Fluid Layout #

Demo: jamesblasco.github.io/fluid_layout

Fluid layout allows you to create responsive layout for mobile, web and desktop from a single codebase.

Let's get started #

Install it #

Follow the installation process here

Understand fluid layout #

Fluid layout aims to help building a responsive experience through all the different screen sizes. Based in the boostrap approach, FluidLayout calculates a padding content (fluid_padding) that changes depending on the parent size. The FluidPadding widget uses that padding to set its size

The screen sizes are divided in 8 breakpoints: ul, xs, s, m, l, xl, ul, and can be accessed through FluidLayout.of(context).breakpoint or context.fluid.breakpoint.

You can create values(int, num, objects, functions, ... whatever variable type) for diferrent screen sizes thanks to the class BreakpointValue. The easiest way is:

final value = context.fluid.value(defaultValue, 
  xs: xsValue,  //if null xs would be defaultValue
  s:  sValue,   //if null s would be defaultValue
  m:  mValue,   //if null m would be defaultValue
  l:  lValue,   //if null l would be defaultValue
  xl: xlValue   //if null xl would be defaultValue
 ) 

LayoutFormat #

By default, LayoutFormat uses the FluidFormat to calculate the breakpoints, the padding and margin for each width.

FluidFormat dinamically changes the page size proportionally to the container width. It uses the breakpoints defined by the material guidelines.

BoostrapFormat adapts the page size according to the breakpoints defined by the boostrap guidelines.

You can also extend LayoutFormat and define you own custom rules for the layout.

Examples #

FluidLayout & FluidPadding #

See web example

class BasicFluidLayout extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return FluidLayout(
      child: Scaffold(
        backgroundColor: Colors.grey[200],
        body: FluidPadding(
          child: Container(
            child: Text(
              'Fluid width',
              style: TextStyle(color: Colors.white),
            ),
            color: Colors.blue,
            alignment: Alignment.center,
          ),
        ),
      ),
    );
  }
}

There is a fixed margin param that can be changed to all the FluidLayout or just for a FluidPadding container

For CustomScrollView there is a SliverFluidPadding equivalent to FluidPadding

FluidGridView #

A staggered grid view that divides the width size in 12 columns and makes easy to build responsive grid layout

See FluidGridView web example

FluidGridView(
  children: List.filled(
    100,
    FluidCell.withFluidHeight(
      size: context.fluid.value(3, m: 3, s: 4, xs: 6), //max 12
      heightSize: context.fluid.value(3, m: 3, s: 4, xs: 6), // max 12
      child: Container(
        color: Colors.red,
        child: Center(child: Text('Item')),
      )),
    ),
)

Customizable params [double spacing, ScrollPhysics physics, bool shrinkWrap] and bool fluid

FluidCell has three methods to build the cell:

• FluidCell.fit({size, child})
• FluidCell.withFluidHeight({size, heightSize, child})
• FluidCell.withFixedHeight({size, height, child})

For CustomScrollView there is a SliverFluidGrid equivalent to FluidGridView

Conditional Layout #

See Conditional Layout web example

if(context.fluid.breakpoint.isLargerThanM)
   return Container(color: Colors.red)
else
   return Container(color: Colors.green)              

Remember you can use context.breakpoint or FluidLayout.of(context).breakpoint

Combine full width widgets with fluid layouts #

Fluid layouts can be built everywhere inside the app and they will calculate their constraints based on their parents sizes, also they can combine very easily in cases we need full screen widgets.

1. Fluid layout with horizontal scroll rows