Day 17: Working with Images in Jetpack Compose – Using Image, Coil, and Best Practices

Excerpt / Introduction:

Displaying images effectively is vital for modern mobile UIs. In Jetpack Compose, we use the Image composable and popular libraries like Coil to handle both local and network images. This post will guide you through everything you need to know to manage images like a pro.

Content:

🧩 Displaying Images with Jetpack Compose

Jetpack Compose introduces a declarative approach to building UIs, and rendering images is no exception.

To display a drawable or resource image:

kotlinCopyEditImage(
    painter = painterResource(id = R.drawable.sample),
    contentDescription = "Sample Image",
    modifier = Modifier.size(200.dp)
)

🌐 Loading Network Images with Coil

Jetpack Compose integrates seamlessly with Coil (an image loading library for Android). Add this dependency:

kotlinCopyEditimplementation("io.coil-kt:coil-compose:2.4.0")

Example using rememberAsyncImagePainter:

kotlinCopyEditImage(
    painter = rememberAsyncImagePainter("https://example.com/image.png"),
    contentDescription = "Remote Image",
    modifier = Modifier
        .fillMaxWidth()
        .height(200.dp)
)

🎯 Best Practices

• Always provide contentDescription for accessibility.
• Use placeholder and error images with Coil:

kotlinCopyEditImage(
    painter = rememberAsyncImagePainter(
        model = "https://example.com/image.png",
        placeholder = painterResource(R.drawable.placeholder),
        error = painterResource(R.drawable.error)
    ),
    contentDescription = null
)

• Avoid loading large images directly — use resizing, scaling, or thumbnail previews.

📂 Image Sources

• painterResource: for drawable resources
• rememberAsyncImagePainter: for remote URLs
• BitmapPainter: for Bitmap objects
• SvgDecoder: if using SVG with Coil

🔗 Internal Links for Learning Flow

• Day 7: Introduction to Jetpack Compose
• Day 8: Layouts in Jetpack Compose
• Day 9: State in Jetpack Compose

🧠 Conclusion

Managing images in Jetpack Compose is straightforward with powerful tools like Image, painterResource, and Coil. With minimal setup, you can handle images from any source while maintaining performance and accessibility.

✅ Checklist for Today:

• Displayed local images using Image
• Loaded network images using Coil
• Added placeholders and error handling
• Applied best practices and internal links