How to adjust text kerning in Android TextView?

Question

Is there a way to adjust the spacing between characters in an Android TextView? I believe this is typically called "kerning".

I'm aware of the android:textScaleX attribute, but that compresses the characters along with the spacing.

Answer 1

I built a custom class that extends TextView and adds a method "setSpacing". The workaround is similar to what @Noah said. The method adds a space between each letter of the String and with SpannedString changes the TextScaleX of the spaces, allowing positive and negative spacing.

Hope that helps someone ^^

/**  * Text view that allows changing the letter spacing of the text.  *   * @author Pedro Barros (pedrobarros.dev at gmail.com)  * @since May 7, 2013  */  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 spacing = Spacing.NORMAL;     private CharSequence originalText = "";       public LetterSpacingTextView(Context context) {         super(context);     }      public LetterSpacingTextView(Context context, AttributeSet attrs){         super(context, attrs);     }      public LetterSpacingTextView(Context context, AttributeSet attrs, int defStyle){         super(context, attrs, defStyle);     }      public float getSpacing() {         return this.spacing;     }      public void setSpacing(float spacing) {         this.spacing = spacing;         applySpacing();     }      @Override     public void setText(CharSequence text, BufferType type) {         originalText = text;         applySpacing();     }      @Override     public CharSequence getText() {         return originalText;     }      private void applySpacing() {         if (this == null || this.originalText == null) return;         StringBuilder builder = new StringBuilder();         for(int i = 0; i < originalText.length(); i++) {             builder.append(originalText.charAt(i));             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((spacing+1)/10), i, i+1, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);             }         }         super.setText(finalText, BufferType.SPANNABLE);     }      public class Spacing {         public final static float NORMAL = 0;     } } 

Using it:

LetterSpacingTextView textView = new LetterSpacingTextView(context); textView.setSpacing(10); //Or any float. To reset to normal, use 0 or LetterSpacingTextView.Spacing.NORMAL textView.setText("My text"); //Add the textView in a layout, for instance: ((LinearLayout) findViewById(R.id.myLinearLayout)).addView(textView); 

Answer 2

If anyone is looking for a simple way to apply the kerning to any string (technically, CharSequence) without using a TextView:

public static Spannable applyKerning(CharSequence src, float kerning) {     if (src == null) return null;     final int srcLength = src.length();     if (srcLength < 2) return src instanceof Spannable                               ? (Spannable)src                               : new SpannableString(src);      final String nonBreakingSpace = "\u00A0";     final SpannableStringBuilder builder = src instanceof SpannableStringBuilder                                            ? (SpannableStringBuilder)src                                            : new SpannableStringBuilder(src);     for (int i = src.length() - 1; i >= 1; i--)     {         builder.insert(i, nonBreakingSpace);         builder.setSpan(new ScaleXSpan(kerning), i, i + 1,                         Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);     }      return builder; } 

Answer 3

AFAIK, you cannot adjust kerning in TextView. You may be able to adjust kerning if you draw the text on the Canvas yourself using the 2D graphics APIs.

Answer 4

Since Android 21, you can use set the letterSpacing attribute.

<TextView
    android:width="..."
    android:height="..."
    android:letterSpacing="1.3"/>