How can I raise up the position of a particular character with Span?

Question

There is a simple characters. "Hello → world!!!"

it's good to see it in XML Design tab. Nothing wrong.

but when i run the app, and the arrow is located at the baseline of TextView.

this is a xml code and design tab.

and the result when i run this app.

I don't understand how the result is.

so I want to put the arrow in the middle like when i see it in the XML Design tab.

how can i do this? can i use Spannable? or Something??

Answer 1

1. You can TextView use android:gravity="center_vertical|left"
2. Here's a trick to help: You can include an image of special characters and insert that image into the output text.

First, add a new Drawable resource file (ic_arrow.xml) in res/drawable, and copy and paste it into it.

<vector android:alpha="0.78" android:height="24dp"
  android:viewportHeight="24.0" android:viewportWidth="24.0"
  android:width="24dp" xmlns:android="http://schemas.android.com/apk/res/android">
  <path android:fillColor="#FF000000" android:pathData="M3,12L21.5,12"
    android:strokeColor="#000000" android:strokeWidth="1"/>
  <path android:fillColor="#FF000000" android:pathData="M21,12L17,8"
    android:strokeColor="#000000" android:strokeWidth="1"/>
  <path android:fillColor="#FF000000" android:pathData="M21,12L17,16"
    android:strokeColor="#000000" android:strokeWidth="1"/>
</vector>

Add code to the activity.

    TextView textView = findViewById(R.id.my_text_view);

    Drawable arrow = ContextCompat.getDrawable(this, R.drawable.ic_arrow);
    Float ascent = textView.getPaint().getFontMetrics().ascent;
    int h = (int) -ascent;
    arrow.setBounds(0,0,h,h);

    SpannableString stringWithImage = new SpannableString("A*B");
    stringWithImage.setSpan(new ImageSpan(arrow, DynamicDrawableSpan.ALIGN_BASELINE), 1, 2, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
    textView.setText(stringWithImage);  

It works like this.