feat: Enable blocks during drags (#9935)

* feat: Enable disabled blocks while dragging

* test: Add tests

packages/blockly/core/dragging/block_drag_strategy.ts

@@ -92,6 +92,12 @@ export class BlockDragStrategy implements IDragStrategy {
   /** Used to persist an event group when snapping is done async. */
   private originalEventGroup = '';
 
+  /**
+   * Map from block IDs to reason(s) why it was disabled, used to restore
+   * disabled state post-drag.
+   */
+  private lastBlockDisabledReasons: Map<string, Set<string>> = new Map();
+
   protected readonly BLOCK_CONNECTION_OFFSET = 10;
 
   /**
@@ -338,6 +344,9 @@ export class BlockDragStrategy implements IDragStrategy {
 
     this.block.setDragging(true);
 
+    // Enable all blocks including children.
+    this.enableAllDraggedBlocks(this.block);
+
     // For keyboard-driven moves, cache a list of valid connection points for
     // use in constrained moved mode.
     if (e instanceof KeyboardEvent) {
@@ -885,6 +894,9 @@ export class BlockDragStrategy implements IDragStrategy {
       );
 
       this.block.setDragging(false);
+
+      // Re-disable the block for its original reasons.
+      this.redisableAllDraggedBlocks(this.block);
     }
 
     if (this.connectionCandidate) {
@@ -979,6 +991,8 @@ export class BlockDragStrategy implements IDragStrategy {
     this.startParentConn = null;
 
     this.block.setDragging(false);
+    // Re-disable the block for its original reasons.
+    this.redisableAllDraggedBlocks(this.block);
     this.dragging = false;
     aria.announceDynamicAriaState(Msg['ANNOUNCE_MOVE_CANCELED']);
   }
@@ -1236,4 +1250,41 @@ export class BlockDragStrategy implements IDragStrategy {
         ? MoveMode.CONSTRAINED
         : MoveMode.UNCONSTRAINED;
   }
+
+  /**
+   * Enables the given block and its children.
+   * Stores the reasons each block was disabled so they can be restored.
+   *
+   * @param block The block to enable.
+   */
+  private enableAllDraggedBlocks(block: BlockSvg) {
+    const oldUndo = eventUtils.getRecordUndo();
+    eventUtils.setRecordUndo(false);
+    this.lastBlockDisabledReasons.clear();
+    // getDescendants includes the block itself.
+    block.getDescendants(false).forEach((descendant) => {
+      const reasons = new Set(descendant.getDisabledReasons());
+      this.lastBlockDisabledReasons.set(descendant.id, reasons);
+      reasons.forEach((reason) => descendant.setDisabledReason(false, reason));
+    });
+    eventUtils.setRecordUndo(oldUndo);
+  }
+
+  /**
+   * Re-disables the given block and its children using their original
+   * disabled reasons.
+   *
+   * @param block The block to re-disable, if applicable.
+   */
+  private redisableAllDraggedBlocks(block: BlockSvg) {
+    console.log('redisable');
+    const oldUndo = eventUtils.getRecordUndo();
+    eventUtils.setRecordUndo(false);
+    block.getDescendants(false).forEach((descendant) => {
+      this.lastBlockDisabledReasons.get(descendant.id)?.forEach((reason) => {
+        descendant.setDisabledReason(true, reason);
+      });
+    });
+    eventUtils.setRecordUndo(oldUndo);
+  }
 }

packages/blockly/tests/mocha/keyboard_movement_test.js

@@ -733,6 +733,52 @@ suite('Keyboard-driven movement', function () {
         cancelMove(this.workspace);
       });
 
+      test('Enables disabled blocks during drag and reenables when committed', function () {
+        const ifBlock = this.workspace.newBlock('controls_if');
+        const repeatBlock = this.workspace.newBlock('controls_repeat');
+        ifBlock.initSvg();
+        ifBlock.render();
+        repeatBlock.initSvg();
+        repeatBlock.render();
+        repeatBlock.previousConnection.connect(
+          ifBlock.getInput('DO0').connection,
+        );
+
+        ifBlock.setDisabledReason(true, 'test');
+        assert.isFalse(ifBlock.isEnabled());
+
+        Blockly.getFocusManager().focusNode(ifBlock);
+        startMove(this.workspace);
+
+        assert.isTrue(ifBlock.isEnabled());
+
+        endMove(this.workspace);
+        assert.isFalse(ifBlock.isEnabled());
+      });
+
+      test('Enables disabled blocks during drag and reenables when cancelled', function () {
+        const ifBlock = this.workspace.newBlock('controls_if');
+        const repeatBlock = this.workspace.newBlock('controls_repeat');
+        ifBlock.initSvg();
+        ifBlock.render();
+        repeatBlock.initSvg();
+        repeatBlock.render();
+        repeatBlock.previousConnection.connect(
+          ifBlock.getInput('DO0').connection,
+        );
+
+        ifBlock.setDisabledReason(true, 'test');
+        assert.isFalse(ifBlock.isEnabled());
+
+        Blockly.getFocusManager().focusNode(ifBlock);
+        startMove(this.workspace);
+
+        assert.isTrue(ifBlock.isEnabled());
+
+        cancelMove(this.workspace);
+        assert.isFalse(ifBlock.isEnabled());
+      });
+
       suite('Statement move tests', function () {
         // Clear the workspace and load start blocks.
         setup(function () {