1 /*
2  * Copyright 2019 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package androidx.compose.ui.text.style
18 
19 import androidx.compose.runtime.Immutable
20 import androidx.compose.runtime.Stable
21 import androidx.compose.ui.util.lerp
22 
23 /**
24  * The amount by which the text is shifted up or down from current the baseline.
25  *
26  * @param multiplier shift the baseline by multiplier * (baseline - ascent)
27  * @constructor
28  * @sample androidx.compose.ui.text.samples.BaselineShiftSample
29  * @sample androidx.compose.ui.text.samples.BaselineShiftAnnotatedStringSample
30  */
31 @Immutable
32 @kotlin.jvm.JvmInline
33 value class BaselineShift(val multiplier: Float) {
34     companion object {
35         /** Default baseline shift for superscript. */
36         @Stable val Superscript = BaselineShift(0.5f)
37 
38         /** Default baseline shift for subscript */
39         @Stable val Subscript = BaselineShift(-0.5f)
40 
41         /** Constant for no baseline shift. */
42         @Stable val None = BaselineShift(0.0f)
43     }
44 }
45 
46 /** Linearly interpolate two [BaselineShift]s. */
47 @Stable
lerpnull48 fun lerp(start: BaselineShift, stop: BaselineShift, fraction: Float): BaselineShift {
49     return BaselineShift(lerp(start.multiplier, stop.multiplier, fraction))
50 }
51