When the Design Brief Says “Make It Look Like Glass”
The request came in during a design review:
“We want the new layout to feel glassy something with depth, light, and a touch of transparency.”
On paper, that sounds straightforward. In reality, it’s one of those UI challenges that sit right between design language and rendering logic. “Glassy” can mean a dozen different things depending on who says it. For designers, it’s about mood and perception. For engineers, it’s about how light and blur interact with the pixel pipeline.
That’s where Jetpack Compose gets interesting. It gives us the tools to think in layers surfaces, gradients, and modifiers without breaking composability. So, when the brief landed, our goal wasn’t just to fake transparency; it was to build a real sense of depth that behaves predictably and performs well.
We quickly learned that depth isn’t about turning down the opacity. It’s about how the background and foreground interact. The background softens; the foreground stays sharp. And when those two parts works in sync, your brain reads the surface as glass instead of just “see-through.”
“Depth happens when context blurs and focus stay clear.”
From that insight, the task became clear: two layers one for the blurred background, one for the crisp content.
That’s the foundation of everything that follows.
Understanding What “Glass” Actually Means in UI
Before touching a single line of Compose code, we had to answer one deceptively simple question:
What does “glass” really mean in digital design?
When designers talk about glass, they’re usually referencing how light behaves through a translucent surface not the surface itself. It’s not just about seeing what’s behind something; it’s about how the background becomes soft, how edges catch light, and how everything feels subtly three-dimensional.
So, the challenge isn’t to make a transparent box.
It’s to recreate how glass interacts with its environment.
“Real glass isn’t transparent it’s reactive.”
That insight guided how we approached the layout in Compose.
If you think about a piece of glass in the real world, it has two distinct layers of perception:
- The background layer the world seen through the glass, slightly blurred, colors diffused.
- The content layer, reflections, borders, or text on top, perfectly sharp and readable.
Those two layers together are what convince the human eye that the surface has depth.
To bring that logic into Compose, we needed a system where both layers could coexist independently:
a blurred base for context and a crisp top for interaction.
That separation would let us fine-tune realism adjusting how soft or strong the effect feels without reworking layouts.
That became our design rule moving forward:
every glass effect is built from at least two coordinated layers nothing more, nothing less.
In the next section, we’ll turn that concept into code and show how GlassContainer makes the illusion both reusable and predictable in Compose.
The Layered Approach
Once we understood glass as a layered material, the next question was how to express that elegantly in Compose.
We didn’t want another “UI trick.” It had to be composable, easy to theme, and lightweight enough to survive in production.
That’s where the idea of GlassContainer came in a layout that manages both the blurred background and the sharp content layer, while keeping its shape and boundaries consistent.
The implementation turned out to be surprisingly simple once the layering concept was right.
“One layer sets the mood; the other defines the focus.”
Here’s the core structure that powers it all:
@Composable
fun GlassContainer(
modifier: Modifier = Modifier,
shape: Shape = RoundedCornerShape(16.dp),
blurRadius: Dp = 12.dp,
backgroundAlpha: Float = 0.15f,
borderAlpha: Float = 0.3f,
borderWidth: Dp = 1.dp,
content: @Composable () -> Unit
) {
val surfaceColor = MaterialTheme.colors.surface
val borderColor = MaterialTheme.colors.border
Box(modifier = modifier.clip(shape)) {
// Background layer with blur
Box(
modifier = Modifier
.matchParentSize()
.blur(radius = blurRadius)
.background(brush = createGlassGradient(surfaceColor, backgroundAlpha))
.border(width = borderWidth, brush = createGlassBorderGradient(borderColor, borderAlpha))
)
// Content layer stays sharp
content()
}
}
The composable uses a Box as the container, clipped to a shape. Inside it, we render two stacked layers:
- The background layer uses
Modifier.matchParentSize()to fill the container exactly. It applies blur, gradient, and border the ingredients that give it that glassy diffusion. - The content layer renders normally, untouched by blur, ensuring text and icons stay crisp.
That single line —
.matchParentSize()
— does most of the heavy lifting.
It locks the blur area to the same dimensions as your content region, preventing misaligned softness or inconsistent edges.
This approach has two big benefits:
- It decouples design from effect. You can drop any composable inside without worrying about visual integrity.
- It stays composable-friendly. No need for custom draw logic or external blur views.
Adding Realism with Gradients
Once the blur was working, we noticed something subtle: the surface still looked too clean.
It was transparent, sure but not alive.
Real glass has micro-variations in brightness and transparency that make it react to its surroundings. Without those, it just feels like a semi-transparent overlay.
So, we started layering gradients.
“Flat transparency looks artificial because real materials bend light unevenly.”
Instead of relying on a single color with reduced opacity, we introduced a vertical gradient.
At the top, it’s slightly brighter mimicking light catching the upper edge.
The middle stays neutral, and the bottom fades softly to maintain depth.
That tiny adjustment changes how your eye perceives the surface:
your brain reads it as curved, reflective, and physical rather than flat.
Here’s the helper we used:
private fun createGlassGradient(baseColor: Color, alpha: Float): Brush {
return Brush.verticalGradient(
colors = listOf(
baseColor.copy(alpha = alpha * 1.1f), // Slightly brighter at top
baseColor.copy(alpha = alpha), // Base opacity
baseColor.copy(alpha = alpha) // Consistent bottom
)
)
}
This gradient works because it introduces just enough contrast for the viewer to infer lighting direction.
It’s not something you consciously notice but it anchors the illusion in realism.
Then we applied a similar idea to the border.
Edges in real glass catch and scatter lighter, which creates that crisp rim glow designers love.
A second vertical gradient for the border gives that highlight near the top and softens it toward the bottom.
private fun createGlassBorderGradient(borderColor: Color, alpha: Float): Brush {
return Brush.verticalGradient(
colors = listOf(
borderColor.copy(alpha = alpha * 1.5f), // Strong highlight
borderColor.copy(alpha = alpha * 0.3f), // Fade in middle
borderColor.copy(alpha = alpha * 0.8f) // Subtle bottom
)
)
}
Together, these gradients make a huge perceptual difference.
The component suddenly stops looking like “just transparency” and starts to behave like a material.
It refracts light, separates itself from the background, and feels consistent across themes. Result after applying gradient:
Reusable Variations That Scale with Your Design
After we got the glass effect looking right, the next challenge was consistency.
We didn’t want each screen or designer to invent their own blur strength or alpha combination.
The real power of Compose is that once a pattern is stable, it should scale effortlessly.
So, we abstracted the effect into variations light and heavy glass containers each tuned for a different purpose.
“Consistency isn’t limitation; it’s leverage.”
The lighter version is subtle good for overlays, cards, or backgrounds where content underneath should still peek through.
The heavier version has stronger blur and opacity, ideal for modals or drawers where you need visual separation.
@Composable
fun LightGlassContainer(/* ... */) {
GlassContainer(
blurRadius = 6.dp,
backgroundAlpha = 0.06f,
borderAlpha = 0.12f
) { content() }
}
@Composable
fun HeavyGlassContainer(/* ... */) {
GlassContainer(
blurRadius = 16.dp,
backgroundAlpha = 0.12f,
borderAlpha = 0.25f
) { content() }
}
This small abstraction turned out to be the real win.
By treating glass as a reusable composable, not a visual trick, we could easily adapt it across our app.
Here’s a closing statement for your article, written in that same casual and smart style, which incorporates your animated background idea.
Taking It Further: Making the Glass Reactive
We’ve successfully built a GlassContainer that’s reusable, theme-friendly, and scales with our design system. We’ve separated the blurred background from the crisp content and added subtle gradients to mimic how real-world light catches an edge.
But we can push this illusion one step further.
Early on, we noted that “real glass isn’t transparent it’s reactive”. Our GlassContainer looks great on a static background, but to make it feel truly alive, it needs something to react to.
This is where a dynamic background comes in. By placing a subtle, animated gradient behind our glass components, the blur effect suddenly has shifting light to catch and diffuse. The glass no longer feels like a static overlay; it feels like a physical object interacting with a living environment.
Here’s a quick way to create a “light bleed” animation, simplified to just the dark-mode colors that match our final design:
// --- Define our dark palette ---
// (Assuming these are defined in your theme)
val blue = Color(0xFF3A7DFF)
val midnight = Color(0xFF161A3C)
val grape = Color(0xFF5A4BFF)
val nearBlack = Color(0xFF0D0F21)
// --------------------------------
@Composable
fun AnimatedLightBleedBackground(
modifier: Modifier = Modifier,
animationDurationMs: Int = 8000,
bleedIntensity: Float = 0.15f
) {
val infiniteTransition = rememberInfiniteTransition(label = "lightBleedTransition")
val animationProgress by infiniteTransition.animateFloat(
initialValue = 0f,
targetValue = 1f,
animationSpec = infiniteRepeatable(
animation = tween(
durationMillis = animationDurationMs,
easing = LinearEasing
),
repeatMode = RepeatMode.Restart
),
label = "lightBleedProgress"
)
val darkColors = remember(bleedIntensity) {
createDarkModeColors(bleedIntensity)
}
Canvas(
modifier = modifier.fillMaxSize()
) {
// Use the provided custom drawing logic
drawNaturalLight(
animationProgress = animationProgress,
colors = darkColors
)
}
}
private fun createDarkModeColors(bleedIntensity: Float): List<Color> {
return listOf(
blue.copy(alpha = bleedIntensity * 1.8f),
midnight.copy(alpha = bleedIntensity * 1.2f),
grape.copy(alpha = bleedIntensity * 0.8f),
midnight.copy(alpha = bleedIntensity * 0.6f),
nearBlack.copy(alpha = bleedIntensity * 0.4f),
Color.Transparent,
Color.Transparent
)
}
/**
* Draws a natural, multi-source light bleed effect that
* animates gently.
*/
private fun DrawScope.drawNaturalLight(
animationProgress: Float,
colors: List<Color>
) {
val lightSourceX = size.width * 0.85f
val lightSourceY = size.height * 0.15f
// Calculate animated positions for the primary light source
val animatedX = lightSourceX + cos(animationProgress * 2 * Math.PI).toFloat() * size.width * 0.02f
val animatedY = lightSourceY + sin(animationProgress * 2 * Math.PI * 0.7f).toFloat() * size.height * 0.015f
// Define multiple light sources for a more complex, natural feel
val lightSources = listOf(
Offset(animatedX, animatedY), // Primary source
Offset(animatedX - size.width * 0.05f, animatedY + size.height * 0.03f), // Secondary
Offset(animatedX + size.width * 0.03f, animatedY - size.height * 0.02f) // Tertiary
)
lightSources.forEachIndexed { index, lightSource ->
// Vary the radius for each light source
val radiusMultiplier = when (index) {
0 -> 1.2f // Main light is largest
1 -> 0.8f
else -> 0.6f
}
// Vary the intensity (alpha) for each light source
val intensityMultiplier = when (index) {
0 -> 1.0f // Main light is brightest
1 -> 0.6f
else -> 0.4f
}
val radius = size.width * radiusMultiplier
// Apply the intensity multiplier to the base colors
val naturalColors = colors.map { color ->
color.copy(alpha = color.alpha * intensityMultiplier)
}
val brush = Brush.radialGradient(
colors = naturalColors,
center = lightSource,
radius = radius
)
drawRect(
brush = brush,
size = size
)
}
}
The Final Combination
Now, we put it all together.
In our main screen, we use a Box to create our layers. The AnimatedLightBleedBackground goes at the very bottom. On top of that, we stack our GlassContainer elements (like the "Account Information" and "Settings" cards).
The result is a UI that feels both deep and dynamic. The animated background provides just enough shifting light for the blurred layer of our glass cards to catch and diffuse. The content on top, like “Settings,” stays perfectly sharp and readable.
This combination is what finally delivers on that initial brief. We didn’t just make a transparent box; we built a small, layered system that creates a believable and truly “glassy” effect.
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