Add banner for binary tiddlers in edit mode

Makes it easier to add tags to a binary tiddler (eg a PDF).

core/modules/widgets/edit-binary.js

@@ -0,0 +1,64 @@
+/*\
+title: $:/core/modules/widgets/edit-binary.js
+type: application/javascript
+module-type: widget
+
+Edit-binary widget; placeholder for editing binary tiddlers
+
+\*/
+(function(){
+
+/*jslint node: true, browser: true */
+/*global $tw: false */
+"use strict";
+
+var BINARY_WARNING_MESSAGE = "$:/core/ui/BinaryWarning";
+
+var Widget = require("$:/core/modules/widgets/widget.js").widget;
+
+var EditBinaryWidget = function(parseTreeNode,options) {
+	this.initialise(parseTreeNode,options);
+};
+
+/*
+Inherit from the base widget class
+*/
+EditBinaryWidget.prototype = new Widget();
+
+/*
+Render this widget into the DOM
+*/
+EditBinaryWidget.prototype.render = function(parent,nextSibling) {
+	var self = this;
+	// Save the parent dom node
+	this.parentDomNode = parent;
+	// Compute our attributes
+	this.computeAttributes();
+	// Execute our logic
+	this.execute();
+	this.renderChildren(parent,nextSibling);
+};
+
+/*
+Compute the internal state of the widget
+*/
+EditBinaryWidget.prototype.execute = function() {
+	// Construct the child widgets
+	this.makeChildWidgets([{
+		type: "transclude",
+		attributes: {
+			tiddler: {type: "string", value: BINARY_WARNING_MESSAGE}
+		}
+	}]);
+};
+
+/*
+Refresh by refreshing our child widget
+*/
+EditBinaryWidget.prototype.refresh = function(changedTiddlers) {
+	return this.refreshChildren(changedTiddlers);
+};
+
+exports["edit-binary"] = EditBinaryWidget;
+
+})();

core/modules/widgets/edit.js

@@ -56,7 +56,15 @@ EditWidget.prototype.execute = function() {
 	}
 	type = type || "text/vnd.tiddlywiki";
 	// Choose the appropriate edit widget
-	var editorType = this.wiki.getTiddlerText(EDITOR_MAPPING_PREFIX + type) || "text";
+	var editorType = this.wiki.getTiddlerText(EDITOR_MAPPING_PREFIX + type);
+	if(!editorType) {
+		var typeInfo = $tw.config.contentTypeInfo[type];
+		if(typeInfo && typeInfo.encoding === "base64") {
+			editorType = "binary";
+		} else {
+			editorType = "text";
+		}
+	}
 	// Make the child widgets
 	this.makeChildWidgets([{
 		type: "edit-" + editorType,