Create Fade and Slide Animations for List of Bullet Points - #8 Flutter Web Tutorial Series By Florian Prümer

Summary by www.lecturesummary.com: Create Fade and Slide Animations for List of Bullet Points - #8 Flutter Web Tutorial Series By Florian Prümer

Adding Slide and Fade Animations to a List of Bullet Points in Flutter

Introduction

In this video, the instructor demonstrates how to quickly and easily add slide and fade animations to a list of bullet points using the SlideTransition

and FadeTransition

widgets in Flutter. The goal is to give the user interface a certain "something" by implementing these simple, easy-to-implement animations.

Key Concepts and Takeaways

Animation Controller

(00:01:44 - 00:02:58)

• To control the animations, we need an AnimationController

  in the BulletList

  class.

• The AnimationController

  is initialized in the initState()

  method, using a TickerProvider

  and a duration of 1 second.

• The forward()

  method of the AnimationController

  is called in initState()

  to start the animation sequence.

Fade Animation

(00:03:08 - 00:03:52)

• To add a fade animation, we wrap the bullet point widget with a FadeTransition

  widget.

• The opacity

  property of the FadeTransition

  is set to the AnimationController

  .

Slide Animation

(00:03:52 - 00:04:41)

• To add a slide animation, we wrap the FadeTransition

  with a SlideTransition

  widget.

• We create a Tween<Offset>

  to define the start and end offsets for the slide animation.

• The animate()

  method of the AnimationController

  is used to animate the offset.

Delaying the Animation

(00:05:13 - 00:05:53)

• To delay the start of the animation, we wrap the AnimationController.forward()

  call in a Timer

  in the initState()

  method.

Staggered Animation

(00:05:53 - 00:07:16)

• To create a staggered animation, where the bullet points slide in one after the other, we use the Interval

  class.

• We replace the AnimationController

  in the BulletPoint

  class with a CurvedAnimation

  , which has the AnimationController

  as its parent and an Interval

  as the curve.

• The start and end values of the Interval

  are calculated based on the index of the bullet point, to create the staggered effect.

Summary

(00:07:47 - 00:08:01)

• The video demonstrates how to add slide and fade animations to a list of bullet points in a Flutter application.

• Key concepts include using an AnimationController

  , FadeTransition

  , SlideTransition

  , Tween<Offset>

  , Timer

  , and Interval

  to create the desired animations.

• The final result is a smooth, staggered animation of the bullet points, which can enhance the user experience of the application.

DeepLearn by www.lecturesummary.com: Create Fade and Slide Animations for List of Bullet Points - #8 Flutter Web Tutorial Series By Florian Prümer

Adding Slide and Fade Animations to a List of Bullet Points in Flutter

Introduction (00:00:00 - 00:00:17)

• Greetings and welcome to another episode of the Flutter web tutorial series

• Today, we will learn how to quickly and easily add slide and fade animations to a list of bullet points using the SlideTransition

  and FadeTransition

  widgets

Slide and Fade Animations (00:00:17 - 00:00:27)

• After this video, you will have the tools to add simple, easy-to-implement slide and fade animations to your Flutter application

• This will give your application a certain something

Shout-out to Hua Suarez (00:00:27 - 00:00:38)

• A quick shout-out to Hua Suarez and his take on the SlideTransition

  and FadeTransition

  widgets

• His work inspired the use of these two widgets for the presenter's website and the adaptation of the code accordingly

• A link to his video and GitHub code is provided in the description

Current Page and Animations (00:00:38 - 00:01:06)

• The current page has a list of bullet points on the right

• When the "About" page is opened, each bullet point has its own slide and fade animation

• The animations are slightly delayed for each bullet point

Implementing the Animations (00:01:06 - 00:01:20)

• The animations are implemented in the "about_view.dart" file

• The code for the animations can be seen in this file

Creating a Bullet List in Flutter

Description

This video covers the process of creating a bullet list in a Flutter application. The bullet list is generated based on the strings received, and each bullet point consists of a circle and the corresponding text. The video also discusses the importance of an animation controller to manage the animations in the bullet list.

Key Points

(00:01:20 - 00:01:30)

• A bullet list consists of a list of bullet points and spacers following each other.

• The list is generated based on the strings received.

(00:01:30 - 00:01:44)

• In each iteration, a bullet point is created, followed by a spacer.

• Each bullet point consists of a circle represented by a character code and the text.

(00:01:44 - 00:02:22)

• Before adding any animation, an animation controller is needed in the bullet list class.

• The animation controller is responsible for starting and controlling the animations.

(00:02:22 - 00:02:38)

• The animation controller is initialized by providing a Ticker provider, which is the state class using the TickerProviderStateMixin

  .

• The duration of the animation is set to 1 second.

(00:02:38 - 00:02:58)

• The forward()

  method of the animation controller is called to start the animation.

• The animation is played every time the about page is opened, and the bullet point list is created.

Bullet Points

• Bullet List: A list of bullet points and spacers

• Bullet Point: Consists of a circle and text

• Animation Controller: Responsible for managing the animations in the bullet list

• Ticker Provider: Provides the state class for the animation controller

• Animation Duration: Set to 1 second for the bullet list animation

Table

Feature	Description
Bullet List	A list of bullet points and spacers
Bullet Point	Consists of a circle and text
Animation Controller	Manages the animations in the bullet list
Ticker Provider	Provides the state class for the animation controller
Animation Duration	Set to 1 second for the bullet list animation

Quotes

"We are creating a bullet point in the first iteration and then on the next iteration, a spacer and so on and so forth."

"We want to initialize our animation controller by providing it with a Tikka provider which will be the state class using the Wi single Tikka provider, state mixing and by providing it with a duration of how long our animation should play for."

Animating Bullet Points

(00:02:58 - 00:03:08)In this section, we set up the animation controller and start the animation sequence.

Key Points:

• Initialize the animation controller in the initState()

  method

• Start the animation sequence using the animation controller

(00:03:08 - 00:03:37)Now, we need to add specific animations to our bullet points. Each bullet point has a slide and fade animation.

Steps:

1. Pass the animation controller to the BulletPoint

   class

2. Create a required class member for the animation controller

3. Pass the animation controller to the BulletList

   class

(00:03:37 - 00:03:52)Let's start by adding the fade animation.

Fade Animation:

• Wrap the bullet point content with a FadeTransition

  widget

• Set the opacity of the FadeTransition

  to the animation controller

(00:03:52 - 00:04:07)Next, we'll add the slide animation.

Slide Animation:

• Wrap the FadeTransition

  with a SlideTransition

  widget

• Create a Tween

  of Offsets

  to define the start and end positions of the slide animation

• The initial offset should be slightly to the right, and the end offset should have no offset

(00:04:07 - 00:04:22)We need to define the position values for the slide animation.

Offset Tween:

• An Offset

  consists of a horizontal and vertical value

• The initial offset will be slightly to the right of the current position

• The end offset will have no offset at all

• The Tween

  will animate between these two offsets, creating the slide animation

(00:04:22 - 00:04:41)The Tween

of Offsets

is used to animate the slide animation.

Tween Animation:

• The Tween

  of Offsets

  is used to define the start and end positions of the slide animation

• The animation is created by animating between these two offsets

• This results in the bullet points sliding in from the right to their final position

Animating Bullet Points with Delays

(00:04:41 - 00:04:57)The video discusses the effect of a sliding motion to animate objects. To achieve this, we need to call the animate()

method and pass in an animation controller.

Key Points:

• Call the animate()

  method

• Pass in an animation controller

(00:04:57 - 00:05:13)The speaker has two main concerns with the current animation:

1. The animation starts playing as soon as the page is opened, not allowing enough time to fully grasp the animation.

2. The bullet points are sliding in all at once, rather than having a slight delay between each one.

Desired Changes:

• Delay the start of the animation

• Introduce a delay between each bullet point

(00:05:13 - 00:05:28)To address the first concern, the speaker suggests wrapping the animation_controller.forward()

method with a timer, delaying the start of the animation by a few hundred milliseconds.

Steps:

1. Go to the initState()

   method of the bullet list

2. Wrap the animation_controller.forward()

   method with a Timer

3. Delay the start of the animation by a few hundred milliseconds

(00:05:28 - 00:05:53)To address the second concern, the speaker explains that the animation should be visualized on a timeline starting from 0 and ending at 1. Currently, all the bullet points are appearing at once, but the goal is to have them appear with a slight delay while still overlapping.

Approach:

• Visualize the animation on a timeline from 0 to 1

• Use the Interval

  class to set a start and end point within the animation timeline

• This will allow the bullet points to appear with a slight delay while still overlapping

(00:05:53 - 00:06:24)The speaker provides an example of how the desired intervals should look like, with each bullet point having a slightly delayed start time but still overlapping.

Example Intervals:

Bullet Point	Start Time	End Time
1	0.0	0.2
2	0.1	0.3
3	0.2	0.4
4	0.3	0.5

By using the Interval

class and setting the appropriate start and end times, the speaker aims to achieve the desired effect of the bullet points appearing with a slight delay while still overlapping.

Adjusting Bullet Point Animations

In this section, we'll learn how to replace the animation controller with a curved animation and how to set the start and end values dynamically based on the index of the current bullet point.

Replacing the Animation Controller with a Curved Animation

(00:06:24 - 00:06:50)

• Replace the animation controller with a curved animation

• Set the parent of the curved animation to the animation controller

• Set the curve to an interval

• The interval needs a start value, end value, and a curve that eases in and out

Dynamically Setting Start and End Values

(00:06:50 - 00:07:16)

• The start and end values depend on the setup of your project

• If you're using the bullet point class multiple times, you need to pass the index of the current bullet point

• Calculate the start and end values dynamically based on the index

• Make sure the start and end values are between 0 and 1

Observing the Smooth Animation

(00:07:16 - 00:07:47)

• After setting the start and end values, the animations should run smoothly as expected

Conclusion

(00:07:47 - 00:08:04)

• Thank the viewers for watching the video

• Encourage them to leave a comment or contact you if they have any further questions

• Wish them a lovely day and see you in the next video