How to dynamically resize text in Android

Question

I want to implement a function,

EditText user when entering text, you can make changes in accordance with the set font size,

For example, Google Docs of Office,

Now I have found a SpannableString method, but some examples seem unable to satisfy my needs.

 int index = input.getSelectionEnd(); SpannableString spann = new SpannableString(show_input); AbsoluteSizeSpan word_size = new AbsoluteSizeSpan(18,true); spann.setSpan(word_size, 0, 1, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE); input.getText().insert(index, spann); 

So is there a way to provide it?

Answer 1

It looks like you want to resize the selected text:

 int start = editText.getSelectionStart(); int end = editText.getSelectionEnd(); Spannable text=(Spannable)editText.getText(); text.setSpan(new AbsoluteSizeSpan(NEW_TEXT_SIZE, true), start, end, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE); editText.setText(text); 

Use AbsoluteSizeSpan to change for actual size or RelativeSizeSpan for proportional size.

Answer 2

I am trying to add TextWatcher (),

 input =(EditText)findViewById(R.id.Input_EditText); input.addTextChangedListener(new TextWatcher() { public void onTextChanged(CharSequence s, int start, int before, int count) { } public void beforeTextChanged(CharSequence s, int start, int count, int after) { } public void afterTextChanged(Editable s) { int index = input.getSelectionEnd(); String nowstr; if(index==0) { //do nothing } else { nowstr = s.toString(); char nowstr_array[] = nowstr.toCharArray(); show_input = String.valueOf(nowstr_array[index-1]); SpannableStringBuilder spann = new SpannableStringBuilder(show_input); AbsoluteSizeSpan word_size = new AbsoluteSizeSpan(40,true); spann.setSpan(word_size, 0, 1, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE); input.getText().insert(index, spann); } } }); 

But this program will fail ...

then i try to do

  Toast.makeText(MainActivity.this, spann, Toast.LENGTH_SHORT).show(); //input.getText().insert(index, spann); 

But it may display ...

That's why?