angular / angular/components

bug(CdkDragDrop): reordering smaller against larger items produce flickering effect

Open
#28,266 3 comments 0 reactions 0 assignees View on GitHub
area: cdk/drag-drop P4
Dominant language
TypeScript
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Description

### Is this a regression?

- [ ] Yes, this behavior used to work in the previous version

### The previous version in which this bug was not present was

_No response_

### Description

When using CdkDragDrop for reordering items with different sizes (e.g. width for horizontal orientation) in a container with greater height then of the elements there is a flickering effects. CdkDragDrop moves larger item really quickly from one side to another.

Try to drag "Iron age" over empty space in container against some wider item (e.g. "Early modern period")

Example uses angular 12, but in angular 17 it works the same.

### Reproduction

StackBlitz link: https://stackblitz.com/edit/angular-fhqz1h?file=src%2Fapp%2Fcdk-drag-drop-horizontal-sorting-example.css,src%2Fapp%2Fcdk-drag-drop-horizontal-sorting-example.ts,src%2Fapp%2Fcdk-drag-drop-horizontal-sorting-example.html

### Expected Behavior

Reorder elements without flickering effects, as it is when reordering elements of the same size or when container is not larger (e.g. greater height for horizontal list).

### Actual Behavior

Larger element in the list that is reordered against moves fast from one side to another.

### Environment

- Angular: 12
- CDK/Material: 12
- Browser(s): any
- Operating System (e.g. Windows, macOS, Ubuntu): any

Contributor guide

Open the contributing guide

Research direction

Start by running the linked StackBlitz reproduction and inspect src/app/cdk-drag-drop-horizontal-sorting-example.css, .ts, and .html. Reproduce dragging “Iron age” over empty space against “Early modern period,” then trace the horizontal CdkDragDrop sorting behavior. Done means differently sized items reorder without flickering, matching same-size and shorter-container behavior.

Written by the indexing model from the issue text.

Assessment

Tech stack
angular, typescript
Domain
frontend
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
45/100

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