Horizontal playground: dragged block appears ~200 px to the left of cursor

[msintov]

Expected Behavior

Block should appear under cursor during drag.

Actual Behavior

Block appears about ~200px to the left of cursor during drag.

Steps to Reproduce

1. Edit scratch-blocks/tests/horizontal_playground.html to turn off scrollbars:
   scrollbars: false,

2. Open scratch-blocks/tests/horizontal playground html in browser

3. Move toolbox to the bottom by selecting "Bottom" from dropdown

4. Select a block with your mouse and drag it to the workspace

Actual results: block appears ~200px to the left of your cursor
Expected results: block appears under cursor

Note: This issue appears to only affect the initial drag out from toolbox. After the initial drag out from the toolbox, the block DOES correctly appear under the cursor during the drag.

Operating System and Browser

Mac OS 10.11.6 Chrome 57

[thisandagain]

@rachel-fenichel Do you have any thoughts on this?

[rachel-fenichel]

Probably an issue in this function: https://github.com/LLK/scratch-blocks/blob/develop/core/flyout_horizontal.js#L389

[rachel-fenichel]

Is this with categories or with a simple toolbox?

[msintov]

Thanks for asking. It's with categories.

[rachel-fenichel]

Probably related: google/blockly#728