How to add a constructor to an existing class in Dart?












0















I'd like to make some convenience/factory constructors for a few common UI classes. For example, TextStyle:



enum Font {
AvenirNext,
AvenirNextCondensed
}

enum Weight {
Regular,
Medium,
DemiBold,
Bold
}

// Use:
// TextStyle(Fonts.AvenirNext, Weight.Medium, 20, Colors.white)

// Maybe it can be even shorter?
// TextStyle(AvenirNext, Medium, 20, Colors.black)


How to go about this in Dart?










share|improve this question



























    0















    I'd like to make some convenience/factory constructors for a few common UI classes. For example, TextStyle:



    enum Font {
    AvenirNext,
    AvenirNextCondensed
    }

    enum Weight {
    Regular,
    Medium,
    DemiBold,
    Bold
    }

    // Use:
    // TextStyle(Fonts.AvenirNext, Weight.Medium, 20, Colors.white)

    // Maybe it can be even shorter?
    // TextStyle(AvenirNext, Medium, 20, Colors.black)


    How to go about this in Dart?










    share|improve this question

























      0












      0








      0








      I'd like to make some convenience/factory constructors for a few common UI classes. For example, TextStyle:



      enum Font {
      AvenirNext,
      AvenirNextCondensed
      }

      enum Weight {
      Regular,
      Medium,
      DemiBold,
      Bold
      }

      // Use:
      // TextStyle(Fonts.AvenirNext, Weight.Medium, 20, Colors.white)

      // Maybe it can be even shorter?
      // TextStyle(AvenirNext, Medium, 20, Colors.black)


      How to go about this in Dart?










      share|improve this question














      I'd like to make some convenience/factory constructors for a few common UI classes. For example, TextStyle:



      enum Font {
      AvenirNext,
      AvenirNextCondensed
      }

      enum Weight {
      Regular,
      Medium,
      DemiBold,
      Bold
      }

      // Use:
      // TextStyle(Fonts.AvenirNext, Weight.Medium, 20, Colors.white)

      // Maybe it can be even shorter?
      // TextStyle(AvenirNext, Medium, 20, Colors.black)


      How to go about this in Dart?







      class constructor dart






      share|improve this question













      share|improve this question











      share|improve this question




      share|improve this question










      asked Nov 25 '18 at 19:36









      GoldenJoeGoldenJoe

      3,78023058




      3,78023058
























          1 Answer
          1






          active

          oldest

          votes


















          1














          How about extending TextStyle like below



          class Font {
          static const AvenirNext = 'AvenirNext';
          static const AvenirNextCondensed = 'AvenirNextCondensed';
          }

          class Weight{
          static const Regular = FontWeight.w400;
          static const Medium = FontWeight.w500;
          static const DemiBold = FontWeight.w700;
          static const Bold = FontWeight.w900;
          }

          class CTextStyle extends TextStyle {
          CTextStyle(String f, FontWeight w, num s, Color c)
          : super(
          fontFamily: f,
          fontWeight: w,
          fontSize: s.toDouble(),
          color: c);
          }
          }


          usage:



          TextStyle myCustom = CTextStyle(Font.AvenirNext, Weight.Medium, 20, Colors.black);





          share|improve this answer





















          • 2





            Alternatively, don't even make a class, and just define top-level factory functions that create a TextStyle object.

            – lrn
            Nov 26 '18 at 6:32











          • Yes , great. I was trying to explain that we can not modify the class .we can only extend it.

            – Saed Nabil
            Nov 26 '18 at 7:57











          • This is great. For sake of academics, what if I kept the enums and constructed an argument list for the super constructor: class TSExt extends TextStyle { //TSExt(Font font, Weight weight, double fontSize, Color color) : super(arguments); TSExt(Font font, Weight weight, double fontSize, Color color){ var args = { // ... }; super(args); } }

            – GoldenJoe
            Nov 26 '18 at 19:15













          • @GoldenJow It seems a good idea , if you tested this approch please, let us know

            – Saed Nabil
            Nov 27 '18 at 9:52











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          1 Answer
          1






          active

          oldest

          votes








          1 Answer
          1






          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes









          1














          How about extending TextStyle like below



          class Font {
          static const AvenirNext = 'AvenirNext';
          static const AvenirNextCondensed = 'AvenirNextCondensed';
          }

          class Weight{
          static const Regular = FontWeight.w400;
          static const Medium = FontWeight.w500;
          static const DemiBold = FontWeight.w700;
          static const Bold = FontWeight.w900;
          }

          class CTextStyle extends TextStyle {
          CTextStyle(String f, FontWeight w, num s, Color c)
          : super(
          fontFamily: f,
          fontWeight: w,
          fontSize: s.toDouble(),
          color: c);
          }
          }


          usage:



          TextStyle myCustom = CTextStyle(Font.AvenirNext, Weight.Medium, 20, Colors.black);





          share|improve this answer





















          • 2





            Alternatively, don't even make a class, and just define top-level factory functions that create a TextStyle object.

            – lrn
            Nov 26 '18 at 6:32











          • Yes , great. I was trying to explain that we can not modify the class .we can only extend it.

            – Saed Nabil
            Nov 26 '18 at 7:57











          • This is great. For sake of academics, what if I kept the enums and constructed an argument list for the super constructor: class TSExt extends TextStyle { //TSExt(Font font, Weight weight, double fontSize, Color color) : super(arguments); TSExt(Font font, Weight weight, double fontSize, Color color){ var args = { // ... }; super(args); } }

            – GoldenJoe
            Nov 26 '18 at 19:15













          • @GoldenJow It seems a good idea , if you tested this approch please, let us know

            – Saed Nabil
            Nov 27 '18 at 9:52
















          1














          How about extending TextStyle like below



          class Font {
          static const AvenirNext = 'AvenirNext';
          static const AvenirNextCondensed = 'AvenirNextCondensed';
          }

          class Weight{
          static const Regular = FontWeight.w400;
          static const Medium = FontWeight.w500;
          static const DemiBold = FontWeight.w700;
          static const Bold = FontWeight.w900;
          }

          class CTextStyle extends TextStyle {
          CTextStyle(String f, FontWeight w, num s, Color c)
          : super(
          fontFamily: f,
          fontWeight: w,
          fontSize: s.toDouble(),
          color: c);
          }
          }


          usage:



          TextStyle myCustom = CTextStyle(Font.AvenirNext, Weight.Medium, 20, Colors.black);





          share|improve this answer





















          • 2





            Alternatively, don't even make a class, and just define top-level factory functions that create a TextStyle object.

            – lrn
            Nov 26 '18 at 6:32











          • Yes , great. I was trying to explain that we can not modify the class .we can only extend it.

            – Saed Nabil
            Nov 26 '18 at 7:57











          • This is great. For sake of academics, what if I kept the enums and constructed an argument list for the super constructor: class TSExt extends TextStyle { //TSExt(Font font, Weight weight, double fontSize, Color color) : super(arguments); TSExt(Font font, Weight weight, double fontSize, Color color){ var args = { // ... }; super(args); } }

            – GoldenJoe
            Nov 26 '18 at 19:15













          • @GoldenJow It seems a good idea , if you tested this approch please, let us know

            – Saed Nabil
            Nov 27 '18 at 9:52














          1












          1








          1







          How about extending TextStyle like below



          class Font {
          static const AvenirNext = 'AvenirNext';
          static const AvenirNextCondensed = 'AvenirNextCondensed';
          }

          class Weight{
          static const Regular = FontWeight.w400;
          static const Medium = FontWeight.w500;
          static const DemiBold = FontWeight.w700;
          static const Bold = FontWeight.w900;
          }

          class CTextStyle extends TextStyle {
          CTextStyle(String f, FontWeight w, num s, Color c)
          : super(
          fontFamily: f,
          fontWeight: w,
          fontSize: s.toDouble(),
          color: c);
          }
          }


          usage:



          TextStyle myCustom = CTextStyle(Font.AvenirNext, Weight.Medium, 20, Colors.black);





          share|improve this answer















          How about extending TextStyle like below



          class Font {
          static const AvenirNext = 'AvenirNext';
          static const AvenirNextCondensed = 'AvenirNextCondensed';
          }

          class Weight{
          static const Regular = FontWeight.w400;
          static const Medium = FontWeight.w500;
          static const DemiBold = FontWeight.w700;
          static const Bold = FontWeight.w900;
          }

          class CTextStyle extends TextStyle {
          CTextStyle(String f, FontWeight w, num s, Color c)
          : super(
          fontFamily: f,
          fontWeight: w,
          fontSize: s.toDouble(),
          color: c);
          }
          }


          usage:



          TextStyle myCustom = CTextStyle(Font.AvenirNext, Weight.Medium, 20, Colors.black);






          share|improve this answer














          share|improve this answer



          share|improve this answer








          edited Nov 26 '18 at 6:31









          lrn

          10.6k1324




          10.6k1324










          answered Nov 26 '18 at 1:47









          Saed NabilSaed Nabil

          1,25329




          1,25329








          • 2





            Alternatively, don't even make a class, and just define top-level factory functions that create a TextStyle object.

            – lrn
            Nov 26 '18 at 6:32











          • Yes , great. I was trying to explain that we can not modify the class .we can only extend it.

            – Saed Nabil
            Nov 26 '18 at 7:57











          • This is great. For sake of academics, what if I kept the enums and constructed an argument list for the super constructor: class TSExt extends TextStyle { //TSExt(Font font, Weight weight, double fontSize, Color color) : super(arguments); TSExt(Font font, Weight weight, double fontSize, Color color){ var args = { // ... }; super(args); } }

            – GoldenJoe
            Nov 26 '18 at 19:15













          • @GoldenJow It seems a good idea , if you tested this approch please, let us know

            – Saed Nabil
            Nov 27 '18 at 9:52














          • 2





            Alternatively, don't even make a class, and just define top-level factory functions that create a TextStyle object.

            – lrn
            Nov 26 '18 at 6:32











          • Yes , great. I was trying to explain that we can not modify the class .we can only extend it.

            – Saed Nabil
            Nov 26 '18 at 7:57











          • This is great. For sake of academics, what if I kept the enums and constructed an argument list for the super constructor: class TSExt extends TextStyle { //TSExt(Font font, Weight weight, double fontSize, Color color) : super(arguments); TSExt(Font font, Weight weight, double fontSize, Color color){ var args = { // ... }; super(args); } }

            – GoldenJoe
            Nov 26 '18 at 19:15













          • @GoldenJow It seems a good idea , if you tested this approch please, let us know

            – Saed Nabil
            Nov 27 '18 at 9:52








          2




          2





          Alternatively, don't even make a class, and just define top-level factory functions that create a TextStyle object.

          – lrn
          Nov 26 '18 at 6:32





          Alternatively, don't even make a class, and just define top-level factory functions that create a TextStyle object.

          – lrn
          Nov 26 '18 at 6:32













          Yes , great. I was trying to explain that we can not modify the class .we can only extend it.

          – Saed Nabil
          Nov 26 '18 at 7:57





          Yes , great. I was trying to explain that we can not modify the class .we can only extend it.

          – Saed Nabil
          Nov 26 '18 at 7:57













          This is great. For sake of academics, what if I kept the enums and constructed an argument list for the super constructor: class TSExt extends TextStyle { //TSExt(Font font, Weight weight, double fontSize, Color color) : super(arguments); TSExt(Font font, Weight weight, double fontSize, Color color){ var args = { // ... }; super(args); } }

          – GoldenJoe
          Nov 26 '18 at 19:15







          This is great. For sake of academics, what if I kept the enums and constructed an argument list for the super constructor: class TSExt extends TextStyle { //TSExt(Font font, Weight weight, double fontSize, Color color) : super(arguments); TSExt(Font font, Weight weight, double fontSize, Color color){ var args = { // ... }; super(args); } }

          – GoldenJoe
          Nov 26 '18 at 19:15















          @GoldenJow It seems a good idea , if you tested this approch please, let us know

          – Saed Nabil
          Nov 27 '18 at 9:52





          @GoldenJow It seems a good idea , if you tested this approch please, let us know

          – Saed Nabil
          Nov 27 '18 at 9:52




















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