Android imitates the custom View implementation of the typewriter effect, and android typewriter

Android imitates the custom View implementation of the typewriter effect, and android typewriter

I. Preface

During the splash interface, words need to be typed in a manner similar to typewriters. Each word is displayed with a typing sound.

Ii. effect demonstration

In this example, the user-defined View demonstrates the following effect (PS: I never know how to record gif animation on Android, and simply run Genymotion Android simulator on PC, then you can use LICEcap to screen recording .).

Iii. Implementation principle:

This is actually not difficult to implement. You can use a timer to continuously call the setText of TextView and play the sound effects of typing during setText. The Code is as follows:

Import java. util. timer; import java. util. timerTask; import android. content. context; import android. media. mediaPlayer; import android. text. textUtils; import android. util. attributeSet; import android. widget. textView; import com. uperone. typetextview. r;/*** simulate typewriter effect ***/public class TypeTextView extends TextView {private Context mContext = null; private MediaPlayer mMediaPlayer = null; private String mShowTex TString = null; private Timer mTypeTimer = null; private OnTypeViewListener mOnTypeViewListener = null; private static final int TYPE_TIME_DELAY = 80; private int duration = TYPE_TIME_DELAY; // The interval between typing and public TypeTextView, attributeSet attrs, int defStyle) {super (context, attrs, defStyle); initTypeTextView (context);} public TypeTextView (Context context, AttributeSet attrs) {super (con Text, attrs); initTypeTextView (context);} public TypeTextView (Context context) {super (context); initTypeTextView (context);} public void setOnTypeViewListener (OnTypeViewListener onTypeViewListener) {mOnTypeViewListener = onTypeViewListener;} public void start (final String textString) {start (textString, TYPE_TIME_DELAY);} public void start (final String textString, final int typeTimeDelay) {if (Te XtUtils. isEmpty (textString) | typeTimeDelay <0) {return;} post (new Runnable () {@ Overridepublic void run () {mShowTextString = textString; mTypeTimeDelay = typeTimeDelay; setText (""); startTypeTimer (); if (null! = MOnTypeViewListener) {mOnTypeViewListener. onTypeStart () ;}}) ;}public void stop () {stopTypeTimer (); stopAudio () ;}private void initTypeTextView (Context context) {mContext = context ;} private void startTypeTimer () {stopTypeTimer (); mTypeTimer = new Timer (); mTypeTimer. schedule (new TypeTimerTask (), mTypeTimeDelay);} private void stopTypeTimer () {if (null! = MTypeTimer) {mTypeTimer. cancel (); mTypeTimer = null;} private void startAudioPlayer () {stopAudio (); playAudio (R. raw. type_in);} private void playAudio (int audioResId) {try {stopAudio (); mMediaPlayer = MediaPlayer. create (mContext, audioResId); mMediaPlayer. start ();} catch (Exception e) {e. printStackTrace () ;}} private void stopAudio () {if (mMediaPlayer! = Null & mMediaPlayer. isPlaying () {mMediaPlayer. stop (); mMediaPlayer. release (); mMediaPlayer = null;} class TypeTimerTask extends TimerTask {@ Overridepublic void run () {post (new Runnable () {@ Overridepublic void run () {if (getText (). toString (). length () <mShowTextString. length () {setText (mShowTextString. substring (0, getText (). toString (). length () + 1); startAudioPlayer (); startTypeTi Mer ();} else {stopTypeTimer (); if (null! = MOnTypeViewListener) {mOnTypeViewListener. onTypeOver () ;}}}) ;}} public interface OnTypeViewListener {public void onTypeStart (); public void onTypeOver ();}}

Iv. Instructions for use:

1. Define in the xml file:

<com.uperone.typetext.view.TypeTextView        android:id="@+id/typeTxtId"        android:layout_width="fill_parent"        android:layout_height="wrap_content"        android:layout_centerVertical="true" />

2. instantiate in code:

mTypeTextView = ( TypeTextView )findViewById(R.id.typeTxtId);mTypeTextView.setOnTypeViewListener( new OnTypeViewListener( ) {@Overridepublic void onTypeStart() {print( "onTypeStart" );}@Overridepublic void onTypeOver() {print( "onTypeOver" );}});

3. Call the start method:

mTypeTextView.start( TEST_DATA );

V,

I uploaded this demo to github. You can download it here and modify it as needed. TypeTextView