[Flutter] 폰트 추가

1. 프로젝트 파일에 ttf 혹은 otf파일 추가
   

2. pubspec.yaml 파일 수정

flutter:
  uses-material-design: true

fonts:
    - family: Pretendard
      fonts:
        - asset: assets/fonts/Pretendard-Thin.ttf
          weight: 100
        - asset: assets/fonts/Pretendard-ExtraLight.ttf
          weight: 200
        - asset: assets/fonts/Pretendard-Light.ttf
          weight: 300
        - asset: assets/fonts/Pretendard-Regular.ttf
          weight: 400
        - asset: assets/fonts/Pretendard-Medium.ttf
          weight: 500
        - asset: assets/fonts/Pretendard-SemiBold.ttf
          weight: 600
        - asset: assets/fonts/Pretendard-Bold.ttf
          weight: 700
        - asset: assets/fonts/Pretendard-ExtraBold.ttf
          weight: 800
        - asset: assets/fonts/Pretendard-Black.ttf
          weight: 900

3. 사용

Text(
	'폰트 테스트 ABCD 1234', 
	style: TextStyle(
		fontFamily: 'Pretendard', 
		fontWeight: FontWeight.bold
	)
)

• 예시

  import 'dart:ui';
  import 'color.dart';
  
  enum Pretendard {
    title1,
    title2,
    title3,
    subtitle1,
    subtitle2,
    subtitle3,
    subtext1,
    subtext2,
    caption,
  }
  
  extension CGTextStyleExtension on Pretendard {
    static const String _fontFamily = 'Pretendard';
  
    TextStyle? textStyle({Color color = CGColor.text_1st}) {
      return TextStyle(
        fontFamily: _fontFamily,
        fontWeight: _getFontWeight(this),
        fontSize:  _getFontSize(this),
        height: _getHeight(this),
        color: color,
      );
    }
  
    static FontWeight _getFontWeight(Pretendard type) {
      switch (type) {
        case Pretendard.title1:
        case Pretendard.title2:
          return FontWeight.w700;
        case Pretendard.title3:
        case Pretendard.subtitle1:
        case Pretendard.subtitle3:
          return FontWeight.w600;
        case Pretendard.subtitle2:
          return FontWeight.w700;
        default:
          return FontWeight.w400;
      }
    }
  
    static double _getFontSize(Pretendard type) {
      switch (type) {
        case Pretendard.title1:
          return 24;
        case Pretendard.title2:
          return 20;
        case Pretendard.title3:
          return 18;
        case Pretendard.subtitle1:
          return 16;
        case Pretendard.subtitle2:
          return 14;
        case Pretendard.subtitle3:
          return 12;
        case Pretendard.subtext1:
          return 16;
        case Pretendard.subtext2:
          return 14;
        case Pretendard.caption:
          return 12;
        default:
          return 16;
      }
    }
  
    static double _getHeight(Pretendard type) {
      switch (type) {
        case Pretendard.title1:
          return 1.2;
        case Pretendard.title2:
          return 1.4;
        case Pretendard.title3:
        case Pretendard.subtitle1:
          return 1.2;
        case Pretendard.subtitle2:
          return 1.2;
        case Pretendard.subtitle3:
          return 1.1;
        case Pretendard.subtext1:
          return 1.3;
        case Pretendard.subtext2:
          return 1.2;
        case Pretendard.caption:
          return 1.2;
        default:
          return 1.0;
      }
    }
  }