How to auto size textview dynamically according to the length of the text in android?
There's now an official solution to this problem. Autosizing TextViews introduced with Android O are available in the Support Library 26 and is backwards compatible all the way down to Android 4.0.
https://developer.android.com/preview/features/autosizing-textview.html
Here's one way to do it, using the support library:
<androidx.appcompat.widget.AppCompatTextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:breakStrategy="balanced"
android:gravity="center_horizontal"
android:maxLines="1"
android:text="Hello world"
android:textSize="300sp"
app:autoSizeTextType="uniform"
tools:targetApi="o"/>
The android:breakStrategy
allows making the text go to the next line nicely, instead of the default behavior which might break the words.
In gradle, use this:
implementation 'androidx.appcompat:appcompat:1.0.0-beta01'
implementation 'com.google.android.material:material:1.0.0-beta01'
Or this:
implementation 'com.android.support:appcompat-v7:28.0.0'
implementation 'com.android.support:design:28.0.0'
Note that it's recommended to set layout restrictions on the TextView (width and/or height), to make sure you will get it right. All depends on your use case.
addTextChangedListener is a listener for Edit Tex. this listener watch the changes of editText and it has three different states.
EditText edt = someEditText;
edt.addTextChangedListener(new TextWatcher() {
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
/*watch the editText on every input and changes, then mange the size by if statements and editText length*/
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
if (edt.getText().toString().length() > 10){
edt.setTextSize(TypedValue.COMPLEX_UNIT_SP, textSizeSmall);
}
else if (edt.getText().toString().length() > 5){
edt.setTextSize(TypedValue.COMPLEX_UNIT_SP, textSizeMedium);
}
}
@Override
public void afterTextChanged(Editable s) {
}
});
Updated: According to question you can create a component(custom view) and extend it from AppCompatTextView name as you want; in its initialization you can add below code:
public class CustomTextView extends AppCompatTextView {
Context ctx;
public CustomTextView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
ctx = context;
init();
}
public CustomTextView(Context context, AttributeSet attrs) {
super(context, attrs);
ctx = context;
init();
}
public CustomTextView(Context context) {
super(context);
ctx = context;
init();
}
public void init() {
setOnTouchListener(null);
addTextChangedListener(new TextWatcher() {
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
if (getText().toString().length() > 10){
setTextSize(TypedValue.COMPLEX_UNIT_SP, textSizeSmall);
}
else if (getText().toString().length() > 5){
setTextSize(TypedValue.COMPLEX_UNIT_SP, textSizeMedium);
}
}
@Override
public void afterTextChanged(Editable s) {
}
});
}
}
you must use it in xml instead of the usual textView