# Custom Painting (Flutter)

> CustomPaint, Canvas API, CustomPainter, drawing operations, performance, clipping

- 22 interview questions
- Senior
- [Interview Questions: Flutter](https://sharpskill.dev/en/technologies/flutter/interview-questions.md)

## 1. Which widget should be used to draw custom graphics in Flutter?

**Answer**

CustomPaint is the dedicated widget for custom drawing in Flutter. It takes a CustomPainter as a parameter containing the drawing logic via the paint() method. This widget creates a canvas where shapes, text, and images can be drawn with full control over every pixel.

## 2. What are the two mandatory methods to implement in a CustomPainter?

**Answer**

A CustomPainter must implement paint() to define what is drawn on the Canvas, and shouldRepaint() to indicate whether the widget should be redrawn when the painter changes. shouldRepaint() returns a boolean and receives the old painter as a parameter to compare states.

## 3. What is the role of the Paint object in Flutter custom drawing?

**Answer**

The Paint object defines the drawing style: color, stroke width, fill style (fill or stroke), line join type, shader effects, and filters. It acts as a configurable brush that determines the appearance of everything drawn on the Canvas.

## 19 more questions available

- What is the difference between PaintingStyle.fill and PaintingStyle.stroke?
- How to draw a circle on a Flutter Canvas?

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