Terminal Message Logger

Create a simple terminal-based message logger that displays log messages with automatic scrolling when the screen fills up. The logger should support clearing the screen and maintaining a scrollable view of messages.

Requirements

Your implementation should create a message logger that:

1. Displays messages on the terminal screen starting from the top
2. Automatically scrolls the screen upward when new messages are added and the screen is full
3. Provides a command to clear all messages from the screen
4. Updates the display properly after each operation

The logger should accept the following commands:

• log <message>: Add a new message to the screen. If the screen is full, scroll to make room.
• clear: Clear all messages from the screen
• quit: Exit the program

Implementation Details

• Messages should be displayed starting at line 1 of the screen
• Each message should be on its own line
• When the screen reaches capacity (height - 2 lines to leave room for input), the next message should cause the screen to scroll up by one line
• After clearing, the next message should start again from the top
• The program should show a simple prompt at the bottom: Command:
• Use double-buffered rendering to avoid flicker

Test Cases

• Logging a single message "Hello" displays it at the top of the screen @test
• Logging multiple messages displays them sequentially line by line @test
• When messages exceed screen height minus 2, the screen scrolls upward and the new message appears at the bottom of the message area @test
• Executing the clear command removes all messages from the screen @test

Implementation

@generates

API

class MessageLogger:
    """
    A terminal-based message logger with automatic scrolling and clearing.
    """

    def __init__(self, screen):
        """
        Initialize the message logger.

        Args:
            screen: The Screen object for terminal control
        """
        pass

    def log_message(self, message):
        """
        Add a message to the logger display.
        Automatically scrolls if screen is full.

        Args:
            message: String message to display
        """
        pass

    def clear_messages(self):
        """
        Clear all messages from the screen.
        """
        pass

    def display(self):
        """
        Render the current state to the screen.
        """
        pass

    def run(self):
        """
        Run the interactive message logger.
        Accepts commands: log <message>, clear, quit
        """
        pass

Dependencies { .dependencies }

asciimatics { .dependency }

Provides terminal control with screen clearing, scrolling, and rendering support.

@satisfied-by