refactor: use history mechanism for block level navigation

core/modules/story.js

@@ -90,12 +90,12 @@ Story.prototype.saveStoryList = function(storyList) {
 	));
 };
 
-Story.prototype.addToHistory = function(navigateTo,navigateFromClientRect) {
+Story.prototype.addToHistory = function(navigateTo,fromPageRect,anchor) {
 	var titles = $tw.utils.isArray(navigateTo) ? navigateTo : [navigateTo];
 	// Add a new record to the top of the history stack
 	var historyList = this.wiki.getTiddlerData(this.historyTitle,[]);
 	$tw.utils.each(titles,function(title) {
-		historyList.push({title: title, fromPageRect: navigateFromClientRect});
+		historyList.push({title: title, fromPageRect: fromPageRect, anchor: anchor});
 	});
 	this.wiki.setTiddlerData(this.historyTitle,historyList,{"current-tiddler": titles[titles.length-1]});
 };

core/modules/storyviews/classic.js

@@ -26,13 +26,26 @@ ClassicStoryView.prototype.navigateTo = function(historyInfo) {
 	}
 	var listItemWidget = this.listWidget.children[listElementIndex],
 		targetElement = listItemWidget.findFirstDomNode();
+	// If anchor is provided, find the element the anchor pointing to
+	var foundAnchor = false;
+	if(targetElement && historyInfo.anchor) {
+		var anchorElement = targetElement.querySelector("[data-anchor-id='" + historyInfo.anchor + "']");
+		if(anchorElement) {
+			targetElement = anchorElement.parentNode;
+			var isBefore = anchorElement.dataset.anchorPreviousSibling === "true";
+			if(isBefore) {
+				targetElement = targetElement.previousSibling;
+			}
+			foundAnchor = true;
+		}
+	}
 	// Abandon if the list entry isn't a DOM element (it might be a text node)
 	if(!targetElement || targetElement.nodeType === Node.TEXT_NODE) {
 		return;
 	}
 	if(duration) {
 		// Scroll the node into view
-		this.listWidget.dispatchEvent({type: "tm-scroll", target: targetElement});
+		this.listWidget.dispatchEvent({type: "tm-scroll", target: targetElement, highlight: foundAnchor});
 	} else {
 		targetElement.scrollIntoView();
 	}

core/modules/utils/dom/scroller.js

@@ -49,7 +49,9 @@ Handle an event
 */
 PageScroller.prototype.handleEvent = function(event) {
 	if(event.type === "tm-scroll") {
-		var options = {};
+		var options = {
+			highlight: event.highlight,
+		};
 		if($tw.utils.hop(event.paramObject,"animationDuration")) {
 			options.animationDuration = event.paramObject.animationDuration;
 		}
@@ -65,14 +67,21 @@ PageScroller.prototype.handleEvent = function(event) {
 
 /*
 Handle a scroll event hitting the page document
+
+options:
+- animationDuration: total time of scroll animation
+- highlight: highlight the element after scrolling, to make it evident. Usually to focus an anchor in the middle of the tiddler.
 */
 PageScroller.prototype.scrollIntoView = function(element,callback,options) {
 	var self = this,
 		duration = $tw.utils.hop(options,"animationDuration") ? parseInt(options.animationDuration) : $tw.utils.getAnimationDuration(),
+		highlight = options.highlight || false,
 		srcWindow = element ? element.ownerDocument.defaultView : window;
 	// Now get ready to scroll the body
 	this.cancelScroll(srcWindow);
 	this.startTime = Date.now();
+	// toggle class to allow trigger the highlight animation
+	$tw.utils.removeClass(element,"tc-focus-highlight");
 	// Get the height of any position:fixed toolbars
 	var toolbar = srcWindow.document.querySelector(".tc-adjust-top-of-scroll"),
 		offset = 0;
@@ -121,6 +130,15 @@ PageScroller.prototype.scrollIntoView = function(element,callback,options) {
 			srcWindow.scrollTo(scrollPosition.x + (endX - scrollPosition.x) * t,scrollPosition.y + (endY - scrollPosition.y) * t);
 			if(t < 1) {
 				self.idRequestFrame = self.requestAnimationFrame.call(srcWindow,drawFrame);
+			} else {
+				// the animation is end.
+				if(highlight) {
+					element.focus({ focusVisible: true });
+					// Using setTimeout to ensure the removal takes effect before adding the class again.
+					setTimeout(function() {
+						$tw.utils.addClass(element,"tc-focus-highlight");
+					}, 50);
+				}
 			}
 		};
 	drawFrame();

core/modules/widgets/anchor.js

@@ -23,8 +23,9 @@ AnchorWidget.prototype.render = function(parent,nextSibling) {
 	this.idNode = this.document.createElement("span");
 	this.idNode.setAttribute("data-anchor-id",this.id);
 	this.idNode.setAttribute("data-anchor-title",this.tiddlerTitle);
-	if(this.before) {
-		this.idNode.setAttribute("data-before","true");
+	// if the actual block is before this node, we need to add a flag to the node
+	if(this.previousSibling) {
+		this.idNode.setAttribute("data-anchor-previous-sibling","true");
 	}
 	this.idNode.className = "tc-anchor";
 	parent.insertBefore(this.idNode,nextSibling);

core/modules/widgets/navigator.js

@@ -138,9 +138,10 @@ NavigatorWidget.prototype.addToStory = function(title,fromTitle) {
 Add a new record to the top of the history stack
 title: a title string or an array of title strings
 fromPageRect: page coordinates of the origin of the navigation
+anchor:optional anchor id in this tiddler
 */
-NavigatorWidget.prototype.addToHistory = function(title,fromPageRect) {
-	this.story.addToHistory(title,fromPageRect,this.historyTitle);
+NavigatorWidget.prototype.addToHistory = function(title,fromPageRect,anchor) {
+	this.story.addToHistory(title,fromPageRect,anchor);
 };
 
 /*
@@ -150,9 +151,8 @@ NavigatorWidget.prototype.handleNavigateEvent = function(event) {
 	event = $tw.hooks.invokeHook("th-navigating",event);
 	if(event.navigateTo) {
 		this.addToStory(event.navigateTo,event.navigateFromTitle);
-		event = $tw.hooks.invokeHook("th-navigating-add-history",event);
 		if(!event.navigateSuppressNavigation) {
-			this.addToHistory(event.navigateTo,event.navigateFromClientRect);
+			this.addToHistory(event.navigateTo,event.navigateFromClientRect,event.toAnchor);
 		}
 	}
 	$tw.hooks.invokeHook("th-navigated",event);