XMerge branch 'master' of ssh://212.235.189.51:22122/codeq-web

7 files changed, 503 insertions, 452 deletions

diff --git a/css/codeq/console.css b/css/codeq/console.css
index 2f5e9cf..c8dd9fd 100644
--- a/css/codeq/console.css
+++ b/css/codeq/console.css
@@ -8,7 +8,7 @@
     background-color: transparent;
     border: none;
     color: inherit;
-    line-height: inherit;
+    line-height: normal;
     margin: 0;
     padding: 0;
 }
diff --git a/index.html b/index.html
index 9a5559b..5ca650a 100644
--- a/index.html
+++ b/index.html
@@ -132,6 +132,7 @@
         <script src="js/codeq/stateMachine.js"></script>
         <script src="js/codeq/comms.js"></script>
         <script src="js/codeq/console.js"></script>
+        <script src="js/codeq/hint.js"></script>
         <script src="js/def_parser.js"></script>
         <!-- <script src="js/codeq/prologPythonLib.js"></script> -->
         <script src="js/codeq/prolog.js"></script>
diff --git a/js/codeq/console.js b/js/codeq/console.js
index 99c1550..57d5a07 100644
--- a/js/codeq/console.js
+++ b/js/codeq/console.js
@@ -160,7 +160,7 @@
     };
 
     codeq.makeConsole = function (jqElt, options) {
-        var lines = [], // console content
+        var lines = [],// console content, line descriptors of the form {'content': 'string', 'classNames': [], 'jqLine': jQuery object, 'row': number}
             maxLines = (options && options.maxLines) || 10000, // how many lines to display at most
             currentRow = 0, // cursor position
             currentCol = 0,
@@ -169,14 +169,72 @@
             inputDisabled = false, // whether to ignore input
             lineBuffered = true, // whether we are line-buffered or not buffered
 
+            renderSpan = function (lineDescriptor, startCol, length) {
+                var jqLine = lineDescriptor.jqLine,
+                    content = lineDescriptor.content,
+                    classes = lineDescriptor.classNames,
+                    endCol = startCol + length,
+                    N = classes ? classes.length : 0,
+                    i = 0,
+                    spans = [], // what to render, items are of the form {'content': string, 'cssClass': string}
+                    entry, classSpan, jq, span, s, prefixDelta, suffixDelta, e;
+                // seek out the first css class
+                while (i < N) {
+                    entry = classes[i];
+                    if (((entry.start + entry.length) > startCol) && (entry.start < endCol)) break;
+                    i++;
+                }
+                if (i < N) {
+                    // render the first span
+                    e = entry.start + entry.length; // end column of this css class
+                    prefixDelta = entry.start < startCol ? startCol - entry.start : 0;
+                    suffixDelta = e > endCol ? e - endCol : 0;
+                    classSpan = entry.length - prefixDelta - suffixDelta;
+                    span = {'content': content.substr(startCol, classSpan), 'cssClass': entry.name};
+                    spans.push(span);
+                    startCol += classSpan;
+                    i++;
+                    // render the rest
+                    while ((startCol < endCol) && (i < N)) {
+                        entry = classes[i];
+                        e = entry.start + entry.length; // end column of this css class
+                        prefixDelta = entry.start < startCol ? startCol - entry.start : 0;
+                        suffixDelta = e > endCol ? e - endCol : 0;
+                        classSpan = entry.length - prefixDelta - suffixDelta;
+                        s = content.substr(startCol, classSpan);
+                        if (entry.name === span.cssClass) {
+                            span.content += s; // join content where the class is the same
+                        }
+                        else {
+                            span = {'content': s, 'cssClass': entry.name};
+                            spans.push(span);
+                        }
+                        startCol += classSpan;
+                        i++;
+                    }
+                }
+                // render any leftover
+                if (startCol < endCol) {
+                    entry = makeClassDescriptor('', startCol, endCol - startCol);
+                    spans.push({'content': content.substring(startCol, endCol), 'cssClass': ''});
+                }
+                // render spans
+                for (i = 0; i < spans.length; i++) {
+                    span = spans[i];
+                    jq = $('<span class="cq-con-text ' + span.cssClass + '"></span>');
+                    jqLine.append(jq);
+                    jq.text(span.content);
+                }
+                return entry; // return the last entry used
+            },
+
             renderLine = function (lineDescriptor) {
                 var jqLine = lineDescriptor.jqLine,
-                    className = 'cq-con-text ' + lineDescriptor.className,
-                    content = lineDescriptor.content || '',
-                    jq1, jq2, jqCursor;
+                    content = lineDescriptor.content,
+                    jqCursor, classDescriptor;
 
                 if (!jqLine) {
-                    jqLine = $('<pre class="cq-con-line ' + lineDescriptor.className + '"></pre>');
+                    jqLine = $('<pre class="cq-con-line"></pre>');
                     if (lineDescriptor.row == 0) {
                         jqContent.prepend(jqLine);
                     }
@@ -196,36 +254,30 @@
                 if (currentRow == lineDescriptor.row) {
                     // mark the cursor in the current line
                     if (currentCol >= content.length) {
-                        jq1 = $('<span class="' + className + '"></span>');
+                        // cursor after the last character
+                        renderSpan(lineDescriptor, 0, content.length);
                         jqCursor = $('<span class="cq-con-cursor">&nbsp;</span>');
-                        jqLine.append(jq1);
                         jqLine.append(jqCursor);
-                        jq1.text(content);
                     }
                     else if (currentCol <= 0) {
-                        jq2 = $('<span class="' + className + '"></span>');
-                        jqCursor = $('<span class="cq-con-cursor"></span>');
+                        // cursor at the first character
+                        classDescriptor = lineDescriptor.classNames[0] || makeClassDescriptor('', 0, content.length);
+                        jqCursor = $('<span class="cq-con-cursor ' + classDescriptor.name + '"></span>');
                         jqLine.append(jqCursor);
-                        jqLine.append(jq2);
                         jqCursor.text(content.charAt(0));
-                        jq2.text(content.substr(1));
+                        renderSpan(lineDescriptor, 1, content.length - 1);
                     }
                     else {
-                        jq1 = $('<span class="' + className + '"></span>');
-                        jq2 = $('<span class="' + className + '"></span>');
-                        jqCursor = $('<span class="cq-con-cursor"></span>');
-                        jqLine.append(jq1);
+                        // cursor somewhere in between
+                        classDescriptor = renderSpan(lineDescriptor, 0, currentCol);
+                        jqCursor = $('<span class="cq-con-cursor ' + classDescriptor.name + '"></span>');
                         jqLine.append(jqCursor);
-                        jqLine.append(jq2);
-                        jq1.text(content.substr(0, currentCol));
                         jqCursor.text(content.charAt(currentCol));
-                        jq2.text(content.substr(currentCol + 1));
+                        renderSpan(lineDescriptor, currentCol + 1, content.length - currentCol - 1);
                     }
                 }
                 else {
-                    jq1 = $('<span class="' + className + '"></span>');
-                    jqLine.append(jq1);
-                    jq1.text(lineDescriptor.content);
+                    renderSpan(lineDescriptor, 0, content.length);
                 }
             },
 
@@ -259,6 +311,126 @@
                 return newLines;
             },
 
+            makeClassDescriptor = function (name, start, length) {
+                return {'name': name, 'start': start, 'length': length};
+            },
+
+            indexOfClassAtOrAfterColumn = function (classes, col) {
+                var N = classes.length,
+                    i;
+                for (i = 0; i < N; i++) {
+                    if (classes[i].start >= col) return i;
+                }
+                return N;
+            },
+
+            insertClass = function (classes, newClassName, startingCol, length) {
+                var newEntry = makeClassDescriptor(newClassName, startingCol, length),
+                    endCol = startingCol + length,
+                    i, N, prevClass, pos, auxEntry, delta;
+                // seek out the position where to insert the new class
+                i = indexOfClassAtOrAfterColumn(classes, startingCol);
+                prevClass = i > 0 ? classes[i-1] : null;
+                // insert the new class
+                classes.splice(i, 0, newEntry);
+                // if needed, adjust the length of the previous class
+                if (prevClass) {
+                    pos = prevClass.start + prevClass.length;
+                    if (pos > startingCol) {
+                        // split the previous class in two, the new class gets inserted in between
+                        delta = pos - startingCol;
+                        auxEntry = makeClassDescriptor(prevClass.name, endCol, delta);
+                        classes.splice(i+1, 0, auxEntry);
+                        prevClass.length = prevClass.length - delta;
+                    }
+                }
+                // readjust positions of the classes after the new one
+                N = classes.length;
+                for (i++; i < N; i++) {
+                    auxEntry = classes[i];
+                    auxEntry.start = endCol;
+                    endCol += auxEntry.length;
+                }
+            },
+
+            removeClasses = function (classes, startCol, length) {
+                var i, entry, endCol, e, prefixDelta, suffixDelta, N;
+                if (!length) return;
+                endCol = startCol + length;
+                for (i = classes.length - 1; i >= 0; i--) {
+                    entry = classes[i];
+                    e = entry.start + entry.length;
+                    if ((e > startCol) && (entry.start < endCol)) {
+                        prefixDelta = entry.start < startCol ? startCol - entry.start : 0;
+                        suffixDelta = e > endCol ? e - endCol : 0;
+                        if ((prefixDelta == 0) && (suffixDelta == 0)) classes.splice(i, 1);
+                        else entry.length = prefixDelta + suffixDelta;
+                    }
+                }
+                // readjust positions
+                N = classes.length;
+                endCol = 0;
+                for (i = 0; i < N; i++) {
+                    entry = classes[i];
+                    entry.start = endCol;
+                    endCol += entry.length;
+                }
+            },
+
+            removeClassesBefore = function (classes, col) {
+                var i = indexOfClassAtOrAfterColumn(classes, col);
+                if (i == 0) return; // nothing to remove
+                classes.splice(0, i);
+            },
+
+            replaceClassesBeforeColumn = function (classes, col, newClassName, newLength) {
+                var i = indexOfClassAtOrAfterColumn(classes, col),
+                    newEntry = makeClassDescriptor(newClassName, 0, newLength);
+                classes.splice(0, i, newEntry);
+            },
+
+            classesBetween = function (classes, startCol, endCol) {
+                var N = classes.length,
+                    result = [],
+                    i, e, entry, prefixDelta, suffixDelta;
+                for (i = 0; i < N; i++) {
+                    entry = classes[i];
+                    e = entry.start + entry.length; // end column of this css class
+                    if ((e > startCol) && (entry.start < endCol)) {
+                        prefixDelta = entry.start < startCol ? startCol - entry.start : 0;
+                        suffixDelta = e > endCol ? e - endCol : 0;
+                        result.push(makeClassDescriptor(entry.name, entry.start + prefixDelta, entry.length - prefixDelta - suffixDelta));
+                    }
+                }
+                return result;
+            },
+
+            mergeClasses = function () {
+                var result = [],
+                    i, arg, j, entry, endCol;
+                for (i = 0; i < arguments.length; i++) {
+                    arg = arguments[i];
+                    if (arg instanceof Array) {
+                        for (j = 0; j < arg.length; j++) result.push(arg[j]);
+                    }
+                    else result.push(arg);
+                }
+                // adjust positions of css classes
+                endCol = 0;
+                for (i = 0; i < result.length; i++) {
+                    entry = result[i];
+                    entry.start = endCol;
+                    endCol += entry.length;
+                }
+                return result;
+            },
+
+            scrollCursorIntoView = function () {
+                var dh = jqContent.height() - jqElt.height();
+                if (dh > 0)
+                    jqElt.scrollTop(dh);
+            },
+
             // the handler object that is returned
             handler = {
                 'setLineBuffered': function () { lineBuffered = true; },
@@ -309,14 +481,15 @@
 
                 'insertRow': function (row, content, className, deferReflow) {
                     // inserts a new row at the position specified
-                    var lineDescriptor, i, jqLine;
+                    var lineDescriptor, i;
+                    if (!className) className = 'output';
                     for (i = lines.length; i < row; i++) {
                         // insert any empty rows
-                        lineDescriptor = {content: '', className: className, row: i};
+                        lineDescriptor = {content: '', classNames: [], row: i};
                         lines.push(lineDescriptor);
                         if (!deferReflow) renderLine(lineDescriptor);
                     }
-                    lineDescriptor = {content: content, className: className, row: row};
+                    lineDescriptor = {content: content, classNames: content.length > 0 ? [makeClassDescriptor(className, 0, content.length)] : [], row: row};
                     if (row >= lines.length) lines.push(lineDescriptor);
                     else lines.splice(row, 0, lineDescriptor);
                     if (!deferReflow) this.reflow(row);
@@ -324,7 +497,7 @@
                 },
 
                 'splice': function (startRow, startCol, endRow, endCol, newText, className) {
-                    var i, j, n, startLine, endLine, newLines, newTextLines, part1, part2;
+                    var i, j, n, startLine, endLine, newLines, part1, part2, s, auxLine;
 
                     if (!className) className = 'output';
                     // pre-process newText, convert it to newLines: an array of strings without newlines
@@ -370,19 +543,25 @@
                         if (newLines.length > 1) {
                             // the first and the last new lines are separate existing lines, modify them
                             startLine.content = part1 + newLines[0];
+                            startLine.classNames = mergeClasses(classesBetween(startLine.classNames, 0, part1.length), makeClassDescriptor(className, part1.length, newLines[0].length));
                             if (startRow == endRow) {
                                 // we need to create one additional line to hold the compositum of the last line and part2
-                                this.insertRow(j, newLines[newLines.length - 1] + part2, className, true);
+                                auxLine = this.insertRow(j, newLines[newLines.length - 1], className, true);
+                                insertClass(auxLine.classNames, auxLine.content.length, part2.length);
+                                auxLine.content = auxLine.content + part2;
                                 j++;
                             }
                             else {
-                                endLine.content = newLines[newLines.length - 1] + part2;
+                                s = newLines[newLines.length - 1];
+                                endLine.content = s + part2;
+                                replaceClassesBeforeColumn(endLine.classNames, endCol, className, s.length);
                                 n--; // retain the last line
                             }
                         }
                         else {
                             // the first and the last new lines are the same existing line
                             startLine.content = part1 + newLines[0] + part2;
+                            startLine.classNames = mergeClasses(classesBetween(startLine.classNames, 0, part1.length), makeClassDescriptor(className, part1.length, newLines[0].length), classesBetween(endLine.classNames, endCol, endCol + part2.length));
                         }
                         // remove the rest of the old lines
                         while (n > 0) {
@@ -422,7 +601,9 @@
                         startRow = lines.length - 1,
                         i, lineDescriptor;
                     if (newLines.length == 0) return; // nothing to do
+                    if (typeof className !== 'string') className = 'output';
                     lineDescriptor = lines[startRow];
+                    insertClass(lineDescriptor.classNames, className, lineDescriptor.content.length, newLines[0].length);
                     lineDescriptor.content = lineDescriptor.content + newLines[0];
                     for (i = 1; i < newLines.length; i++) {
                         lineDescriptor = this.insertRow(startRow + i, newLines[i], className, true);
@@ -441,20 +622,25 @@
                         part1 = currentContent.substring(0, currentCol),
                         part2 = currentContent.substring(currentCol),
                         newLines = formNewLines(text),
-                        i, n;
+                        i, n, auxLine;
+                    if (typeof className !== 'string') className = 'output';
                     if (newLines.length == 0) return; // nothing to do
                     else if (newLines.length == 1) {
+                        insertClass(currentLine.classNames, className, part1.length, newLines[0].length);
                         currentLine.content = part1 + newLines[0] + part2;
                         if (!dontMoveCursor) currentCol += newLines[0].length;
                         renderLine(currentLine);
                     }
                     else {
+                        currentLine.classNames = mergeClasses(classesBetween(currentLine.classNames, 0, part1.length), makeClassDescriptor(className, part1.length, newLines[0].length));
                         currentLine.content = part1 + newLines[0];
                         n = newLines.length - 1;
                         for (i = 1; i < n; i++) {
                             this.insertRow(startRow + i, newLines[i], className, true);
                         }
-                        this.insertRow(startRow + n, newLines[n] + part2, className, true);
+                        auxLine = this.insertRow(startRow + n, newLines[n], className, true);
+                        insertClass(auxLine.classNames, auxLine.content.length, part2.length);
+                        auxLine.content = auxLine.content + part2;
                         if (!dontMoveCursor) {
                             currentRow = startRow + n;
                             currentCol = newLines[n].length;
@@ -485,6 +671,7 @@
                         leftmost = typeof this.leftmostCol === 'number' && this.leftmostCol || 0;
                     if ((currentCol > leftmost) && (currentCol <= content.length)) {
                         currentCol--;
+                        removeClasses(lineDescriptor.classNames, currentCol, 1);
                         lineDescriptor.content = content.substring(0, currentCol) + content.substring(currentCol + 1);
                         renderLine(lineDescriptor);
                     }
@@ -494,6 +681,7 @@
                     var lineDescriptor = lines[currentRow],
                         content = lineDescriptor.content;
                     if ((currentCol >= 0) && (currentCol < content.length)) {
+                        removeClasses(lineDescriptor.classNames, currentCol, 1);
                         lineDescriptor.content = content.substring(0, currentCol) + content.substring(currentCol + 1);
                         renderLine(lineDescriptor);
                     }
@@ -554,10 +742,8 @@
 
             handleInput = function (chars) {
                 var isPastedFromClipboard = clipboardPasteInProgress || !aKeyIsDown,
-                    newLines = chars.split('\n'),
-                    N = newLines.length,
-                    lastLineIndex = N - 1,
-                    i, promise;
+                    cookedChars = chars, // the default
+                    cookedPromise, cookedLines, lastCookedLineIndex, i;
 
                 if (inputDisabled || internallyDisabled) {
                     // flatly ignore
@@ -566,69 +752,70 @@
                 }
 
                 internallyDisabled = true;
-                promise = Q();
+                cookedPromise = Q();
 
-                for (i = 0; i < N; i++) {
-                    promise = promise
-                        .then((function (newLine, lineIndex) {return function () {
-                            var cookedChars = lineIndex < lastLineIndex ? newLine + '\n' : newLine, // default
-                                thisRow = currentRow,
-                                leftmost = typeof handler.leftmostCol === 'number' && handler.leftmostCol || 0,
-                                dh;
-
-                            // first cook the input
-                            if (typeof handler.onKeypress === 'function') {
-                                // only invoke the handler if the newLine is not an empty string, otherwise cookedChars = ''
-                                try {
-                                    cookedChars = cookedChars && handler.onKeypress(cookedChars, isPastedFromClipboard);
-                                }
-                                catch (e) {
-                                    codeq.log.error('Error during invocation of terminal onKeypress: ' + e, e);
-                                }
-                            }
+                // first cook the input
+                if (typeof handler.onKeypress === 'function') {
+                    // only invoke the handler if the newLine is not an empty string, otherwise cookedChars = ''
+                    try {
+                        cookedChars = cookedChars && handler.onKeypress(cookedChars, isPastedFromClipboard);
+                    }
+                    catch (e) {
+                        codeq.log.error('Error during invocation of terminal onKeypress: ' + e, e);
+                    }
+                }
 
-                            if (!cookedChars) {
-                                // nothing to append
-                                return;
-                            }
+                if (typeof cookedChars !== 'string') cookedLines = [''];
+                else cookedLines = cookedChars.split('\n');
+                lastCookedLineIndex = cookedLines.length - 1;
+
+                // now serve the cooking
+                for (i = 0; i <= lastCookedLineIndex; i++) {
+                    cookedPromise = cookedPromise
+                        .then(scrollCursorIntoView) // scroll to bottom on input
+                        .then((function (cookedLine, cookedLineIndex) {return function () {
+                            var thisRow = currentRow,
+                                leftmost = typeof handler.leftmostCol === 'number' && handler.leftmostCol || 0;
+
+                                if (cookedLine) handler.insertAtCursor(cookedLine, 'input'); // append what we have to the display
+                                if (cookedLineIndex < lastCookedLineIndex) {
+                                    // press on "enter" must be simulated -> jump to the start of the next line, which is first added
+                                    currentRow++;
+                                    currentCol = 0;
+                                    handler.insertRow(currentRow, '', 'input', true);
+                                    handler.reflow(currentRow - 1); // the previous line must be rendered without a cursor, and the new line must be rendered completely
+                                }
 
-                            // now serve the cooking
-                            handler.insertAtCursor(cookedChars, 'input'); // append what we have to the display
-                            // scroll to bottom on input
-                            dh = jqContent.height() - jqElt.height();
-                            if (dh > 0)
-                                jqElt.scrollTop(dh);
-
-                            if (typeof handler.onInput === 'function') { // now tell the owner what we've done
-                                if (lineBuffered) {
-                                    if (thisRow < currentRow) {
-                                        // in line-buffered mode emit each line separately, except for the last (current) line
+                                if (typeof handler.onInput === 'function') { // now tell the owner what we've done
+                                    if (lineBuffered) {
+                                        if (thisRow < currentRow) {
+                                            // in line-buffered mode emit each line separately, except for the last (current) line
+                                            try {
+                                                return handler.onInput(lines[thisRow].content.substring(leftmost));
+                                            }
+                                            catch (e) {
+                                                codeq.log.error('Error while invoking terminal onInput: ' + e, e);
+                                            }
+                                        }
+                                    }
+                                    else if (cookedLine) {
                                         try {
-                                            return handler.onInput(lines[thisRow].content.substring(leftmost));
+                                            return handler.onInput(cookedLine);
                                         }
                                         catch (e) {
                                             codeq.log.error('Error while invoking terminal onInput: ' + e, e);
                                         }
                                     }
                                 }
-                                else if (cookedChars) {
-                                    try {
-                                        return handler.onInput(cookedChars);
-                                    }
-                                    catch (e) {
-                                        codeq.log.error('Error while invoking terminal onInput: ' + e, e);
-                                    }
-                                }
-                            }
-
-                        };})(newLines[i], i))
+                        };})(cookedLines[i], i))
                         .fail(function (e) {
                             codeq.log.error('Error in handleInput loop: ' + e, e);
                         });
                 }
 
-                promise.fin(function () {
+                cookedPromise.fin(function () {
                     internallyDisabled = false;
+                    scrollCursorIntoView();
                 }).done();
 
                 clipboardPasteInProgress = false;
@@ -739,7 +926,7 @@
             lines.push({content: options.greeting, className: 'greeting'});
             currentRow++;
         }
-        lines.push({content: '', className: 'input'}); // initial input line
+        lines.push({content: '', classNames: []}); // initial input line
         render();
 
         return handler;
diff --git a/js/codeq/hint.js b/js/codeq/hint.js
new file mode 100644
index 0000000..c22f39f
--- /dev/null
+++ b/js/codeq/hint.js
@@ -0,0 +1,193 @@
+/**
+ * Creates a hint handler, displaying hints inside the provided jqHints <div>.
+ */
+
+(function () {
+    // constants
+    var firstCharacterPos = {'line': 0, 'ch': 0},
+        sel_no_scroll = {'scroll': false};
+
+    codeq.makeHinter = function (jqHints, jqEditor, editor, hintDefs) {
+        var hintCounter = 0, // for generating unique class-names
+            hintCleaners = [],
+
+            clearHints = function () {
+                var i;
+                for (i = hintCleaners.length - 1; i >= 0; i--) {
+                    hintCleaners[i]();
+                }
+                hintCleaners.length = 0;
+                hintCounter = 0;
+            },
+
+            addMark = function (start, end) {
+                var posStart = editor.posFromIndex(start),
+                    posEnd = editor.posFromIndex(end),
+                    doc = editor.getDoc(),
+                    mark = doc.markText(posStart, posEnd, {'className': 'editor-mark _emark_' + hintCounter}),
+                    result = {'start': posStart, 'end': posEnd, 'mark': mark, 'className': '_emark_' + hintCounter};
+                hintCleaners.push(function () { mark.clear(); mark = null; doc = null; result.mark = null; });
+                hintCounter++;
+                return result;
+            },
+
+            processTemplate = function (template, args) {
+                if (!args)
+                    return template;
+                return template.replace(/\[%=(\w+)%\]/g, function(match, name) {
+                    return args[name];
+                });
+            },
+
+            typeHandlers = {
+                'static': function (type, template, serverHint) {
+                    var jqContainer, jqButton, promise, i, lastIndex;
+                    if (template instanceof Array) { // unwrap the template if there's only one
+                        if (template.length == 0) template = '';
+                        else if (template.length == 1) template = template[0] + '';
+                    }
+                    if (template instanceof Array) {
+                        codeq.log.debug('Processing an array of static hints');
+                        jqContainer = $('<div class="hint-static-group"></div>');
+                        jqButton = $('<button type="button">More...</button>'); // TODO: translate "more"
+                        jqHints.append(jqContainer);
+                        lastIndex = template.length - 1;
+                        promise = Q();
+                        for (i = 0; i <= lastIndex; i++) {
+                            promise = promise.then((function (tmpl, index) {
+                                return Q.Promise(function (resolve, reject) {
+                                    var message = processTemplate(tmpl, serverHint.args),
+                                        onClick;
+                                    jqContainer.append('<div class="hint-static">' + message + '</div>');
+                                    if (index < lastIndex) {
+                                        onClick = function () {
+                                            jqButton.off('click', onClick);
+                                            jqButton.remove();
+                                            resolve();
+                                        };
+                                        jqContainer.append(jqButton);
+                                        jqButton.on('click', onClick);
+                                    }
+                                    else {
+                                        resolve();
+                                    }
+                                });
+                            })(template[i], i));
+                        }
+                        promise.done();
+                    }
+                    else {
+                        codeq.log.debug('Processing a single static hint');
+                        var message = processTemplate(template, serverHint.args);
+                        jqHints.append('<div class="hint-static">' + message + '</div>');
+                    }
+                    // no hint cleaner here, a static hint remains on the screen
+                },
+
+                'popup': function (type, template, serverHint) {
+                    codeq.log.debug('Processing popup hint');
+                    var message = processTemplate(template, serverHint.args),
+                        mark = addMark(serverHint.start, serverHint.end), // add the mark
+                        jqMark = jqEditor.find('.' + mark.className);
+
+                    jqMark.popover({'content': message, 'html': true, 'placement': 'auto bottom', 'trigger': 'hover focus click', 'container': 'body'});
+                    hintCleaners.push(function () { if (jqMark) { jqMark.popover('destroy'); jqMark = null; } });
+
+                    mark.mark.on('', function () {});
+                },
+
+                'dropdown': function (type, template, serverHint) {
+                    codeq.log.debug('Processing dropdown hint');
+                    var completion = null, // the completion object, created in showHint()
+                        close = function () {
+                            if (completion) {
+                                completion.close();
+                                completion = null;
+                            }
+                        };
+
+                    if (/*(editor.listSelections().length > 1) ||*/ editor.somethingSelected()) {
+                        // showHint() doesn't work if a selection is activeparts
+                        editor.setSelection(firstCharacterPos, firstCharacterPos, sel_no_scroll); // deselect anything
+                    }
+
+                    editor.showHint({
+                        hint: function () {
+                            var hints = {
+                                list: serverHint.choices,
+                                from: editor.posFromIndex(serverHint.start),
+                                to: editor.posFromIndex(serverHint.end)
+                            };
+                            completion = editor.state.completionActive;
+                            return hints;
+                        },
+                        completeOnSingleClick: true,
+                        completeSingle: false
+                    });
+
+                    hintCleaners.push(close);
+                }
+            };
+
+        return {
+            /**
+             * Processes and display appropriately the server hints.
+             * TODO: sort hints so static and popup hints come first, and a (single) drop-down hint last
+             *
+             * @param {ServerHint[]} serverHints an array of hints from the server
+             */
+            'handle': function (serverHints) {
+                var n = serverHints.length,
+                    /** number */ i,
+                    /** ServerHint */ serverHint,
+                    /** HintDefinition */ hintDef,
+                    hintType, hintTemplate, t, fn, indices;
+                clearHints();
+                mainLoop:
+                for (i = 0; i < n; i++) {
+                    serverHint = serverHints[i];
+                    hintDef = hintDefs[serverHint.id];
+                    if (!hintDef) {
+                        codeq.log.error('Undefined hint ' + serverHint.id);
+                        continue;
+                    }
+                    if (serverHint.indices) {
+                        indices = serverHint.indices;
+                        for (i = 0; i < indices.length; i++) {
+                            hintDef = hintDef[indices[i]];
+                            if (!hintDef) {
+                                codeq.log.error('Undefined hint ' + serverHint.id + ' with indices ' + serverHint.indices);
+                                continue mainLoop;
+                            }
+                        }
+                    }
+                    t = typeof hintDef;
+                    if (t === 'object') {
+                        hintType = hintDef.type;
+                        hintTemplate = hintDef.message;
+                    }
+                    else if (t === 'string') {
+                        hintType = 'static';
+                        hintTemplate = hintDef;
+                    }
+                    else {
+                        codeq.log.error('Unsupported hint definition: ' + t);
+                        continue;
+                    }
+
+                    fn = typeHandlers[hintType];
+                    if (!fn) codeq.log.error('Unsupported hint type: ' + hintType);
+                    else fn(hintType, hintTemplate, serverHint);
+                }
+            },
+
+            'destroy': function () {
+                clearHints();
+                jqHints.empty();
+                jqHints = null;
+                jqEditor = null;
+                editor = null;
+            }
+        };
+    };
+})();
\ No newline at end of file
diff --git a/js/codeq/startup.js b/js/codeq/startup.js
index 2f7df97..ccef9f9 100644
--- a/js/codeq/startup.js
+++ b/js/codeq/startup.js
@@ -77,6 +77,7 @@ $(document).ready(function () {
                             })
                             .fail(function (reason) {
                                 $('#disabled').css('display', 'none');
+                                codeq.log.error('Login request failed: ' + reason, reason);
                                 alert('Login request failed: ' + reason);
                             })
                             .done();
diff --git a/js/prolog.js b/js/prolog.js
index 5406af4..1082392 100644
--- a/js/prolog.js
+++ b/js/prolog.js
@@ -9,6 +9,7 @@
     //codeq.makePrologTerminalHandler = function (jqConsole, editor, problem_id, activityHandler) {
     var makePrologTerminalHandler = function (jqConsole, editor, problem_id, activityHandler) {
         var promptMode = true, // default: query composition; alternative: query result browsing
+            manualStop = false, // if the user stopped showing next answers (false) or if there are no more answers (true)
             terminal = codeq.makeConsole(jqConsole, {
                 'greeting': 'CodeQ Prolog terminal proxy'
             }),
@@ -25,7 +26,7 @@
                 }
                 if (promptMode) {
                     terminal.setLineBuffered();
-                    terminal.append('.\n?- ', 'output');
+                    terminal.append(manualStop ? '?- ' : '.\n?- ', 'output');
                 }
             },
             tcf = function terminalCommandFailed (error) {
@@ -50,6 +51,7 @@
         terminal.onInput = function (command) {
             if (promptMode) {
                 promptMode = false;
+                manualStop = false;
                 terminal.setNotBuffered();
                 return codeq.comms.sendQuery({
                     'problem_id': problem_id,
@@ -71,6 +73,7 @@
                 }
                 else {
                     // stop searching for answers
+                    manualStop = true;
                     return codeq.comms.sendQuery({
                         'problem_id': problem_id,
                         'step': 'end',
@@ -147,119 +150,7 @@
             editor = CodeMirror(jqEditor[0], { cursorHeight: 0.85, lineNumbers: true, matchBrackets: true }),
             activityHandler = codeq.makeActivityHandler(editor, problem.id),
             terminal = makePrologTerminalHandler(jqConsole, editor, problem.id, activityHandler),
-            hintDefs = problem.hint,
-            hintCounter = 0, // for generating unique class-names
-            hintCleaners = [],
-            clearHints = function () {
-                var i;
-                for (i = hintCleaners.length - 1; i >= 0; i--) {
-                    hintCleaners[i]();
-                }
-                hintCleaners.length = 0;
-                hintCounter = 0;
-            },
-            addMark = function (start, end) {
-                var posStart = editor.posFromIndex(start),
-                    posEnd = editor.posFromIndex(end),
-                    doc = editor.getDoc(),
-                    mark = doc.markText(posStart, posEnd, {className: 'editor-mark _emark_' + hintCounter}),
-                    result = {start: posStart, end: posEnd, mark: mark, className: '_emark_' + hintCounter};
-                hintCleaners.push(function () { mark.clear(); mark = null; doc = null; result.mark = null; });
-                hintCounter++;
-                return result;
-            },
-            processTemplate = function (template, args) {
-                if (!args)
-                    return template;
-                return template.replace(/\[%=(\w+)%\]/g, function(match, name) {
-                    return args[name];
-                });
-            },
-            hintHandlers = {
-                'static': function (type, template, serverHint) {
-                    codeq.log.debug('Processing static hint');
-                    var message = processTemplate(template, serverHint.args);
-                    jqHints.append('<div class="hint-static">' + message + '</div>');
-                    // no hint cleaner here, a static hint remains on the screen
-                },
-                'popup': function (type, template, serverHint) {
-                    codeq.log.debug('Processing popup hint');
-                    var message = processTemplate(template, serverHint.args),
-                        mark = addMark(serverHint.start, serverHint.end), // add the mark
-                        jqMark = jqEditor.find('.' + mark.className);
-/*                        jqPopup = null,
-                        onBlur = function () {
-                            codeq.log.debug('Removing popup');
-                            if (jqPopup) {
-                                jqPopup.off('blur', onBlur);
-                                jqPopup.remove();
-                                jqPopup = null;
-                            }
-                        };
-
-                    window.jqMark = jqMark; // TODO: DEBUG
-
-                    jqMark.on('click', function () {
-                        if (jqPopup) return;
-                        codeq.log.debug('Showing popup');
-                        var pos = mark.mark.find(), // results in {from: {line: number, ch: number}, to: {line: number, ch: number}}
-                            left = pos.from.ch < pos.to.ch ? pos.from.ch : pos.to.ch,
-                            down = pos.from.line < pos.to.line ? pos.to.line : pos.from.line;
-                        jqPopup = $('<div style="position: absolute;" class="editor-popup ' + mark.className + '"></div>').html(template);
-                        editor.addWidget({line: down, ch: left}, jqPopup[0], true);
-                        jqPopup = jqEditor.find('.editor-popup.' + mark.className);
-                        setTimeout(function () {jqPopup.trigger('focus'); jqPopup.on('click', onBlur);}, 50); // event handlers can be registered only when the DOM elements is part of the document
-                        window.jqPopup = jqPopup; // TODO: DEBUG
-                    });
-
-                    hintCleaners.push(function () {
-                        if (jqPopup) {
-                            jqPopup.off('blur', onBlur);
-                            jqPopup.remove();
-                            jqPopup = null;
-                        }
-                        if (jqMark) {
-                            jqMark = null;
-                        }
-                        mark = null;
-                    });*/
-
-                    jqMark.popover({content: message, html: true, placement: 'auto bottom', trigger: 'hover focus click', container: 'body'});
-                    hintCleaners.push(function () { if (jqMark) { jqMark.popover('destroy'); jqMark = null; } });
-
-                    mark.mark.on('', function () {});
-                },
-                'dropdown': function (type, template, serverHint) {
-                    codeq.log.debug('Processing dropdown hint');
-                    var completion = null, // the completion object, created in showHint()
-                        close = function () {
-                            if (completion) {
-                                completion.close();
-                                completion = null;
-                            }
-                        };
-
-                    if ((editor.listSelections().length > 1) || editor.somethingSelected()) {
-                        // showHint() doesn't work if a selection is activeparts
-                    }
-
-                    editor.showHint({
-                        hint: function () {
-                            var hints = {
-                                list: serverHint.choices,
-                                from: editor.posFromIndex(serverHint.start),
-                                to: editor.posFromIndex(serverHint.end)
-                            };
-                            completion = editor.state.completionActive;
-                            return hints;
-                        },
-                        completeOnSingleClick: true,
-                        completeSingle: false
-                    });
-
-                    hintCleaners.push(close);
-                }
-            };
+            hinter = codeq.makeHinter(jqHints, jqEditor, editor, problem.hint);
 
         editor.setValue(info.solution);
         $('#title').text(problem.slug);
@@ -278,73 +169,6 @@
             }
         });
 
-        var handler = {
-            destroy: function () {
-                terminal.destroy();
-                jqDescription.empty();
-                jqEditor.empty(); // TODO: perhaps you do not want to "free" the editor, just empty it
-                jqConsole.empty(); // TODO: the same with the console
-                jqHints.empty(); // TODO: just make static references to these
-                jqDescription = null;
-                jqEditor = null;
-                jqConsole = null;
-                jqHints = null;
-            },
-
-            /**
-             * Processes and display appropriately the server hints.
-             * TODO: sort hints so static and popup hints come first, and a (single) drop-down hint last
-             *
-             * @param {ServerHint[]} serverHints an array of hints from the server
-             */
-            processServerHints: function (serverHints) {
-                var n = serverHints.length,
-                    /** number */ i,
-                    /** ServerHint */ serverHint,
-                    /** HintDefinition */ hintDef,
-                    hintType, hintTemplate, t, fn;
-                clearHints();
-                for (i = 0; i < n; i++) {
-                    serverHint = serverHints[i];
-                    hintDef = hintDefs[serverHint.id];
-                    if (serverHint.indices) {
-                        indices = serverHint.indices
-                        for (i = 0; i < indices.length; i++) {
-                            hintDef = hintDef[indices[i]];
-                            if (!hintDef)
-                                break;
-                        }
-                    }
-                    if (!hintDef) {
-                        codeq.log.error('Undefined hint ' + serverHint.id + ' with indices ' + serverHint.indices);
-                        continue;
-                    }
-                    t = typeof hintDef;
-                    if (t === 'object') {
-                        hintType = hintDef.type;
-                        hintTemplate = hintDef.message;
-                    }
-                    else if (t === 'string') {
-                        hintType = 'static';
-                        hintTemplate = hintDef;
-                    }
-                    else {
-                        codeq.log.error('Unsupported hint definition: ' + t);
-                        continue;
-                    }
-
-                    fn = hintHandlers[hintType];
-                    if (!fn) codeq.log.error('Unsupported hint type: ' + hintType);
-                    else fn(hintType, hintTemplate, serverHint);
-                }
-            }
-        };
-
-        var jqButtons = $('#block-toolbar button');
-//        $(jqButtons.get(0)).on('click', function () { handler.processServerHints([{id:'x_must_be_female'}]); });
-//        $(jqButtons.get(1)).on('click', function () { handler.processServerHints([{id:'popup_unknown', start: 20, end: 26}]); });
-//        $(jqButtons.get(2)).on('click', function () { handler.processServerHints([{id:'drop_down', start: 20, end: 26, choices:['ena', 'dva', 'tri']}]); });
-
         $('#btn_code_hint').on('click', function () {
             terminal.append('hint.\n', 'input');
             terminal.inputDisable();
@@ -357,7 +181,7 @@
                 .then(
                     function hintSuccess(data) {
                         if (data.code === 0)
-                            handler.processServerHints(data.hints);
+                            hinter.handle(data.hints);
                         else
                             terminal.append(data.message + '\n', 'error');
                     },
@@ -383,7 +207,7 @@
                 .then(
                     function testSuccess(data) {
                         if (data.code === 0)
-                            handler.processServerHints(data.hints);
+                            hinter.handle(data.hints);
                         else
                             terminal.append(data.message + '\n', 'error');
                     },
@@ -398,6 +222,18 @@
                 .done();
         });
 
-        return handler;
+        return {
+            destroy: function () {
+                hinter.destroy();
+                terminal.destroy();
+                jqDescription.empty();
+                jqEditor.empty(); // TODO: perhaps you do not want to "free" the editor, just empty it
+                jqConsole.empty(); // TODO: the same with the console
+                jqDescription = null;
+                jqEditor = null;
+                jqConsole = null;
+                jqHints = null;
+            }
+        };
     };
 })();
diff --git a/js/python.js b/js/python.js
index fd2b9b1..4a2ac92 100644
--- a/js/python.js
+++ b/js/python.js
@@ -65,7 +65,8 @@
             'queueTrace': function (trace) {
                 trace['dt'] = deltaActivityMillis();
                 queue.push(trace);
-                if (ts === null) setTimeout(timer, 10000); // flush every 10 seconds
+                if (ts === null) ts = setTimeout(timer, 10000); // flush every 10 seconds
+                return this;
             },
             'flush': flush,
             'addAndPurge': function (trace) {
@@ -99,119 +100,7 @@
             editor = CodeMirror(jqEditor[0], { cursorHeight: 0.85, lineNumbers: true, matchBrackets: true, mode: 'python' }),
             activityHandler = codeq.makeActivityHandler(editor, problem.id),
             terminal = makePythonTerminalHandler(jqConsole, editor, problem.id, activityHandler),
-            hintDefs = problem.hint,
-            hintCounter = 0, // for generating unique class-names
-            hintCleaners = [],
-            clearHints = function () {
-                var i;
-                for (i = hintCleaners.length - 1; i >= 0; i--) {
-                    hintCleaners[i]();
-                }
-                hintCleaners.length = 0;
-                hintCounter = 0;
-            },
-            addMark = function (start, end) {
-                var posStart = editor.posFromIndex(start),
-                    posEnd = editor.posFromIndex(end),
-                    doc = editor.getDoc(),
-                    mark = doc.markText(posStart, posEnd, {className: 'editor-mark _emark_' + hintCounter}),
-                    result = {start: posStart, end: posEnd, mark: mark, className: '_emark_' + hintCounter};
-                hintCleaners.push(function () { mark.clear(); mark = null; doc = null; result.mark = null; });
-                hintCounter++;
-                return result;
-            },
-            processTemplate = function (template, args) {
-                if (!args)
-                    return template;
-                return template.replace(/\[%=(\w+)%\]/g, function(match, name) {
-                    return args[name];
-                });
-            },
-            hintHandlers = {
-                'static': function (type, template, serverHint) {
-                    codeq.log.debug('Processing static hint');
-                    var message = processTemplate(template, serverHint.args);
-                    jqHints.append('<div class="hint-static">' + message + '</div>');
-                    // no hint cleaner here, a static hint remains on the screen
-                },
-                'popup': function (type, template, serverHint) {
-                    codeq.log.debug('Processing popup hint');
-                    var message = processTemplate(template, serverHint.args),
-                        mark = addMark(serverHint.start, serverHint.end), // add the mark
-                        jqMark = jqEditor.find('.' + mark.className);
-/*                        jqPopup = null,
-                        onBlur = function () {
-                            codeq.log.debug('Removing popup');
-                            if (jqPopup) {
-                                jqPopup.off('blur', onBlur);
-                                jqPopup.remove();
-                                jqPopup = null;
-                            }
-                        };
-
-                    window.jqMark = jqMark; // TODO: DEBUG
-
-                    jqMark.on('click', function () {
-                        if (jqPopup) return;
-                        codeq.log.debug('Showing popup');
-                        var pos = mark.mark.find(), // results in {from: {line: number, ch: number}, to: {line: number, ch: number}}
-                            left = pos.from.ch < pos.to.ch ? pos.from.ch : pos.to.ch,
-                            down = pos.from.line < pos.to.line ? pos.to.line : pos.from.line;
-                        jqPopup = $('<div style="position: absolute;" class="editor-popup ' + mark.className + '"></div>').html(template);
-                        editor.addWidget({line: down, ch: left}, jqPopup[0], true);
-                        jqPopup = jqEditor.find('.editor-popup.' + mark.className);
-                        setTimeout(function () {jqPopup.trigger('focus'); jqPopup.on('click', onBlur);}, 50); // event handlers can be registered only when the DOM elements is part of the document
-                        window.jqPopup = jqPopup; // TODO: DEBUG
-                    });
-
-                    hintCleaners.push(function () {
-                        if (jqPopup) {
-                            jqPopup.off('blur', onBlur);
-                            jqPopup.remove();
-                            jqPopup = null;
-                        }
-                        if (jqMark) {
-                            jqMark = null;
-                        }
-                        mark = null;
-                    });*/
-
-                    jqMark.popover({content: message, html: true, placement: 'auto bottom', trigger: 'hover focus click', container: 'body'});
-                    hintCleaners.push(function () { if (jqMark) { jqMark.popover('destroy'); jqMark = null; } });
-
-                    mark.mark.on('', function () {});
-                },
-                'dropdown': function (type, template, serverHint) {
-                    codeq.log.debug('Processing dropdown hint');
-                    var completion = null, // the completion object, created in showHint()
-                        close = function () {
-                            if (completion) {
-                                completion.close();
-                                completion = null;
-                            }
-                        };
-
-                    if ((editor.listSelections().length > 1) || editor.somethingSelected()) {
-                        // showHint() doesn't work if a selection is activeparts
-                    }
-
-                    editor.showHint({
-                        hint: function () {
-                            var hints = {
-                                list: serverHint.choices,
-                                from: editor.posFromIndex(serverHint.start),
-                                to: editor.posFromIndex(serverHint.end)
-                            };
-                            completion = editor.state.completionActive;
-                            return hints;
-                        },
-                        completeOnSingleClick: true,
-                        completeSingle: false
-                    });
-
-                    hintCleaners.push(close);
-                }
-            };
+            hinter = codeq.makeHinter(jqHints, jqEditor, editor, problem.hint);
 
         editor.setValue(info.solution);
         $('#title').text(problem.slug);
@@ -230,75 +119,7 @@
             }
         });
 
-        var handler = {
-            destroy: function () {
-                terminal.destroy();
-                jqDescription.empty();
-                jqEditor.empty(); // TODO: perhaps you do not want to "free" the editor, just empty it
-                jqConsole.empty(); // TODO: the same with the console
-                jqHints.empty(); // TODO: just make static references to these
-                jqDescription = null;
-                jqEditor = null;
-                jqConsole = null;
-                jqHints = null;
-            },
-
-            /**
-             * Processes and display appropriately the server hints.
-             * TODO: sort hints so static and popup hints come first, and a (single) drop-down hint last
-             *
-             * @param {ServerHint[]} serverHints an array of hints from the server
-             */
-            processServerHints: function (serverHints) {
-                var n = serverHints.length,
-                    /** number */ i,
-                    /** ServerHint */ serverHint,
-                    /** HintDefinition */ hintDef,
-                    hintType, hintTemplate, t, fn;
-                clearHints();
-                for (i = 0; i < n; i++) {
-                    serverHint = serverHints[i];
-                    hintDef = hintDefs[serverHint.id];
-                    if (serverHint.indices) {
-                        indices = serverHint.indices
-                        for (i = 0; i < indices.length; i++) {
-                            hintDef = hintDef[indices[i]];
-                            if (!hintDef)
-                                break;
-                        }
-                    }
-                    if (!hintDef) {
-                        codeq.log.error('Undefined hint ' + serverHint.id + ' with indices ' + serverHint.indices);
-                        continue;
-                    }
-                    t = typeof hintDef;
-                    if (t === 'object') {
-                        hintType = hintDef.type;
-                        hintTemplate = hintDef.message;
-                    }
-                    else if (t === 'string') {
-                        hintType = 'static';
-                        hintTemplate = hintDef;
-                    }
-                    else {
-                        codeq.log.error('Unsupported hint definition: ' + t);
-                        continue;
-                    }
-
-                    fn = hintHandlers[hintType];
-                    if (!fn) codeq.log.error('Unsupported hint type: ' + hintType);
-                    else fn(hintType, hintTemplate, serverHint);
-                }
-            }
-        };
-
-        var jqButtons = $('#block-toolbar button');
-//        $(jqButtons.get(0)).on('click', function () { handler.processServerHints([{id:'x_must_be_female'}]); });
-//        $(jqButtons.get(1)).on('click', function () { handler.processServerHints([{id:'popup_unknown', start: 20, end: 26}]); });
-//        $(jqButtons.get(2)).on('click', function () { handler.processServerHints([{id:'drop_down', start: 20, end: 26, choices:['ena', 'dva', 'tri']}]); });
-
         $('#btn_code_hint').on('click', function () {
-//            handler.processServerHints([{id:'drop_down', start: 20, end: 26, choices:['ena', 'dva', 'tri']}]);
             var doc = editor.getDoc();
             codeq.comms.sendHint({
                 'language': 'python',
@@ -307,7 +128,7 @@
             }).then(
                 function hintSuccess(data) {
                     if (data.code === 0)
-                        handler.processServerHints(data.hints);
+                        hinter.handle(data.hints);
                     else
                         terminal.append('error: ' + data.message);
                 },
@@ -325,7 +146,7 @@
             }).then(
                 function testSuccess(data) {
                     if (data.code === 0)
-                        handler.processServerHints(data.hints);
+                        hinter.handle(data.hints);
                     else
                         terminal.append('error: ' + data.message);
                 },
@@ -340,6 +161,18 @@
             'text': ''
         });
 
-        return handler;
+        return {
+            destroy: function () {
+                hinter.destroy();
+                terminal.destroy();
+                jqDescription.empty();
+                jqEditor.empty(); // TODO: perhaps you do not want to "free" the editor, just empty it
+                jqConsole.empty(); // TODO: the same with the console
+                jqDescription = null;
+                jqEditor = null;
+                jqConsole = null;
+                jqHints = null;
+            }
+        };
     };
 })();