From a0e90627f7c7b81393d912b2a48d4d7165040b88 Mon Sep 17 00:00:00 2001
From: Rachel Fenichel <fenichel@google.com>
Date: Thu, 13 Sep 2018 13:37:21 -0700
Subject: [PATCH] Add some functions for insertion markers

---
 core/block.js     | 72 +++++++++++++++++++++++++++++++++++++++++++++++
 core/block_svg.js | 18 ++++++++++++
 2 files changed, 90 insertions(+)

diff --git a/core/block.js b/core/block.js
index 8b451bd6c..32262446c 100644
--- a/core/block.js
+++ b/core/block.js
@@ -146,6 +146,13 @@ Blockly.Block = function(workspace, prototypeName, opt_id) {
   /** @type {boolean} */
   this.RTL = workspace.RTL;
 
+  /**
+   * True if this block is an insertion marker.
+   * @type {boolean}
+   * @protected
+   */
+  this.isInsertionMarker_ = false;
+
   // Copy the type-specific functions and data from the prototype.
   if (prototypeName) {
     /** @type {string} */
@@ -508,6 +515,29 @@ Blockly.Block.prototype.getNextBlock = function() {
   return this.nextConnection && this.nextConnection.targetBlock();
 };
 
+/**
+ * Return the previous statement block directly connected to this block.
+ * @return {Blockly.Block} The previous statement block or null.
+ */
+Blockly.Block.prototype.getPreviousBlock = function() {
+  return this.previousConnection && this.previousConnection.targetBlock();
+};
+
+/**
+ * Return the connection on the first statement input on this block, or null if
+ * there are none.
+ * @return {Blockly.Connection} The first statement connection or null.
+ * @package
+ */
+Blockly.Block.prototype.getFirstStatementConnection = function() {
+  for (var i = 0, input; input = this.inputList[i]; i++) {
+    if (input.connection && input.connection.type == Blockly.NEXT_STATEMENT) {
+      return input.connection;
+    }
+  }
+  return null;
+};
+
 /**
  * Return the top-most block in this block's tree.
  * This will return itself if this block is at the top level.
@@ -655,6 +685,25 @@ Blockly.Block.prototype.setShadow = function(shadow) {
   this.isShadow_ = shadow;
 };
 
+/**
+ * Get whether this block is an insertion marker block or not.
+ * @return {boolean} True if an insertion marker.
+ * @package
+ */
+Blockly.Block.prototype.isInsertionMarker = function() {
+  return this.isInsertionMarker_;
+};
+
+/**
+ * Set whether this block is an insertion marker block or not.
+ * Once set this cannot be unset.
+ * @param {boolean} insertionMarker True if an insertion marker.
+ * @package
+ */
+Blockly.Block.prototype.setInsertionMarker = function(insertionMarker) {
+  this.isInsertionMarker_ = insertionMarker;
+};
+
 /**
  * Get whether this block is editable or not.
  * @return {boolean} True if editable.
@@ -710,6 +759,29 @@ Blockly.Block.prototype.setConnectionsHidden = function(hidden) {
   }
 };
 
+/**
+ * Find the connection on this block that corresponds to the given connection
+ * on the other block.
+ * Used to match connections between a block and its insertion marker.
+ * @param {!Blockly.Block} otherBlock The other block to match against.
+ * @param {!Blockly.Connection} conn The other connection to match.
+ * @return {Blockly.Connection} the matching connection on this block, or null.
+ * @package
+ */
+Blockly.Block.prototype.getMatchingConnection = function(otherBlock, conn) {
+  var connections = this.getConnections_(true);
+  var otherConnections = otherBlock.getConnections_(true);
+  if (connections.length != otherConnections.length) {
+    throw Error("Connection lists did not match in length.");
+  }
+  for (var i = 0; i < otherConnections.length; i++) {
+    if (otherConnections[i] == conn) {
+      return connections[i];
+    }
+  }
+  return null;
+};
+
 /**
  * Set the URL of this block's help page.
  * @param {string|Function} url URL string for block help, or function that
diff --git a/core/block_svg.js b/core/block_svg.js
index 54445d3ff..83dd77a8f 100644
--- a/core/block_svg.js
+++ b/core/block_svg.js
@@ -794,6 +794,24 @@ Blockly.BlockSvg.prototype.setShadow = function(shadow) {
   this.updateColour();
 };
 
+/**
+ * Set whether this block is an insertion marker block or not.
+ * Once set this cannot be unset.
+ * @param {boolean} insertionMarker True if an insertion marker.
+ * @package
+ */
+Blockly.BlockSvg.prototype.setInsertionMarker = function(insertionMarker) {
+  if (this.isInsertionMarker_ == insertionMarker) {
+    return;  // No change.
+  }
+  this.isInsertionMarker_ = insertionMarker;
+  if (this.isInsertionMarker_) {
+    this.setColour(Blockly.INSERTION_MARKER_COLOUR);
+    Blockly.utils.addClass(/** @type {!Element} */ (this.svgGroup_),
+        'blocklyInsertionMarker');
+  }
+};
+
 /**
  * Return the root node of the SVG or null if none exists.
  * @return {Element} The root SVG node (probably a group).