NEW FEATURES: Drop Zone, Layout Builder, Window Background Blur

[Wanna-Pizza]

Description

New Feature: Layout Builder

Allows to know size,position of widget.

New Feature: DropZone

DropZone - widget that must have child widget (ft.Container as example) to drop files inside of it.

New Feature: WIndow Bacgkround Blur

Adding nice transparency effect to your Flet App.

Motivation

Such functionality should be by default in Flet. Such as DropZone, or LayoutBuilder, for building more complex interfaces. Acrylic - to make it look beautiful ;)

Knows Problem

LayoutBuilder may not be built correctly. In terms of, not fully optimized. But you at least have a working example of LayoutBuilder, maybe you should improve it. Because my knowledge of Dart is not good.

Test Code DropZone

import flet as ft

def main(page: ft.Page):
    page.add(
        ft.DropZone(
            content=ft.Container(ft.Text('Drop here!'),width=500,height=500,alignment=ft.alignment.center,bgcolor='red'),
            on_dropped=lambda e: print(f'Dropped: {e.files}'),
            on_entered=lambda e: print('Entered'),
            on_exited=lambda e: print('Exited')
            )
    )
ft.app(target=main)

Test Code Window Blur

import flet as ft

def main(page: ft.Page):
    page.add(ft.Text('Acrylic!'))
    page.bgcolor = 'transparent'
    page.window.bgblur = ft.bgblur.TABBED #ACRYLIC, MICA, TABBED, AERO
    page.update()
    
ft.app(target=main)

Test Code LayoutBuilder

import flet as ft

def main(page: ft.Page):
    page.add(
        ft.LayoutBuilder(
            content=ft.Container(ft.Text('LayoutBuilder'),expand=True,alignment=ft.alignment.center),
            update_size_on_init=True, # will trigger "on_change" at first build.
            expand=True,
            on_change=lambda e: print(e.width,e.height,e.x,e.y)
        
        )
    )
ft.app(target=main)

Type of change

• New feature (non-breaking change which adds functionality)
• This change requires a documentation update

Checklist

• I signed the CLA.
• I have performed a self-review of my own code
• My changes generate no new warnings
• New and existing tests pass locally with my changes

Screenshots

Additional details

Link to these features:
https://pub.dev/packages/desktop_drop
https://pub.dev/packages/flutter_acrylic
https://api.flutter.dev/flutter/widgets/LayoutBuilder-class.html

Summary by Sourcery

Add new features including Layout Builder, DropZone, and Window Background Blur to enhance the application's UI capabilities. Integrate the Flutter Acrylic package to support the new blur effect.

New Features:

• Introduce a Layout Builder feature to determine the size and position of widgets.
• Add a DropZone widget to enable file dropping functionality within a child widget.
• Implement a Window Background Blur feature to add transparency effects to the application.

Enhancements:

• Integrate the Flutter Acrylic package to support window background blur effects.

[CLAassistant]

All committers have signed the CLA.