Auto Scale TextView Text to Fit within Bounds
android, scale, textview, word-wrap
Solution
From June 2018 Android officially started supporting this feature for Android 4.0 (API level 14) and higher. Check it out at: Autosizing TextViews
With Android 8.0 (API level 26) and higher:
<?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" />
Programmatically:
setAutoSizeTextTypeUniformWithConfiguration(int autoSizeMinTextSize, int autoSizeMaxTextSize,
int autoSizeStepGranularity, int unit)
textView.setAutoSizeTextTypeUniformWithConfiguration(
1, 17, 1, TypedValue.COMPLEX_UNIT_DIP);
Android versions prior to Android 8.0 (API level 26):
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:layout_width="match_parent"
android:layout_height="200dp"
app:autoSizeTextType="uniform"
app:autoSizeMinTextSize="12sp"
app:autoSizeMaxTextSize="100sp"
app:autoSizeStepGranularity="2sp" />
</LinearLayout>
Programmatically:
TextViewCompat.setAutoSizeTextTypeUniformWithConfiguration(
TextView textView, int autoSizeMinTextSize, int autoSizeMaxTextSize, int autoSizeStepGranularity, int unit)
TextViewCompat.setAutoSizeTextTypeUniformWithConfiguration(textView, 1, 17, 1,
TypedValue.COMPLEX_UNIT_DIP);
Attention: TextView must have layout_width="match_parent" or absolute size!
Problem
I'm looking for an optimal way to resize wrapping text in a `TextView` so that it will fit within its getHeight and getWidth bounds. I'm not simply looking for a way to wrap the text- I want to make sure it both wraps and is small enough to fit entirely on the screen. I've seen a few cases on StackOverflow where auto resizing was needed, but they are either very special cases with hack solutions, have no solution, or involve re-drawing the `TextView` recursively until it is small enough (which is memory intense and forces the user to watch the text shrink step-by-step with every recursion). But I'm sure somebody out there has found a good solution that doesn't involve what I'm doing: writing several heavy routines that parse and measure the text, resize the text, and repeat until a suitably small size has been found. What routines does `TextView` use to wrap the text? Couldn't those be somehow used to predict whether text will be small enough? tl;dr: is there a best-practice way to auto-resize a `TextView` to fit, wrapped, in its getHeight and getWidth bounds?