Android - Expandable TextView with Animation

Question

I have a TextView which firstly shows a small portion of a long text.

The user can press a "see more" button to expand the TextView and see the rest of that text.

Making tests, I can reach that by simply interchange the value of TextView.setMaxLines between 4 for collapsing and Integer.MAX_VALUE for expanding.

Now, I would like that this behavior would be accompanied by an animation. I know that in this question one solution is almost done, but I tried to implement it and I have no success.

Can someone help me with this?

Answer 1

You can check my blog post on ExpandableTexTView:

The idea is, initially the TextView will show a small portion of a long text and when it is clicked, it will show the rest of the text.

So here is the code that how I solved it.

package com.rokonoid.widget;  import android.content.Context; import android.content.res.TypedArray; import android.text.SpannableStringBuilder; import android.util.AttributeSet; import android.view.View; import android.widget.TextView; /**  * User: Bazlur Rahman Rokon  * Date: 9/7/13 - 3:33 AM  */ public class ExpandableTextView extends TextView {     private static final int DEFAULT_TRIM_LENGTH = 200;     private static final String ELLIPSIS = ".....";      private CharSequence originalText;     private CharSequence trimmedText;     private BufferType bufferType;     private boolean trim = true;     private int trimLength;      public ExpandableTextView(Context context) {         this(context, null);     }      public ExpandableTextView(Context context, AttributeSet attrs) {         super(context, attrs);          TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.ExpandableTextView);         this.trimLength = typedArray.getInt(R.styleable.ExpandableTextView_trimLength, DEFAULT_TRIM_LENGTH);         typedArray.recycle();          setOnClickListener(new OnClickListener() {             @Override             public void onClick(View v) {                 trim = !trim;                 setText();                 requestFocusFromTouch();             }         });     }      private void setText() {         super.setText(getDisplayableText(), bufferType);     }      private CharSequence getDisplayableText() {         return trim ? trimmedText : originalText;     }      @Override     public void setText(CharSequence text, BufferType type) {         originalText = text;         trimmedText = getTrimmedText(text);         bufferType = type;         setText();     }      private CharSequence getTrimmedText(CharSequence text) {         if (originalText != null && originalText.length() > trimLength) {             return new SpannableStringBuilder(originalText, 0, trimLength + 1).append(ELLIPSIS);         } else {             return originalText;         }     }      public CharSequence getOriginalText() {         return originalText;     }      public void setTrimLength(int trimLength) {         this.trimLength = trimLength;         trimmedText = getTrimmedText(originalText);         setText();     }      public int getTrimLength() {         return trimLength;     } } 

And add the following line in your attr.xml

<?xml version="1.0" encoding="utf-8"?> <resources>     <declare-styleable name="ExpandableTextView">         <attr name="trimLength" format="integer"/>     </declare-styleable> </resources> 

Put the following in your main.xml

<?xml version="1.0" encoding="utf-8"?>  <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"      android:orientation="vertical"      android:layout_width="fill_parent"      android:layout_height="fill_parent">       <com.rokonoid.widget.ExpandableTextView          android:id="@+id/lorem_ipsum"          android:layout_width="fill_parent"          android:layout_height="wrap_content"/>   </LinearLayout> 

And test your activity

package com.rokonoid.widget;  import android.app.Activity; import android.os.Bundle;  public class MyActivity extends Activity {      @Override     public void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.main);          String yourText = "Lorem ipsum dolor sit amet, consectetur adipiscing elit. " +                 "Ut volutpat interdum interdum. Nulla laoreet lacus diam, vitae " +                 "sodales sapien commodo faucibus. Vestibulum et feugiat enim. Donec " +                 "semper mi et euismod tempor. Sed sodales eleifend mi id varius. Nam " +                 "et ornare enim, sit amet gravida sapien. Quisque gravida et enim vel " +                 "volutpat. Vivamus egestas ut felis a blandit. Vivamus fringilla " +                 "dignissim mollis. Maecenas imperdiet interdum hendrerit. Aliquam" +                 " dictum hendrerit ultrices. Ut vitae vestibulum dolor. Donec auctor ante" +                 " eget libero molestie porta. Nam tempor fringilla ultricies. Nam sem " +                 "lectus, feugiat eget ullamcorper vitae, ornare et sem. Fusce dapibus ipsum" +                 " sed laoreet suscipit. ";          ExpandableTextView expandableTextView = (ExpandableTextView) findViewById(R.id.lorem_ipsum);         expandableTextView.setText(yourText);     } } 

Reference: Android – Expandable TextView