Discover the SlidingUpPanel: A Comprehensive Guide

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Discover the SlidingUpPanel: A Comprehensive Guide

The SlidingUpPanel is a versatile Flutter widget that enables the smooth and intuitive integration of a draggable panel into your app. With its seamless transitions and customizable options, it empowers you to create engaging user experiences.

Essential Features

  • Draggable Panel: The heart of the SlidingUpPanel is its draggable panel, which can be effortlessly adjusted by users.
  • Customizable Panel: You have complete control over the design of the panel, allowing you to tailor it to your app's aesthetic and functionality.
  • Multiple Configurations: The SlidingUpPanel offers various configurations, making it adaptable to a wide range of scenarios.

Getting Started

Including the SlidingUpPanel in your project is a breeze:

dependencies:
  sliding_up_panel: ^2.0.0+1

Simple Usage

There are two primary methods for using the SlidingUpPanel:

1. SlidingUpPanel as the Root Widget (Recommended)

@override
Widget build(BuildContext context) {
  return Scaffold(
    appBar: AppBar(title: Text("SlidingUpPanelExample")),
    body: SlidingUpPanel(
      panel: Center(child: Text("This is the sliding Widget")),
      body: Center(child: Text("This is the Widget behind the sliding panel")),
    ),
  );
}

2. Nesting the SlidingUpPanel

@override
Widget build(BuildContext context) {
  return Scaffold(
    appBar: AppBar(title: Text("SlidingUpPanelExample")),
    body: Stack(children: [
      Center(child: Text("This is the Widget behind the sliding panel")),
      SlidingUpPanel(
        panel: Center(child: Text("This is the sliding Widget")),
      )
    ]),
  );
}

Customization Options

The SlidingUpPanel provides a plethora of customization options to meet your specific requirements:

  • panel: The Widget that slides into view.
  • collapsed: The Widget displayed overtop the panel when collapsed.
  • body: The Widget that lies underneath the sliding panel.
  • header: A persistent widget that floats above the panel and attaches to its top.
  • footer: A persistent widget that floats above the panel and attaches to its bottom.
  • minHeight: The height of the sliding panel when fully collapsed.
  • maxHeight: The height of the sliding panel when fully open.
  • snapPoint: A point between minHeight and maxHeight that the panel snaps to while animating. (beta)
  • border: A border to draw around the sliding panel sheet.
  • borderRadius: Rounded corners for the sliding panel sheet.
  • boxShadow: Shadows cast behind the sliding panel sheet.
  • color: The color of the sliding panel sheet.
  • padding: The amount to inset the children of the sliding panel sheet.
  • margin: Empty space surrounding the sliding panel sheet.
  • renderPanelSheet: Set to false to remove the sheet the panel sits upon for more advanced customization.
  • panelSnapping: Enable or disable the panel's snapping behavior.
  • backdropEnabled: Show a darkening shadow over the body as the panel slides open.
  • backdropColor: Color of the backdrop shadow.
  • backdropOpacity: Opacity of the backdrop shadow.
  • backdropTapClosesPanel: Close the panel by tapping the backdrop.
  • controller: Control the panel state using a PanelController.
  • onPanelSlide: Callback executed as the panel slides.
  • onPanelOpened: Callback executed when the panel is fully opened.
  • onPanelClosed: Callback executed when the panel is fully collapsed.
  • parallaxEnabled: Achieve a parallax effect as the panel slides.
  • parallaxOffset: Specify the extent of the parallax effect.
  • isDraggable: Toggle the user's ability to drag the panel.
  • slideDirection: Choose between UP or DOWN for the panel's sliding direction.
  • defaultPanelState: Open or closed state for the panel by default.

Example Customization

To enable a darkening backdrop as the panel opens:

@override
Widget build(BuildContext context) {
  return SlidingUpPanel(
    backdropEnabled: true,
    panel: Center(child: Text("This is the sliding Widget")),
    body: Scaffold(
      appBar: AppBar(title: Text("SlidingUpPanelExample")),
      body: Center(child: Text("This is the Widget behind the sliding panel")),
    ),
  );
}

Advanced Techniques

1. Using the PanelController

The PanelController provides programmatic control over the panel's position and state:

PanelController _pc = new PanelController();
@override
Widget build(BuildContext context) {
  return SlidingUpPanel(
    controller: _pc,
    panel: Center(child: Text("This is the sliding Widget")),
    body: _body(),
  );
}
Widget _body() {
  return Container(
    child: Column(
      children: [
        RaisedButton(child: Text("Open"), onPressed: () => _pc.open()),
        RaisedButton(child: Text("Close"), onPressed: () => _pc.close()),
      ],
    ),
  );
}

2. Creating Scrollable Elements in the Panel

The panel can contain scrollable elements, such as ListView:

@override
Widget build(BuildContext context) {
  return SlidingUpPanel(
    panel: _scrollingList(),
    body: Center(child: Text("This is the Widget behind the sliding panel")),
  );
}
Widget _scrollingList() {
  return ListView.builder(
    itemCount: 50,
    itemBuilder: (BuildContext context, int i) {
      return Container(
        padding: const EdgeInsets.all(12.0),
        child: Text("$i"),
      );
    },
  );
}

Conclusion

The SlidingUpPanel is a powerful and versatile widget that seamlessly integrates into your Flutter projects. With its customizable features and advanced capabilities, it empowers you to create engaging and intuitive user experiences.

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