blink::EventHandler (Blink core input handling)
Blink28623 Syys 2025

blink::EventHandler (Blink core input handling)

Scroll chain builder and overscroll chaining logic. Blink’s EventHandler is responsible for building the scroll chain (the sequence of nested scrollable ancestors) when the user scrolls an element . It determines how scroll events propagate up through parent containers and when to terminate the chain. Crucially, it respects the CSS overscroll-behavior of each element to decide if overscroll should propagate or stop at that element. For example, if an inner element is scrolled to its boundary, by default the scroll chains to its parent – but if that element’s style has overscroll-behavior: contain or none, the chain is broken and the overscroll is handled locally . To implement non-root elastic overscroll, one must modify how EventHandler (and associated scroll logic) interprets these style flags and sends overscroll events: instead of always bubbling to the root, it should allow an overscroll at the element itself when appropriate. In short, EventHandler is where the blink style system meets input: it ensures the scroll chain and overscroll-behavior rules are applied, so the developer must understand it to route overscroll to non-root scrollers.

Jaksot(392)

View Transitions Flow

View Transitions Flow

17 Joulu 202548min

CSS Ink Overflow: Definition, Effects, and Clipping

CSS Ink Overflow: Definition, Effects, and Clipping

The provided text offers a comprehensive technical exploration of ink overflow in CSS, distinguishing it from scrollable overflow. Ink overflow is defined as purely decorative or visual effects—like s...

16 Joulu 202540min

Blink’s CSS Bucketing and Style Resolution Optimization

Blink’s CSS Bucketing and Style Resolution Optimization

The provided source offers a highly detailed internal technical analysis of CSS "bucketing" within Chrome's Blink engine, which is the mechanism used to optimize CSS style matching by partitioning rul...

16 Joulu 202536min

Blink PaintPropertyTreeBuilder: Lifecycle, Operation, and Integration

Blink PaintPropertyTreeBuilder: Lifecycle, Operation, and Integration

The provided text offers a comprehensive technical examination of the PaintPropertyTreeBuilder within Blink’s rendering engine, detailing its function during the PrePaint phase of the document lifecyc...

16 Joulu 202531min

Blink's Flat Tree, Slotting, and Shadow DOM Internals

Blink's Flat Tree, Slotting, and Shadow DOM Internals

The provided text explains the internal workings of slotting and the flat tree within the Chromium/Blink rendering engine, detailing how Shadow DOM encapsulation is reconciled with the structure used ...

16 Joulu 202537min

CSS Scroll Mechanics and Blink Implementation Deep Dive

CSS Scroll Mechanics and Blink Implementation Deep Dive

The provided text is a deep technical analysis of CSS layout, scrolling, and Blink (Chromium) implementation, focusing heavily on modern web engine architecture. It begins by explaining fundamental CS...

14 Joulu 202559min

CSS Selectors Level 4: Specificity, Performance, and Scoping

CSS Selectors Level 4: Specificity, Performance, and Scoping

The provided text offers a comprehensive technical overview of CSS Selectors Level 4, detailing its fundamental role in binding style declarations to elements and its broad utility across CSS and Java...

13 Joulu 202528min

CSS Values and Units Level 4: The Foundation

CSS Values and Units Level 4: The Foundation

The provided document is an extensive technical overview of the CSS Values and Units Module Level 4, which defines the foundational system for how all values, units, and mathematical expressions are p...

13 Joulu 202527min