Added rough version of d3 word cloud.

common/lib/xmodule/xmodule/js/src/word_cloud/d3.layout.cloud.js

+// Word cloud layout by Jason Davies, http://www.jasondavies.com/word-cloud/
+// Algorithm due to Jonathan Feinberg, http://static.mrfeinberg.com/bv_ch03.pdf
+(function(exports) {
+  function cloud() {
+    var size = [256, 256],
+        text = cloudText,
+        font = cloudFont,
+        fontSize = cloudFontSize,
+        fontStyle = cloudFontNormal,
+        fontWeight = cloudFontNormal,
+        rotate = cloudRotate,
+        padding = cloudPadding,
+        spiral = archimedeanSpiral,
+        words = [],
+        timeInterval = Infinity,
+        event = d3.dispatch("word", "end"),
+        timer = null,
+        cloud = {};
+
+    cloud.start = function() {
+      var board = zeroArray((size[0] >> 5) * size[1]),
+          bounds = null,
+          n = words.length,
+          i = -1,
+          tags = [],
+          data = words.map(function(d, i) {
+            d.text = text.call(this, d, i);
+            d.font = font.call(this, d, i);
+            d.style = fontStyle.call(this, d, i);
+            d.weight = fontWeight.call(this, d, i);
+            d.rotate = rotate.call(this, d, i);
+            d.size = ~~fontSize.call(this, d, i);
+            d.padding = cloudPadding.call(this, d, i);
+            return d;
+          }).sort(function(a, b) { return b.size - a.size; });
+
+      if (timer) clearInterval(timer);
+      timer = setInterval(step, 0);
+      step();
+
+      return cloud;
+
+      function step() {
+        var start = +new Date,
+            d;
+        while (+new Date - start < timeInterval && ++i < n && timer) {
+          d = data[i];
+          d.x = (size[0] * (Math.random() + .5)) >> 1;
+          d.y = (size[1] * (Math.random() + .5)) >> 1;
+          cloudSprite(d, data, i);
+          if (place(board, d, bounds)) {
+            tags.push(d);
+            event.word(d);
+            if (bounds) cloudBounds(bounds, d);
+            else bounds = [{x: d.x + d.x0, y: d.y + d.y0}, {x: d.x + d.x1, y: d.y + d.y1}];
+            // Temporary hack
+            d.x -= size[0] >> 1;
+            d.y -= size[1] >> 1;
+          }
+        }
+        if (i >= n) {
+          cloud.stop();
+          event.end(tags, bounds);
+        }
+      }
+    }
+
+    cloud.stop = function() {
+      if (timer) {
+        clearInterval(timer);
+        timer = null;
+      }
+      return cloud;
+    };
+
+    cloud.timeInterval = function(x) {
+      if (!arguments.length) return timeInterval;
+      timeInterval = x == null ? Infinity : x;
+      return cloud;
+    };
+
+    function place(board, tag, bounds) {
+      var perimeter = [{x: 0, y: 0}, {x: size[0], y: size[1]}],
+          startX = tag.x,
+          startY = tag.y,
+          maxDelta = Math.sqrt(size[0] * size[0] + size[1] * size[1]),
+          s = spiral(size),
+          dt = Math.random() < .5 ? 1 : -1,
+          t = -dt,
+          dxdy,
+          dx,
+          dy;
+
+      while (dxdy = s(t += dt)) {
+        dx = ~~dxdy[0];
+        dy = ~~dxdy[1];
+
+        if (Math.min(dx, dy) > maxDelta) break;
+
+        tag.x = startX + dx;
+        tag.y = startY + dy;
+
+        if (tag.x + tag.x0 < 0 || tag.y + tag.y0 < 0 ||
+            tag.x + tag.x1 > size[0] || tag.y + tag.y1 > size[1]) continue;
+        // TODO only check for collisions within current bounds.
+        if (!bounds || !cloudCollide(tag, board, size[0])) {
+          if (!bounds || collideRects(tag, bounds)) {
+            var sprite = tag.sprite,
+                w = tag.width >> 5,
+                sw = size[0] >> 5,
+                lx = tag.x - (w << 4),
+                sx = lx & 0x7f,
+                msx = 32 - sx,
+                h = tag.y1 - tag.y0,
+                x = (tag.y + tag.y0) * sw + (lx >> 5),
+                last;
+            for (var j = 0; j < h; j++) {
+              last = 0;
+              for (var i = 0; i <= w; i++) {
+                board[x + i] |= (last << msx) | (i < w ? (last = sprite[j * w + i]) >>> sx : 0);
+              }
+              x += sw;
+            }
+            delete tag.sprite;
+            return true;
+          }
+        }
+      }
+      return false;
+    }
+
+    cloud.words = function(x) {
+      if (!arguments.length) return words;
+      words = x;
+      return cloud;
+    };
+
+    cloud.size = function(x) {
+      if (!arguments.length) return size;
+      size = [+x[0], +x[1]];
+      return cloud;
+    };
+
+    cloud.font = function(x) {
+      if (!arguments.length) return font;
+      font = d3.functor(x);
+      return cloud;
+    };
+
+    cloud.fontStyle = function(x) {
+      if (!arguments.length) return fontStyle;
+      fontStyle = d3.functor(x);
+      return cloud;
+    };
+
+    cloud.fontWeight = function(x) {
+      if (!arguments.length) return fontWeight;
+      fontWeight = d3.functor(x);
+      return cloud;
+    };
+
+    cloud.rotate = function(x) {
+      if (!arguments.length) return rotate;
+      rotate = d3.functor(x);
+      return cloud;
+    };
+
+    cloud.text = function(x) {
+      if (!arguments.length) return text;
+      text = d3.functor(x);
+      return cloud;
+    };
+
+    cloud.spiral = function(x) {
+      if (!arguments.length) return spiral;
+      spiral = spirals[x + ""] || x;
+      return cloud;
+    };
+
+    cloud.fontSize = function(x) {
+      if (!arguments.length) return fontSize;
+      fontSize = d3.functor(x);
+      return cloud;
+    };
+
+    cloud.padding = function(x) {
+      if (!arguments.length) return padding;
+      padding = d3.functor(x);
+      return cloud;
+    };
+
+    return d3.rebind(cloud, event, "on");
+  }
+
+  function cloudText(d) {
+    return d.text;
+  }
+
+  function cloudFont() {
+    return "serif";
+  }
+
+  function cloudFontNormal() {
+    return "normal";
+  }
+
+  function cloudFontSize(d) {
+    return Math.sqrt(d.value);
+  }
+
+  function cloudRotate() {
+    return (~~(Math.random() * 6) - 3) * 30;
+  }
+
+  function cloudPadding() {
+    return 1;
+  }
+
+  // Fetches a monochrome sprite bitmap for the specified text.
+  // Load in batches for speed.
+  function cloudSprite(d, data, di) {
+    if (d.sprite) return;
+    c.clearRect(0, 0, (cw << 5) / ratio, ch / ratio);
+    var x = 0,
+        y = 0,
+        maxh = 0,
+        n = data.length;
+    di--;
+    while (++di < n) {
+      d = data[di];
+      c.save();
+      c.font = d.style + " " + d.weight + " " + ~~((d.size + 1) / ratio) + "px " + d.font;
+      var w = c.measureText(d.text + "m").width * ratio,
+          h = d.size << 1;
+      if (d.rotate) {
+        var sr = Math.sin(d.rotate * cloudRadians),
+            cr = Math.cos(d.rotate * cloudRadians),
+            wcr = w * cr,
+            wsr = w * sr,
+            hcr = h * cr,
+            hsr = h * sr;
+        w = (Math.max(Math.abs(wcr + hsr), Math.abs(wcr - hsr)) + 0x1f) >> 5 << 5;
+        h = ~~Math.max(Math.abs(wsr + hcr), Math.abs(wsr - hcr));
+      } else {
+        w = (w + 0x1f) >> 5 << 5;
+      }
+      if (h > maxh) maxh = h;
+      if (x + w >= (cw << 5)) {
+        x = 0;
+        y += maxh;
+        maxh = 0;
+      }
+      if (y + h >= ch) break;
+      c.translate((x + (w >> 1)) / ratio, (y + (h >> 1)) / ratio);
+      if (d.rotate) c.rotate(d.rotate * cloudRadians);
+      c.fillText(d.text, 0, 0);
+      c.restore();
+      d.width = w;
+      d.height = h;
+      d.xoff = x;
+      d.yoff = y;
+      d.x1 = w >> 1;
+      d.y1 = h >> 1;
+      d.x0 = -d.x1;
+      d.y0 = -d.y1;
+      x += w;
+    }
+    var pixels = c.getImageData(0, 0, (cw << 5) / ratio, ch / ratio).data,
+        sprite = [];
+    while (--di >= 0) {
+      d = data[di];
+      var w = d.width,
+          w32 = w >> 5,
+          h = d.y1 - d.y0,
+          p = d.padding;
+      // Zero the buffer
+      for (var i = 0; i < h * w32; i++) sprite[i] = 0;
+      x = d.xoff;
+      if (x == null) return;
+      y = d.yoff;
+      var seen = 0,
+          seenRow = -1;
+      for (var j = 0; j < h; j++) {
+        for (var i = 0; i < w; i++) {
+          var k = w32 * j + (i >> 5),
+              m = pixels[((y + j) * (cw << 5) + (x + i)) << 2] ? 1 << (31 - (i % 32)) : 0;
+          if (p) {
+            if (j) sprite[k - w32] |= m;
+            if (j < w - 1) sprite[k + w32] |= m;
+            m |= (m << 1) | (m >> 1);
+          }
+          sprite[k] |= m;
+          seen |= m;
+        }
+        if (seen) seenRow = j;
+        else {
+          d.y0++;
+          h--;
+          j--;
+          y++;
+        }
+      }
+      d.y1 = d.y0 + seenRow;
+      d.sprite = sprite.slice(0, (d.y1 - d.y0) * w32);
+    }
+  }
+
+  // Use mask-based collision detection.
+  function cloudCollide(tag, board, sw) {
+    sw >>= 5;
+    var sprite = tag.sprite,
+        w = tag.width >> 5,
+        lx = tag.x - (w << 4),
+        sx = lx & 0x7f,
+        msx = 32 - sx,
+        h = tag.y1 - tag.y0,
+        x = (tag.y + tag.y0) * sw + (lx >> 5),
+        last;
+    for (var j = 0; j < h; j++) {
+      last = 0;
+      for (var i = 0; i <= w; i++) {
+        if (((last << msx) | (i < w ? (last = sprite[j * w + i]) >>> sx : 0))
+            & board[x + i]) return true;
+      }
+      x += sw;
+    }
+    return false;
+  }
+
+  function cloudBounds(bounds, d) {
+    var b0 = bounds[0],
+        b1 = bounds[1];
+    if (d.x + d.x0 < b0.x) b0.x = d.x + d.x0;
+    if (d.y + d.y0 < b0.y) b0.y = d.y + d.y0;
+    if (d.x + d.x1 > b1.x) b1.x = d.x + d.x1;
+    if (d.y + d.y1 > b1.y) b1.y = d.y + d.y1;
+  }
+
+  function collideRects(a, b) {
+    return a.x + a.x1 > b[0].x && a.x + a.x0 < b[1].x && a.y + a.y1 > b[0].y && a.y + a.y0 < b[1].y;
+  }
+
+  function archimedeanSpiral(size) {
+    var e = size[0] / size[1];
+    return function(t) {
+      return [e * (t *= .1) * Math.cos(t), t * Math.sin(t)];
+    };
+  }
+
+  function rectangularSpiral(size) {
+    var dy = 4,
+        dx = dy * size[0] / size[1],
+        x = 0,
+        y = 0;
+    return function(t) {
+      var sign = t < 0 ? -1 : 1;
+      // See triangular numbers: T_n = n * (n + 1) / 2.
+      switch ((Math.sqrt(1 + 4 * sign * t) - sign) & 3) {
+        case 0:  x += dx; break;
+        case 1:  y += dy; break;
+        case 2:  x -= dx; break;
+        default: y -= dy; break;
+      }
+      return [x, y];
+    };
+  }
+
+  // TODO reuse arrays?
+  function zeroArray(n) {
+    var a = [],
+        i = -1;
+    while (++i < n) a[i] = 0;
+    return a;
+  }
+
+  var cloudRadians = Math.PI / 180,
+      cw = 1 << 11 >> 5,
+      ch = 1 << 11,
+      canvas,
+      ratio = 1;
+
+  if (typeof document !== "undefined") {
+    canvas = document.createElement("canvas");
+    canvas.width = 1;
+    canvas.height = 1;
+    ratio = Math.sqrt(canvas.getContext("2d").getImageData(0, 0, 1, 1).data.length >> 2);
+    canvas.width = (cw << 5) / ratio;
+    canvas.height = ch / ratio;
+  } else {
+    // node-canvas support
+    var Canvas = require("canvas");
+    canvas = new Canvas(cw << 5, ch);
+  }
+
+  var c = canvas.getContext("2d"),
+      spirals = {
+        archimedean: archimedeanSpiral,
+        rectangular: rectangularSpiral
+      };
+  c.fillStyle = "red";
+  c.textAlign = "center";
+
+  exports.cloud = cloud;
+})(typeof exports === "undefined" ? d3.layout || (d3.layout = {}) : exports);

common/lib/xmodule/xmodule/js/src/word_cloud/word_cloud_main.js

 (function (requirejs, require, define) {
 define('WordCloudMain', ['logme'], function (logme) {
 
+    var hash = 0;
+
 WordCloudMain.prototype = {
 
 'submitAnswer': function () {
@@ -36,16 +38,62 @@ WordCloudMain.prototype = {
 }, // End-of: 'submitAnswer': function (answer, answerEl) {
 
 'showWordCloud': function(response){
+    var words,
+        _this = this,
+        fill = d3.scale.category20();
+
     console.log('Show word cloud with next:');
     console.log(response);
-    
+
     inputSection = this.wordCloudEl.find('#input-cloud-section');
     resultSection = this.wordCloudEl.find('#result-cloud-section');
-    
+
     resultSection.text('TODO: Word cloud canvas');
     inputSection.hide();
     resultSection.show();
-},
+
+    words = response.top_words;
+
+    d3.layout.cloud().size([5, 5])
+        .words(words)
+        .rotate(function () {
+            return ~~(Math.random() * 2) * 90;
+        })
+        .font('Impact')
+        .fontSize(function (d) {
+            return d.size;
+        })
+        .on('end', draw)
+        .start();
+
+    // End of executable code.
+    return;
+
+    function draw(words) {
+        d3.select('.word_cloud_d3_' + _this.hash).append('svg')
+            .attr('width', 500)
+            .attr('height', 500)
+            .append('g')
+            // .attr('transform', 'translate(125,125)')
+            .selectAll('text')
+            .data(words)
+            .enter().append('text')
+            .style('font-size', function (d) {
+                return d.size + 'px';
+            })
+            .style('font-family', 'Impact')
+            .style('fill', function (d, i) {
+                return fill(i);
+            })
+            .attr('text-anchor', 'middle')
+            .attr('transform', function (d) {
+                return 'translate(' + [d.x, d.y] + ')rotate(' + d.rotate + ')';
+            })
+            .text(function (d) {
+                return d.text;
+            });
+    }
+}
 
 }; // End-of: WordCloudMain.prototype = {
 
@@ -53,6 +101,7 @@ return WordCloudMain;
 
 function WordCloudMain(el) {
     var _this;
+
     this.wordCloudEl = $(el).find('.word_cloud');
     if (this.wordCloudEl.length !== 1) {
         // We require one question DOM element.
@@ -61,6 +110,26 @@ function WordCloudMain(el) {
         return;
     }
 
+    hash += 1;
+    this.hash = hash;
+    this.wordCloudEl.addClass('word_cloud_d3_' + this.hash);
+
+    this.configJson = null;
+    try {
+        this.configJson = JSON.parse(this.wordCloudEl.find('.word_cloud_div').html());
+    } catch (err) {
+        logme('ERROR: Incorrect JSON config was given.');
+        logme(err.message);
+
+        return;
+    }
+
+    if (this.configJson.hasOwnProperty('status') && this.configJson.status === 'success') {
+        this.showWordCloud(this.configJson);
+
+        return;
+    }
+
     this.inputSaveEl = $(el).find('input.save');
 
     // Get the URL to which we will post the users words.

common/lib/xmodule/xmodule/word_cloud_module.py

@@ -44,6 +44,8 @@ class WordCloudModule(WordCloudFields, XModule):
     js = {
       'coffee': [resource_string(__name__, 'js/src/javascript_loader.coffee')],
       'js': [resource_string(__name__, 'js/src/word_cloud/logme.js'),
+             resource_string(__name__, 'js/src/word_cloud/d3.min.js'),
+             resource_string(__name__, 'js/src/word_cloud/d3.layout.cloud.js'),
              resource_string(__name__, 'js/src/word_cloud/word_cloud.js'),
              resource_string(__name__, 'js/src/word_cloud/word_cloud_main.js')]
          }