Add `Shift + Enter` to Create New Line in Multi-line Text Input

[rifkybujana]

Add Shift + Enter to Create New Line in Multi-line Text Input

Description: We need to add functionality to support Shift + Enter to create a new line in the multi-line text input. Currently, pressing Enter submits the input, but users should be able to use Shift + Enter to add new lines while continuing to compose their message.

Tasks:

1. Modify the multi-line text input behavior:

   • Add support for detecting the Shift + Enter key combination.
   • Ensure that when Shift + Enter is pressed, a new line is inserted into the text input rather than submitting the message.
   • Keep Enter functionality unchanged so it still submits the input when pressed without the Shift key.

2. Ensure compatibility with existing input functionality:

   • Ensure that all other functionalities in the multi-line text input (e.g., word wrapping, text highlighting) continue to work correctly after adding the Shift + Enter feature.
   • Verify that pressing Enter alone still triggers the expected submit behavior.

3. UI feedback for new line insertion:

   • Ensure the text input box correctly expands or adjusts when a new line is added using Shift + Enter.
   • Ensure that word wrapping, padding, and formatting are maintained as new lines are inserted.

4. Testing:

   • Test Shift + Enter functionality across different platforms (Linux, macOS, Windows) to ensure consistency.
   • Test the multi-line input for various scenarios, such as inserting new lines at different positions, submitting text with and without new lines, and handling very long multi-line inputs.

5. Update documentation:

   • Add documentation or tooltips (if applicable) to inform users about the Shift + Enter feature for adding new lines.
   • Update any existing documentation or UI help sections to reflect this functionality.

Acceptance Criteria:

• Shift + Enter inserts a new line in the multi-line text input without submitting the message.
• The Enter key alone still submits the input as before.
• The multi-line text input box adjusts correctly when new lines are added, maintaining proper text wrapping and layout.
• Testing confirms consistent behavior across platforms.

Additional Context:

• The project uses ImGui for UI rendering, so ensure the feature integrates smoothly within the existing system.
• Users expect a familiar experience when composing multi-line messages, so this feature should mimic the behavior seen in common text editors and messaging apps.