Feb 8, 2014

Example of using TextUtils.commaEllipsize()

TextUtils.commaEllipsize() converts a CharSequence of the comma-separated form "Andy, Bob, Charles, David" that is too wide to fit into the specified width into one like "Andy, Bob, 2 more".

Here is a example:
TextUtils.commaEllipsize() example
TextUtils.commaEllipsize() example
  • When updateEllipsizedText() called in onCreate() to update myText1, because the views have not been shown here, getMeasuredWidth() inside updateEllipsizedText() return 0, so nothing shown on myText1.
  • To update myText2 after views layout, implement OnGlobalLayoutListener() to call updateEllipsizedText().

package com.example.androidtextutils;

import android.os.Bundle;
import android.app.Activity;
import android.text.TextPaint;
import android.text.TextUtils;
import android.view.ViewTreeObserver;
import android.view.ViewTreeObserver.OnGlobalLayoutListener;
import android.widget.TextView;

public class MainActivity extends Activity {

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  final TextView myText1 = (TextView) findViewById(R.id.mytext1);
  final TextView myText2 = (TextView) findViewById(R.id.mytext2);

  final String days = "Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday";
  
  //views not yet layouted, getMeasuredWidth() inside updateEllipsizedText() return 0
  //nothing display on myText1!
  updateEllipsizedText(myText1, days);

  //update myText2 with TextUtils.commaEllipsize() String after layouted
  ViewTreeObserver viewTreeObserver = myText2.getViewTreeObserver();
  if (viewTreeObserver.isAlive()) {
   viewTreeObserver.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
      @Override
      public void onGlobalLayout() {
       //removeGlobalOnLayoutListener() was deprecated in API level 16. 
       //Use removeOnGlobalLayoutListener() instead
       myText2.getViewTreeObserver().removeGlobalOnLayoutListener(this);
       //for API 16
       //myText.getViewTreeObserver().removeOnGlobalLayoutListener(this);
       updateEllipsizedText(myText2, days);
      }
     });
  }
 }

 private void updateEllipsizedText(TextView tv, String text) {
  TextPaint p = tv.getPaint();
  tv.setText(text);
  float avail = tv.getMeasuredWidth();
  String oneMore = "one more";
  String more = "%d more";
  CharSequence ellipsizedText = TextUtils.commaEllipsize(text, p, avail,
    oneMore, more);
  tv.setText(ellipsizedText);
 }

}

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:orientation="vertical"
    tools:context=".MainActivity" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="android-coding.blogspot.com" />

    <TextView
        android:id="@+id/mytext1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textStyle="bold" />
    <TextView
        android:id="@+id/mytext2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textStyle="bold|italic" />

</LinearLayout>

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