%s'>"+
 		"<div class='ui label scope-left' style='color: %s !important; background-color: %s !important'>%s</div>"+
-		"<div class='ui label scope-middle' style='background: linear-gradient(-80deg, %s 48%%, %s 52%% 0%%);'>&nbsp;</div>"+
 		"<div class='ui label scope-right' style='color: %s !important; background-color: %s !important''>%s</div>"+
 		"</span>",
 		description,
 		textColor, scopeColor, scopeText,
-		itemColor, scopeColor,
 		textColor, itemColor, itemText)
 }
 

web_src/less/_repository.less

@@ -2831,11 +2831,11 @@
 
 .labels-list .label {
   margin: 2px 0;
-  display: inline-block !important;
+  display: inline-flex !important;
   line-height: 1.3em; // there is a `font-size: 1.25em` for inside emoji, so here the line-height needs to be larger slightly
 }
 
-// Scoped labels with different colors on left and right, and slanted divider in the middle
+// Scoped labels with different colors on left and right
 .scope-parent {
   background: none !important;
   padding: 0 !important;
@@ -2844,23 +2844,12 @@
 .ui.label.scope-left {
   border-bottom-right-radius: 0;
   border-top-right-radius: 0;
-  padding-right: 0;
-  margin-right: 0;
-}
-
-.ui.label.scope-middle {
-  width: 12px;
-  border-radius: 0;
-  padding-left: 0;
-  padding-right: 0;
-  margin-left: 0;
   margin-right: 0;
 }
 
 .ui.label.scope-right {
   border-bottom-left-radius: 0;
   border-top-left-radius: 0;
-  padding-left: 0;
   margin-left: 0;
 }