Add TimelineCornerIndicatorComponent and TimelineLegendComponent

[kyasbal]

Adding 2 components used in the new timeline components.

TimelineCornerIndicatorComponent
It changes to the Scaling mode when user holds shift key.

TimelineLegendsComponent

[gemini-code-assist]

Summary of Changes

Hello @kyasbal, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request integrates two essential UI components into the timeline feature to improve user interaction and comprehension. The corner indicator clearly communicates the current navigation mode and offers guidance for scaling, while the legend component provides a comprehensive explanation of the visual elements within the timeline, such as different revision statuses and event categories. These additions aim to make the timeline more intuitive and informative for users.

Highlights

• New UI Components for Timeline: Introduced two new Angular components: TimelineCornerIndicatorComponent and TimelineLegendComponent, designed to enhance the user experience of timeline visualizations.
• Timeline Corner Indicator: The TimelineCornerIndicatorComponent provides visual feedback on the current scroll mode (Move or Scale) and offers a hint to the user on how to activate scaling mode by holding the SHIFT key and scrolling.
• Timeline Legend: The TimelineLegendComponent displays an expandable legend for the timeline, allowing users to understand the meaning of different revision states and event types. It dynamically shows legends based on the selected timeline data and allows toggling between revision and event explanations.
• Storybook Integration: Storybook stories have been added for both new components, providing isolated demonstrations of their various states and functionalities, which aids in development and testing.

Using Gemini Code Assist

The full guide for Gemini Code Assist can be found on our documentation page, here are some quick tips.

Invoking Gemini

You can request assistance from Gemini at any point by creating a comment using either /gemini <command> or @gemini-code-assist <command>. Below is a summary of the supported commands on the current page.

Feature	Command	Description
Code Review	/gemini review	Performs a code review for the current pull request in its current state.
Pull Request Summary	/gemini summary	Provides a summary of the current pull request in its current state.
Comment	@gemini-code-assist	Responds in comments when explicitly tagged, both in pull request comments and review comments.
Help	/gemini help	Displays a list of available commands.

Customization

To customize Gemini Code Assist for GitHub experience, repository maintainers can create a configuration file and/or provide a custom code review style guide (such as PEP-8 for Python) by creating and adding files to a .gemini/ folder in the base of the repository. Detailed instructions can be found here.

Limitations & Feedback

Gemini Code Assist may make mistakes. Please leave feedback on any instances where its feedback is incorrect or counter productive. You can react with 👍 and 👎 on @gemini-code-assist comments. If you're interested in giving your feedback about your experience with Gemini Code Assist for Github and other Google products, sign up here.

You can also get AI-powered code generation, chat, as well as code reviews directly in the IDE at no cost with the Gemini Code Assist IDE Extension.

Footnotes

1. Review the Privacy Notices, Generative AI Prohibited Use Policy, Terms of Service, and learn how to configure Gemini Code Assist in GitHub here. Gemini can make mistakes, so double check it and use code with caution. ↩

[gemini-code-assist]

Code Review

This pull request introduces two new components, TimelineCornerIndicatorComponent and TimelineLegendComponent, which are used in the new timeline feature. The implementation is solid and makes good use of modern Angular features like signals and the new control flow syntax. My review includes a few suggestions to enhance maintainability and readability. Specifically, I've recommended refactoring a template to be more concise, using SCSS variables for better style management, removing unused CSS, and fixing a minor typo. Overall, this is a great addition.

[gemini-code-assist]

To improve template readability and reduce redundancy, you can use the @if/@else control flow syntax. This avoids repeating ngClass and ternary operators for the icon and text, making the template cleaner. This also reduces the number of calls to isCurrentScalingMode().

  <div class="scroll-mode-indicator">
    <div class="label">Scroll Mode:</div>
    @if (isCurrentScalingMode()) {
      <mat-icon class="scale">zoom_out_map</mat-icon>
      <div class="mode scale">Scale</div>
    } @else {
      <mat-icon class="move">open_with</mat-icon>
      <div class="mode move">Move</div>
    }
  </div>

[renamoo]

Only a nit about text so LGTM