How "Android" Changes TextView font spacing

Method:

1. Custom fonts, where you add spacing, more complex
2. Space between letters, not desirable, the width is not flexible
3. Use Textscalex and space, custom TextView, let Textscalex only change the spacing, do not change the font
4. Carbon OnDraw, each time you draw a character, manually control the position of each character.

The code for Method 3 is provided below, with a reference to the link:

Https://stackoverflow.com/questions/14283246/change-text-kerning-or-spacing-in-textview

Package Nl.raakict.android.spc.widget;import Android.content.context;import Android.text.spannable;import Android.text.spannablestring;import Android.text.style.scalexspan;import Android.util.attributeset;import Android.widget.textview;public class Letterspacingtextview extends TextView {private float letterspacing = Letterspaci Ng.    Biggest;    Private Charsequence Originaltext = "";    Public Letterspacingtextview (Context context) {super (context);        } public Letterspacingtextview (context context, AttributeSet Attrs) {Super (context, attrs);        Originaltext = Super.gettext ();        Applyletterspacing ();    This.invalidate (); } public Letterspacingtextview (context context, AttributeSet attrs, int defstyle) {Super (context, Attrs, defstyl    e);    } public float getletterspacing () {return letterspacing;        } public void setletterspacing (float letterspacing) {this.letterspacing = letterspacing;    Applyletterspacing ();  }  @Override public void SetText (charsequence text, Buffertype type) {originaltext = text;    Applyletterspacing ();    } @Override Public Charsequence GetText () {return originaltext;        } private void Applyletterspacing () {StringBuilder builder = new StringBuilder ();            for (int i = 0; i < originaltext.length (); i++) {String c = "" + Originaltext.charat (i);            Builder.append (C.tolowercase ());            if (I+1 < Originaltext.length ()) {builder.append ("\u00a0");        }} spannablestring Finaltext = new Spannablestring (builder.tostring ());                if (builder.tostring (). Length () > 1) {for (int i = 1; i < builder.tostring (). Length (); i+=2) {            Finaltext.setspan (New Scalexspan ((letterspacing+1)/10), I, i+1, spannable.span_exclusive_exclusive);    }} super.settext (Finaltext, buffertype.spannable);      } public class Letterspacing {  Public final static float NORMAL = 0;        Public final static Float Normalbig = (float) 0.025;        Public final static Float BIG = (float) 0.05;    Public final static Float biggest = (float) 0.2; }}

　　

How "Android" Changes TextView font spacing