Angular Animation Trigger: Button Click to Fade

This challenge focuses on implementing a basic animation in an Angular application. You will create a component with a button that, when clicked, triggers a visual fade-in animation for a text element. This is a common requirement for enhancing user experience by providing visual feedback and making interfaces feel more dynamic.

Problem Description

Your task is to build an Angular component that demonstrates how to trigger animations based on user interaction. Specifically, you need to implement the following:

1. Component Structure: Create an Angular component that contains a button and a paragraph element.
2. Animation Definition: Define a simple CSS transition or Angular's animation API to control the opacity of the paragraph element. The animation should make the paragraph fade in.
3. Trigger Mechanism: Implement logic so that clicking the button toggles the visibility (and therefore triggers the fade-in animation) of the paragraph element.
4. State Management: Manage the state of the paragraph's visibility to control when the animation should occur.

Key Requirements:

• The paragraph should be initially hidden (or have zero opacity).
• Clicking the button should cause the paragraph to fade into view.
• Clicking the button again should cause the paragraph to fade out of view.
• The animation should be smooth (e.g., a gradual change in opacity over a short duration).

Expected Behavior:

When the application loads, the paragraph element should not be visible. Upon clicking the button for the first time, the paragraph should smoothly fade in. Upon clicking the button a second time, the paragraph should smoothly fade out. Subsequent clicks should toggle the fade-in/fade-out behavior.

Edge Cases to Consider:

• Rapid clicking: Ensure the animation behaves predictably even if the button is clicked multiple times in quick succession.

Examples

Example 1:

Initial State:

[Button: "Toggle Text"]

(The text paragraph is not visible)

After clicking the button once:

[Button: "Toggle Text"]
This text fades in.

Explanation: The paragraph was initially hidden. Clicking the button triggered the fade-in animation, making it visible.

Example 2:

State after Example 1:

[Button: "Toggle Text"]
This text fades in.

After clicking the button a second time:

[Button: "Toggle Text"]

(The text paragraph fades out and is no longer visible)

Explanation: Clicking the button again triggered the fade-out animation, returning the paragraph to a hidden state.

Constraints

• The animation duration should be between 200ms and 500ms.
• The animation should primarily involve changes in opacity.
• The solution should be implemented using TypeScript and Angular's built-in animation capabilities (e.g., @angular/animations).

Notes

This challenge encourages the use of Angular's animations module. Consider how to bind a component property to an animation state and how to define the animation itself. You might find the trigger, state, style, and animate functions useful. Think about how you can conditionally apply styles or classes to control the animation's trigger.