From 3d8ade3ebe6bf29a739f5a478594bec463a50a64 Mon Sep 17 00:00:00 2001
From: linonetwo <linonetwo012@gmail.com>
Date: Sat, 16 Sep 2023 04:45:07 +0800
Subject: [PATCH] feat: redirect tm-focus-selector event to check parent or
 sibling

---
 boot/boot.js                                  | 14 +++++++++
 .../parsers/wikiparser/rules/blockid.js       |  2 +-
 core/modules/startup/rootwidget.js            |  2 ++
 core/modules/widgets/blockid.js               | 29 +++++++++++++++++--
 core/modules/widgets/link.js                  |  8 +++++
 themes/tiddlywiki/vanilla/base.tid            | 13 +++++++++
 6 files changed, 65 insertions(+), 3 deletions(-)

diff --git a/boot/boot.js b/boot/boot.js
index 06d4628c0..2636cb8f4 100644
--- a/boot/boot.js
+++ b/boot/boot.js
@@ -2674,6 +2674,20 @@ $tw.hooks.addHook = function(hookName,definition) {
 	}
 };
 
+/*
+Delete hooks from the hashmap
+*/
+$tw.hooks.removeHook = function(hookName,definition) {
+	if($tw.utils.hop($tw.hooks.names,hookName)) {
+		var index = $tw.hooks.names[hookName].findIndex(function(hook) {
+			return hook === definition;
+		});
+		if(index !== -1) {
+			$tw.hooks.names[hookName].splice(index, 1);
+		}
+	}
+};
+
 /*
 Invoke the hook by key
 */
diff --git a/core/modules/parsers/wikiparser/rules/blockid.js b/core/modules/parsers/wikiparser/rules/blockid.js
index 84a0be41a..61438981b 100644
--- a/core/modules/parsers/wikiparser/rules/blockid.js
+++ b/core/modules/parsers/wikiparser/rules/blockid.js
@@ -39,7 +39,7 @@ exports.parse = function() {
 			id: {type: "string", value: blockId || blockBeforeId},
 			// `true` means the block is before this node, in parent node's children list.
 			// `false` means the block is this node's parent node.
-			before: {type: "boolean", value: Boolean(blockBeforeId)},
+			previousSibling: {type: "boolean", value: Boolean(blockBeforeId)},
 		},
 		children: []
 	}];
diff --git a/core/modules/startup/rootwidget.js b/core/modules/startup/rootwidget.js
index 716275cda..580c0e94d 100644
--- a/core/modules/startup/rootwidget.js
+++ b/core/modules/startup/rootwidget.js
@@ -72,6 +72,8 @@ exports.startup = function() {
 	});
 	// Install the tm-focus-selector message
 	$tw.rootWidget.addEventListener("tm-focus-selector",function(event) {
+		event = $tw.hooks.invokeHook("th-focus-selector",event);
+		if (!event) return;
 		var selector = event.param || "",
 			element,
 		    	baseElement = event.event && event.event.target ? event.event.target.ownerDocument : document;
diff --git a/core/modules/widgets/blockid.js b/core/modules/widgets/blockid.js
index e5902ee35..0d915ab7a 100644
--- a/core/modules/widgets/blockid.js
+++ b/core/modules/widgets/blockid.js
@@ -18,9 +18,13 @@ BlockIdWidget.prototype.render = function(parent,nextSibling) {
 	this.computeAttributes();
 	// Execute our logic
 	this.execute();
+	$tw.hooks.removeHook("th-focus-selector",this.hookFocusElementEvent);
+	this.hookFocusElementEvent = this.hookFocusElementEvent.bind(this);
+	$tw.hooks.addHook("th-focus-selector",this.hookFocusElementEvent);
 	// Create an invisible DOM element with data that can be accessed from JS or CSS
 	this.spanDomNode = this.document.createElement("span");
-	this.spanDomNode.setAttribute("data-id",this.id);
+	this.spanDomNode.id = this.id;
+	this.spanDomNode.setAttribute("data-block-id",this.id);
 	if(this.before) {
 		this.spanDomNode.setAttribute("data-before","true");
 	}
@@ -29,13 +33,34 @@ BlockIdWidget.prototype.render = function(parent,nextSibling) {
 	this.domNodes.push(this.spanDomNode);
 };
 
+BlockIdWidget.prototype.hookFocusElementEvent = function(event) {
+	var id = event.param.replace('#','');
+	if(id !== this.id) {
+		return event;
+	}
+	var element = this.parentDomNode;
+	// need to check if the block is before this node
+	if(this.previousSibling) {
+		element = element.previousSibling;
+	}
+	element.focus({ focusVisible: true });
+	// toggle class to trigger highlight animation
+	$tw.utils.removeClass(element,"tc-focus-highlight");
+	$tw.utils.addClass(element,"tc-focus-highlight");
+	return false;
+};
+
+BlockIdWidget.prototype.removeChildDomNodes = function() {
+	$tw.hooks.removeHook("th-focus-selector",this.hookFocusElementEvent);
+};
+
 /*
 Compute the internal state of the widget
 */
 BlockIdWidget.prototype.execute = function() {
 	// Get the id from the parse tree node or manually assigned attributes
 	this.id = this.getAttribute("id");
-	this.before = this.getAttribute("before");
+	this.previousSibling = this.getAttribute("previousSibling");
 	// Make the child widgets
 	this.makeChildWidgets();
 };
diff --git a/core/modules/widgets/link.js b/core/modules/widgets/link.js
index 6f199d395..12fc2da23 100755
--- a/core/modules/widgets/link.js
+++ b/core/modules/widgets/link.js
@@ -167,6 +167,13 @@ LinkWidget.prototype.handleClickEvent = function(event) {
 		shiftKey: event.shiftKey,
 		event: event
 	});
+	if(this.toBlockId) {
+		this.dispatchEvent({
+			type: "tm-focus-selector",
+			param: "#" + this.toBlockId,
+			event: event,
+		});
+	}
 	if(this.domNodes[0].hasAttribute("href")) {
 		event.preventDefault();
 	}
@@ -180,6 +187,7 @@ Compute the internal state of the widget
 LinkWidget.prototype.execute = function() {
 	// Pick up our attributes
 	this.to = this.getAttribute("to",this.getVariable("currentTiddler"));
+	this.toBlockId = this.getAttribute("toBlockId");
 	this.tooltip = this.getAttribute("tooltip");
 	this["aria-label"] = this.getAttribute("aria-label");
 	this.linkClasses = this.getAttribute("class");
diff --git a/themes/tiddlywiki/vanilla/base.tid b/themes/tiddlywiki/vanilla/base.tid
index 4603589ae..b7cb1a3fc 100644
--- a/themes/tiddlywiki/vanilla/base.tid
+++ b/themes/tiddlywiki/vanilla/base.tid
@@ -2413,6 +2413,19 @@ html body.tc-body.tc-single-tiddler-window {
 	color: <<colour alert-highlight>>;
 }
 
+@keyframes fadeHighlight {
+	0% {
+		background-color: <<colour highlight-background>>;
+	}
+	100% {
+		background-color: transparent;
+	}
+}
+
+.tc-focus-highlight {
+	animation: fadeHighlight 2s forwards;
+}
+
 @media (min-width: <<sidebarbreakpoint>>) {
 
 	.tc-static-alert {