diff --git a/Architype.js b/Architype.js
index fb16c69..55f6d6f 100644
--- a/Architype.js
+++ b/Architype.js
@@ -8,7 +8,6 @@ class Architype {
     // TODO: make theme selectable
     this.container_.classList.add('dark');
 
-    addEventListener('resize', (e) => { this.onResize(e); });
     document.addEventListener('keydown',
                               (e) => { this.onKeyDown(e); },
                               { capture: true });
@@ -17,9 +16,9 @@ class Architype {
     this.container_.appendChild(this.editorElem_);
     this.editor_ = new Editor(this.editorElem_);
 
-    this.grid_ = document.createElement('div');
-    this.grid_.classList.add('grid');
-    this.container_.appendChild(this.grid_);
+    this.gridElem_ = document.createElement('div');
+    this.container_.appendChild(this.gridElem_);
+    this.grid_ = new Grid(this.gridElem_);
 
     this.generation_ = 0;
     this.renderGeneration_ = -1;
@@ -97,8 +96,7 @@ class Architype {
     if (e.data.generation > this.drawGeneration_) {
       // Received newer than we've drawn; redraw
       this.drawGeneration_ = e.data.generation;
-      this.draw(e.data.steps);
-      this.fixSizes();
+      this.grid_.draw(e.data.steps);
     }
 
     this.startRender();
@@ -119,142 +117,6 @@ class Architype {
     this.renderGeneration_ = this.serialized_.generation;
     render.postMessage(this.serialized_);
   }
-
-  // TODO: factor out draw/grid code
-  onResize(e) {
-    this.fixSizes();
-  }
-
-  draw(steps) {
-    this.grid_.innerHTML = '';
-    this.toSize_ = [];
-
-    for (let step of steps) {
-      switch (step.type) {
-        case 'size':
-          this.drawGrid(step.size);
-          break;
-
-        case 'arrow':
-          this.drawArrow(step.pos, step.cls);
-          break;
-
-        case 'graphLabel':
-          this.drawGraphLabel(step.min, step.max, step.label);
-          break;
-
-        case 'group':
-          this.drawGroup(step.min, step.max, step.label);
-          break;
-
-        case 'line':
-          this.drawLine(step.pos, step.cls);
-          break;
-
-        case 'linkLabel':
-          this.drawLinkLabel(step.pos, step.label);
-          break;
-
-        case 'node':
-          this.drawNode(step.label, step.pos);
-          break;
-      }
-    }
-  }
-
-  drawGrid(size) {
-    this.grid_.style.gridTemplateColumns =
-        'repeat(' + size[0] + ',1fr)';
-    this.grid_.style.gridTemplateRows =
-        'repeat(' + size[1] +
-        ',minmax(0, calc((100vw - var(--editor-width)) / ' +
-        size[0] + ')))';
-  }
-
-  drawArrow(pos, cls) {
-    let svg = document.createElementNS('http://www.w3.org/2000/svg', 'svg');
-    svg.classList.add('gridArrow');
-    svg.classList.add(cls);
-    svg.style.gridColumn = pos[0] + 1;
-    svg.style.gridRow = pos[1] + 1;
-    this.grid_.appendChild(svg);
-
-    let use = document.createElementNS('http://www.w3.org/2000/svg', 'use');
-    svg.appendChild(use);
-    use.setAttributeNS('http://www.w3.org/1999/xlink', 'xlink:href', '#' + cls);
-  }
-
-  drawGraphLabel(min, max, label) {
-    let elem = document.createElement('div');
-    this.grid_.appendChild(elem);
-    elem.classList.add('gridGraphLabel');
-    elem.style.gridColumn = (min[0] + 1) + ' / ' + (max[0] + 2);
-    elem.style.gridRow = (min[1] + 1) + ' / ' + (max[1] + 2);
-    elem.innerText = label;
-    this.toSize_.push(elem);
-  }
-
-  drawGroup(min, max, label) {
-    let group = document.createElement('div');
-    this.grid_.appendChild(group);
-    group.classList.add('gridGroup');
-    group.style.gridColumn = (min[0] + 1) + ' / ' + (max[0] + 2);
-    group.style.gridRow = (min[1] + 1) + ' / ' + (max[1] + 2);
-
-    if (label != '') {
-      let labelNode = document.createElement('div');
-      this.grid_.appendChild(labelNode);
-      labelNode.classList.add('gridGroupLabel');
-      labelNode.innerText = label;
-      labelNode.style.gridColumn = (min[0] + 1) + ' / ' + (max[0] + 2);
-      labelNode.style.gridRow = min[1] + 1;
-      this.toSize_.push(labelNode);
-    }
-  }
-
-  drawLine(pos, cls) {
-    let svg = document.createElementNS('http://www.w3.org/2000/svg', 'svg');
-    svg.classList.add('gridLines');
-    svg.style.gridColumn = pos[0] + 1;
-    svg.style.gridRow = pos[1] + 1;
-    this.grid_.appendChild(svg);
-
-    let use = document.createElementNS('http://www.w3.org/2000/svg', 'use');
-    svg.appendChild(use);
-    use.setAttributeNS('http://www.w3.org/1999/xlink', 'xlink:href', '#' + cls);
-  }
-
-  drawLinkLabel(pos, label) {
-    let elem = document.createElement('div');
-    elem.classList.add('gridLinkLabel');
-    this.grid_.appendChild(elem);
-    elem.innerText = label;
-    elem.style.gridColumn = pos[0] + 1;
-    elem.style.gridRow = pos[1] + 1;
-    this.toSize_.push(elem);
-  }
-
-  drawNode(label, pos) {
-    let node = document.createElement('div');
-    node.classList.add('gridNode');
-    this.grid_.appendChild(node);
-    node.innerText = label;
-    node.style.gridColumn = pos[0] + 1;
-    node.style.gridRow = pos[1] + 1;
-    this.toSize_.push(node);
-  }
-
-  fixSizes() {
-    for (let node of this.toSize_) {
-      node.style.fontSize = null;
-      for (let size = 30;
-           size && (node.scrollWidth > node.clientWidth ||
-                    node.scrollHeight > node.clientHeight);
-           --size) {
-        node.style.fontSize = size + 'px';
-      }
-    }
-  }
 }
 
 <!--# include file="Editor.js" -->
diff --git a/Grid.js b/Grid.js
index cfc42cc..ccb7b25 100644
--- a/Grid.js
+++ b/Grid.js
@@ -1,2 +1,146 @@
 class Grid {
+  constructor(container) {
+    this.container_ = container;
+    this.container_.classList.add('grid');
+
+    this.toSize_ = [];
+    addEventListener('resize', (e) => { this.onResize(e); });
+  }
+
+  onResize(e) {
+    this.fixSizes();
+  }
+
+  draw(steps) {
+    this.container_.innerHTML = '';
+    this.toSize_ = [];
+
+    for (let step of steps) {
+      switch (step.type) {
+        case 'size':
+          this.drawGrid(step.size);
+          break;
+
+        case 'arrow':
+          this.drawArrow(step.pos, step.cls);
+          break;
+
+        case 'graphLabel':
+          this.drawGraphLabel(step.min, step.max, step.label);
+          break;
+
+        case 'group':
+          this.drawGroup(step.min, step.max, step.label);
+          break;
+
+        case 'line':
+          this.drawLine(step.pos, step.cls);
+          break;
+
+        case 'linkLabel':
+          this.drawLinkLabel(step.pos, step.label);
+          break;
+
+        case 'node':
+          this.drawNode(step.label, step.pos);
+          break;
+      }
+    }
+
+    this.fixSizes();
+  }
+
+  drawGrid(size) {
+    this.container_.style.gridTemplateColumns =
+        'repeat(' + size[0] + ',1fr)';
+    this.container_.style.gridTemplateRows =
+        'repeat(' + size[1] +
+        ',minmax(0, calc((100vw - var(--editor-width)) / ' +
+        size[0] + ')))';
+  }
+
+  drawArrow(pos, cls) {
+    let svg = document.createElementNS('http://www.w3.org/2000/svg', 'svg');
+    svg.classList.add('gridArrow');
+    svg.classList.add(cls);
+    svg.style.gridColumn = pos[0] + 1;
+    svg.style.gridRow = pos[1] + 1;
+    this.container_.appendChild(svg);
+
+    let use = document.createElementNS('http://www.w3.org/2000/svg', 'use');
+    svg.appendChild(use);
+    use.setAttributeNS('http://www.w3.org/1999/xlink', 'xlink:href', '#' + cls);
+  }
+
+  drawGraphLabel(min, max, label) {
+    let elem = document.createElement('div');
+    this.container_.appendChild(elem);
+    elem.classList.add('gridGraphLabel');
+    elem.style.gridColumn = (min[0] + 1) + ' / ' + (max[0] + 2);
+    elem.style.gridRow = (min[1] + 1) + ' / ' + (max[1] + 2);
+    elem.innerText = label;
+    this.toSize_.push(elem);
+  }
+
+  drawGroup(min, max, label) {
+    let group = document.createElement('div');
+    this.container_.appendChild(group);
+    group.classList.add('gridGroup');
+    group.style.gridColumn = (min[0] + 1) + ' / ' + (max[0] + 2);
+    group.style.gridRow = (min[1] + 1) + ' / ' + (max[1] + 2);
+
+    if (label != '') {
+      let labelNode = document.createElement('div');
+      this.container_.appendChild(labelNode);
+      labelNode.classList.add('gridGroupLabel');
+      labelNode.innerText = label;
+      labelNode.style.gridColumn = (min[0] + 1) + ' / ' + (max[0] + 2);
+      labelNode.style.gridRow = min[1] + 1;
+      this.toSize_.push(labelNode);
+    }
+  }
+
+  drawLine(pos, cls) {
+    let svg = document.createElementNS('http://www.w3.org/2000/svg', 'svg');
+    svg.classList.add('gridLines');
+    svg.style.gridColumn = pos[0] + 1;
+    svg.style.gridRow = pos[1] + 1;
+    this.container_.appendChild(svg);
+
+    let use = document.createElementNS('http://www.w3.org/2000/svg', 'use');
+    svg.appendChild(use);
+    use.setAttributeNS('http://www.w3.org/1999/xlink', 'xlink:href', '#' + cls);
+  }
+
+  drawLinkLabel(pos, label) {
+    let elem = document.createElement('div');
+    elem.classList.add('gridLinkLabel');
+    this.container_.appendChild(elem);
+    elem.innerText = label;
+    elem.style.gridColumn = pos[0] + 1;
+    elem.style.gridRow = pos[1] + 1;
+    this.toSize_.push(elem);
+  }
+
+  drawNode(label, pos) {
+    let node = document.createElement('div');
+    node.classList.add('gridNode');
+    this.container_.appendChild(node);
+    node.innerText = label;
+    node.style.gridColumn = pos[0] + 1;
+    node.style.gridRow = pos[1] + 1;
+    this.toSize_.push(node);
+  }
+
+  fixSizes() {
+    for (let node of this.toSize_) {
+      node.style.fontSize = null;
+      for (let size = 30;
+           size && (node.scrollWidth > node.clientWidth ||
+                    node.scrollHeight > node.clientHeight);
+           --size) {
+        node.style.fontSize = size + 'px';
+      }
+    }
+  }
 }