Одинаковое количество точек при просмотре текста пароля на андроид

Question

У меня есть TextView с паролем пользователей, и я должен позволить им показать / скрыть его. Поэтому я создал кнопку с функцией показать / скрыть.

Когда пароль находится в режиме скрытия, мне нужно показать одинаковое количество точек, например пять точек.

Я написал следующий код, но когда пароль пытается скрыться, я получаю сообщение об ошибке. (Написал ниже)

Может ли кто-нибудь мне помочь?

Код:

public class CustomPasswordTransformation  extends PasswordTransformationMethod {

    @Override
    public CharSequence getTransformation(CharSequence source, View view) {
        return new PasswordCharSequence(source);
    }

    private class PasswordCharSequence implements CharSequence {
        private CharSequence mSource;

        public PasswordCharSequence(CharSequence source) {
            mSource = source;
        }
        public char charAt(int index) {
            return '*';
        }
        public int length() {
            return 5;
        }
        public CharSequence subSequence(int start, int end) {
            return mSource.subSequence(start, end); 
        }
    }
}

И это ошибка:

E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.debug, PID: 19891
java.lang.IndexOutOfBoundsException
    at android.graphics.Paint.getRunAdvance(Paint.java:2346)
    at android.text.TextLine.handleText(TextLine.java:748)
    at android.text.TextLine.handleRun(TextLine.java:898)
    at android.text.TextLine.measureRun(TextLine.java:417)
    at android.text.TextLine.measure(TextLine.java:296)
    at android.text.TextLine.metrics(TextLine.java:270)
    at android.text.Layout.getLineExtent(Layout.java:1053)
    at android.text.Layout.getLineWidth(Layout.java:1019)
    at android.widget.TextView.desired(TextView.java:6811)
    at android.widget.TextView.onMeasure(TextView.java:6877)
    at android.view.View.measure(View.java:18850)
    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5963)
    at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1465)
    at android.widget.LinearLayout.measureHorizontal(LinearLayout.java:1112)
    at android.widget.LinearLayout.onMeasure(LinearLayout.java:632)
    at android.view.View.measure(View.java:18850)
    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5963)
    at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1465)
    at android.widget.LinearLayout.measureVertical(LinearLayout.java:748)
    at android.widget.LinearLayout.onMeasure(LinearLayout.java:630)
    at android.view.View.measure(View.java:18850)
    at android.widget.RelativeLayout.measureChild(RelativeLayout.java:677)
    at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:480)
    at android.view.View.measure(View.java:18850)
    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5963)
    at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1465)
    at android.widget.LinearLayout.measureVertical(LinearLayout.java:748)
    at android.widget.LinearLayout.onMeasure(LinearLayout.java:630)
    at android.view.View.measure(View.java:18850)
    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5963)
    at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1465)
    at android.widget.LinearLayout.measureHorizontal(LinearLayout.java:1112)
    at android.widget.LinearLayout.onMeasure(LinearLayout.java:632)
    at android.view.View.measure(View.java:18850)
    at android.support.v7.widget.RecyclerView$LayoutManager.measureChildWithMargins(RecyclerView.java:8994)
    at android.support.v7.widget.LinearLayoutManager.layoutChunk(LinearLayoutManager.java:1585)
    at android.support.v7.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1519)
    at android.support.v7.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:614)
    at android.support.v7.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:3812)
    at android.support.v7.widget.RecyclerView.dispatchLayout(RecyclerView.java:3529)
    at android.support.v7.widget.RecyclerView.onLayout(RecyclerView.java:4082)
    at android.view.View.layout(View.java:16692)
    at android.view.ViewGroup.layout(ViewGroup.java:5449)
    at android.support.v4.widget.SwipeRefreshLayout.onLayout(SwipeRefreshLayout.java:606)
    at android.view.View.layout(View.java:16692)
    at android.view.ViewGroup.layout(ViewGroup.java:5449)
    at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1743)
    at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1586)
    at android.widget.LinearLayout.onLayout(LinearLayout.java:1495)
    at android.view.View.layout(View.java:16692)
    at android.view.ViewGroup.layout(ViewGroup.java:5449)
    at android.support.v4.view.ViewPager.onLayout(ViewPager.java:1769)
    at android.view.View.layout(View.java:16692)
    at android.view.ViewGroup.layout(ViewGroup.java:5449)
    at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1743)
    at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1586)
    at android.widget.LinearLayout.onLayout(LinearLayout.java:1495)
    at android.view.View.layout(View.java:16692)
    at android.view.ViewGroup.layout(ViewGroup.java:5449)
    at android.widget.FrameLayout.layoutChildren(FrameLayout.java:336)
    at android.widget.FrameLayout.onLayout(Fram

Answer 1

Вам необходимо вернуть длину последовательности символов, которую вы указали при вводе.

В вашем коде вам нужно заменить 5 на source.length () в функции length.

открытый класс CustomPasswordTransformation расширяет PasswordTransformationMethod {

@Override
public CharSequence getTransformation(CharSequence source, View view) {
    return new PasswordCharSequence(source);
}

private class PasswordCharSequence implements CharSequence {
    private CharSequence mSource;

    public PasswordCharSequence(CharSequence source) {
        mSource = source;
    }
    public char charAt(int index) {
        return '*';
    }
    public int length() {
        return source.length();
    }
    public CharSequence subSequence(int start, int end) {
        return mSource.subSequence(start, end); 
    }
}

}