fixed :open completions for slow computers. We now yield

incremental results, and the user gets more completion, the more often
he presses tab. Need to find out, how to change the "Waiting..." message
to "More results...". Also reminds me, how ugly the completion context
code is partly. We should try to clean it up and remove/merge useless
function to make it's interface smaller and more side-effect free.

common/content/completion.js

@@ -528,7 +528,9 @@ CompletionContext.prototype = {
 
     cancelAll: function ()
     {
-        for (let [,context] in Iterator(this.contextList))
+        // Kris: contextList gives undefined. And why do we have contexts and contextList?
+        // I am not too much of a fan of a huge API for classes
+        for (let [,context] in Iterator(this.top.contexts))
         {
             if (context.cancel)
                 context.cancel();
@@ -1576,6 +1578,7 @@ function Completion() //{{{
             context.filterFunc = null;
             context.cancel = function () services.get("autoCompleteSearch").stopSearch();
             context.compare = null;
+            // TODO: shouldn't this timer be deleted by context.cancel?
             let timer = new Timer(50, 100, function (result) {
                 context.incomplete = result.searchResult >= result.RESULT_NOMATCH_ONGOING;
                 context.completions = [
@@ -1583,16 +1586,28 @@ function Completion() //{{{
                         for (i in util.range(0, result.matchCount))
                 ];
             });
-            services.get("autoCompleteSearch").stopSearch();
+            context.generate = function () {
-            services.get("autoCompleteSearch").startSearch(context.filter, "", context.result, {
+                let minItems = context.minItems || 1;
-                onSearchResult: function onSearchResult(search, result)
+                services.get("autoCompleteSearch").stopSearch();
-                {
+                services.get("autoCompleteSearch").startSearch(context.filter, "", context.result, {
-                    context.result = result;
+                    onSearchResult: function (search, result)
-                    timer.tell(result);
+                    {
-                    if (result.searchResult <= result.RESULT_SUCCESS)
+                        context.result = result;
-                        timer.flush();
+                        timer.tell(result);
-                }
+                        if (result.searchResult <= result.RESULT_SUCCESS)
-            });
+                            timer.flush();
+                    }
+                });
+
+                let end = Date.now() + 5000;
+                while (context.incomplete && context.completions.length < minItems && Date.now() < end)
+                    liberator.threadYield(false, true);
+
+                // context.message = "More results..."; // very very strange, if I enable this line, completions don't work;
+                services.get("autoCompleteSearch").stopSearch();
+
+                return context.completions;
+            }
         },
 
         macro: function macro(context)

common/content/liberator.js

@@ -1362,6 +1362,7 @@ const liberator = (function () //{{{
                 callback.call(self);
         },
 
+        // TODO: interruptable not used?
         threadYield: function (flush, interruptable)
         {
             let mainThread = services.get("threadManager").mainThread;

common/content/ui.js

@@ -336,7 +336,7 @@ function CommandLine() //{{{
                     else
                         idx = this.selected + 1;
                     break;
-                case this.RESET:
+                case this.RESET: // TODO: never used for now
                     idx = null;
                     break;
                 default:
@@ -360,22 +360,37 @@ function CommandLine() //{{{
         tab: function tab(reverse)
         {
             autocompleteTimer.flush();
+
             // Check if we need to run the completer.
+            let numElementsNeeded;
+            if (this.selected == null)
+                numElementsNeeded = reverse ? 100000 : 1; // better way to specify give me all items than setting to a very large number?
+            else
+                numElementsNeeded = reverse ? this.selected : this.selected + 2; // this.selected is zero-based
+
             if (this.context.waitingForTab || this.wildIndex == -1)
-                this.complete(true, true);
-
-            // Would prefer to only do this check when no completion
-            // is available, but there are complications.
-            if (this.items.length == 0 || this.context.incomplete)
             {
-                // No items. Wait for any unfinished completers.
+                this.complete(true, true);
-                let end = Date.now() + 5000;
-                while (this.context.incomplete && /* this.items.length == 0 && */ Date.now() < end)
-                    liberator.threadYield(true, true);
-
-                if (this.items.length == 0)
-                    return liberator.beep();
             }
+            else if (this.context.incomplete && numElementsNeeded > this.items.length)
+            {
+                for (let [, context] in Iterator(this.context.contexts))
+                {
+                    if (context.incomplete && context.generate)
+                    {
+                        // regenerate twice as many items as needed, as regenerating
+                        // to often looks visually bad
+                        context.minItems = numElementsNeeded * 2; // TODO: document minItems, or find a better way
+                        context.regenerate = true;
+                        context._generate(); // HACK
+                    }
+                    if (this.items.length >= numElementsNeeded)
+                        break;
+                }
+            }
+
+            if (this.items.length == 0)
+                return liberator.beep();
 
             switch (this.wildtype.replace(/.*:/, ""))
             {
@@ -1435,11 +1450,9 @@ function CommandLine() //{{{
         {
             autocompleteTimer.reset();
 
-            // liberator.dump("Resetting completions...");
             if (completions)
             {
                 completions.context.cancelAll();
-
                 completions.wildIndex = -1;
                 completions.previewClear();
             }