Add mul/div by scaler to Dimen

Summary:
Support multiplication/division of `Dimen` by non-dimensional scaler:
```Kotlin
1.px * 42.0  // 42.px
val padding = component.gap / 2.0
```

Reviewed By: zielinskimz

Differential Revision: D59061617

fbshipit-source-id: 6c551cfce034cba58a17e8c9612965943b8d3624

litho-rendercore/src/main/java/com/facebook/rendercore/Dimen.kt

@@ -49,8 +49,86 @@ value class Dimen @PublishedApi internal constructor(val encodedValue: Long) {
       else -> "NaN"
     }
   }
+
+  operator fun times(other: Double): Dimen {
+    return Dimen(
+        when {
+          // DP case
+          encodedValue and NAN_MASK != NAN_MASK ->
+              doubleToRawLongBits(longBitsToDouble(encodedValue) * other)
+          // PX case
+          encodedValue and PX_FLAG == PX_FLAG ->
+              encodePxInt(((encodedValue and PAYLOAD_MASK).toInt() * other).toInt())
+          // SP case
+          encodedValue and SP_FLAG == SP_FLAG ->
+              encodeSpFloat(
+                  (intBitsToFloat((encodedValue and PAYLOAD_MASK).toInt()) * other).toFloat())
+          else -> doubleToRawLongBits(Double.NaN)
+        })
+  }
+
+  operator fun times(other: Float): Dimen {
+    return Dimen(
+        when {
+          // DP case
+          encodedValue and NAN_MASK != NAN_MASK ->
+              doubleToRawLongBits(longBitsToDouble(encodedValue) * other)
+          // PX case
+          encodedValue and PX_FLAG == PX_FLAG ->
+              encodePxInt(((encodedValue and PAYLOAD_MASK).toInt() * other).toInt())
+          // SP case
+          encodedValue and SP_FLAG == SP_FLAG ->
+              encodeSpFloat(
+                  (intBitsToFloat((encodedValue and PAYLOAD_MASK).toInt()) * other).toFloat())
+          else -> doubleToRawLongBits(Double.NaN)
+        })
+  }
+
+  operator fun times(other: Int): Dimen {
+    return Dimen(
+        when {
+          // DP case
+          encodedValue and NAN_MASK != NAN_MASK ->
+              doubleToRawLongBits(longBitsToDouble(encodedValue) * other)
+          // PX case
+          encodedValue and PX_FLAG == PX_FLAG ->
+              encodePxInt((encodedValue and PAYLOAD_MASK).toInt() * other)
+          // SP case
+          encodedValue and SP_FLAG == SP_FLAG ->
+              encodeSpFloat(intBitsToFloat(encodedValue.and(PAYLOAD_MASK).toInt()) * other)
+          else -> doubleToRawLongBits(Double.NaN)
+        })
+  }
+
+  operator fun div(other: Double): Dimen = this * (1.0 / other)
+
+  operator fun div(other: Float): Dimen = this * (1f / other)
+
+  operator fun div(other: Int): Dimen {
+    return Dimen(
+        when {
+          // DP case
+          encodedValue and NAN_MASK != NAN_MASK ->
+              doubleToRawLongBits(longBitsToDouble(encodedValue) / other)
+          // PX case
+          encodedValue and PX_FLAG == PX_FLAG ->
+              encodePxInt((encodedValue and PAYLOAD_MASK).toInt() / other)
+          // SP case
+          encodedValue and SP_FLAG == SP_FLAG ->
+              encodeSpFloat(intBitsToFloat(encodedValue.and(PAYLOAD_MASK).toInt()) / other)
+          else -> doubleToRawLongBits(Double.NaN)
+        })
+  }
+
+  operator fun unaryMinus(): Dimen = this * -1
 }
 
+operator fun Double.times(other: Dimen): Dimen = other * this
+
+operator fun Float.times(other: Dimen): Dimen = other * this
+
+operator fun Int.times(other: Dimen): Dimen = other * this
+
 /** Creates a Dimen with a constant dp (density-independent pixels) value. */
 inline val Int.dp: Dimen
   get() = Dimen(doubleToRawLongBits(this.toDouble()))

litho-rendercore/src/test/java/com/facebook/rendercore/DimenTest.kt

@@ -197,6 +197,46 @@ class DimenTest {
     Dimen(Double.NaN.toRawBits()).toPixels(resourceResolver)
   }
 
+  @Test
+  fun `dimen mul div`() {
+    assertThat(10.sp * 5.0).isEqualTo(50.sp)
+    assertThat(10.dp * 5.0).isEqualTo(50.dp)
+    assertThat(10.px * 5.0).isEqualTo(50.px)
+    assertThat(5.0 * 10.sp).isEqualTo(50.sp)
+    assertThat(5.0 * 10.dp).isEqualTo(50.dp)
+    assertThat(5.0 * 10.px).isEqualTo(50.px)
+
+    assertThat(10.sp / 2.0).isEqualTo(5.sp)
+    assertThat(10.dp / 2.0).isEqualTo(5.dp)
+    assertThat(10.px / 2.0).isEqualTo(5.px)
+
+    assertThat(10.sp * 5f).isEqualTo(50.sp)
+    assertThat(10.dp * 5f).isEqualTo(50.dp)
+    assertThat(10.px * 5f).isEqualTo(50.px)
+    assertThat(5f * 10.sp).isEqualTo(50.sp)
+    assertThat(5f * 10.dp).isEqualTo(50.dp)
+    assertThat(5f * 10.px).isEqualTo(50.px)
+
+    assertThat(10.sp / 2f).isEqualTo(5.sp)
+    assertThat(10.dp / 2f).isEqualTo(5.dp)
+    assertThat(10.px / 2f).isEqualTo(5.px)
+
+    assertThat(10.sp * 5).isEqualTo(50.sp)
+    assertThat(10.dp * 5).isEqualTo(50.dp)
+    assertThat(10.px * 5).isEqualTo(50.px)
+    assertThat(5 * 10.sp).isEqualTo(50.sp)
+    assertThat(5 * 10.dp).isEqualTo(50.dp)
+    assertThat(5 * 10.px).isEqualTo(50.px)
+
+    assertThat(10.sp / 2).isEqualTo(5.sp)
+    assertThat(10.dp / 2).isEqualTo(5.dp)
+    assertThat(10.px / 2).isEqualTo(5.px)
+
+    assertThat(-(10.sp)).isEqualTo((-10).sp)
+    assertThat(-(10.dp)).isEqualTo((-10).dp)
+    assertThat(-(10.px)).isEqualTo((-10).px)
+  }
+
   private class MockResourceResolver(val density: Float, val scaledDensity: Float) :
       ResourceResolver(
           ApplicationProvider.getApplicationContext<Context>(),