Add context menu 'delete' in editor for browsers without it

_locales/en/messages.json

@@ -191,6 +191,10 @@
     "message": "Enable",
     "description": "Label for the button to enable a style"
   },
+  "editDeleteText": {
+    "message": "Delete",
+    "description": "Label for the context menu item in the editor to delete selected text"
+  },
   "exportLabel": {
     "message": "Export",
     "description": "Label for the button to export a style ('edit' page) or all styles ('manage' page)"

background.js

@@ -116,6 +116,23 @@ const contextMenus = {
 	},
 };
 
+// detect browsers without Delete by looking at the end of UA string
+// Google Chrome: Safari/#
+// but skip CentBrowser: Safari/# plus Shockwave Flash in plugins
+// Vivaldi: Vivaldi/#
+if (/Vivaldi\/[\d.]+$/.test(navigator.userAgent)
+	|| /Safari\/[\d.]+$/.test(navigator.userAgent)
+	&& ![...navigator.plugins].some(p => p.name == 'Shockwave Flash')) {
+	contextMenus.editDeleteText = {
+		title: 'editDeleteText',
+		contexts: ['editable'],
+		documentUrlPatterns: [OWN_ORIGIN + 'edit*'],
+		click: (info, tab) => {
+			chrome.tabs.sendMessage(tab.id, {method: 'editDeleteText'});
+		},
+	};
+}
+
 chrome.contextMenus.onClicked.addListener((info, tab) =>
 	contextMenus[info.menuItemId].click(info, tab));
 

edit.js

@@ -325,6 +325,7 @@ function setupCodeMirror(textarea, index) {
 		hotkeyRerouter.setState(false);
 		cm.display.wrapper.classList.add("CodeMirror-active");
 	});
+	cm.on('mousedown', (cm, event) => toggleContextMenuDelete.call(cm, event));
 
 	var resizeGrip = cm.display.wrapper.appendChild(document.createElement("div"));
 	resizeGrip.className = "resize-grip";
@@ -1168,11 +1169,28 @@ function initHooks() {
 		document.querySelector("#lint h2").addEventListener("click", toggleLintReport);
 	}
 
+	document.querySelectorAll(
+		'input:not([type]), input[type="text"], input[type="search"], input[type="number"]')
+		.forEach(e => e.addEventListener('mousedown', toggleContextMenuDelete));
+
 	setupGlobalSearch();
 	setCleanGlobal();
 	updateTitle();
 }
 
+
+function toggleContextMenuDelete(event) {
+	if (event.button == 2) {
+		chrome.contextMenus.update('editDeleteText', {
+			enabled: Boolean(
+				this.selectionStart != this.selectionEnd ||
+				this.somethingSelected && this.somethingSelected()
+			),
+		});
+	}
+}
+
+
 function maximizeCodeHeight(sectionDiv, isLast) {
 	var cm = sectionDiv.CodeMirror;
 	var stats = maximizeCodeHeight.stats = maximizeCodeHeight.stats || {totalHeight: 0, deltas: []};
@@ -1662,6 +1680,10 @@ chrome.runtime.onMessage.addListener(function(request, sender, sendResponse) {
 			if (request.prefName == "editor.smartIndent") {
 				CodeMirror.setOption("smartIndent", request.value);
 			}
+			break;
+		case 'editDeleteText':
+			document.execCommand('delete');
+			break;
 	}
 });