Unexpected redraw

[SanmerDev]

Bug

• Other state changes cause the PlotPanel to redraw the image.
• Frequent state changes lead to multiple redraws, then throw IllegalStateException: SvgSkikoView is disposed.

Expected

• Whether to redraw should be decided based on whether the figure has changed.

Platform

• android 13

Dependencies

• compose 1.6.0-alpha08
• kotlin 1.9.10
• skiko-android 0.7.84
• lets-plot 4.0.1
• lets-plot-kotlin 4.4.3
• lets-plot-compose 1.0.0

Sample

import android.util.Log
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.Row
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.layout.requiredHeight
import androidx.compose.foundation.rememberScrollState
import androidx.compose.foundation.verticalScroll
import androidx.compose.material3.MaterialTheme
import androidx.compose.material3.Scaffold
import androidx.compose.material3.Switch
import androidx.compose.material3.Text
import androidx.compose.runtime.Composable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.remember
import androidx.compose.runtime.setValue
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.unit.dp
import org.jetbrains.letsPlot.geom.geomDensity
import org.jetbrains.letsPlot.letsPlot
import org.jetbrains.letsPlot.skia.compose.PlotPanel

@Composable
fun TestScreen() {
    // irrelevant value
    var enable by remember { mutableStateOf(false) }

    // remember data and figure
    val rand = java.util.Random()
    val data by remember {
        mutableStateOf(
            mapOf(
                "rating" to List(200) { rand.nextGaussian() } + List(200) { rand.nextGaussian() * 1.5 + 1.5 },
                "cond" to List(200) { "A" } + List(200) { "B" }
            )
        )
    }
    val plot by remember {
        mutableStateOf(letsPlot(data) +
                geomDensity(color = "dark_green", alpha = .3) {
                    x = "rating"; fill = "cond"
                }
        )
    }

    Scaffold { innerPadding ->
        Column(
            modifier = Modifier
                .verticalScroll(rememberScrollState())
                .padding(innerPadding)
                .padding(all = 16.dp),
            verticalArrangement = Arrangement.spacedBy(16.dp)
        ) {
            Row(
                modifier = Modifier.fillMaxWidth(),
                verticalAlignment = Alignment.CenterVertically
            ) {
                Text(
                    text = "Irrelevant Value",
                    style = MaterialTheme.typography.bodyLarge,
                    modifier = Modifier.weight(1f)
                )

                Switch(
                    checked = enable,
                    onCheckedChange = { enable = it }
                )
            }

            PlotPanel(
                figure = plot,
                preserveAspectRatio = false,
                modifier = Modifier
                    .requiredHeight(240.dp)
                    .fillMaxWidth(),
                computationMessagesHandler = { messages ->
                    messages.forEach {
                        Log.d("PlotPanel", it)
                    }
                }
            )
        }
    }
}

[changhexuefei]

This situation also occurs in Windows. When the page is updated, the PlotPanel flashes with a black background.

[SanmerDev]

https://github.com/JetBrains/lets-plot-skia/blob/14ca8b85b9de3708b1ad50c785314dac3a975717/lets-plot-compose/src/androidMain/kotlin/org/jetbrains/letsPlot/skia/compose/PlotPanel.kt#L30 I think this issue may come from here, the provider does not remember, which causes it to be recreated when recompose.

[changhexuefei]

Hello, please tell me how to update the code of this library. I use it in the following way.

[alshan]

@changhexuefei hi, your setup looks fine providing the variables used are defined correctly in your project.

You may want to specify versions directly as shown here: https://github.com/JetBrains/lets-plot-skia#compose-desktop

[changhexuefei]

@alshan Hello, I want to use the code after fixing the unexpected redraw problem, do I have to wait until a new version is released.

[IKupriyanov-HORIS]

@changhexuefei hi! Yes, the fix is not yet released.

[alshan]

That's correct, you will be able to upgrade as soon as new version is released.

[changhexuefei]

@alshan @IKupriyanov-HORIS ok,thanks.