Implement ColorFilterSetting (#859)

* Implement ColorFilterSetting

* Initial ColorFilterSetting

* Cleanup

---------

Co-authored-by: GG Bond <whatever@tagkong.com>

app/src/main/kotlin/com/hippo/ehviewer/ui/reader/ColorFilterSetting.kt

@@ -1,23 +1,85 @@
 package com.hippo.ehviewer.ui.reader
 
+import androidx.compose.animation.AnimatedVisibility
 import androidx.compose.foundation.layout.Column
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.Brightness5
+import androidx.compose.material3.Icon
+import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableIntStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
 import androidx.compose.ui.res.stringArrayResource
 import androidx.compose.ui.res.stringResource
+import androidx.core.graphics.alpha
+import androidx.core.graphics.blue
+import androidx.core.graphics.green
+import androidx.core.graphics.red
 import com.hippo.ehviewer.R
 import com.hippo.ehviewer.Settings
 import com.hippo.ehviewer.asMutableState
 
 @Composable
 fun ColorFilterSetting() = Column {
+    val customBrightness = Settings.customBrightness.asMutableState()
     SwitchChoice(
         title = stringResource(id = R.string.pref_custom_brightness),
-        field = Settings.customBrightness.asMutableState(),
+        field = customBrightness,
     )
+    AnimatedVisibility(visible = customBrightness.value) {
+        val brightness = Settings.customBrightnessValue.asMutableState()
+        SliderChoice(
+            startSlot = { Icon(imageVector = Icons.Default.Brightness5, contentDescription = null) },
+            endSlot = { Text(text = "${brightness.value}") },
+            range = -75..100,
+            field = brightness,
+        )
+    }
+    val colorFilter = Settings.colorFilter.asMutableState()
     SwitchChoice(
         title = stringResource(id = R.string.pref_custom_color_filter),
-        field = Settings.colorFilter.asMutableState(),
+        field = colorFilter,
     )
+    AnimatedVisibility(visible = colorFilter.value) {
+        var color by Settings.colorFilterValue.asMutableState()
+        val rf = remember { mutableIntStateOf(color.red) }
+        val r by rf
+        val gf = remember { mutableIntStateOf(color.green) }
+        val g by gf
+        val bf = remember { mutableIntStateOf(color.blue) }
+        val b by bf
+        val af = remember { mutableIntStateOf(color.alpha) }
+        val a by af
+        color = (a shl 24) or (r shl 16) or (g shl 8) or (b)
+        Column {
+            SliderChoice(
+                startSlot = { Text(text = "R") },
+                endSlot = { Text(text = "$r") },
+                range = 0..255,
+                field = rf,
+            )
+            SliderChoice(
+                startSlot = { Text(text = "G") },
+                endSlot = { Text(text = "$g") },
+                range = 0..255,
+                field = gf,
+            )
+            SliderChoice(
+                startSlot = { Text(text = "B") },
+                endSlot = { Text(text = "$b") },
+                range = 0..255,
+                field = bf,
+            )
+            SliderChoice(
+                startSlot = { Text(text = "A") },
+                endSlot = { Text(text = "$a") },
+                range = 0..255,
+                field = af,
+            )
+        }
+    }
     SpinnerChoice(
         title = stringResource(id = R.string.pref_color_filter_mode),
         entries = stringArrayResource(id = R.array.color_filter_modes),

app/src/main/kotlin/com/hippo/ehviewer/ui/reader/Widget.kt

@@ -14,6 +14,7 @@ import androidx.compose.material3.DropdownMenu
 import androidx.compose.material3.DropdownMenuItem
 import androidx.compose.material3.Icon
 import androidx.compose.material3.Slider
+import androidx.compose.material3.SliderDefaults
 import androidx.compose.material3.Switch
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
@@ -24,6 +25,8 @@ import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.platform.LocalConfiguration
 import androidx.compose.ui.unit.dp
 
 @Composable
@@ -92,12 +95,26 @@ fun SliderChoice(
         verticalAlignment = Alignment.CenterVertically,
     ) {
         startSlot()
+        val configuration = LocalConfiguration.current
+        // https://m3.material.io/components/sliders/specs
+        // Tick width is 2 dp
+        val maxTickCount = configuration.screenWidthDp / 6
+        val steps = range.last - range.first - 1
+        val showTicks = steps < maxTickCount
         Slider(
             value = value.toFloat(),
             onValueChange = { value = it.toInt() },
             modifier = Modifier.weight(1f).padding(8.dp),
             valueRange = (range.first.toFloat())..(range.last.toFloat()),
-            steps = range.last - range.first - 1,
+            steps = steps,
+            colors = if (showTicks) {
+                SliderDefaults.colors()
+            } else {
+                SliderDefaults.colors(
+                    activeTickColor = Color.Transparent,
+                    inactiveTickColor = Color.Transparent,
+                )
+            },
         )
         endSlot()
     }