F3.2 Android: agregar pad manuscrito PNG para firmas

This commit is contained in:
2026-09-07 16:18:28 -03:00
parent d14cf737c0
commit c9f1434462
@@ -0,0 +1,138 @@
package com.korexlabs.dhinspeccion.ui
import android.graphics.Bitmap
import android.graphics.Canvas as AndroidCanvas
import android.graphics.Color as AndroidColor
import android.graphics.Paint
import androidx.compose.foundation.Canvas
import androidx.compose.foundation.background
import androidx.compose.foundation.gestures.detectDragGestures
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.height
import androidx.compose.foundation.layout.padding
import androidx.compose.material3.Button
import androidx.compose.material3.MaterialTheme
import androidx.compose.material3.OutlinedButton
import androidx.compose.material3.Text
import androidx.compose.runtime.Composable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateListOf
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.remember
import androidx.compose.runtime.setValue
import androidx.compose.ui.Modifier
import androidx.compose.ui.geometry.Offset
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.graphics.StrokeCap
import androidx.compose.ui.input.pointer.consume
import androidx.compose.ui.input.pointer.pointerInput
import androidx.compose.ui.layout.onSizeChanged
import androidx.compose.ui.platform.LocalContext
import androidx.compose.ui.unit.IntSize
import androidx.compose.ui.unit.dp
import java.io.File
import java.io.FileOutputStream
@Composable
fun SignaturePad(
label: String,
enabled: Boolean = true,
onCaptured: (File) -> Unit,
) {
val context = LocalContext.current
val strokes = remember { mutableStateListOf<List<Offset>>() }
var currentStroke by remember { mutableStateOf<List<Offset>>(emptyList()) }
var canvasSize by remember { mutableStateOf(IntSize.Zero) }
Column(verticalArrangement = Arrangement.spacedBy(8.dp)) {
Text(label, fontWeight = androidx.compose.ui.text.font.FontWeight.SemiBold)
Text(
"Firmá dentro del recuadro. La imagen se guarda como PNG y se incorpora al hash del Acta.",
style = MaterialTheme.typography.bodySmall,
)
Canvas(
modifier = Modifier
.fillMaxWidth()
.height(190.dp)
.background(Color.White)
.onSizeChanged { canvasSize = it }
.pointerInput(enabled) {
if (!enabled) return@pointerInput
detectDragGestures(
onDragStart = { position -> currentStroke = listOf(position) },
onDrag = { change, _ ->
change.consume()
currentStroke = currentStroke + change.position
},
onDragEnd = {
if (currentStroke.size > 1) strokes.add(currentStroke)
currentStroke = emptyList()
},
onDragCancel = { currentStroke = emptyList() },
)
},
) {
val all = strokes + listOf(currentStroke)
all.forEach { stroke ->
stroke.zipWithNext().forEach { (start, end) ->
drawLine(
color = Color.Black,
start = start,
end = end,
strokeWidth = 4.dp.toPx(),
cap = StrokeCap.Round,
)
}
}
}
Row(Modifier.fillMaxWidth(), horizontalArrangement = Arrangement.spacedBy(8.dp)) {
OutlinedButton(
onClick = { strokes.clear(); currentStroke = emptyList() },
enabled = enabled && (strokes.isNotEmpty() || currentStroke.isNotEmpty()),
modifier = Modifier.weight(1f),
) { Text("Limpiar") }
Button(
onClick = {
val width = canvasSize.width.coerceAtLeast(1)
val height = canvasSize.height.coerceAtLeast(1)
val targetWidth = 1000
val targetHeight = 400
val scaleX = targetWidth.toFloat() / width.toFloat()
val scaleY = targetHeight.toFloat() / height.toFloat()
val bitmap = Bitmap.createBitmap(targetWidth, targetHeight, Bitmap.Config.ARGB_8888)
val native = AndroidCanvas(bitmap)
native.drawColor(AndroidColor.WHITE)
val paint = Paint(Paint.ANTI_ALIAS_FLAG).apply {
color = AndroidColor.BLACK
strokeWidth = 7f
strokeCap = Paint.Cap.ROUND
strokeJoin = Paint.Join.ROUND
style = Paint.Style.STROKE
}
strokes.forEach { stroke ->
stroke.zipWithNext().forEach { (start, end) ->
native.drawLine(
start.x * scaleX,
start.y * scaleY,
end.x * scaleX,
end.y * scaleY,
paint,
)
}
}
val file = File.createTempFile("DH_FIRMA_", ".png", context.cacheDir)
FileOutputStream(file).use { stream ->
check(bitmap.compress(Bitmap.CompressFormat.PNG, 100, stream))
}
bitmap.recycle()
onCaptured(file)
},
enabled = enabled && strokes.isNotEmpty(),
modifier = Modifier.weight(1f),
) { Text("Usar firma") }
}
}
}