# Widgets 02 | Text ## What is the Text? This problem is very fooling but needs to know, The text show our string and it also is a widget in the flutter, we can use it as a common widget, so be careful about their parameters. | Facebook Page | Twitter | GitHub | ​ | | ------------------------------------------------------- | ----------------------------------------- | ------------------------------------ | - | | ​[Flutter Open](https://www.facebook.com/flutteropen) ​ | ​[NieBin](https://twitter.com/niebin_gg)​ | ​[NieBin](https://github.com/nb312)​ | ​ | ## Before start In the widgets 01, we create a page to show our container, also we create a page show our `Text`. The way of creating a page is the same as before, you do not care about this, you just focus on the `Text` widget now. We will put them all in the `children` as follows. ```dart class TextPage extends StatefulWidget { @override _TextState createState() => _TextState(); } class _TextState extends State { @override Widget build(BuildContext context) { return Scaffold( appBar: AppBar( title: Text("Text"), ), body: SingleChildScrollView( child: Column( crossAxisAlignment: CrossAxisAlignment.start, children: [ Text("Hello World"), ], ), ), ); } } ``` ![](https://3262132263-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LW5X4rCYpodwj4P1c8s%2F-LWCFbgS3D7ruTrJ1caf%2F-LWCMTzVTH-3kc0N9w3G%2Ftext-01.png?alt=media\&token=fdf6cda3-3498-4621-bab9-118f85729694) Then, we can put our Text into the `children` to continue our tutorial. ## Constructor You must make a custom to look at the constructor of the widgets before using it. ```dart Text(this.data, { Key key, this.style, this.textAlign, this.textDirection, this.locale, this.softWrap, this.overflow, this.textScaleFactor, this.maxLines, this.semanticsLabel, }) ``` The `this.data` is where we put the `String`, this is easy to understand, we do not talk about this. the `style` is most common to use. `this.locale` control its language,this time I don't plan to talk about it, I will write another article to explain it. So let's talk about the parameters one by one. ## style Let's look at its definition. ```dart final TextStyle style; ``` It is a `TextStyle` class, look at its definition,so many important parameters are here,such as the `fontSize`, `color`, `height`. ```dart TextStyle({ this.inherit = true, this.color, this.fontSize, this.fontWeight, this.fontStyle, this.letterSpacing, this.wordSpacing, this.textBaseline, this.height, this.locale, this.foreground, this.background, this.shadows, this.decoration, this.decorationColor, this.decorationStyle, this.debugLabel, String fontFamily, String package, } ``` The function of these parameters is a definition with its name. The `color` parameter control the color of `Text`.The `fontSize` controls its font size. We just show an example for simple param. ```dart Text( "TextStyle with easy parameters", style: TextStyle( color: Colors.black, fontSize: 22.0, background: Paint() ..color = Color(0xffc7e5b4) ..style = PaintingStyle.fill, ), ) ``` ![](https://3262132263-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LW5X4rCYpodwj4P1c8s%2F-LWCFbgS3D7ruTrJ1caf%2F-LWCb_viYIL1DxnweOdX%2Ftext-02.png?alt=media\&token=ef305d56-f334-4ef8-8f54-12eda9e20391) We just change the parameters，they will show as follows. ```dart Text( "TextStyle with easy parameters", style: TextStyle( color: Colors.white, fontSize: 14.0, background: Paint() ..color = Color(0xffF2A7B3) ..style = PaintingStyle.fill, ), ) ``` ![](https://3262132263-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LW5X4rCYpodwj4P1c8s%2F-LWCFbgS3D7ruTrJ1caf%2F-LWCcz8UHoKXaxt43f_n%2Ftext-03.png?alt=media\&token=b31cbc3d-fe4c-4566-bd93-bf2dc1889ea0) Above code, we can learn how to use `color` ,`fontSize` and `background`t,the background is a Paint that controls the color or other things, I don't want to expand this for more detail. #### **1. foreground** ```dart final Paint foreground; ``` We can see that the `foreground` is also as the `background` above, so just use the `Paint`,the `..`is a special operator in the flutter. ```dart var p= Paint() ..color = Color(0xffA8CBFD) ..style = PaintingStyle.fill); ``` Is same as below. ```dart var p= Paint(); p.color = Color(0xffA8CBFD); p.style = PaintingStyle.fill); ``` We just code as follows. ```dart Text( "TextStyle with foreground", style: TextStyle( fontSize: 40, foreground: Paint() ..color = Color(0xffA8CBFD) ..strokeWidth = 1 ..style = PaintingStyle.stroke), ) ``` ![](https://3262132263-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LW5X4rCYpodwj4P1c8s%2F-LWCdqiB4n2-T0a4mGhB%2F-LWChULiMlfF-6JZabbK%2Ftext-04.png?alt=media\&token=01f00ed1-ebff-476d-a91f-638fc1375814) The paint draw the `Text` with the foreground, be careful that we can't use the color parameter with this, so you can only choose one parameter. #### 2. fontWeight ```dart final FontWeight fontWeight; ``` You can see the definition, the class is `FontWeight`, you can use its constant with a fore definition. We will use the `FontWeight.w700` , it represents bold text. The other constants you can find in the class `FontWeight`,remain to you. ```dart Text( "TextStyle with fontWeight", style: TextStyle( fontSize: 20, color: RED, fontWeight: FontWeight.w700, ), ) ``` ![](https://3262132263-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LW5X4rCYpodwj4P1c8s%2F-LWCdqiB4n2-T0a4mGhB%2F-LWClOaB-bmpZUicmrAb%2Ftext-05.png?alt=media\&token=13111740-8aa7-42d3-aa47-3075e338fe72) #### 3. fontStyle We know the type is `FontStyle`, we use its only two constants.As follows, this example will show an italic text. ```dart Text( "TextStyle with fontStyle", style: TextStyle( fontSize: 20, color: BLUE_LIGHT, fontStyle: FontStyle.italic, ), ) ``` ![](https://3262132263-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LW5X4rCYpodwj4P1c8s%2F-LWCdqiB4n2-T0a4mGhB%2F-LWCnDeWqSHwpUj459zZ%2Ftext-06.png?alt=media\&token=42d01f65-558f-46fc-a6b0-87d87a691433) #### 4. letterSpacing The parameter will control the distance between the letter inside a word. For example, the word `Hello`if set this param, the distance between `H,e,l,l,o` will depend on this param. ```dart Text( "TextStyle with letterSpacing 4", style: TextStyle( fontSize: 16, color: Colors.black, background: Paint()..color = GREEN, letterSpacing: 4, ), ), SizedBox( height: 10, ), Text( "TextStyle with letterSpacing 20", style: TextStyle( fontSize: 16, color: Colors.black, background: Paint()..color = GREEN, letterSpacing: 10, ), ) ``` ![](https://3262132263-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LW5X4rCYpodwj4P1c8s%2F-LWCdqiB4n2-T0a4mGhB%2F-LWCq8S2-6EeDERVI3Jp%2Ftext-07.png?alt=media\&token=98b0ec95-6d8f-495d-b51d-19df132aec07) #### 5. wordSpacing The parameter controls the distance between the two words, I will set two different `wordSpacing` to compare. ```dart Text( "TextStyle with wordSpacing 1", style: TextStyle( fontSize: 16, color: Colors.black, background: Paint()..color = RED, wordSpacing: 1), ), Text( "TextStyle with wordSpacing 20", style: TextStyle( fontSize: 16, color: Colors.black, background: Paint()..color = RED, wordSpacing: 20), ) ``` ![](https://3262132263-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LW5X4rCYpodwj4P1c8s%2F-LWFSMv1y6lZJYh6Xnaa%2F-LWFTL0LkVkXgs9c25kv%2Ftext-08.png?alt=media\&token=1757372e-dcff-44ca-bd5b-7605a9ace123) #### 6. shadows When we see the definition of the `shadows`, we can see this. ```dart final List shadows; ``` The `Shadow` constructor is below. ```dart const Shadow({ this.color = const Color(_kColorDefault), this.offset = Offset.zero, this.blurRadius = 0.0, } ``` The `offset` is the direction from the origin point of the widget, the `blurRadius` is the distance of the blurred space. So let's see an example. ```dart Text( "TextStyle with Shadow", style: TextStyle(fontSize: 30, color: BLUE_DEEP, shadows: [ Shadow(color: RED, offset: Offset(1, 2), blurRadius: 2) ]), ), Text( "TextStyle with Shadow", style: TextStyle(fontSize: 30, color: RED, shadows: [ Shadow( color: Colors.black, offset: Offset(1, 4), blurRadius: 1), Shadow(color: BLUE_DEEP, offset: Offset(2, 1), blurRadius: 2) ]), ), ``` ![](https://3262132263-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LW5X4rCYpodwj4P1c8s%2F-LWFZabE0UOoqTIb7sRa%2F-LWFcf6JuYyyRZXM7x6_%2Ftext-09.png?alt=media\&token=f2c17270-ae51-42b3-968a-e8de2f60101c) #### 7. decoration In this part, I will tell three params:`decoration, decorationColor, decorationStyle`. They draw the same line show in the Text, the `decoration` controls the location, `decorationColor` control the color, `decorationStyle` control the shape. The definition is below. ```dart final TextDecoration decoration; final Color decorationColor; final TextDecorationStyle decorationStyle; ``` Let's see an example. ```dart Text( "TextStyle with decoration underline", style: TextStyle( fontSize: 20, background: Paint()..color = GREEN, decoration: TextDecoration.underline, decorationColor: Colors.red, decorationStyle: TextDecorationStyle.wavy), ), Text( "TextStyle with decoration lineThrough", style: TextStyle( fontSize: 20, background: Paint()..color = BLUE_LIGHT, decoration: TextDecoration.lineThrough, decorationColor: Colors.black, decorationStyle: TextDecorationStyle.double), ), ``` ![](https://3262132263-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LW5X4rCYpodwj4P1c8s%2F-LWFZabE0UOoqTIb7sRa%2F-LWFgtVV56YuAnCB7TaW%2Ftext-10.png?alt=media\&token=17f79ea3-32bc-4082-81f2-562c74ee7b6b) #### 8. fontFamily This parameter changes the typeface for the font. It is a bit difficult, but be patient. First, we should download a typeface file on the web and in our project, I put into the `assets/font`. You should know the folders are created by myself, you can do that too. ![](https://3262132263-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LW5X4rCYpodwj4P1c8s%2F-LWFZabE0UOoqTIb7sRa%2F-LWFrLFMpaMII2AgFiyU%2Ftext-11.png?alt=media\&token=d6323822-a654-424b-ac1c-c53422d214cf) Then, config the `pubspec.yaml` file in our project,as I note with the red rectangle and paste the config as well. ![](https://3262132263-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LW5X4rCYpodwj4P1c8s%2F-LWFZabE0UOoqTIb7sRa%2F-LWFszwc-f-HPdRmtJOv%2Ftext-12.png?alt=media\&token=369e2cd0-9f13-4918-ab0f-b5a00da41a5d) ```yaml flutter: # The following line ensures that the Material Icons font is # included with your application, so that you can use the icons in # the material Icons class. uses-material-design: true assets: - assets/images/ - assets/font/ fonts: - family: manigu fonts: - asset: assets/font/ManigueStaile.ttf ``` Finally, we can use the font name `manigu`as we set above. ```dart Text( "Flutter open: TextStyle with fontFamily", style: TextStyle(fontFamily: "manigu", fontSize: 40, color: RED), ) ``` ![](https://3262132263-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LW5X4rCYpodwj4P1c8s%2F-LWFZabE0UOoqTIb7sRa%2F-LWFu6Ku2nDpVKZ2Eh0k%2Ftext-13.png?alt=media\&token=b3ae12cb-f38c-400f-8f44-87a00c4e288f) It is easy for use, if you want more detail about the typeface to use, you can [click this link](https://flutter.io/docs/cookbook/design/fonts#from-packages). So far, we finish the using of `TextStyle`, let's look at the other using. ## textAlign This param controls the `Text` location in the parent widget, I will show you it in a `Container`. The `TextAlign` constants are below, I just use the `end` to show. | 1 | 2 | 3 | | ----- | ------- | ----- | | left | center | right | | start | justify | end | ```dart Container( constraints: BoxConstraints.expand(height: 40), color: BLUE, child: Text( "TextAlign end", style: TextStyle(background: Paint()..color = RED), textAlign: TextAlign.end, ), ) ``` ![](https://3262132263-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LW5X4rCYpodwj4P1c8s%2F-LWGK_gP5stFIfeGrajR%2F-LWGLa_-ITUrnQvQtHKy%2Ftext-14.png?alt=media\&token=2aaa3579-7c52-4fcc-9287-5fe60eddd54f) ## textDirection Normally, we draw the `Text` from left from right, but we can change it with the `textDirection` parameter. ```dart Container( color: YELLOW, constraints: BoxConstraints.expand(height: 40, width: 160), child: Text( "textDirection draw from right to left", textDirection: TextDirection.rtl, ), ) ``` ![](https://3262132263-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LW5X4rCYpodwj4P1c8s%2F-LWGK_gP5stFIfeGrajR%2F-LWGSQCrE20Sw_O3dZJp%2Ftext-15.png?alt=media\&token=80aa2362-e2ff-4d10-9490-acbe1f7ba50f) ## softWrap This param will control the whether or not the show all content when there is not enough space for the text to show. If true means that it will show the all content, otherwise not show. ```dart Container( color: RED, constraints: BoxConstraints.expand(height: 40, width: 160), child: Text("softWrap true Text Text Text Text", softWrap: true), ), Container( color: BLUE, constraints: BoxConstraints.expand(height: 40, width: 160), child: Text("softWrap false Text Text Text Text", softWrap: false), ) ``` ![](https://3262132263-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LW5X4rCYpodwj4P1c8s%2F-LWGK_gP5stFIfeGrajR%2F-LWGUYZ3COM1mgLTOBMe%2Ftext-16.png?alt=media\&token=bd8541e9-9938-49bb-a571-a4469b2a2401) ## overflow When there is not enough place to show, how we hand the end part, the overflow is a choice to handle this, above we end just cover the other part, but we can end with three points like follows, you also can use `clip`,`fade`. ```dart Container( color: YELLOW, constraints: BoxConstraints.expand(height: 40, width: 240), child: Text( "overflow TextOverflow.ellipsis: Text Text Text", softWrap: false, overflow: TextOverflow.ellipsis, ), ), ``` ![](https://3262132263-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LW5X4rCYpodwj4P1c8s%2F-LWGK_gP5stFIfeGrajR%2F-LWGWdnweRV396V32MmE%2Ftext-17.png?alt=media\&token=8681a065-075b-4624-a196-c1b7f073f331) ## maxLines Also, you can use the `maxLines` to limit the space, in above part we can see the Text show two lines when there is no space in the horizontal direction. ```dart Container( color: RED_LIGHT, constraints: BoxConstraints.expand(height: 40, width: 230), child: Text( "max lines = 1 content content content content content", maxLines: 1, overflow: TextOverflow.ellipsis, ), ) ``` ![](https://3262132263-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LW5X4rCYpodwj4P1c8s%2F-LWGK_gP5stFIfeGrajR%2F-LWGZ2WMc2k_2bKkXXQ6%2Ftext-18.png?alt=media\&token=504e1129-53f7-47e3-9c82-b127f50d5a2e) ## textScaleFactor When we want to make the `Text` larger or more little, we can use the `fontSize` to change its size. But there is another choice to change its scale, the `textScaleFactor`. It depends on the `fontSize`, for example, when we set `fontSize=10 ,textScaleFactor =2`, the real scale of the `Text` will be equal to 20, means that the real-scale= `fontSize*textScaleFactor` for the `Text`. ```dart Text( "textScaleFactor = 1 fontSize = 16 ", style: TextStyle(fontSize: 16, color: BLUE), textScaleFactor: 1, ), Text( "textScaleFactor = 1.5 fontSize = 20 ", style: TextStyle(fontSize: 16, color: RED), textScaleFactor: 1.2, ), ``` ![](https://3262132263-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LW5X4rCYpodwj4P1c8s%2F-LWGK_gP5stFIfeGrajR%2F-LWGadcCEIqWIvk9sLI4%2Ftext-19.png?alt=media\&token=1dd17abe-e9d8-4a27-9d16-293ae5973c6a) ## Conclusion Today we learn how to use the Text, the most common used param is the style, it mainly controls the Text itself, but some other parameters are controlled with its parent widget. But you needn't know all of them, it's just used with your requirement. Thanks for your reading! The end. #### Whole code in [GitHub](https://github.com/FlutterOpen/flutter-widgets-examples),star to support. | Facebook Page | Twitter | QQ Group | GitHub | ​ | | ------------------------------------------------------- | ----------------------------------------- | --------- | ------------------------------------ | - | | ​[Flutter Open](https://www.facebook.com/flutteropen) ​ | ​[NieBin](https://twitter.com/niebin_gg)​ | 963828159 | ​[NieBin](https://github.com/nb312)​ | ​ |