# Text Scrolling Implementation in Simplicitty

This document outlines the implementation of text scrolling in the Simplicitty terminal emulator project.

## Overview

The implementation adds the ability to scroll through text content when it doesn't fit completely in the window. The scrolling is implemented on a line-by-line basis, allowing users to navigate through the content using keyboard shortcuts.

## Key Components

1. **Scroll State Management**:
   - Added `scroll_offset` to track the current scroll position (in visual lines)
   - Added `max_scroll_offset` to limit scrolling to available content

2. **Viewport Calculation**:
   - Modified `get_visible_line_range()` to consider the scroll offset when determining visible lines
   - Added `update_max_scroll_offset()` to recalculate the maximum scroll position based on content and viewport size

3. **Scrolling Methods**:
   - `scroll_up(lines)`: Move viewport up by specified number of lines
   - `scroll_down(lines)`: Move viewport down by specified number of lines
   - `page_up()`: Scroll up by one page (viewport height)
   - `page_down()`: Scroll down by one page (viewport height)

4. **Keyboard Controls**:
   - Ctrl+Up/Down: Scroll one line up/down
   - Page Up/Down: Scroll one page up/down
   - Ctrl+Home/End: Scroll to top/bottom of content

## Implementation Details

The scrolling implementation works by adjusting the `scroll_offset` value, which determines which visual lines are rendered in the viewport. The `get_visible_line_range()` function uses this offset to calculate which logical lines should be rendered.

When the window is resized or content changes, the `max_scroll_offset` is recalculated to ensure scrolling remains within valid bounds.

## Future Improvements

1. Add mouse wheel support for scrolling
2. Implement smooth scrolling animations
3. Add a visual scrollbar indicator
4. Preserve horizontal scroll position when navigating vertically