minibar: remember current input

If you leave the minibar and later return, the previous input will be
restored. One input string per grammar is rememebered, so you can also switch
back and forth between grammars without losing the input.
This is implemented using localStorage, i.e. the data is stored locally on
the user's device.

1 files changed, 54 insertions, 14 deletions

diff --git a/src/www/minibar/minibar_input.js b/src/www/minibar/minibar_input.js
index ece9c2b3c..f96137c22 100644
--- a/src/www/minibar/minibar_input.js
+++ b/src/www/minibar/minibar_input.js
@@ -43,16 +43,18 @@ function Input(server,translations,opts) { // Input object constructor
     this.previous=null;
 
     this.from_menu.onchange=bind(this.change_language,this);
-    this.startcat_menu.onchange=bind(this.clear_all,this);
+    this.startcat_menu.onchange=bind(this.change_startcat,this);
 }
 
 Input.prototype.change_grammar=function (grammar) {
+    var t=this;
     grammar.browse={} // for caching output from the browse command
-    this.grammar=grammar;
-    update_language_menu(this.from_menu,grammar);
-    set_initial_language(this.options,this.from_menu,grammar);
-    this.update_startcat_menu(grammar)
-    this.change_language();
+    t.grammar=grammar;
+    t.local=mi_local(t.server.current_grammar_url)
+    update_language_menu(t.from_menu,grammar);
+    set_initial_language(t.options,t.from_menu,grammar,t.local.get("from"));
+    t.update_startcat_menu(grammar)
+    t.change_language();
 }
 
 Input.prototype.update_startcat_menu=function (grammar) {
@@ -60,22 +62,34 @@ Input.prototype.update_startcat_menu=function (grammar) {
     menu.innerHTML="";
     var cats=grammar.categories;
     for(var cat in cats) menu.appendChild(option(cats[cat],cats[cat]))
-    if(grammar.startcat) menu.value=grammar.startcat;
+    var startcat=this.local.get("startcat") || grammar.startcat;
+    if(startcat) menu.value=startcat;
     else {
 	insertFirst(menu,option("Default",""));
 	menu.value="";
     }
 }
 
+Input.prototype.change_startcat=function () {
+    this.local.put("startcat",this.startcat_menu.value)
+    this.clear_all();
+}
+
 Input.prototype.change_language=function () {
     this.current.from=this.from_menu.value;
-    this.clear_all();
+    this.local.put("from",this.current.from)
+    var old_current=this.local.get("current");
+    var new_input= old_current && old_current.from==this.current.from
+	           ? old_current.input : ""
+    this.clear_all1();
+    this.add_words(new_input)
 }
 
 
 Input.prototype.clear_all2=function() {
     with(this) {
 	current.input="";
+	local.put("current",current)
 	previous=null;
 	clear(surface)
 	if(surface.typed) surface.appendChild(surface.typed)
@@ -92,10 +106,8 @@ Input.prototype.clear_all1=function() {
 }
 
 Input.prototype.clear_all=function() {
-    with(this) {
-	clear_all1();
-	get_completions();
-    }
+    this.clear_all1();
+    this.get_completions();
 }
 
 Input.prototype.get_completions=function() {
@@ -271,6 +283,7 @@ Input.prototype.add_word1=function(s) {
     with(this) {
 	previous={ input: current.input, previous: previous };
 	current.input+=s;
+	local.put("current",current)
 	var w=span_class("word",text(s));
 	if(surface.typed) surface.insertBefore(w,surface.typed);
 	else surface.appendChild(w);
@@ -283,6 +296,7 @@ Input.prototype.delete_last=function() {
 	    surface.typed.value="";
 	else if(previous) {
 	    current.input=previous.input;
+	    local.put("current",current)
 	    previous=previous.previous;
 	    if(surface.typed) {
 		surface.removeChild(surface.typed.previousSibling);
@@ -431,8 +445,34 @@ Input.prototype.browse=function(id,cont) {
 
 /* --- Auxiliary functions -------------------------------------------------- */
 
-function set_initial_language(options,menu,grammar) {
-    if(grammar.userLanguage) menu.value=grammar.userLanguage;
+
+function mi_local(grammar_url) {
+    function dummy() {
+	return {
+	    get: function(name,def) { return def },
+	    put: function(name,value) { }
+	}
+    }
+    function real() {
+	var prefix="gf.minibar_input."+grammar_url+"."
+	return {
+	    get: function (name,def) {
+		var id=prefix+name
+		return localStorage[id] ? JSON.parse(localStorage[id]) : def;
+	    },
+	    put: function (name,value) {
+		var id=prefix+name;
+		localStorage[id]=JSON.stringify(value);
+	    }
+	}
+    }
+    return window.localStorage ? real() : dummy()
+}
+
+
+function set_initial_language(options,menu,grammar,old_from) {
+    var user_from=old_from || grammar.userLanguage;
+    if(user_from) menu.value=user_from; // !! What if the language was removed?
     else if(options.default_source_language) {
 	for(var i=0;i<menu.options.length;i++) {
 	    var o=menu.options[i].value;