luci-base: ui.js: rework dropdown focus behavior

Drop mouse following focus behavior as it interferes with custom value inputs,
rely on CSS based hover effects instead.

Also slightly improve keyboard navigation by auto-focussing the custom value
input when entering the last dropdown choice via arrow down or tab key, and
by allowing to leave the text input again with the arrow up key.

Fixes: #6903
Signed-off-by: Jo-Philipp Wich <jo@mein.io>

modules/luci-base/htdocs/luci-static/resources/ui.js

@@ -1187,8 +1187,6 @@ var UIDropdown = UIElement.extend(/** @lends LuCI.ui.Dropdown.prototype */ {
 			window.addEventListener('touchstart', this.closeAllDropdowns);
 		}
 		else {
-			sb.addEventListener('mouseover', this.handleMouseover.bind(this));
-			sb.addEventListener('mouseout', this.handleMouseout.bind(this));
 			sb.addEventListener('focus', this.handleFocus.bind(this));
 
 			canary.addEventListener('focus', this.handleCanaryFocus.bind(this));
@@ -1340,7 +1338,8 @@ var UIDropdown = UIElement.extend(/** @lends LuCI.ui.Dropdown.prototype */ {
 		sb.insertBefore(pv, ul.nextElementSibling);
 
 		li.forEach(function(l) {
-			l.setAttribute('tabindex', 0);
+			if (!l.hasAttribute('unselectable'))
+				l.setAttribute('tabindex', 0);
 		});
 
 		sb.lastElementChild.setAttribute('tabindex', 0);
@@ -1581,20 +1580,6 @@ var UIDropdown = UIElement.extend(/** @lends LuCI.ui.Dropdown.prototype */ {
 		elem.focus();
 	},
 
-	/** @private */
-	handleMouseout: function(ev) {
-		var sb = ev.currentTarget;
-
-		if (!sb.hasAttribute('open'))
-			return;
-
-		sb.querySelectorAll('.focus').forEach(function(e) {
-			e.classList.remove('focus');
-		});
-
-		sb.querySelector('ul.dropdown').focus();
-	},
-
 	/** @private */
 	createChoiceElement: function(sb, value, label) {
 		var tpl = sb.querySelector(this.options.create_template),
@@ -1826,7 +1811,12 @@ var UIDropdown = UIElement.extend(/** @lends LuCI.ui.Dropdown.prototype */ {
 
 			case 40:
 				if (active && active.nextElementSibling) {
-					this.setFocus(sb, active.nextElementSibling);
+					var li = active.nextElementSibling;
+					this.setFocus(sb, li);
+					if (this.options.create && li == li.parentNode.lastElementChild) {
+						var input = li.querySelector('input');
+						if (input) input.focus();
+					}
 					ev.preventDefault();
 				}
 				else if (document.activeElement === ul) {
@@ -1857,19 +1847,6 @@ var UIDropdown = UIElement.extend(/** @lends LuCI.ui.Dropdown.prototype */ {
 		this.closeDropdown(sb, true);
 	},
 
-	/** @private */
-	handleMouseover: function(ev) {
-		var sb = ev.currentTarget;
-
-		if (!sb.hasAttribute('open'))
-			return;
-
-		var li = findParent(ev.target, 'li');
-
-		if (li && li.parentNode.classList.contains('dropdown'))
-			this.setFocus(sb, li);
-	},
-
 	/** @private */
 	handleFocus: function(ev) {
 		var sb = ev.currentTarget;
@@ -1888,7 +1865,8 @@ var UIDropdown = UIElement.extend(/** @lends LuCI.ui.Dropdown.prototype */ {
 	/** @private */
 	handleCreateKeydown: function(ev) {
 		var input = ev.currentTarget,
-		    sb = findParent(input, '.cbi-dropdown');
+		    li = findParent(input, 'li'),
+		    sb = findParent(li, '.cbi-dropdown');
 
 		switch (ev.keyCode) {
 		case 13:
@@ -1901,19 +1879,28 @@ var UIDropdown = UIElement.extend(/** @lends LuCI.ui.Dropdown.prototype */ {
 			input.value = '';
 			input.blur();
 			break;
+
+		case 38:
+			if (li.previousElementSibling) {
+				this.handleCreateBlur(ev);
+				this.setFocus(sb, li.previousElementSibling, true);
+			}
+			break;
 		}
 	},
 
 	/** @private */
 	handleCreateFocus: function(ev) {
 		var input = ev.currentTarget,
-		    cbox = findParent(input, 'li').querySelector('input[type="checkbox"]'),
+		    li = findParent(input, 'li'),
+		    cbox = li.querySelector('input[type="checkbox"]'),
 		    sb = findParent(input, '.cbi-dropdown');
 
 		if (cbox)
 			cbox.checked = true;
 
 		sb.setAttribute('locked-in', '');
+		this.setFocus(sb, li, true);
 	},
 
 	/** @private */