Perform rudimentary ansi color level detection (#711)

There is a lot to add here, but this gets us off the ground.

gradle/libs.versions.toml

@@ -2,7 +2,6 @@
 jetbrains-compose = "1.7.3"
 kotlin = "2.1.10"
 kotlinx-coroutines = "1.10.1"
-mordant = "3.0.2"
 
 [libraries]
 kotlin-plugin-core = { module = "org.jetbrains.kotlin:kotlin-gradle-plugin", version.ref = "kotlin" }
@@ -29,9 +28,6 @@ spotless-gradlePlugin = "com.diffplug.spotless:spotless-plugin-gradle:7.0.2"
 ktlint-core = "com.pinterest.ktlint:ktlint-cli:1.3.1"
 ktlint-composeRules = "io.nlopez.compose.rules:ktlint:0.4.22"
 
-mordant-core = { module = "com.github.ajalt.mordant:mordant-core", version.ref = "mordant" }
-mordant-jvmJna = { module = "com.github.ajalt.mordant:mordant-jvm-jna", version.ref = "mordant" }
-
 clikt = "com.github.ajalt.clikt:clikt:5.0.3"
 codepoints = "de.cketti.unicode:kotlin-codepoints:0.9.0"
 finalizationHook = "com.jakewharton.finalization:finalization-hook:0.1.0"

mosaic-runtime/build.gradle

@@ -22,7 +22,6 @@ kotlin {
 				implementation projects.mosaicTerminal
 				implementation libs.androidx.collection
 				implementation libs.finalizationHook
-				implementation libs.mordant.core
 				implementation libs.codepoints
 			}
 		}
@@ -34,12 +33,6 @@ kotlin {
 				implementation libs.assertk
 			}
 		}
-
-		jvmMain {
-			dependencies {
-				implementation libs.mordant.jvmJna
-			}
-		}
 	}
 
 	compilerOptions.freeCompilerArgs.add('-Xexpect-actual-classes')

mosaic-runtime/src/commonMain/kotlin/com/jakewharton/mosaic/ansi.kt

@@ -1,7 +1,5 @@
 package com.jakewharton.mosaic
 
-import com.github.ajalt.mordant.rendering.AnsiLevel as MordantAnsiLevel
-import com.jakewharton.mosaic.ui.AnsiLevel
 import com.jakewharton.mosaic.ui.Color
 import kotlin.math.roundToInt
 
@@ -49,15 +47,6 @@ internal const val ansiBgColorOffset = 10
 internal const val ansiSelectorColor256 = 5
 internal const val ansiSelectorColorRgb = 2
 
-internal fun MordantAnsiLevel.toMosaicAnsiLevel(): AnsiLevel {
-	return when (this) {
-		MordantAnsiLevel.NONE -> AnsiLevel.NONE
-		MordantAnsiLevel.ANSI16 -> AnsiLevel.ANSI16
-		MordantAnsiLevel.ANSI256 -> AnsiLevel.ANSI256
-		MordantAnsiLevel.TRUECOLOR -> AnsiLevel.TRUECOLOR
-	}
-}
-
 // simpler version without full conversion to HSV
 // https://github.com/ajalt/colormath/blob/4a0cc9796c743cb4965407204ee63b40aaf22fca/colormath/src/commonMain/kotlin/com/github/ajalt/colormath/model/RGB.kt#L301
 internal fun Color.toAnsi16Code(): Int {

mosaic-runtime/src/commonMain/kotlin/com/jakewharton/mosaic/mosaic.kt

@@ -21,7 +21,6 @@ import androidx.lifecycle.Lifecycle
 import androidx.lifecycle.LifecycleOwner
 import androidx.lifecycle.LifecycleRegistry
 import androidx.lifecycle.compose.LocalLifecycleOwner
-import com.github.ajalt.mordant.terminal.Terminal as MordantTerminal
 import com.jakewharton.finalization.withFinalizationHook
 import com.jakewharton.mosaic.layout.KeyEvent
 import com.jakewharton.mosaic.layout.MosaicNode
@@ -92,8 +91,6 @@ private const val StageDefaultQueries = 1
 private const val StageNormalOperation = 0
 
 internal suspend fun runMosaic(isTest: Boolean, content: @Composable () -> Unit) {
-	val mordantTerminal = MordantTerminal()
-
 	// Entering raw mode can fail, so perform it before any additional control sequences which change
 	// settings. We also need to be in character mode to query capabilities with control sequences.
 	val rawMode = if (!isTest && env("MOSAIC_RAW_MODE") != "false") {
@@ -291,7 +288,7 @@ internal suspend fun runMosaic(isTest: Boolean, content: @Composable () -> Unit)
 			}
 
 			val rendering = createRendering(
-				ansiLevel = mordantTerminal.terminalInfo.ansiLevel.toMosaicAnsiLevel(),
+				ansiLevel = detectAnsiLevel(),
 				synchronizedRendering = supportsSynchronizedRendering,
 			)
 
@@ -299,7 +296,7 @@ internal suspend fun runMosaic(isTest: Boolean, content: @Composable () -> Unit)
 			val mosaicComposition = MosaicComposition(
 				coroutineContext = coroutineContext + clock,
 				onDraw = { rootNode ->
-					mordantTerminal.rawPrint(rendering.render(rootNode).toString())
+					print(rendering.render(rootNode).toString())
 				},
 				keyEvents = keyEvents,
 				terminalState = terminalState,

mosaic-runtime/src/commonMain/kotlin/com/jakewharton/mosaic/terminal.kt

@@ -3,6 +3,7 @@ package com.jakewharton.mosaic
 import androidx.compose.runtime.Immutable
 import androidx.compose.runtime.ProvidableCompositionLocal
 import androidx.compose.runtime.compositionLocalOf
+import com.jakewharton.mosaic.ui.AnsiLevel
 import com.jakewharton.mosaic.ui.unit.IntSize
 import dev.drewhamilton.poko.Poko
 
@@ -32,3 +33,20 @@ internal inline fun Terminal.copy(
 	darkTheme: Boolean = this.darkTheme,
 	size: IntSize = this.size,
 ) = Terminal(focused, darkTheme, size)
+
+internal fun detectAnsiLevel(): AnsiLevel {
+	if (env("NO_COLOR").orEmpty().isNotEmpty()) {
+		return AnsiLevel.NONE
+	}
+	val term = env("COLORTERM") ?: env("TERM") ?: "dumb"
+	if (term.contains("24bit", ignoreCase = true) || term.contains("truecolor", ignoreCase = true)) {
+		return AnsiLevel.TRUECOLOR
+	}
+	if (term.contains("256")) {
+		return AnsiLevel.ANSI256
+	}
+	if (term != "dumb") {
+		return AnsiLevel.ANSI16
+	}
+	return AnsiLevel.NONE
+}