Use Context Menu registry for block-level menu options (#4032)

Use registry for block-level context menu items.

core/block_svg.js

@@ -17,6 +17,7 @@ goog.require('Blockly.Block');
 goog.require('Blockly.blockAnimations');
 goog.require('Blockly.blockRendering.IPathObject');
 goog.require('Blockly.ContextMenu');
+goog.require('Blockly.ContextMenuRegistry');
 goog.require('Blockly.Events');
 goog.require('Blockly.Events.Ui');
 goog.require('Blockly.Events.BlockMove');
@@ -716,87 +717,8 @@ Blockly.BlockSvg.prototype.generateContextMenu = function() {
   if (this.workspace.options.readOnly || !this.contextMenu) {
     return null;
   }
-  // Save the current block in a variable for use in closures.
-  var block = this;
-  var menuOptions = [];
-
-  if (!this.isInFlyout) {
-    if (this.isDeletable() && this.isMovable()) {
-      menuOptions.push(Blockly.ContextMenu.blockDuplicateOption(block));
-    }
-
-    if (this.workspace.options.comments && !this.collapsed_ &&
-        this.isEditable()) {
-      menuOptions.push(Blockly.ContextMenu.blockCommentOption(block));
-    }
-
-    if (this.isMovable()) {
-      if (!this.collapsed_) {
-        // Option to make block inline.
-        for (var i = 1; i < this.inputList.length; i++) {
-          if (this.inputList[i - 1].type != Blockly.NEXT_STATEMENT &&
-              this.inputList[i].type != Blockly.NEXT_STATEMENT) {
-            // Only display this option if there are two value or dummy inputs
-            // next to each other.
-            var inlineOption = {enabled: true};
-            var isInline = this.getInputsInline();
-            inlineOption.text = isInline ?
-                Blockly.Msg['EXTERNAL_INPUTS'] : Blockly.Msg['INLINE_INPUTS'];
-            inlineOption.callback = function() {
-              block.setInputsInline(!isInline);
-            };
-            menuOptions.push(inlineOption);
-            break;
-          }
-        }
-        // Option to collapse block
-        if (this.workspace.options.collapse) {
-          var collapseOption = {enabled: true};
-          collapseOption.text = Blockly.Msg['COLLAPSE_BLOCK'];
-          collapseOption.callback = function() {
-            block.setCollapsed(true);
-          };
-          menuOptions.push(collapseOption);
-        }
-      } else {
-        // Option to expand block.
-        if (this.workspace.options.collapse) {
-          var expandOption = {enabled: true};
-          expandOption.text = Blockly.Msg['EXPAND_BLOCK'];
-          expandOption.callback = function() {
-            block.setCollapsed(false);
-          };
-          menuOptions.push(expandOption);
-        }
-      }
-    }
-
-    if (this.workspace.options.disable && this.isEditable()) {
-      // Option to disable/enable block.
-      var disableOption = {
-        text: this.isEnabled() ?
-            Blockly.Msg['DISABLE_BLOCK'] : Blockly.Msg['ENABLE_BLOCK'],
-        enabled: !this.getInheritedDisabled(),
-        callback: function() {
-          var group = Blockly.Events.getGroup();
-          if (!group) {
-            Blockly.Events.setGroup(true);
-          }
-          block.setEnabled(!block.isEnabled());
-          if (!group) {
-            Blockly.Events.setGroup(false);
-          }
-        }
-      };
-      menuOptions.push(disableOption);
-    }
-
-    if (this.isDeletable()) {
-      menuOptions.push(Blockly.ContextMenu.blockDeleteOption(block));
-    }
-  }
-
-  menuOptions.push(Blockly.ContextMenu.blockHelpOption(block));
+  var menuOptions = Blockly.ContextMenuRegistry.registry.getContextMenuOptions(
+      Blockly.ContextMenuRegistry.ScopeType.BLOCK, {block: this});
 
   // Allow the block to add or modify menuOptions.
   if (this.customContextMenu) {

core/contextmenu.js

@@ -203,98 +203,6 @@ Blockly.ContextMenu.callbackFactory = function(block, xml) {
 
 // Helper functions for creating context menu options.
 
-/**
- * Make a context menu option for deleting the current block.
- * @param {!Blockly.BlockSvg} block The block where the right-click originated.
- * @return {!Object} A menu option, containing text, enabled, and a callback.
- * @package
- */
-Blockly.ContextMenu.blockDeleteOption = function(block) {
-  // Option to delete this block but not blocks lower in the stack.
-  // Count the number of blocks that are nested in this block.
-  var descendantCount = block.getDescendants(false).length;
-  var nextBlock = block.getNextBlock();
-  if (nextBlock) {
-    // Blocks in the current stack would survive this block's deletion.
-    descendantCount -= nextBlock.getDescendants(false).length;
-  }
-  var deleteOption = {
-    text: descendantCount == 1 ? Blockly.Msg['DELETE_BLOCK'] :
-        Blockly.Msg['DELETE_X_BLOCKS'].replace('%1', String(descendantCount)),
-    enabled: true,
-    callback: function() {
-      Blockly.Events.setGroup(true);
-      block.dispose(true, true);
-      Blockly.Events.setGroup(false);
-    }
-  };
-  return deleteOption;
-};
-
-/**
- * Make a context menu option for showing help for the current block.
- * @param {!Blockly.BlockSvg} block The block where the right-click originated.
- * @return {!Object} A menu option, containing text, enabled, and a callback.
- * @package
- */
-Blockly.ContextMenu.blockHelpOption = function(block) {
-  var url = (typeof block.helpUrl == 'function') ?
-      block.helpUrl() : block.helpUrl;
-  var helpOption = {
-    enabled: !!url,
-    text: Blockly.Msg['HELP'],
-    callback: function() {
-      block.showHelp();
-    }
-  };
-  return helpOption;
-};
-
-/**
- * Make a context menu option for duplicating the current block.
- * @param {!Blockly.BlockSvg} block The block where the right-click originated.
- * @return {!Object} A menu option, containing text, enabled, and a callback.
- * @package
- */
-Blockly.ContextMenu.blockDuplicateOption = function(block) {
-  var enabled = block.isDuplicatable();
-  var duplicateOption = {
-    text: Blockly.Msg['DUPLICATE_BLOCK'],
-    enabled: enabled,
-    callback: function() {
-      Blockly.duplicate(block);
-    }
-  };
-  return duplicateOption;
-};
-
-/**
- * Make a context menu option for adding or removing comments on the current
- * block.
- * @param {!Blockly.BlockSvg} block The block where the right-click originated.
- * @return {!Object} A menu option, containing text, enabled, and a callback.
- * @package
- */
-Blockly.ContextMenu.blockCommentOption = function(block) {
-  var commentOption = {
-    enabled: !Blockly.utils.userAgent.IE
-  };
-  // If there's already a comment, add an option to delete it.
-  if (block.getCommentIcon()) {
-    commentOption.text = Blockly.Msg['REMOVE_COMMENT'];
-    commentOption.callback = function() {
-      block.setCommentText(null);
-    };
-  } else {
-    // If there's no comment, add an option to create a comment.
-    commentOption.text = Blockly.Msg['ADD_COMMENT'];
-    commentOption.callback = function() {
-      block.setCommentText('');
-    };
-  }
-  return commentOption;
-};
-
 /**
  * Make a context menu option for deleting the current workspace comment.
  * @param {!Blockly.WorkspaceCommentSvg} comment The workspace comment where the

core/contextmenu_items.js

@@ -20,65 +20,71 @@ goog.requireType('Blockly.BlockSvg');
 
 /** Option to undo previous action. */
 Blockly.ContextMenuItems.registerUndo = function() {
-  var undoOption = {};
-  undoOption.displayText = function() {
-    return Blockly.Msg['UNDO'];
+  /** @type {!Blockly.ContextMenuRegistry.RegistryItem} */
+  var undoOption = {
+    displayText: function() {
+      return Blockly.Msg['UNDO'];
+    },
+    preconditionFn: function(/** @type {!Blockly.ContextMenuRegistry.Scope} */ scope) {
+      if (scope.workspace.getUndoStack().length > 0) {
+        return 'enabled';
+      }
+      return 'disabled';
+    },
+    callback: function(/** @type {!Blockly.ContextMenuRegistry.Scope} */ scope) {
+      scope.workspace.undo(false);
+    },
+    scopeType: Blockly.ContextMenuRegistry.ScopeType.WORKSPACE,
+    id: 'undoWorkspace',
+    weight: 0,
   };
-  undoOption.preconditionFn = function(scope) {
-    if (scope.workspace.undoStack_.length > 0) {
-      return 'enabled';
-    }
-    return 'disabled';
-  };
-  undoOption.callback = function(scope) {
-    scope.workspace.undo(false);
-  };
-  undoOption.scopeType = Blockly.ContextMenuRegistry.ScopeType.WORKSPACE;
-  undoOption.id = 'undoWorkspace';
-  undoOption.weight = 0;
   Blockly.ContextMenuRegistry.registry.register(undoOption);
 };
 
 /** Option to redo previous action. */
 Blockly.ContextMenuItems.registerRedo = function() {
-  var redoOption = {};
-  redoOption.displayText = function() { return Blockly.Msg['REDO']; };
-  redoOption.preconditionFn = function(scope) {
-    if (scope.workspace.redoStack_.length > 0) {
-      return 'enabled';
-    }
-    return 'disabled';
+  /** @type {!Blockly.ContextMenuRegistry.RegistryItem} */
+  var redoOption = {
+    displayText: function() { return Blockly.Msg['REDO']; },
+    preconditionFn: function(/** @type {!Blockly.ContextMenuRegistry.Scope} */ scope) {
+      if (scope.workspace.getRedoStack().length > 0) {
+        return 'enabled';
+      }
+      return 'disabled';
+    },
+    callback: function(/** @type {!Blockly.ContextMenuRegistry.Scope} */ scope) {
+      scope.workspace.undo(true);
+    },
+    scopeType: Blockly.ContextMenuRegistry.ScopeType.WORKSPACE,
+    id: 'redoWorkspace',
+    weight: 0,
   };
-  redoOption.callback = function(scope) {
-    scope.workspace.undo(true);
-  };
-  redoOption.scopeType = Blockly.ContextMenuRegistry.ScopeType.WORKSPACE;
-  redoOption.id = 'redoWorkspace';
-  redoOption.weight = 0;
   Blockly.ContextMenuRegistry.registry.register(redoOption);
 };
     
 /** Option to clean up blocks. */
 Blockly.ContextMenuItems.registerCleanup = function() {
-  var cleanOption = {};
-  cleanOption.displayText = function() {
-    return Blockly.Msg['CLEAN_UP'];
-  };
-  cleanOption.preconditionFn = function(scope) {
-    if (scope.workspace.isMovable()) {
-      if (scope.workspace.getTopBlocks(false).length > 1) {
-        return 'enabled';
+  /** @type {!Blockly.ContextMenuRegistry.RegistryItem} */
+  var cleanOption = {
+    displayText: function() {
+      return Blockly.Msg['CLEAN_UP'];
+    },
+    preconditionFn: function(/** @type {!Blockly.ContextMenuRegistry.Scope} */ scope) {
+      if (scope.workspace.isMovable()) {
+        if (scope.workspace.getTopBlocks(false).length > 1) {
+          return 'enabled';
+        }
+        return 'disabled';
       }
-      return 'disabled';
-    }
-    return 'hidden';
+      return 'hidden';
+    },
+    callback: function(/** @type {!Blockly.ContextMenuRegistry.Scope} */ scope) {
+      scope.workspace.cleanUp();
+    },
+    scopeType: Blockly.ContextMenuRegistry.ScopeType.WORKSPACE,
+    id: 'cleanWorkspace',
+    weight: 0,
   };
-  cleanOption.callback = function(scope) {
-    scope.workspace.cleanUp();
-  };
-  cleanOption.scopeType = Blockly.ContextMenuRegistry.ScopeType.WORKSPACE;
-  cleanOption.id = 'cleanWorkspace';
-  cleanOption.weight = 0;
   Blockly.ContextMenuRegistry.registry.register(cleanOption);
 };
   
@@ -103,63 +109,67 @@ Blockly.ContextMenuItems.toggleOption_ = function(shouldCollapse, topBlocks) {
 
 /** Option to collapse all blocks. */
 Blockly.ContextMenuItems.registerCollapse = function() {
-  var collapseOption = {};
-  collapseOption.displayText = function() {
-    return Blockly.Msg['COLLAPSE_ALL'];
-  };
-  collapseOption.preconditionFn = function(scope) {
-    if (scope.workspace.options.collapse) {
-      var topBlocks = scope.workspace.getTopBlocks(false);
-      for (var i = 0; i < topBlocks.length; i++) {
-        var block = topBlocks[i];
-        while (block) {
-          if (!block.isCollapsed()) {
-            return 'enabled';
+  /** @type {!Blockly.ContextMenuRegistry.RegistryItem} */
+  var collapseOption = {
+    displayText:  function() {
+      return Blockly.Msg['COLLAPSE_ALL'];
+    },
+    preconditionFn:  function(/** @type {!Blockly.ContextMenuRegistry.Scope} */ scope) {
+      if (scope.workspace.options.collapse) {
+        var topBlocks = scope.workspace.getTopBlocks(false);
+        for (var i = 0; i < topBlocks.length; i++) {
+          var block = topBlocks[i];
+          while (block) {
+            if (!block.isCollapsed()) {
+              return 'enabled';
+            }
+            block = block.getNextBlock();
           }
-          block = block.getNextBlock();
         }
+        return 'disabled';
       }
-      return 'disabled';
-    }
-    return 'hidden';
+      return 'hidden';
+    },
+    callback:  function(/** @type {!Blockly.ContextMenuRegistry.Scope} */ scope) {
+      Blockly.ContextMenuItems.toggleOption_(true, scope.workspace.getTopBlocks(true));
+    },
+    scopeType:  Blockly.ContextMenuRegistry.ScopeType.WORKSPACE,
+    id:  'collapseWorkspace',
+    weight:  0,
   };
-  collapseOption.callback = function(scope) {
-    Blockly.ContextMenuItems.toggleOption_(true, scope.workspace.getTopBlocks(true));
-  };
-  collapseOption.scopeType = Blockly.ContextMenuRegistry.ScopeType.WORKSPACE;
-  collapseOption.id = 'collapseWorkspace';
-  collapseOption.weight = 0;
   Blockly.ContextMenuRegistry.registry.register(collapseOption);
 };
   
 /** Option to expand all blocks. */
 Blockly.ContextMenuItems.registerExpand = function() {
-  var expandOption = {};
-  expandOption.displayText = function() {
-    return Blockly.Msg['EXPAND_ALL'];
-  };
-  expandOption.preconditionFn = function(scope) {
-    if (scope.workspace.options.collapse) {
-      var topBlocks = scope.workspace.getTopBlocks(false);
-      for (var i = 0; i < topBlocks.length; i++) {
-        var block = topBlocks[i];
-        while (block) {
-          if (block.isCollapsed()) {
-            return 'enabled';
+  /** @type {!Blockly.ContextMenuRegistry.RegistryItem} */
+  var expandOption = {
+    displayText: function() {
+      return Blockly.Msg['EXPAND_ALL'];
+    },
+    preconditionFn: function(/** @type {!Blockly.ContextMenuRegistry.Scope} */ scope) {
+      if (scope.workspace.options.collapse) {
+        var topBlocks = scope.workspace.getTopBlocks(false);
+        for (var i = 0; i < topBlocks.length; i++) {
+          var block = topBlocks[i];
+          while (block) {
+            if (block.isCollapsed()) {
+              return 'enabled';
+            }
+            block = block.getNextBlock();
           }
-          block = block.getNextBlock();
         }
+        return 'disabled';
       }
-      return 'disabled';
-    }
-    return 'hidden';
+      return 'hidden';
+    },
+    callback: function(/** @type {!Blockly.ContextMenuRegistry.Scope} */ scope) {
+      Blockly.ContextMenuItems.toggleOption_(false, scope.workspace.getTopBlocks(true));
+    },
+    scopeType: Blockly.ContextMenuRegistry.ScopeType.WORKSPACE,
+    id: 'toggleWorkspace',
+    weight: 0,
   };
-  expandOption.callback = function(scope) {
-    Blockly.ContextMenuItems.toggleOption_(false, scope.workspace.getTopBlocks(true));
-  };
-  expandOption.scopeType = Blockly.ContextMenuRegistry.ScopeType.WORKSPACE;
-  expandOption.id = 'toggleWorkspace';
-  expandOption.weight = 0;
   Blockly.ContextMenuRegistry.registry.register(expandOption);
 };
   
@@ -218,42 +228,51 @@ Blockly.ContextMenuItems.deleteNext_ = function(deleteList, eventGroup) {
   
 /** Option to delete all blocks. */
 Blockly.ContextMenuItems.registerDeleteAll = function() {
-  var deleteOption = {};
-  deleteOption.displayText = function(scope) {
-    var deletableBlocksLength =
-        Blockly.ContextMenuItems.getDeletableBlocks_(scope.workspace).length;
-    if (deletableBlocksLength == 1) {
-      return Blockly.Msg['DELETE_BLOCK'];
-    } else {
-      return Blockly.Msg['DELETE_X_BLOCKS'].replace('%1', String(deletableBlocksLength));
-    }
+  /** @type {!Blockly.ContextMenuRegistry.RegistryItem} */
+  var deleteOption = {
+    displayText: function(/** @type {!Blockly.ContextMenuRegistry.Scope} */ scope) {
+      if (!scope.workspace) {
+        return;
+      }
+      var deletableBlocksLength =
+          Blockly.ContextMenuItems.getDeletableBlocks_(scope.workspace).length;
+      if (deletableBlocksLength == 1) {
+        return Blockly.Msg['DELETE_BLOCK'];
+      } else {
+        return Blockly.Msg['DELETE_X_BLOCKS'].replace('%1', String(deletableBlocksLength));
+      }
+    },
+    preconditionFn: function(/** @type {!Blockly.ContextMenuRegistry.Scope} */ scope) {
+      if (!scope.workspace) {
+        return;
+      }
+      var deletableBlocksLength =
+         Blockly.ContextMenuItems.getDeletableBlocks_(scope.workspace).length;
+      return deletableBlocksLength > 0 ? 'enabled' : 'disabled';
+    },
+    callback: function(/** @type {!Blockly.ContextMenuRegistry.Scope} */ scope) {
+      if (!scope.workspace) {
+        return;
+      }
+      scope.workspace.cancelCurrentGesture();
+      var deletableBlocks = Blockly.ContextMenuItems.getDeletableBlocks_(scope.workspace);
+      var eventGroup = Blockly.utils.genUid();
+      if (deletableBlocks.length < 2) {
+        Blockly.ContextMenuItems.deleteNext_(deletableBlocks, eventGroup);
+      } else {
+        Blockly.confirm(
+            Blockly.Msg['DELETE_ALL_BLOCKS'].replace('%1', deletableBlocks.length),
+            function(ok) {
+              if (ok) {
+                Blockly.ContextMenuItems.deleteNext_(deletableBlocks, eventGroup);
+              }
+            });
+      }
+    },
+    scopeType: Blockly.ContextMenuRegistry.ScopeType.WORKSPACE,
+    id: 'workspaceDelete',
+    weight: 0,
   };
-  deleteOption.preconditionFn = function(scope) {
-    var deletableBlocksLength =
-        Blockly.ContextMenuItems.getDeletableBlocks_(scope.workspace).length;
-    return deletableBlocksLength > 0 ? 'enabled' : 'disabled';
-  };
-  deleteOption.callback = function(scope) {
-    if (scope.workspace.currentGesture_) {
-      scope.workspace.currentGesture_.cancel();
-    }
-    var deletableBlocks = Blockly.ContextMenuItems.getDeletableBlocks_(scope.workspace);
-    var eventGroup = Blockly.utils.genUid();
-    if (deletableBlocks.length < 2) {
-      Blockly.ContextMenuItems.deleteNext_(deletableBlocks, eventGroup);
-    } else {
-      Blockly.confirm(
-          Blockly.Msg['DELETE_ALL_BLOCKS'].replace('%1', deletableBlocks.length),
-          function(ok) {
-            if (ok) {
-              Blockly.ContextMenuItems.deleteNext_(deletableBlocks, eventGroup);
-            }
-          });
-    }
-  };
-  deleteOption.scopeType = Blockly.ContextMenuRegistry.ScopeType.WORKSPACE;
-  deleteOption.id = 'workspaceDelete';
-  deleteOption.weight = 0;
   Blockly.ContextMenuRegistry.registry.register(deleteOption);
 };
 
@@ -270,6 +289,239 @@ Blockly.ContextMenuItems.registerWorkspaceOptions_ = function() {
   Blockly.ContextMenuItems.registerDeleteAll();
 };
 
+/** Option to duplicate a block. */
+Blockly.ContextMenuItems.registerDuplicate = function() {
+  /** @type {!Blockly.ContextMenuRegistry.RegistryItem} */
+  var duplicateOption = {
+    displayText: function() {
+      return Blockly.Msg['DUPLICATE_BLOCK'];
+    },
+    preconditionFn: function(/** @type {!Blockly.ContextMenuRegistry.Scope} */ scope) {
+      var block = scope.block;
+      if (!block.isInFlyout && block.isDeletable() && block.isMovable()) {
+        if (block.isDuplicatable()) {
+          return 'enabled';
+        }
+        return 'disabled';
+      }
+      return 'hidden';
+    },
+    callback: function(/** @type {!Blockly.ContextMenuRegistry.Scope} */ scope) {
+      if (scope.block) {
+        Blockly.duplicate(scope.block);
+      }
+    },
+    scopeType: Blockly.ContextMenuRegistry.ScopeType.BLOCK,
+    id: 'blockDuplicate',
+    weight: 0,
+  };
+  Blockly.ContextMenuRegistry.registry.register(duplicateOption);
+};
+
+/** Option to add or remove block-level comment. */
+Blockly.ContextMenuItems.registerComment = function() {
+  /** @type {!Blockly.ContextMenuRegistry.RegistryItem} */
+  var commentOption = {
+    displayText: function(/** @type {!Blockly.ContextMenuRegistry.Scope} */ scope) {
+      if (scope.block.getCommentIcon()) {
+        // If there's already a comment,  option is to remove.
+        return Blockly.Msg['REMOVE_COMMENT'];
+      }
+      // If there's no comment yet, option is to add.
+      return Blockly.Msg['ADD_COMMENT'];
+    },
+    preconditionFn: function(/** @type {!Blockly.ContextMenuRegistry.Scope} */ scope) {
+      var block = scope.block;
+      // IE doesn't support necessary features for comment editing.
+      if (!Blockly.utils.userAgent.IE && !block.isInFlyout && block.workspace.options.comments &&
+        !block.isCollapsed() && block.isEditable()) {
+        return 'enabled';
+      }
+      return 'hidden';
+    },
+    callback: function(/** @type {!Blockly.ContextMenuRegistry.Scope} */ scope) {
+      var block = scope.block;
+      if (block.getCommentIcon()) {
+        block.setCommentText(null);
+      } else {
+        block.setCommentText('');
+      }
+    },
+    scopeType: Blockly.ContextMenuRegistry.ScopeType.BLOCK,
+    id: 'blockComment',
+    weight: 0,
+  };
+  Blockly.ContextMenuRegistry.registry.register(commentOption);
+};
+
+/** Option to inline variables. */
+Blockly.ContextMenuItems.registerInline = function() {
+  /** @type {!Blockly.ContextMenuRegistry.RegistryItem} */
+  var inlineOption = {
+    displayText: function(/** @type {!Blockly.ContextMenuRegistry.Scope} */ scope) {
+      return (scope.block.getInputsInline()) ?
+          Blockly.Msg['EXTERNAL_INPUTS'] : Blockly.Msg['INLINE_INPUTS'];
+    },
+    preconditionFn: function(/** @type {!Blockly.ContextMenuRegistry.Scope} */ scope) {
+      var block = scope.block;
+      if (!block.isInFlyout && block.isMovable() && !block.isCollapsed()) {
+        for (var i = 1; i < block.inputList.length; i++) {
+          // Only display this option if there are two value or dummy inputs next to each other.
+          if (block.inputList[i - 1].type != Blockly.NEXT_STATEMENT &&
+              block.inputList[i].type != Blockly.NEXT_STATEMENT) {
+            return 'enabled';
+          }
+        }
+      }
+      return 'hidden';
+    },
+    callback: function(/** @type {!Blockly.ContextMenuRegistry.Scope} */ scope) {
+      scope.block.setInputsInline(!scope.block.getInputsInline());
+    },
+    scopeType: Blockly.ContextMenuRegistry.ScopeType.BLOCK,
+    id: 'blockInline',
+    weight: 0,
+  };
+  Blockly.ContextMenuRegistry.registry.register(inlineOption);
+};
+
+/** Option to collapse or expand a block. */
+Blockly.ContextMenuItems.registerCollapseExpandBlock = function() {
+  /** @type {!Blockly.ContextMenuRegistry.RegistryItem} */
+  var collapseExpandOption = {
+    displayText: function(/** @type {!Blockly.ContextMenuRegistry.Scope} */ scope) {
+      if (scope.block.isCollapsed()) {
+        return Blockly.Msg['EXPAND_BLOCK'];
+      }
+      return Blockly.Msg['COLLAPSE_BLOCK'];
+    },
+    preconditionFn: function(/** @type {!Blockly.ContextMenuRegistry.Scope} */ scope) {
+      var block = scope.block;
+      if (!block.isInFlyout && block.isMovable()) {
+        return 'enabled';
+      }
+      return 'hidden';
+    },
+    callback: function(/** @type {!Blockly.ContextMenuRegistry.Scope} */ scope) {
+      scope.block.setCollapsed(!scope.block.isCollapsed());
+    },
+    scopeType: Blockly.ContextMenuRegistry.ScopeType.BLOCK,
+    id: 'blockCollapseExpand',
+    weight: 0,
+  };
+  Blockly.ContextMenuRegistry.registry.register(collapseExpandOption);
+};
+
+/** Option to disable or enable a block. */
+Blockly.ContextMenuItems.registerDisable = function() {
+  /** @type {!Blockly.ContextMenuRegistry.RegistryItem} */
+  var disableOption = {
+    displayText: function(/** @type {!Blockly.ContextMenuRegistry.Scope} */ scope) {
+      return (scope.block.isEnabled()) ?
+          Blockly.Msg['DISABLE_BLOCK'] : Blockly.Msg['ENABLE_BLOCK'];
+    },
+    preconditionFn: function(/** @type {!Blockly.ContextMenuRegistry.Scope} */ scope) {
+      var block = scope.block;
+      if (!block.isInFlyout && block.workspace.options.disable && block.isEditable()) {
+        if (block.getInheritedDisabled()) {
+          return 'disabled';
+        }
+        return 'enabled';
+      }
+      return 'hidden';
+    },
+    callback: function(/** @type {!Blockly.ContextMenuRegistry.Scope} */ scope) {
+      var block = scope.block;
+      var group = Blockly.Events.getGroup();
+      if (!group) {
+        Blockly.Events.setGroup(true);
+      }
+      block.setEnabled(!block.isEnabled());
+      if (!group) {
+        Blockly.Events.setGroup(false);
+      }
+    },
+    scopeType: Blockly.ContextMenuRegistry.ScopeType.BLOCK,
+    id: 'blockDisable',
+    weight: 0,
+  };
+  Blockly.ContextMenuRegistry.registry.register(disableOption);
+};
+
+/** Option to delete a block. */
+Blockly.ContextMenuItems.registerDelete = function() {
+  /** @type {!Blockly.ContextMenuRegistry.RegistryItem} */
+  var deleteOption = {
+    displayText: function(/** @type {!Blockly.ContextMenuRegistry.Scope} */ scope) {
+      var block = scope.block;
+      // Count the number of blocks that are nested in this block.
+      var descendantCount = block.getDescendants(false).length;
+      var nextBlock = block.getNextBlock();
+      if (nextBlock) {
+        // Blocks in the current stack would survive this block's deletion.
+        descendantCount -= nextBlock.getDescendants(false).length;
+      }
+      return (descendantCount == 1) ? Blockly.Msg['DELETE_BLOCK'] :
+          Blockly.Msg['DELETE_X_BLOCKS'].replace('%1', String(descendantCount));
+    },
+    preconditionFn: function(/** @type {!Blockly.ContextMenuRegistry.Scope} */ scope) {
+      if (!scope.block.isInFlyout && scope.block.isDeletable()) {
+        return 'enabled';
+      }
+      return 'hidden';
+    },
+    callback: function(/** @type {!Blockly.ContextMenuRegistry.Scope} */ scope) {
+      Blockly.Events.setGroup(true);
+      scope.block.dispose(true, true);
+      Blockly.Events.setGroup(false);
+    },
+    scopeType: Blockly.ContextMenuRegistry.ScopeType.BLOCK,
+    id: 'blockDelete',
+    weight: 0,
+  };
+  Blockly.ContextMenuRegistry.registry.register(deleteOption);
+};
+
+/** Option to open help for a block. */
+Blockly.ContextMenuItems.registerHelp = function() {
+  /** @type {!Blockly.ContextMenuRegistry.RegistryItem} */
+  var helpOption = {
+    displayText: function() {
+      return Blockly.Msg['HELP'];
+    },
+    preconditionFn: function(/** @type {!Blockly.ContextMenuRegistry.Scope} */ scope) {
+      var block = scope.block;
+      var url = (typeof block.helpUrl == 'function') ?
+          block.helpUrl() : block.helpUrl;
+      if (url) {
+        return 'enabled';
+      }
+      return 'hidden';
+    },
+    callback: function(/** @type {!Blockly.ContextMenuRegistry.Scope} */ scope) {
+      scope.block.showHelp();
+    },
+    scopeType: Blockly.ContextMenuRegistry.ScopeType.BLOCK,
+    id: 'blockHelp',
+    weight: 0,
+  };
+  Blockly.ContextMenuRegistry.registry.register(helpOption);
+};
+
+/**
+ * Registers all block-scoped context menu items.
+ * @private
+ */
+Blockly.ContextMenuItems.registerBlockOptions_ = function() {
+  Blockly.ContextMenuItems.registerDuplicate();
+  Blockly.ContextMenuItems.registerComment();
+  Blockly.ContextMenuItems.registerInline();
+  Blockly.ContextMenuItems.registerCollapseExpandBlock();
+  Blockly.ContextMenuItems.registerDisable();
+  Blockly.ContextMenuItems.registerDelete();
+  Blockly.ContextMenuItems.registerHelp();
+};
+
 /**
  * Registers all default context menu items. This should be called once per instance of
  * ContextMenuRegistry.
@@ -277,5 +529,6 @@ Blockly.ContextMenuItems.registerWorkspaceOptions_ = function() {
  */
 Blockly.ContextMenuItems.registerDefaultOptions = function() {
   Blockly.ContextMenuItems.registerWorkspaceOptions_();
+  Blockly.ContextMenuItems.registerBlockOptions_();
 };
   

core/workspace.js

@@ -558,6 +558,24 @@ Blockly.Workspace.prototype.hasBlockLimits = function() {
   return this.options.maxBlocks != Infinity || !!this.options.maxInstances;
 };
 
+/**
+ * Gets the undo stack for workplace.
+ * @return {!Array.<!Blockly.Events.Abstract>} undo stack
+ * @package
+ */
+Blockly.Workspace.prototype.getUndoStack = function() {
+  return this.undoStack_;
+};
+
+/**
+ * Gets the redo stack for workplace.
+ * @return {!Array.<!Blockly.Events.Abstract>} redo stack
+ * @package
+ */
+Blockly.Workspace.prototype.getRedoStack = function() {
+  return this.redoStack_;
+};
+
 /**
  * Undo or redo the previous action.
  * @param {boolean} redo False if undo, true if redo.