added error inputfield

app/src/main/java/be/ugent/sel/studeez/common/composable/TextFieldComposable.kt

@@ -1,11 +1,11 @@
 package be.ugent.sel.studeez.common.composable
 
 import androidx.annotation.StringRes
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.text.KeyboardActions
 import androidx.compose.foundation.text.KeyboardOptions
-import androidx.compose.material.Icon
+import androidx.compose.material.*
-import androidx.compose.material.IconButton
-import androidx.compose.material.OutlinedTextField
-import androidx.compose.material.Text
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.Email
 import androidx.compose.material.icons.filled.Lock
@@ -14,10 +14,15 @@ import androidx.compose.runtime.*
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.res.painterResource
 import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.input.ImeAction
 import androidx.compose.ui.text.input.KeyboardType
 import androidx.compose.ui.text.input.PasswordVisualTransformation
 import androidx.compose.ui.text.input.VisualTransformation
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
 import be.ugent.sel.studeez.common.ext.fieldModifier
+import be.ugent.sel.studeez.resources
+import kotlin.math.sin
 import be.ugent.sel.studeez.R.drawable as AppIcon
 import be.ugent.sel.studeez.R.string as AppText
 
@@ -85,6 +90,90 @@ fun EmailField(
     )
 }
 
+@Composable
+fun LabeledNumberInputField(
+    value: Int,
+    onNewValue: (Int) -> Unit,
+    @StringRes label: Int,
+    singleLine: Boolean = false
+) {
+    var number by remember { mutableStateOf(value) }
+    OutlinedTextField(
+        value = number.toString(),
+        singleLine = singleLine,
+        label = { Text(resources().getString(label)) },
+        keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Number),
+        onValueChange = {typedInt ->
+            val isNumber = typedInt.matches(Regex("[1-9]+\\d*]"))
+            if (isNumber) {
+                number = typedInt.toInt()
+                onNewValue(typedInt.toInt())
+            }
+        }
+    )
+}
+
+@Composable
+fun LabeledErrorTextField(
+    modifier: Modifier = Modifier,
+    initialValue: String,
+    @StringRes label: Int,
+    singleLine: Boolean = false,
+    errorText: String,
+    keyboardType: KeyboardType,
+    predicate: (String) -> Boolean,
+    onNewCorrectValue: (String) -> Unit
+) {
+    var value by remember {
+        mutableStateOf(initialValue)
+    }
+
+    var isValid by remember {
+        mutableStateOf(predicate(value))
+    }
+
+    Column {
+        OutlinedTextField(
+            modifier = modifier.fieldModifier(),
+            value = value,
+            onValueChange = { newText ->
+                value = newText
+                isValid = predicate(value)
+                if (isValid) {
+                    onNewCorrectValue(newText)
+                }
+            },
+            singleLine = singleLine,
+            label = { Text(text = resources().getString(label)) },
+            isError = !isValid,
+            keyboardOptions = KeyboardOptions(
+                keyboardType = keyboardType,
+                imeAction = ImeAction.Done
+            )
+        )
+
+        if (!isValid) {
+            Text(
+                modifier = Modifier.padding(start = 16.dp),
+                text = errorText,
+                color = MaterialTheme.colors.error
+            )
+        }
+    }
+}
+
+fun isNumber(string: String): Boolean {
+    return string.matches(Regex("[1-9]+\\d*"))
+}
+
+
+
+ @Preview(showBackground = true)
+ @Composable
+ fun IntInputPreview() {
+     LabeledNumberInputField(value = 1, onNewValue = {}, label = AppText.email)
+ }
+
 @Composable
 fun PasswordField(
     value: String,