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)

Chrome Compositor Architecture: LayerTreeHost and LayerTreeHostImpl

Chrome Compositor Architecture: LayerTreeHost and LayerTreeHostImpl

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3 Loka 202534min

Chromium Blink's Layer Recycle Tree Optimization

Chromium Blink's Layer Recycle Tree Optimization

The sources provide an extensive technical explanation of the Chromium/Blink rendering pipeline, focusing specifically on the compositor's layer trees and a performance optimization known as the Recyc...

3 Loka 202529min

Chromium Compositor's CalculateDrawProperties: Scrolling and Overscroll

Chromium Compositor's CalculateDrawProperties: Scrolling and Overscroll

The sources provide an extremely detailed, line-by-line breakdown of the Chromium compositor function CalculateDrawProperties, explaining how it prepares the active layer tree for rendering. A primary...

3 Loka 202530min

Git Rebase and Interactive Rebase for Chromium Development

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The sources provide a comprehensive guide to Git rebasing and interactive rebasing, explaining how these powerful tools rewrite commit history to maintain a clean, linear project record. They detail t...

2 Loka 202536min

Chrome Finch System Technical Guide and Rollouts

Chrome Finch System Technical Guide and Rollouts

The source text provides an exhaustive technical guide to Chrome’s Finch (Variations) system, a mechanism used for running field trials and A/B experiments to control browser features remotely. This s...

1 Loka 20251h 14min

Chromium Compositor Input: Handler and Proxy Deep Dive

Chromium Compositor Input: Handler and Proxy Deep Dive

The source provides a detailed technical analysis of how the Chromium web browser manages user input to ensure a responsive and smooth user experience, even when the main thread is occupied. It center...

1 Loka 202531min

Current Overscroll System Architecture Deep Dive

Current Overscroll System Architecture Deep Dive

The provided document offers an in-depth technical architectural overview of the overscroll system, primarily within the Chromium browser. It explains how browsers handle scroll gestures that go beyon...

29 Syys 202535min

cc Transform and Scroll Trees

cc Transform and Scroll Trees

The source text details the architecture of Chromium's compositor, focusing on the tandem operation of two critical data structures: the Transform Tree and the Scroll Tree. The Transform Tree manages ...

28 Syys 202527min