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(391)

7 Blink View Transition Discovery and UA Stylesheet Generation

7 Blink View Transition Discovery and UA Stylesheet Generation

This document details how the Blink rendering engine manages the technical lifecycle of View Transitions by coordinating DOM updates with visual animations. Once a developer triggers a transition, the...

27 Tammi 31min

6 Blink and Compositor Handshake in View Transitions

6 Blink and Compositor Handshake in View Transitions

The provided text explains the technical handshake between the Blink rendering engine and the compositor during a web view transition. To ensure visual continuity, the system captures a snapshot of th...

27 Tammi 30min

Evolution of CSS: Working Group Drafts and Processes

Evolution of CSS: Working Group Drafts and Processes

The provided text outlines the operations and standardizing procedures of the W3C CSS Working Group, which manages the evolution of web presentation through a modular specification system. It details ...

27 Tammi 38min

5 View Transition Mechanics: Pre-paint and Snapshot Coordination

5 View Transition Mechanics: Pre-paint and Snapshot Coordination

The provided text explains how the Blink rendering engine manages view transitions by utilizing a stable coordinate space known as the snapshot root. This mechanism ensures that animations remain cons...

27 Tammi 27min

4 Blink View Transition Pseudo-Element Tree and Layout Integration

4 Blink View Transition Pseudo-Element Tree and Layout Integration

The provided text explains how the Blink rendering engine manages View Transitions by generating a temporary pseudo-element subtree to represent page changes. This system acts as an overlay, capturing...

26 Tammi 39min

GEM Modern CSS Scroll Positioning and Visibility Specifications

GEM Modern CSS Scroll Positioning and Visibility Specifications

These sources detail the CSS and DOM specifications that govern how elements are positioned and animated when moved into a user's visible area. The documentation introduces scroll-padding and scroll-m...

25 Tammi 33min

[GENERAL] Modern CSS Scroll Positioning and Visibility Specifications

[GENERAL] Modern CSS Scroll Positioning and Visibility Specifications

These sources collectively define the technical standards for how web browsers handle scrolling and element visibility. The documentation details the CSSOM View Module's specific algorithm for the scr...

25 Tammi 30min

Modern CSS Scroll Positioning and Visibility Specifications

Modern CSS Scroll Positioning and Visibility Specifications

These sources collectively define the technical standards for scroll-into-view behavior within modern CSS specifications, covering how elements are positioned and animated when navigated to or targete...

25 Tammi 38min