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Nandani Sharma
Nandani Sharma

Posted on • Originally published at canopas.com

How to Drag and Drop using Modifier.dragAndDropSource/Target - Jetpack Compose

In January 2024, a significant Jetpack Compose update introduced dragAndDropSourceand dragAndDropTarget modifiers, simplifying drag-and-drop interactions compared to the manual approach I previously demonstrated.

You can check it out here.

Table of contents

  • Background
    • Let's Get Started
    • Design Composable to Show Food Items
    • Composable to Show Users
    • Add Drag Source
    • Add Drop Target
  • Conclusion

Let’s Get Started

We’ll divide implementation into 4 simple steps to make each step easy to understand.

We’re using the same example of the original post. Let’s quickly have a look at our UI components.

- Design Composable to Show Food Items

fun FoodItemCard(foodItem: FoodItem) {
    Card(
        elevation = CardDefaults.elevatedCardElevation(defaultElevation = 10.dp),
        colors = CardDefaults.elevatedCardColors(
            containerColor = Color.White,
        ), shape = RoundedCornerShape(24.dp),
        modifier = Modifier.padding(8.dp)
    ) {
        Row(
            verticalAlignment = Alignment.CenterVertically,
            modifier = Modifier.padding(10.dp)
        ) {
            Image(
                painter = painterResource(id = foodItem.image),
                contentDescription = null,
                contentScale = ContentScale.Crop,
                modifier = Modifier
                    .size(130.dp)
                    .clip(RoundedCornerShape(16.dp))

            )

            Spacer(modifier = Modifier.width(20.dp))
            Column(modifier = Modifier.weight(1f)) {
                Text(
                    text = foodItem.name,
                    fontSize = 22.sp,
                    color = Color.DarkGray
                )
                Spacer(modifier = Modifier.height(6.dp))
                Text(
                    text = "$${foodItem.price}",
                    fontSize = 18.sp,
                    color = Color.Black,
                    fontWeight = FontWeight.ExtraBold
                )
            }
        }
    }
}

LazyColumn(
    modifier = Modifier.fillMaxSize(),
    contentPadding = PaddingValues(horizontal = 10.dp)
) {
    items(items = foodList) { food ->
        FoodItemCard(foodItem = food)
    }
}
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Here's our Food item card.

Food items with their price

- Composable to Show Users
Now, Let’s add composable to show Persons, we’ll show the profile image and the person’s name on the card.

@Composable
fun PersonCard(person: Person) {
        Column(
            modifier = Modifier
                .padding(6.dp)
                .shadow(elevation = 4.dp, shape = RoundedCornerShape(16.dp))
                .width(width = 120.dp)
                .fillMaxHeight(0.8f)
                .background(Color.White, RoundedCornerShape(16.dp)),
            verticalArrangement = Arrangement.Center,
            horizontalAlignment = Alignment.CenterHorizontally
        ) {
            Image(
                painter = painterResource(id = person.profile), contentDescription = null,
                modifier = Modifier
                    .size(70.dp)
                    .clip(CircleShape),
                contentScale = ContentScale.Crop
            )
            Spacer(modifier = Modifier.height(10.dp))
            Text(
                text = person.name,
                fontSize = 18.sp,
                color = Color.Black,
                fontWeight = FontWeight.Bold
            )
        }
}

// To show a list of users
LazyRow(
    modifier = Modifier
        .fillMaxHeight(0.3f)
        .fillMaxWidth()
        .background(Color.LightGray, shape = RoundedCornerShape(topEnd = 10.dp, topStart = 10.dp))
        .padding(vertical = 10.dp)
        .align(Alignment.BottomCenter),
    verticalAlignment = Alignment.CenterVertically,
    horizontalArrangement = Arrangement.Center
) {
    items(items = persons) { person ->
        PersonCard(person)
    }
}
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And here’s the result:

3 person with their name

- Add Drag Source

Before we jump into implementation let’s have a quick look at the modifier

Modifier.dragAndDropSource

This Modifier in Jetpack Compose enables an element to become a source for drag-and-drop operations when applied to it.

@Composable
fun MyDraggableComponent() {
    Box(
        modifier = Modifier
            .size(100.dp)
            .background(Color.Blue)
            .dragAndDropSource(
                drawDragDecoration = {
                    // Provide visual representation of the dragged item
                }
            ) {
                // Logic to handle drag-and-drop operation
                startTransfer (/* data to transfer */ )
            }
    ) { /* Content of the draggable component*/ }
}
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To read the full version, please visit Canopas Blog.

This blog post was originally published on Canopas.

Conclusion

In conclusion, the introduction of the dragAndDropTarget and dragAndDropSourcemodifiers in Jetpack Compose simplifies the addition of drag-and-drop features.

This streamlined process is a significant improvement over the previous method, showcasing Jetpack Compose's commitment to enhancing developer experiences.

Consider incorporating these modifiers into your projects for a more interactive and enjoyable user experience.

Happy coding! 🚀✨

Top comments (1)

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carsonreed432 profile image
carson Reed

Peet's Coffee logo is a distinct and recognizable symbol of the brand’s commitment to high-quality, artisanal coffee. The logo features a simple yet bold design, with the brand's name in a clean, modern font, paired with a circular emblem that often includes an image of a coffee bean or cup. This minimalist approach reflects Peet's dedication to quality and craftsmanship, focusing on the purity of its coffee beans. The choice of earthy tones and the iconic dark brown color are also a nod to the natural origins of coffee, symbolizing warmth, richness, and authenticity. The logo’s timeless design is not only visually appealing but also conveys Peet's legacy as a pioneer in the specialty coffee industry since 1966.