Reusability of Jetpack Compose Components

Jetpack Compose is a modern and powerful user interface toolkit for building native Android apps.

One of its key features is the ability to create reusable components that can be easily shared and reused across different parts of an app. In this article, we’ll explore the different ways in which Jetpack Compose components can be made reusable and how to best utilize this feature in your app development.

Custom Composable Functions

One way to create reusable components in Jetpack Compose is through the use of custom composable functions. These functions can take in parameters and return a composable element that can be used in different parts of the app. For example, you could create a custom button composable that takes in text, background color, rounded radius, trailing icon, leading icon, and an onClick listener, and then use that button on multiple screens throughout the app.

@Composable
fun MyButton(
    text: String,
    textColor: Color = Color.White,
    backgroundColor: Color = Color.Blue,
    roundedRadius: Dp = 8.dp,
    height: Dp = 46.dp,
    trailingIcon: @Composable() () -> Unit ={},
    leadingIcon: @Composable() () -> Unit ={},
    onClick: () -> Unit
) {
    Surface(
        color = backgroundColor,
        shape = RoundedCornerShape(roundedRadius)
    ){
          Box(modifier = Modifier
                        .height(height = height)
                        .clickable{ onClick() }
                        .padding(horizontal = 10.dp)){
                          Row(
                             horizontalArrangement = Arrangement.Center,
                            verticalAlignment = Alignment.CenterVertically
                            ){
                                leadingIcon()
                                Text(text, color = textColor)
                                trailingIcon()
                            }
                        }
                    }
              }

You can use this custom button composable in your app like this:

MyButton( text = "My Custom Button",
	  backgroundColor = Color.Blue,
          roundedRadius = 8.dp,
          leadingIcon = {
                        Icon(Icons.Filled.Star, contentDescription = null)
                    },
	  onClick = {
                        // Perform action when button is clicked
                    }
       )

Stateful Composable Functions

Another way to create reusable components is through the use of stateful composable functions. These functions can maintain their own internal state and can be reused in different parts of the app without having to pass in the state as a parameter. This is useful for creating complex UI elements that have multiple interacting parts, such as a calendar or a form.

@Composable
fun MyCounter() {
    var count by remember { mutableStateOf(0) }
  Column {
        Text("Count: $count")
        Button(onClick = { count++ }) {
            Text("Increment")
        }
    }
}

In this example, we have a MyCounter function that uses the remember function to create a state object for the count variable. The remember keyword creates a state object that is automatically managed by the Compose runtime and can be used in the composable function.

The MyCounter function is a stateful composable function because it has a variable that can change over time and maintain its state. The MyCounter function displays the current count on the screen and a button that, when pressed, increments the count.

The MyCounter function can be used in different parts of the app and it will always maintain its state, this is the main benefit of using stateful composable functions.

It’s worth mentioning that, when working with stateful composable functions, it’s important to consider the best practices for state management in Jetpack Compose, such as keeping the state as close to the composable that uses it as possible, and avoiding global state if possible.

Built-in Reusable Components

Jetpack Compose also provides some built-in reusable components that you can use in your app, such as Text, Button, and Card. These components can be customized with different styles and attribute to match the look and feel of your app.

Conclusion

Jetpack Compose is a powerful tool for creating reusable and customizable UI components, which allows developers to focus on the logic and features of their apps, and not on the UI.

With its easy-to-use and powerful features, Jetpack Compose is definitely worth exploring for any Android developer looking to improve the maintainability and scalability of their apps.

Happy coding! 🚀