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Resize Shapes

Thibaud edited this page 2026-03-19 22:40:54 +01:00

Table of Contents

• Plan: Resize Shapes
• Overview
• Current State
• Implementation Plan
• 1. ResizeHandle enum
• 2. Controller changes
• 3. Shape interface changes
• 4. Visual feedback
• Files to modify
• Alternative consideration

Plan: Resize Shapes

Overview

Add the ability to resize shapes by dragging corner handles on selected shapes.

Current State

• Selection already draws red corner handles via ShapeDraftman.drawHandlerIfSelected()
• Controller handles mouse events for selection and moving
• Selection uses SelectionAttributes on shapes

Implementation Plan

1. ResizeHandle enum

• Create ResizeHandle enum in shapes/ package with positions: NW, N, NE, E, SE, S, SW, W
• Each handle knows its cursor type

2. Controller changes

• Add mouse state: resizing (boolean), activeHandle (ResizeHandle), resizeOrigin (Point)
• Add getHandleAt(Point) method to find which handle is clicked
• Modify mouse handlers:
  • mousePressed: If click is on a handle, enter resize mode
  • mouseDragged: If resizing, calculate delta and call shape's resize method
  • mouseReleased: Exit resize mode
• Add cursor changes based on handle position

3. Shape interface changes

• Add resize(ResizeHandle handle, int dx, int dy) method to Shape interface
• Implement in AbstractShape or each concrete shape
• For basic shapes (rectangle, circle, triangle):
  • Rectangle: adjust width/height based on handle
  • Circle: adjust radius (maintain aspect ratio or allow ellipse)
  • Triangle: adjust vertices

4. Visual feedback

• Update ShapeDraftman to use different handle positions (not just corners)
• Consider showing resize preview during drag

Files to modify

• shapes/Shape.java - add resize method
• ui/Controller.java - mouse handling for resize
• shapes/SRectangle.java, SCircle.java, STriangle.java - implement resize logic

Alternative consideration

• Could use a separate Resizer class to keep Controller clean
• Could implement resize in AbstractShape for common logic