如何以编程方式在RelativeLayout中添加底部填充以覆盖textView的内容

Question

How can padding be added to the bottom of the textview programmatically? I noticed that there is some padding above the text but not below. What can be done in order to add some black padding at the bottom just like at the top? It would make the text view a lot more legible (especially for letters that extend below the baseline ie g and y ).

TextView tv1 = v.findViewById(R.id.textView1);
String myString = " " + getString(R.string.magnify) + " ";
Spannable spanna = new SpannableString(myString);
spanna.setSpan(new BackgroundColorSpan(Color.BLACK), 0, myString.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
spanna.setSpan(new ForegroundColorSpan(ContextCompat.getColor(getContext(), R.color.yellow)), 0, myString.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
tv2.setText(spanna);

Answer 1

You can use: yourTextView.setPadding(0, 10, 0, 0); Android - How to set padding for TextView in ListView or ExpandableListView

Or increase the TextviewHeight and centre the text.

Answer 2

With this custom ReplacementSpan, text is drawn "vertically center"

final SpannableString spannableString = new SpannableString(myString);
stringBuilder.append(spannableString);
stringBuilder.setSpan(new TagSpan(Color.BLACK, Color.MAGENTA), 0, myString.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
testTextView.setText(stringBuilder, TextView.BufferType.SPANNABLE);

Class TagSpan

public class TagSpan extends ReplacementSpan {
    private RectF mRect;
    private int mBackgroundColor;
    private int mForegroundColor;

    public TagSpan(int backgroundColor, int foregroundColor) {
        this.mRect = new RectF();
        this.mBackgroundColor = backgroundColor;
        this.mForegroundColor = foregroundColor;
    }

    @Override
    public void draw(Canvas canvas, CharSequence text, int start, int end, float x, int top, int y, int bottom, Paint paint) {
        // Background
        mRect.set(x, top, x + paint.measureText(text, start, end), bottom);
        paint.setColor(mBackgroundColor);
        canvas.drawRect(mRect, paint);

        // Text
        paint.setColor(mForegroundColor);
        int xPos = Math.round(x);
        int yPos = (int) (0 + ((canvas.getHeight() / 2) - ((paint.descent() + paint.ascent()) / 2)));
        canvas.drawText(text, start, end, xPos, yPos, paint);
    }

    @Override
    public int getSize(Paint paint, CharSequence text, int start, int end, Paint.FontMetricsInt fm) {
        return Math.round(paint.measureText(text, start, end));
    }

}

Not exactly answer to "bottom padding" request but solve part of your problem I think.

( Original post )

Answer 3

Set RelativeLayout.LayoutParams for Textview

TextView tv1 = v.findViewById(R.id.textView1);
String myString = " " + getString(R.string.magnify) + " ";
Spannable spanna = new SpannableString(myString);
spanna.setSpan(new BackgroundColorSpan(Color.BLACK), 0, myString.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
spanna.setSpan(new ForegroundColorSpan(ContextCompat.getColor(getContext(), R.color.yellow)), 0, myString.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
tv1.setText(spanna);

RelativeLayout.LayoutParams params= new RelativeLayout.LayoutParams(
                ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);
        params.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM, tv1.getId());
        tv1.setLayoutParams(params);