When developing a chess game today, I stumbled upon a peculiar behavior in Chromium browsers while implementing draggable elements. If you've ever noticed that dragging an element causes it to inherit its parent’s background, you're not alone. This odd effect can be quite a nuisance, but fortunately, there are ways to fix it.

 

Understanding the Issue

The issue arises when a draggable element seems to take on the background of its parent element during the drag action. This can lead to unexpected and unwanted visual results, especially if the parent element's background is distinct or patterned.

To understand why this happens, let's delve into some technical insights:

• The HTML draggable attribute (draggable="true") seems to force the element to inherit the parent’s background.

• According to the HTML Living Standard, the drag data store default feedback is dependent on the user agent (browser). This means different browsers might handle draggable elements differently.

Here's a snippet from the HTML Living Standard that highlights this:

"Update the drag data store default feedback as appropriate for the user agent. If the user is dragging the selection, then the selection would likely be the basis for this feedback; if the user is dragging an element, then that element's rendering would be used; if the drag began outside the user agent, then the platform conventions for determining the drag feedback should be used."

Because of this browser-dependent behavior, the default feedback during a drag action can vary, making it challenging to create a consistent user experience.

 

Fixing the Issue

Through some research and experimentation, I found two effective ways to fix this issue:

• Using position: relative and z-index: By setting the draggable element’s position to relative and applying a z-index, you can ensure it retains its own background.

[draggable] { position: relative; z-index: 1; }

• Using CSS Transforms: Applying a small transformation to the draggable element can also resolve the issue.

[draggable] { transform: translate(0,0); }

 

Why These Fixes Work

1. position and z-index: By setting the position to relative and giving it a z-index, you force the element to create a new stacking context. This prevents the draggable element from inheriting the parent’s background during the drag operation.

2. CSS Transforms: Using a small transformation disrupts the default rendering process enough to ensure that the draggable element maintains its own background. The translateX and translateY values can be minimal and should not visibly affect the element’s position.

 

Conclusion

Browser inconsistencies can be frustrating, especially when dealing with visual feedback during drag-and-drop operations. By understanding the underlying causes and applying these CSS fixes, you can ensure your draggable elements display correctly across different browsers.

Have you encountered any other weird browser behaviors? Share your experiences and solutions in the comments below!

 

Photo by Denny Müller on Unsplash