Architecture Issue: PageView is a God Class

[Ethran]

(by Claude AI)

Description

The PageView.kt class (over 900 lines) has taken on too many responsibilities, becoming a "God Object." It violates the Single Responsibility Principle by trying to handle:

• Data Repository Proxying: Proxying methods for fetching, adding, or deleting strokes and images via PageDataManager.
• Coordinate Transformations: Calculating zoom, scrolling, screen offsets, and relative geometry logic (toScreenCoordinates, toPageCoordinates).
• Rendering & Caching: Maintaining windowedBitmap, windowedCanvas, drawing the page background (drawBgToCanvas), and handling large background processing jobs (loadPage()).
• Selection Handling: Calculating lasso selection boxes and checking point bounds (applyPageCutOffset).

This makes the PageView class extremely difficult to read, maintain, and test.

Recommended Fix

Extract responsibilities from PageView into distinct, cohesive components:

1. PageGeometryManager or ViewportState: A standalone class dedicated to tracking the zoom level, scroll offset, and transforming points between screen and page coordinate systems.
2. PageRenderer: A dedicated rendering component to manage the windowedBitmap cache and draw the page layers (drawOnCanvasFromPage, background grid).
3. Data Delegation: Remove the proxy methods from PageView. Let EditorViewModel directly talk to PageDataManager for DB operations like addStrokes(), instead of passing through PageView. PageView should only receive data passively to display it, not manage its lifecycle.