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Terminal Size

JLine provides facilities for detecting and responding to changes in the terminal size. This is essential for creating responsive terminal applications that adapt to different terminal dimensions.

Getting Terminal Size​

You can get the current terminal size using the getSize() method of the Terminal class:

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This example demonstrates how to get the initial terminal size and how to respond to terminal resize events by redrawing a box that adapts to the new dimensions.

Creating Responsive UIs​

For more complex applications, you can create responsive UIs that adapt to different terminal sizes:

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This example shows how to create a UI that changes its layout based on the available width, similar to responsive web design.

Best Practices​

When handling terminal size in JLine, keep these best practices in mind:

  1. Always Check Size: Always check the terminal size before drawing content to avoid unexpected wrapping or scrolling.

  2. Handle Resize Events: Register a handler for the WINCH signal to detect terminal resize events.

  3. Responsive Design: Design your UI to adapt to different terminal sizes, not just a fixed size.

  4. Minimum Size: Define a minimum terminal size for your application and provide a graceful fallback for smaller terminals.

  5. Efficient Redrawing: When redrawing after a resize, only update what's necessary to avoid flickering.

  6. User Feedback: Provide feedback if the terminal is too small for your application to function properly.

  7. Testing: Test your application with different terminal sizes to ensure it behaves as expected.

  8. Accessibility: Consider users who may be using terminals with unusual dimensions or constraints.

By properly handling terminal size, you can create command-line applications that provide a good user experience across a wide range of terminal emulators and window sizes.