AndroidFontUtils.android.kt
/*
* Copyright 2021 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package androidx.compose.ui.text.font
import android.graphics.Typeface
import android.os.Build
import androidx.annotation.DoNotInline
import androidx.annotation.RequiresApi
internal val FontWeight.Companion.AndroidBold
get() = W600
/**
* Lookup style used by [android.graphics.Typeface].
*
* May return one of:
* - [Typeface.BOLD_ITALIC]
* - [Typeface.BOLD]
* - [Typeface.ITALIC]
* - [Typeface.NORMAL]
*/
internal fun getAndroidTypefaceStyle(fontWeight: FontWeight, fontStyle: FontStyle): Int {
val isBold = fontWeight >= FontWeight.AndroidBold
val isItalic = fontStyle == FontStyle.Italic
return getAndroidTypefaceStyle(isBold, isItalic)
}
/**
* Lookup android typeface style without requiring a [FontWeight] or [FontStyle] object.
*
* May return one of:
* - [Typeface.BOLD_ITALIC]
* - [Typeface.BOLD]
* - [Typeface.ITALIC]
* - [Typeface.NORMAL]
*/
internal fun getAndroidTypefaceStyle(isBold: Boolean, isItalic: Boolean): Int {
return if (isItalic && isBold) {
Typeface.BOLD_ITALIC
} else if (isBold) {
Typeface.BOLD
} else if (isItalic) {
Typeface.ITALIC
} else {
Typeface.NORMAL
}
}
/**
* Creates a Typeface object based on the system installed fonts. [genericFontFamily] is used
* to define the main family to create the Typeface such as serif, sans-serif.
*
* [fontWeight] is used to define the thickness of the Typeface. Before Android 28 font weight
* cannot be defined therefore this function assumes anything at and above [FontWeight.W600]
* is bold and any value less than [FontWeight.W600] is normal.
*
* @param genericFontFamily generic font family name such as serif, sans-serif
* @param fontWeight the font weight to create the typeface in
* @param fontStyle the font style to create the typeface in
*/
internal fun createAndroidTypeface(
genericFontFamily: String? = null,
fontWeight: FontWeight = FontWeight.Normal,
fontStyle: FontStyle = FontStyle.Normal
): Typeface {
if (fontStyle == FontStyle.Normal &&
fontWeight == FontWeight.Normal &&
genericFontFamily.isNullOrEmpty()
) {
return Typeface.DEFAULT
}
return if (Build.VERSION.SDK_INT < 28) {
val targetStyle = getAndroidTypefaceStyle(fontWeight, fontStyle)
if (genericFontFamily.isNullOrEmpty()) {
Typeface.defaultFromStyle(targetStyle)
} else {
Typeface.create(genericFontFamily, targetStyle)
}
} else {
val familyTypeface = if (genericFontFamily == null) {
Typeface.DEFAULT
} else {
Typeface.create(genericFontFamily, Typeface.NORMAL)
}
TypefaceHelperMethodsApi28.create(
familyTypeface,
fontWeight.weight,
fontStyle == FontStyle.Italic
)
}
}
/**
* Creates a Typeface using Typface.create(Typeface, ...) with API level branching.
*/
internal fun createAndroidTypeface(
typeface: Typeface,
fontWeight: FontWeight = FontWeight.Normal,
fontStyle: FontStyle = FontStyle.Normal
): Typeface {
return if (Build.VERSION.SDK_INT < 28) {
val targetStyle = getAndroidTypefaceStyle(fontWeight, fontStyle)
Typeface.create(typeface, targetStyle)
} else {
TypefaceHelperMethodsApi28.create(
typeface,
fontWeight.weight,
fontStyle == FontStyle.Italic
)
}
}
/**
* This class is here to ensure that the classes that use this API will get verified and can be
* AOT compiled. It is expected that this class will soft-fail verification, but the classes
* which use this method will pass.
*/
@RequiresApi(28)
internal object TypefaceHelperMethodsApi28 {
@RequiresApi(28)
@DoNotInline
fun create(typeface: Typeface, finalFontWeight: Int, finalFontStyle: Boolean) =
Typeface.create(typeface, finalFontWeight, finalFontStyle)
}