feat: Add IPathObject.updateReplacing()

Author: gonfunko

core/block_svg.ts

@@ -1735,11 +1735,7 @@ export class BlockSvg
    * @internal
    */
   fadeForReplacement(add: boolean) {
-    if (add) {
-      this.addClass('blocklyReplaceable');
-    } else {
-      this.removeClass('blocklyReplaceable');
-    }
+    this.pathObject.updateReplacing?.(add);
   }
 
   /**

core/renderers/common/i_path_object.ts

@@ -106,4 +106,13 @@ export interface IPathObject {
    * @param blockStyle The block style to use.
    */
   setStyle?(blockStyle: BlockStyle): void;
+
+  /**
+   * Add or remove styling indicating that a block will be bumped out and
+   * replaced by another block that is mid-move.
+   *
+   * @param replacing True if the block is at risk of being replaced, false
+   *     otherwise.
+   */
+  updateReplacing?(replacing: boolean): void;
 }

core/renderers/common/path_object.ts

@@ -191,6 +191,17 @@ export class PathObject implements IPathObject {
     this.setClass_('blocklyDraggable', enable);
   }
 
+  /**
+   * Add or remove styling indicating that a block will be bumped out and
+   * replaced by another block that is mid-move.
+   *
+   * @param replacing True if the block is at risk of being replaced, false
+   *     otherwise.
+   */
+  updateReplacing(replacing: boolean) {
+    this.setClass_('blocklyReplaceable', replacing);
+  }
+
   /** Adds the given path as a connection highlight for the given connection. */
   addConnectionHighlight(
     connection: RenderedConnection,