Mark fields as dirty when the workspace becomes visible. (#3072)

* Mark fields as dirty when the workspace becomes visible.

core/block_svg.js

@@ -540,6 +540,16 @@ Blockly.BlockSvg.prototype.getBoundingRectangle = function() {
   return new Blockly.utils.Rect(top, bottom, left, right);
 };
 
+/**
+ * Notify every input on this block to mark its fields as dirty.
+ * A dirty field is a field that needs to be re-rendererd.
+ */
+Blockly.BlockSvg.prototype.markDirty = function() {
+  for (var i = 0, input; input = this.inputList[i]; i++) {
+    input.markDirty();
+  }
+};
+
 /**
  * Set whether the block is collapsed or not.
  * @param {boolean} collapsed True if collapsed.

core/field.js

@@ -688,6 +688,17 @@ Blockly.Field.prototype.setText = function(_newText) {
   throw Error('setText method is deprecated');
 };
 
+/**
+ * Force a rerender of the block that this field is installed on, which will
+ * rerender this field and adjust for any sizing changes.
+ * Other fields on the same block will not rerender, because their sizes have
+ * already been recorded.
+ * @package
+ */
+Blockly.Field.prototype.markDirty = function() {
+  this.isDirty_ = true;
+};
+
 /**
  * Force a rerender of the block that this field is installed on, which will
  * rerender this field and adjust for any sizing changes.

core/input.js

@@ -206,6 +206,16 @@ Blockly.Input.prototype.setVisible = function(visible) {
   return renderList;
 };
 
+/**
+ * Mark all fields on this input as dirty.
+ * @package
+ */
+Blockly.Input.prototype.markDirty = function() {
+  for (var y = 0, field; field = this.fieldRow[y]; y++) {
+    field.markDirty();
+  }
+};
+
 /**
  * Change a connection's compatibility.
  * @param {string|Array.<string>|null} check Compatible value type or

core/workspace_svg.js

@@ -1079,6 +1079,12 @@ Blockly.WorkspaceSvg.prototype.setVisible = function(isVisible) {
     this.toolbox_.HtmlDiv.style.display = isVisible ? 'block' : 'none';
   }
   if (isVisible) {
+    var blocks = this.getAllBlocks(false);
+    // Tell each block on the workspace to mark its fields as dirty.
+    for (var i = blocks.length - 1; i >= 0; i--) {
+      blocks[i].markDirty();
+    }
+
     this.render();
     if (this.toolbox_) {
       this.toolbox_.position();