Introduce Story object

A lightweight object to encapsulate manipulation of the story and
history lists

core/modules/story.js

@@ -0,0 +1,136 @@
+/*\
+title: $:/core/modules/story.js
+type: application/javascript
+module-type: global
+
+Lightweight object for managing interactions with the story and history lists.
+
+\*/
+(function(){
+
+/*jslint node: true, browser: true */
+/*global $tw: false */
+"use strict";
+
+/*
+Construct Story object with options:
+wiki: reference to wiki object to use to resolve tiddler titles
+storyTitle: title of story list tiddler
+historyTitle: title of history list tiddler
+*/
+function Story(options) {
+	options = options || {};
+	this.wiki = options.wiki || $tw.wiki;
+	this.storyTitle = options.storyTitle || "$:/StoryList";
+	this.historyTitle = options.historyTitle || "$:/HistoryList";
+};
+
+Story.prototype.navigateTiddler = function(navigateTo,navigateFromTitle,navigateFromClientRect) {
+	this.addToStory(navigateTo,navigateFromTitle);
+	this.addToHistory(navigateTo,navigateFromClientRect);
+};
+
+Story.prototype.getStoryList = function() {
+	return this.wiki.getTiddlerList(this.storyTitle) || [];
+};
+
+Story.prototype.addToStory = function(navigateTo,navigateFromTitle,options) {
+	options = options || {};
+	var storyList = this.getStoryList();
+	// See if the tiddler is already there
+	var slot = storyList.indexOf(navigateTo);
+	// Quit if it already exists in the story river
+	if(slot >= 0) {
+		return;
+	}
+	// First we try to find the position of the story element we navigated from
+	var fromIndex = storyList.indexOf(navigateFromTitle);
+	if(fromIndex >= 0) {
+		// The tiddler is added from inside the river
+		// Determine where to insert the tiddler; Fallback is "below"
+		switch(options.openLinkFromInsideRiver) {
+			case "top":
+				slot = 0;
+				break;
+			case "bottom":
+				slot = storyList.length;
+				break;
+			case "above":
+				slot = fromIndex;
+				break;
+			case "below": // Intentional fall-through
+			default:
+				slot = fromIndex + 1;
+				break;
+		}
+	} else {
+		// The tiddler is opened from outside the river. Determine where to insert the tiddler; default is "top"
+		if(options.openLinkFromOutsideRiver === "bottom") {
+			// Insert at bottom
+			slot = storyList.length;
+		} else {
+			// Insert at top
+			slot = 0;
+		}
+	}
+	// Add the tiddler
+	storyList.splice(slot,0,navigateTo);
+	// Save the story
+	this.saveStoryList(storyList);
+};
+
+Story.prototype.saveStoryList = function(storyList) {
+	var storyTiddler = this.wiki.getTiddler(this.storyTitle);
+	this.wiki.addTiddler(new $tw.Tiddler(
+		{title: this.storyTitle},
+		storyTiddler,
+		{list: storyList}
+	));
+};
+
+Story.prototype.addToHistory = function(navigateTo,navigateFromClientRect) {
+	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});
+	});
+	this.wiki.setTiddlerData(this.historyTitle,historyList,{"current-tiddler": titles[titles.length-1]});
+};
+
+Story.prototype.storyCloseTiddler = function(targetTitle) {
+// TBD
+};
+
+Story.prototype.storyCloseAllTiddlers = function() {
+// TBD
+};
+
+Story.prototype.storyCloseOtherTiddlers = function(targetTitle) {
+// TBD
+};
+
+Story.prototype.storyEditTiddler = function(targetTitle) {
+// TBD
+};
+
+Story.prototype.storyDeleteTiddler = function(targetTitle) {
+// TBD
+};
+
+Story.prototype.storySaveTiddler = function(targetTitle) {
+// TBD
+};
+
+Story.prototype.storyCancelTiddler = function(targetTitle) {
+// TBD
+};
+
+Story.prototype.storyNewTiddler = function(targetTitle) {
+// TBD
+};
+
+exports.Story = Story;
+
+
+})();

core/modules/wiki.js

@@ -1175,14 +1175,8 @@ fromPageRect: page coordinates of the origin of the navigation
 historyTitle: title of history tiddler (defaults to $:/HistoryList)
 */
 exports.addToHistory = function(title,fromPageRect,historyTitle) {
-	historyTitle = historyTitle || "$:/HistoryList";
-	var titles = $tw.utils.isArray(title) ? title : [title];
-	// Add a new record to the top of the history stack
-	var historyList = this.getTiddlerData(historyTitle,[]);
-	$tw.utils.each(titles,function(title) {
-		historyList.push({title: title, fromPageRect: fromPageRect});
-	});
-	this.setTiddlerData(historyTitle,historyList,{"current-tiddler": titles[titles.length-1]});
+	var story = new $tw.Story({wiki: this, historyTitle: historyTitle});
+	story.addToHistory(title,fromPageRect);
 };
 
 /*