Flutter Custom Themes: Crafting your own design system.
November 22, 2023
Widgets are one of the basic foundations that build Flutter. Widgets encapsulate anything in an app, from structural to stylistic ones. They define how the app should be laid out. This deep dive aims to understand Flutter widgets and what they offer in terms of their framework and lifecycle. By understanding how widgets are used, developers can exploit them fully to design efficient, responsive, and visually appealing applications.
The Framework of Flutter Widgets
Flutter’s widget tree works with the idea that everything you see in your application is a widget. Widgets ranging from basic texts to complex layouts that structure whole apps are considered building blocks of UIs. A widget hierarchy thus structures all these widgets in a tree-like manner. It starts at the entry point with roots spreading down to tiny components such as buttons or images. This organizes components logically and optimizes UI updates and state changes.
Stateless vs Stateful
Flutter divides its widgets into two main categories: Stateless and Stateful. In Flutter, Stateless widgets are immutable. This means that their parameters cannot change (all values are final). A stateless widget is ideal when part of the UI depends only on received configuration information without changing any required runtime activities. This is unlike a stateful one, where the properties might change during its lifecycle. Understanding these two types of widgets forms the basis for creating reactive, scalable, pleasurably dynamic user interfaces.
Inheritance-based UI Construction
Furthermore, Flutter encourages inheritance-based UI construction. This implies that customization or creation of new widgets happens by combining small widgets rather than extending them directly, as other frameworks do. This programming model allows for greater flexibility, increasing code reuse opportunities across multiple projects. Developers can quickly build tailored complex UIs by assembling simple widgets already available inside Flutter’s library. They can also use widgets they created beforehand. This makes it more intuitive and easy to adapt to new needs because this approach breaks down development into smaller parts.
Advanced Exploration of Flutter Widgets and Their Lifecycle
Each Flutter widget has a life cycle that shows the various states it undergoes. It covers from when it is placed in the widget tree until it is eventually removed. By understanding this, one can optimize application performance and ensure that users have a good experience. The lifecycle begins with widget creation and continues through updates, layout, painting, and finally, disposal.
Redrawing
There are situations where a widget might be redrawn because its state has changed or as a result of user interactions. This differentiation is mostly important for the Flutter app’s Stateful widgets. That is because there are specific lifecycle methods provided by this framework, including:
You must understand the methods of these two types of widgets to trigger UI updates at the right moments.
Rendering
In this case, Flutter’s widget lifecycle is also quite closely tied to rendering. This allows widgets to update and render efficiently. Flutter employs a rendering engine to paint UI based on the widget tree while observing the constraints and properties set by each widget. This connection between the widget lifecycle and rendering leads to efficiency in managing resource-intensive activities, such as rendering animations or complex UIs. This ensures smooth performance even on different devices.
