Added context menu items to show and hide all comments

This commit adds two new options to the block editor's context menu to
show and hide all the comments on the workspace.
Resolves #1422

appinventor/blocklyeditor/src/msg/en/_messages.js

@@ -90,6 +90,8 @@ Blockly.Msg.en.switch_language_to_english = {
     Blockly.Msg.DISABLE_SNAPPING = 'Disable Snap to Grid';
     Blockly.Msg.DISABLE_ALL_BLOCKS = 'Disable All Blocks';
     Blockly.Msg.ENABLE_ALL_BLOCKS = 'Enable All Blocks';
+    Blockly.Msg.HIDE_ALL_COMMENTS = 'Hide All Comments';
+    Blockly.Msg.SHOW_ALL_COMMENTS = 'Show All Comments';
 
 // Variable renaming.
     Blockly.MSG_CHANGE_VALUE_TITLE = 'Change value:';

appinventor/blocklyeditor/src/workspace_svg.js

@@ -740,6 +740,36 @@ Blockly.WorkspaceSvg.prototype.customContextMenu = function(menuOptions) {
   };
   menuOptions.push(disableAll);
 
+  // Show all comments
+  var showAll = {enabled: true};
+  showAll.text = Blockly.Msg.SHOW_ALL_COMMENTS;
+  showAll.callback = function() {
+    var allBlocks = Blockly.mainWorkspace.getAllBlocks();
+    Blockly.Events.setGroup(true);
+    for (var x = 0, block; block = allBlocks[x]; x++) {
+      if (block.comment != null) {
+        block.comment.setVisible(true);
+      }
+    }
+    Blockly.Events.setGroup(false);
+  };
+  menuOptions.push(showAll);
+
+  // Hide all comments
+  var hideAll = {enabled: true};
+  hideAll.text = Blockly.Msg.HIDE_ALL_COMMENTS;
+  hideAll.callback = function() {
+    var allBlocks = Blockly.mainWorkspace.getAllBlocks();
+    Blockly.Events.setGroup(true);
+    for (var x = 0, block; block = allBlocks[x]; x++) {
+      if (block.comment != null) {
+        block.comment.setVisible(false);
+      }
+    }
+    Blockly.Events.setGroup(false);
+  };
+  menuOptions.push(hideAll);
+
   // Retrieve from backpack option.
   var backpackRetrieve = {enabled: true};
   backpackRetrieve.text = Blockly.Msg.BACKPACK_GET + " (" +