linebender/druid

Add missing layout widgets

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#659 opened on Mar 14, 2020

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 (3 comments) (0 reactions) (0 assignees)Rust (9,091 stars) (567 forks)batch import
enhancementhelp wanted

Description

There are a number of basic layout widgets in flutter that we don't have.

  • LimitedBox: A widget that checks if incoming constraints are infinite, and constraints them.
  • FittedBox: A widget that fits a child within itself, in a number of ways (fill, fit, fillHeight, etc).
  • FractionallySizedBox: use a fraction of available space
  • AspectRatio: maintain an aspect ratio (this should report if it is passed tight constraints) #1645
  • OverflowBox: allow a child to overflow
  • ConstrainedBox: impose arbitrary(?) constraints on child? I think this should probably be represented as Fn(BoxConstraints) -> BoxConstraints or something.

In any case: none of these are super-duper-urgent, but I think we would like to have all of them eventually.

Contributor guide

Tech stack
rust
Domain
frontend
Issue type
feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
over 1 week
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
Basic RustUnderstanding of druid's widget system
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
55
Research direction
This issue requests the implementation of several layout widgets (LimitedBox, FittedBox, FractionallySizedBox, OverflowBox, ConstrainedBox) similar to Flutter's. The existing widgets in druid (e.g., in 'src/widget/') should be studied for patterns. Each widget requires handling of box constraints and child sizing. The linked Flutter docs provide the expected behavior. Start with LimitedBox as it is the simplest, then move to FittedBox which has multiple fitting modes. Ensure that AspectRatio is already implemented (see #1645). There are no blocking pull requests or assignees, but the issue is old; fresh contributions are welcome. Check the druid widget source and constraints module for integration.