Make block comments an optional module. (#3053)

Measured as a 5 KB *increase* in code size, but that's because some other commit just landed between my tests. It's like running down an up escalator.

blocks/procedures.js

@@ -28,6 +28,7 @@ goog.provide('Blockly.Blocks.procedures');
 
 goog.require('Blockly');
 goog.require('Blockly.Blocks');
+goog.require('Blockly.Comment');
 goog.require('Blockly.FieldCheckbox');
 goog.require('Blockly.FieldLabel');
 goog.require('Blockly.FieldTextInput');

build.py

@@ -248,6 +248,7 @@ class Gen_compressed(threading.Thread):
     params.append(("js_code", """
 goog.provide('Blockly');
 goog.provide('Blockly.Blocks');
+goog.provide('Blockly.Comment');
 goog.provide('Blockly.FieldCheckbox');
 goog.provide('Blockly.FieldColour');
 goog.provide('Blockly.FieldDropdown');

core/block.js

@@ -27,7 +27,6 @@
 goog.provide('Blockly.Block');
 
 goog.require('Blockly.Blocks');
-goog.require('Blockly.Comment');
 goog.require('Blockly.Connection');
 goog.require('Blockly.Events');
 goog.require('Blockly.Events.BlockChange');

core/block_svg.js

@@ -1092,6 +1092,9 @@ Blockly.BlockSvg.prototype.setCommentText = function(text) {
   var changedState = false;
   if (typeof text == 'string') {
     if (!this.comment) {
+      if (!Blockly.Comment) {
+        throw Error('Missing require for Blockly.Comment');
+      }
       this.comment = new Blockly.Comment(this);
       changedState = true;
     }

core/requires.js

@@ -27,26 +27,41 @@
 
 goog.provide('Blockly.requires');
 
-// Blockly Core.
+// Blockly Core (absolutely mandatory).
 goog.require('Blockly');
-goog.require('Blockly.Mutator');
+
+
+// If block comments aren't required, then Blockly.inject's "comments"
+// configuration must be false, and no blocks may be loaded from XML which
+// define comments.
+goog.require('Blockly.Comment');
+// If a trashcan on the workspace isn't required, then Blockly.inject's
+// "trashcan" configuration must be false.
 goog.require('Blockly.Trashcan');
+// If zoom controls aren't required, then Blockly.inject's
+// "zoom"/"controls" configuration must be false.
 goog.require('Blockly.ZoomControls');
-// Blockly Fields.
-goog.require('Blockly.FieldAngle');
-goog.require('Blockly.FieldCheckbox');
-goog.require('Blockly.FieldColour');
-// Date picker commented out since it increases footprint by 60%.
-// Add it only if you need it.
-// goog.require('Blockly.FieldDate');
-goog.require('Blockly.FieldDropdown');
-goog.require('Blockly.FieldLabelSerializable');
-goog.require('Blockly.FieldImage');
-goog.require('Blockly.FieldTextInput');
-goog.require('Blockly.FieldMultilineInput');
-goog.require('Blockly.FieldNumber');
-goog.require('Blockly.FieldVariable');
+
+
+// Block dependencies.
+// None of these should be required since individual block files should
+// include the requirements they depend on.
+// goog.require('Blockly.Mutator');
+// goog.require('Blockly.FieldAngle');
+// goog.require('Blockly.FieldCheckbox');
+// goog.require('Blockly.FieldColour');
+// goog.require('Blockly.FieldDropdown');
+// goog.require('Blockly.FieldLabelSerializable');
+// goog.require('Blockly.FieldImage');
+// goog.require('Blockly.FieldTextInput');
+// goog.require('Blockly.FieldMultilineInput');
+// goog.require('Blockly.FieldNumber');
+// goog.require('Blockly.FieldVariable');
+
+
 // Blockly Renderers.
+// At least one renderer is mandatory.  Geras is the default one.
+// Others may be chosen using Blockly.inject's "renderer" configuration.
 goog.require('Blockly.geras.Renderer');
-goog.require('Blockly.thrasos.Renderer');
-goog.require('Blockly.zelos.Renderer');
+// goog.require('Blockly.thrasos.Renderer');
+// goog.require('Blockly.zelos.Renderer');

gulpfile.js

@@ -141,6 +141,7 @@ gulp.task('build-blocks', function () {
   const provides = `
 goog.provide('Blockly');
 goog.provide('Blockly.Blocks');
+goog.provide('Blockly.Comment');
 goog.provide('Blockly.FieldCheckbox');
 goog.provide('Blockly.FieldColour');
 goog.provide('Blockly.FieldDropdown');