Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Change lightness of annotation color if it's not readable on pie/bar #971

Merged
merged 2 commits into from
Dec 20, 2023
Merged

Change lightness of annotation color if it's not readable on pie/bar #971

Show file tree
Hide file tree
Changes from 1 commit
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
6ded09a
Change lightness of annotation color if it's not readable on pie/bar.
OLarionova-HORIS Dec 20, 2023
6005c06
Update notebook.
OLarionova-HORIS Dec 20, 2023
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
Next Next commit
Change lightness of annotation color if it's not readable on pie/bar.
  • Loading branch information
@OLarionova-HORIS
OLarionova-HORIS committed Dec 20, 2023
commit 6ded09abd802b9f10b782d935d01297776c382e2
6 changes: 6 additions & 0 deletions commons/src/commonMain/kotlin/org/jetbrains/letsPlot/commons/values/Colors.kt
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -193,6 +193,12 @@ object Colors {
return (luminance(color) + .05) / (luminance(other) + .05)
}

fun contrastRatio(color: Color, other: Color): Double {
val l1 = luminance(color)
val l2 = luminance(other)
return (max(l1, l2) + .05) / (min(l1, l2) + .05)
}

fun luminance(color: Color): Double {
return .2126 * colorLuminance(color.red) + .7152 * colorLuminance(color.green) + .0722 * colorLuminance(color.blue)
}
Expand Down
2 changes: 1 addition & 1 deletion plot-base/src/commonMain/kotlin/org/jetbrains/letsPlot/core/plot/base/geom/BarGeom.kt
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -101,7 +101,7 @@ open class BarGeom : GeomBase() {
val labelColor = when {
barRect.contains(textRect) -> {
alpha = 0.0
AnnotationsUtil.chooseColor(p.fill()!!)
AnnotationsUtil.chooseColor(annotations.textStyle.color, p.fill()!!)
}
else -> {
alpha = 0.75
Expand Down
2 changes: 1 addition & 1 deletion plot-base/src/commonMain/kotlin/org/jetbrains/letsPlot/core/plot/base/geom/PieGeom.kt
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -438,7 +438,7 @@ class PieGeom : GeomBase(), WithWidth, WithHeight {
)
}
val textColor = when (side) {
Side.INSIDE -> AnnotationsUtil.chooseColor(sector.p.fill()!!)
Side.INSIDE -> AnnotationsUtil.chooseColor(annotations.textStyle.color, sector.p.fill()!!)
else -> annotations.textStyle.color
}
return AnnotationLabel(
Expand Down
24 changes: 21 additions & 3 deletions .../src/commonMain/kotlin/org/jetbrains/letsPlot/core/plot/base/geom/util/AnnotationsUtil.kt
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -5,6 +5,9 @@

package org.jetbrains.letsPlot.core.plot.base.geom.util

import org.jetbrains.letsPlot.commons.colorspace.HSL
import org.jetbrains.letsPlot.commons.colorspace.hslFromRgb
import org.jetbrains.letsPlot.commons.colorspace.rgbFromHsl
import org.jetbrains.letsPlot.commons.geometry.DoubleVector
import org.jetbrains.letsPlot.commons.values.Color
import org.jetbrains.letsPlot.commons.values.Colors
Expand All @@ -25,9 +28,24 @@ object AnnotationsUtil {
)
}

fun chooseColor(background: Color) = when {
Colors.luminance(background) < 0.5 -> Color.WHITE // if fill is dark
else -> Color.BLACK
private const val LIGHTER_LUMINANCE = 0.85
private const val DARKER_LUMINANCE = 0.15
// WCAG recommend a minimum contrast ratio of 4.5:1 for normal text and 3:1 for large text
private const val CONTRAST_RATIO = 3.0

fun chooseColor(textColor: Color, background: Color): Color {
val contrastRatio = Colors.contrastRatio(background, textColor)
if (contrastRatio >= CONTRAST_RATIO) {
return textColor
}
val newLightness = when {
Colors.luminance(background) < 0.5 -> LIGHTER_LUMINANCE
else -> DARKER_LUMINANCE
}
val hsl = hslFromRgb(textColor)
return rgbFromHsl(
HSL(hsl.h, hsl.s, newLightness)
)
}

data class TextParams(
Expand Down