GF Flutter Appbar

Flutter Appbar is an action button that is placed on the top of the screen and is a static one. It basically consists of a toolbar and other widgets that can also be used inside the Flutter Appbar.

GFAppBar is a Flutter Appbar that consists of a leading button and the actions button in the appbar which will be fixed on the top. Flutter Appbar provides flexible space for any widgets.

Flutter SliverAppbar is a Flutter Appbar that provides a certain height for the appbar which will be scrollable and after some extend of scrolling the appbar will be a fixed one at the top like a normal appbar.

GF Flutter Appbar and its Usage:

A GFAppBar is a Flutter AppBar widget that consists of a toolbar and potentially other widgets, such as a GFTabBar and FlexibleSpaceBar. The GFAppBar displays the toolbar widgets, leading, title, and actions.

GFAppbar has a menu icon button or flutter appbar icon on the top left corner that can be changed according to the need. The leading appbar button parameter is used to change the default menu icon button.

The below example code shows a simple appbar ****with a flutter appbar back button on the **leading parameter** which is used to go back to the previous page.

import 'package:getwidget/getwidget.dart';

GFAppBar(
  leading:  GFIconButton(
    icon: Icon(
      Icons.message,
      color: Colors.white,
    ),
    onPressed: () {},
    type: GFButtonType.transparent,
  ),
  title: Text("GF Appbar"),
  actions: <Widget>[
    GFIconButton(
      icon: Icon(
        Icons.favorite,
        color: Colors.white,
      ),
      onPressed: () {},
      type: GFButtonType.transparent,
    ),
  ],
),

GF Flutter Appbar with SearchBar

GFAppbar has a parameter called[searchBar](https://docs.getwidget.dev/gf-search%20bar/)wherein it is a boolean variable. If the searchBar is given the valuetruethen it displays a search bar textfield in the title space of the appbar with leading, trailing options.

The below example demo code shows the example of how to pass the parameter.

import 'package:getwidget/getwidget.dart';

GFAppBar(
  leading:  GFIconButton(
    icon: Icon(
      Icons.message,
      color: Colors.white,
    ),
    onPressed: () {},
    type: GFButtonType.transparent,
  ),
  searchBar: true,
  title: Text("GF Appbar"),
  actions: <Widget>[
    GFIconButton(
      icon: Icon(
        Icons.favorite,
        color: Colors.white,
      ),
      onPressed: () {},
      type: GFButtonType.transparent,
    ),
  ],
),

GF Flutter custom Appbar with Segmented Tabs

Segmented tabs can also be used inside the GFAppbar. In the title field of the Appbar just define the Segmented tab code and the work will be done.

The example below code shows a simple segmented tab inside Appbar.

import 'package:getwidget/getwidget.dart';

TabController tabController;
  @override
  void initState() {
    super.initState();
    tabController = TabController(length: 3, vsync: this);
  }

  @override
  void dispose() {
    tabController.dispose();
    super.dispose();
  }

  return Scaffold(
      appBar: GFAppBar(
        backgroundColor: GFColors.getGFColor(GFColor.dark),
        title:   GFSegmentTabs(
          tabController: tabController,
          tabBarColor: GFColors.getGFColor(GFColor.light),
          labelColor: GFColors.getGFColor(GFColor.white),
          unselectedLabelColor: GFColors.getGFColor(GFColor.dark),
          indicator: BoxDecoration(
            color: GFColors.getGFColor(GFColor.dark),
          ),
          indicatorPadding: EdgeInsets.all(8.0),
          indicatorWeight: 2.0,
          border: Border.all(color: Colors.white, width: 1.0),
             length: 3,
              tabs: <Widget>[
                Text(
                  "Tab1",
                ),
                Text(
                  "Tab2",
                ),
                Text(
                  "Tab3",
                ),
              ],
            ),
          ),
 body: GFTabBarView(controller: tabController, children: <Widget>[
   Center(
     child: Text('Tab 1'),
   ),
   Center(
     child: Text('Tab 2'),
   ),
   Center(
     child: Text('Tab 3'),
   ),
 ]),
);

GF Flutter Appbar Search Bar Custom Properties

The look and feel of the GFAppbar search bar can be customized using the GFAppbar properties.

Name	Description
searchBar	If true, displays search bar in the title space
searchHintText	It takes the text to displays the search bar hint text
searchHintStyle	It styles the [searchHintText]
searchTextStyle	It styles the search text
searchBarColorTheme	It defines the search bar icons color theme
searchController	Controls the text being edited. If null, this widget will create its own [TextEditingController]
onChanged	Called when the user initiates a change to the TextField's value: when they have inserted or deleted text
onSubmitted	Called when the user indicates that they are done editing the text in the field.
onTap	Called for each distinct tap except for every second tap of a double tap. If the text field is created with enabled false, taps will not be recognized.

GF Flutter Appbar Custom Properties

Look and feel of the GFAppbar can be customized using the GFAppbar properties.

Name	Description
leading	A widget to display before the [title]
automaticallyImplyLeading	Controls whether we should try to imply the leading widget if null. If true and [leading] is null, automatically try to deduce what the leading widget should be. If false and [leading] is null, leading space is given to [title]. If leading widget is not null, this parameter has no effect.
title	The primary widget displayed in the app bar. Typically a [Text] widget containing a description of the current contents of the app.
actions	Widgets to display after the [title] widget. Typically these widgets are [IconButton]s representing common operations. For less common operations, consider using a [PopupMenuButton] as the last action.
flexibleSpace	<p>This widget is stacked behind the toolbar and the tab bar. It's height will</p><p>be the same as the app bar's overall height.</p>
bottom	This widget appears across the bottom of the app bar. Typically a [TabBar]. Only widgets that implement [PreferredSizeWidget] can be used at the bottom of an app bar.
elevation	The z-coordinate at which to place this app bar relative to its parent. This controls the size of the shadow below the app bar. The value is non-negative.
shape	The material's shape as well its shadow. A shadow is only displayed if the [elevation] is greater than zero.
backgroundColor	The color to change background color of the app bar's material.
brightness	The brightness of the app bar's material. Typically this is set along with [backgroundColor], [iconTheme], [textTheme].
iconTheme	The color, opacity, and size to use for app bar icons. Typically this is set along with [backgroundColor], [brightness], [textTheme].
actionsIconTheme	The color, opacity, and size to use for the icons that appear in the appbar's [actions]. This should only be used when the [actions] should be themed differently than the icon that appears in the app bar's [leading] widget.
textTheme	The typographic styles to use for text in the app bar. Typically this is set along with [brightness] [backgroundColor], [iconTheme].
primary	Whether this app bar is being displayed at the top of the screen. If true, the app bar's toolbar elements and [bottom] widget will be padded on top by the height of the system status bar. The layout of the [flexibleSpace] is not affected by the [primary] property.
centerTitle	Whether the title should be centered. Defaults to being adapted to the current [TargetPlatform].
titleSpacing	<p>The spacing around [title] content on the horizontal axis. This spacing is applied even if there is no [leading] content or [actions]. If you want</p><p>[title] to take all the space available, set this value to 0.0.</p>
toolbarOpacity	How opaque the toolbar part of the app bar is. A value of 1.0 is fully opaque, and a value of 0.0 is fully transparent.
bottomOpacity	How opaque the bottom part of the app bar is. A value of 1.0 is fully opaque, and a value of 0.0 is fully transparent.
preferredSize	A size whose height is the sum of [kToolbarHeight] and the [bottom] widget's preferred height. [Scaffold] uses this size to set its app bar's height.
searchBar	If true, displays search bar in the title space