Auto sizing text

​ Three ways provided(by The Support Library 26.0).

• Default
• Granularity
• Preset Sizes

​ :warning: CAUTION :

1. “wrap_content” for layout_width or layout_height attribute is not recommended.

​ It may produce unexpected results.

1. android:autoSizeTextType="" is ‘TextView’ attribute not EditText.

1. Default

The default dimensions for uniform scaling are minTextSize = 12sp, maxTextSize = 112sp, and granularity = 1px.

XML expression

<?xml version="1.0" encoding="utf-8"?>
<TextView
    android:layout_width="match_parent"
    android:layout_height="200dp"
    android:autoSizeTextType="uniform" />

Programmatical expression

TextViewCompat.setAutoSizeTextTypeWithDefaults(TextView textview, int autoSizeTextType)

2. Granularity

It defining a range of minimum and maximum text sizes and a dimension that specifies the size of each step.

XML expression

<?xml version="1.0" encoding="utf-8"?>
<TextView
    android:layout_width="match_parent"
    android:layout_height="200dp"
    android:autoSizeTextType="uniform"
    android:autoSizeMinTextSize="12sp"
    android:autoSizeMaxTextSize="100sp"
    android:autoSizeStepGranularity="2sp" />

Programmatical expression

setAutoSizeTextTypeUniformWithConfiguration(int autoSizeMinTextSize, int autoSizeMaxTextSize, int autoSizeStepGranularity, int unit)

3. Preset Sizes

Specifying all the values.

Add array resource

<resources>
  <array name="autosize_text_sizes">
    <item>10sp</item>
    <item>12sp</item>
    <item>20sp</item>
    <item>40sp</item>
    <item>100sp</item>
  </array>
</resources>

//in res/values/arrays.xml

XML expression

<?xml version="1.0" encoding="utf-8"?>
<TextView
    android:layout_width="match_parent"
    android:layout_height="200dp"
    android:autoSizeTextType="uniform"
    android:autoSizePresetSizes="@array/autosize_text_sizes" />

Programmatical expression

setAutoSizeTextTypeUniformWithPresetSizes(int[] presetSizes, int unit)

Synchronize EditText with TextView auto sized

Set attribute (e.g. ‘android:autoSizeTextType=”uniform”’) to TextView(TextView title).

Call EditText(EditText editor).setTextSize in titles callback ViewTreeObserver.OnGlobalLayoutListener.

title.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
            @Override
            public void onGlobalLayout() {
                //Calling EditText.setText in lifecycle mothod (e.g. Activity.onCreate or onResume) may be produce setting unexpected size.
                int textSizePx = (int) title.getTextSize();
                editor.setTextSize(TypedValue.COMPLEX_UNIT_PX, textSizePx)
            }
        });