The Group model represents a collection of users who share expenses together. Each group tracks its members, balance, and visual identity.
Data Class Definition
package com.example.divvy.models
import com.example.divvy.components.GroupIcon
import kotlinx.serialization.Serializable
@Serializable
data class Group(
val id: String,
val name: String,
val emoji: String = "",
val icon: GroupIcon = GroupIcon.Group,
val memberCount: Int = 0,
val balanceCents: Long = 0L,
val currency: String = "USD",
val createdBy: String = ""
) {
/** Positive = you are owed, negative = you owe */
val isOwed: Boolean get() = balanceCents >= 0
val formattedBalance: String
get() {
val dollars = kotlin.math.abs(balanceCents) / 100.0
return "$${String.format("%.2f", dollars)}"
}
val balanceLabel: String
get() = if (isOwed) "You are owed ${formattedBalance}" else "You owe ${formattedBalance}"
}
Fields
Unique identifier for the group
Display name of the group (e.g., “Roommates”, “Europe Trip”)
Optional emoji character to display alongside the group icon
icon
GroupIcon
default:"GroupIcon.Group"
Visual icon for the group. See [GroupIcon] for available options.
Number of members currently in the group
Current user’s balance in cents. Positive values indicate the user is owed money, negative values indicate the user owes money.
Three-letter ISO currency code for the group’s transactions
User ID of the member who created the group
Computed Properties
The Group model includes several computed properties for convenient UI display:
isOwed
val isOwed: Boolean get() = balanceCents >= 0
true if the current user is owed money (balance is positive or zero), false if they owe money.
val formattedBalance: String
get() {
val dollars = kotlin.math.abs(balanceCents) / 100.0
return "$${String.format("%.2f", dollars)}"
}
balanceLabel
val balanceLabel: String
get() = if (isOwed) "You are owed ${formattedBalance}" else "You owe ${formattedBalance}"
Relationships
- Members: A group contains multiple users. See GroupMember for member details.
- Expenses: A group can have many expenses. See Expense and GroupExpense models.
- Balances: Each member has a balance within the group. See MemberBalance.
Usage Examples
Creating a Group
val group = Group(
id = "grp_123",
name = "Roommates",
icon = GroupIcon.Home,
memberCount = 3,
balanceCents = 1550L, // User is owed $15.50
currency = "USD",
createdBy = "user_abc"
)
Accessing Computed Properties
val group = Group(
id = "grp_123",
name = "Roommates",
balanceCents = -2500L // User owes $25.00
)
println(group.isOwed) // false
println(group.formattedBalance) // "$25.00"
println(group.balanceLabel) // "You owe $25.00"
Repository Operations
From [GroupRepository.kt]:
// Create a new group
suspend fun createGroup(name: String, icon: GroupIcon): Group {
val id = "grp_${UUID.randomUUID()}"
return Group(id = id, name = name, icon = icon, createdBy = "u_me")
}
// Get a group by ID
fun getGroup(groupId: String): Flow<Group>
// Update group details
suspend fun updateGroup(groupId: String, name: String, icon: GroupIcon)
// Delete a group
suspend fun deleteGroup(groupId: String)
Serialization
The Group model uses Kotlin Serialization with the @Serializable annotation. All fields are serialized with their property names (no custom @SerialName annotations).