TextAutoSize
- Cmn
interface TextAutoSize
Interface used by Text composables to override text size to automatically grow or shrink text to fill the layout bounds.
import androidx.compose.foundation.layout.Box import androidx.compose.foundation.layout.size import androidx.compose.foundation.text.BasicText import androidx.compose.foundation.text.TextAutoSize import androidx.compose.ui.Modifier import androidx.compose.ui.unit.dp Box(modifier = Modifier.size(200.dp)) { // The text will find the biggest available font size that fits in the box. BasicText(text = "Hello World", autoSize = TextAutoSize.StepBased()) }
Summary
Public companion functions | ||
|---|---|---|
TextAutoSize | Automatically size the text with the biggest font size that fits the available space. | Cmn |
Public functions | ||
|---|---|---|
operator Boolean | This type is used in performance-sensitive paths and requires providing equality guarantees. | Cmn |
TextUnit | TextAutoSizeLayoutScope.getFontSize(Calculates font size and provides access to | Cmn |
Int | hashCode()This type is used in performance-sensitive paths and requires providing identity guarantees. | Cmn |
Public companion functions
StepBased
fun StepBased(
minFontSize: TextUnit = TextAutoSizeDefaults.MinFontSize,
maxFontSize: TextUnit = TextAutoSizeDefaults.MaxFontSize,
stepSize: TextUnit = 0.25.sp
): TextAutoSize
Automatically size the text with the biggest font size that fits the available space.
When text auto size is performed with TextOverflow.Ellipsis, TextOverflow.StartEllipsis or TextOverflow.MiddleEllipsis (e.g. by specifying textOverflow on BasicText), this implementation will consider the text to be fitting the available space if it is not ellipsized.
| Parameters | |
|---|---|
minFontSize: TextUnit = TextAutoSizeDefaults.MinFontSize | The smallest potential font size of the text. Default = 12.sp. This must be smaller than |
maxFontSize: TextUnit = TextAutoSizeDefaults.MaxFontSize | The largest potential font size of the text. Default = 112.sp. This must be larger than |
stepSize: TextUnit = 0.25.sp | The smallest difference between potential font sizes. Specifically, every font size, when subtracted by |
| Returns | |
|---|---|
TextAutoSize | AutoSize instance with the step-based configuration. Using this in a compatible composable will cause its text to be sized as above. |
Public functions
equals
operator fun equals(other: Any?): Boolean
This type is used in performance-sensitive paths and requires providing equality guarantees. Using a data class is sufficient. Singletons may implement this function with referential equality (this === other). Instances with no properties may implement this function by checking the type of the other object.
| Returns | |
|---|---|
Boolean | true if both AutoSize instances are identical. |
getFontSize
fun TextAutoSizeLayoutScope.getFontSize(
constraints: Constraints,
text: AnnotatedString
): TextUnit
Calculates font size and provides access to TextAutoSizeLayoutScope, which offers TextAutoSizeLayoutScope.performLayout to lay out the text and use the measured size.
import androidx.compose.foundation.layout.size import androidx.compose.foundation.text.BasicText import androidx.compose.foundation.text.TextAutoSize import androidx.compose.foundation.text.modifiers.TextAutoSizeLayoutScope import androidx.compose.runtime.Composable import androidx.compose.runtime.remember import androidx.compose.ui.text.AnnotatedString import androidx.compose.ui.unit.Constraints import androidx.compose.ui.unit.TextUnit import androidx.compose.ui.unit.sp data class PresetsTextAutoSize(private val presets: Array<TextUnit>) : TextAutoSize { override fun TextAutoSizeLayoutScope.getFontSize( constraints: Constraints, text: AnnotatedString, ): TextUnit { var lastTextSize: TextUnit = TextUnit.Unspecified for (presetSize in presets) { val layoutResult = performLayout(constraints, text, presetSize) if ( layoutResult.size.width <= constraints.maxWidth && layoutResult.size.height <= constraints.maxHeight ) { lastTextSize = presetSize } else { break } } return lastTextSize } } @Composable fun App() { val autoSize = remember { PresetsTextAutoSize(arrayOf(10.sp, 14.sp, 21.sp)) } BasicText(text = "Hello World", autoSize = autoSize) }
| Returns | |
|---|---|
TextUnit | The derived optimal font size |
| See also | |
|---|---|
performLayout |