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package android.lib.widget.verticalmarqueetextview;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Typeface;
import android.os.Handler;
import android.os.Looper;
import android.util.AttributeSet;
import android.util.Log;
import android.view.Gravity;
import android.view.ViewGroup;
import android.view.Window;
import android.widget.ScrollView;
import android.widget.TextView;

 * A {@link TextView} with vertical marquee effect. The animation speed can be set using
 * {@link #setMarqueeSpeed(int)} or through XML declaration. By default, the marquee effect
 * animation starts automatically when this view is attached to a {@link Window}.
 * Set {@code autoStartMarquee} to {@code false} to disable this behavior.
public class VerticalMarqueeTextView extends ScrollView {
    private static final String TAG = VerticalMarqueeTextView.class.getName();

    private static final int MIN_MARQUEE_SPEED = 1;
    private static final int MAX_MARQUEE_SPEED = 1000;

    private static final double SECOND = 1000;

    private Handler handler;

    private TextView textView;

    private int     marqueeSpeed;
    private boolean marqueeStarted;
    private boolean marqueePaused;
    private boolean isAnimating;

    private int unitDisplacement;

    public VerticalMarqueeTextView(final Context context) {

        this.init(context, null);

    public VerticalMarqueeTextView(final Context context, final AttributeSet attrs) {
        super(context, attrs);

        this.init(context, attrs);

    public VerticalMarqueeTextView(final Context context, final AttributeSet attrs, final int defStyle) {
        super(context, attrs, defStyle);

        this.init(context, attrs);

     * Returns the text content of this text view.
     * @return The text content of this text view.
    public CharSequence getText() {
        return this.textView.getText();

     * Sets a string for this text view.
     * @param text The text to set.
    public void setText(final CharSequence text) {

     * Returns the speed of the marquee effect animation.
     * @return The speed of the marquee effect animation.
    public int getMarqueeSpeed() {
        return this.marqueeSpeed;

     * Sets the speed of the marquee effect animation. Valid range is [1, 1000].
     * @param marqueeSpeed The speed of the marquee effect animation to set. Valid range is [1, 1000].
    public void setMarqueeSpeed(final int marqueeSpeed) {
        this.marqueeSpeed = Math.min(VerticalMarqueeTextView.MAX_MARQUEE_SPEED, Math.max(VerticalMarqueeTextView.MIN_MARQUEE_SPEED, marqueeSpeed));

     * Starts the marquee effect animation.
    public void startMarquee() {
        this.marqueeStarted = true;
        this.marqueePaused  = false;

        if (!this.isAnimating) {
            this.isAnimating = true;

            new Thread(new Runnable() {
                public void run() {

     * Stops the marquee effect animation.
    public void stopMarquee() {
        this.marqueeStarted = false;

    protected void onAttachedToWindow() {

        if (this.marqueeStarted) {

    protected void onDetachedFromWindow() {

        this.marqueePaused = true;

    protected float getTopFadingEdgeStrength() {
        if (this.getChildCount() == 0) {
            return 0;

        final int length  = this.getVerticalFadingEdgeLength();
        final int scrollY = this.textView.getScrollY();

        if (scrollY < length) {
            return scrollY / (float)length;

        return 1;

    private void init(final Context context, final AttributeSet attrs) {
        this.handler = new Handler(Looper.getMainLooper());

        // 1dp per cycle
        this.unitDisplacement = Math.round(this.getResources().getDisplayMetrics().density);

        this.textView = new TextView(context);
        this.addView(this.textView, new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT));
        this.textView.scrollTo(0, -this.getHeight());


        if (attrs != null) {
            final TypedArray array = context.obtainStyledAttributes(attrs, R.styleable.VerticalMarqueeTextView, 0, 0);


            final int textRes = array.getResourceId(R.styleable.VerticalMarqueeTextView_text, 0);
            if (textRes > 0) {

            this.textView.setTextColor(array.getColor(R.styleable.VerticalMarqueeTextView_textColor, context.getResources().getColor(android.R.color.primary_text_light)));

            final int textColorRes = array.getResourceId(R.styleable.VerticalMarqueeTextView_textColor, 0);
            if (textColorRes > 0) {

            final float textSize = array.getDimension(R.styleable.VerticalMarqueeTextView_textSize, 0);
            if (textSize > 0) {

            final int textSizeRes = array.getResourceId(R.styleable.VerticalMarqueeTextView_textSize, 0);
            if (textSizeRes > 0) {

            final int typeface = array.getInt(R.styleable.VerticalMarqueeTextView_typeface, 0);
            this.textView.setTypeface(typeface == 1 ? Typeface.SANS_SERIF : typeface == 2 ? Typeface.SERIF : typeface == 3 ? Typeface.MONOSPACE : Typeface.DEFAULT, array.getInt(R.styleable.VerticalMarqueeTextView_textStyle, Typeface.NORMAL));

            final int textAppearance = array.getResourceId(R.styleable.VerticalMarqueeTextView_textAppearance, 0);
            if (textAppearance > 0) {
                this.textView.setTextAppearance(context, textAppearance);

            this.setMarqueeSpeed(array.getInt(R.styleable.VerticalMarqueeTextView_marqueeSpeed, 0));

            final int marqueeSpeedRes = array.getResourceId(R.styleable.VerticalMarqueeTextView_marqueeSpeed, 0);
            if (marqueeSpeedRes > 0) {

            final boolean autoStartMarquee = array.getBoolean(R.styleable.VerticalMarqueeTextView_autoStartMarquee, true);

            if (autoStartMarquee) {
                this.marqueeStarted = true;


    private void animateTextView() {
        final Runnable runnable = new VerticalMarqueeTextView.MarqueeRunnable(this.textView);

        long previousMillis = 0;

        while (VerticalMarqueeTextView.this.marqueeStarted && !VerticalMarqueeTextView.this.marqueePaused) {
            final long currentMillis = System.currentTimeMillis();

            if (currentMillis >= previousMillis) {

                previousMillis = currentMillis + (long)(VerticalMarqueeTextView.SECOND / VerticalMarqueeTextView.this.marqueeSpeed);

            try {
                Thread.sleep((long)(VerticalMarqueeTextView.SECOND / VerticalMarqueeTextView.this.marqueeSpeed));
            } catch (final InterruptedException e) {
                Log.v(VerticalMarqueeTextView.TAG, e.getMessage(), e);

        this.isAnimating = false;

    private final class MarqueeRunnable implements Runnable {
        private final ViewGroup parent;
        private final TextView  textView;

         * Creates a new instance of {@link VerticalMarqueeTextView.MarqueeRunnable}.
         * @param textView The {@link TextView} to apply marquee effect.
        public MarqueeRunnable(final TextView textView) {
            this.parent   = (ViewGroup)textView.getParent();
            this.textView = textView;

        public void run() {
            final int height       = this.heightOf(this.textView);
            final int parentHeight = this.parent.getHeight();

            if (height > 0 && parentHeight > 0 && height > parentHeight) {
                if (this.textView.getScrollY() >= height) {
                    this.textView.scrollTo(0, -parentHeight);
                } else {
                    this.textView.scrollBy(0, VerticalMarqueeTextView.this.unitDisplacement);


         * Returns the standard height (i.e. without text effects such as shadow) of all the text of
         * the given {@link TextView}.
         * @param textView The {@link TextView} to determine the height of all its text content.
         * @return The standard height of all the text content of the given {@link TextView}.
        private int heightOf(final TextView textView) {
            return textView.getLineCount() > 0 ? textView.getLineHeight() * textView.getLineCount() : 0;