feat(android): Fix rendering, stability, and UI components

Major improvements to the Android A2UI client to resolve blank screen issues and enhance UI rendering.
Key Changes:
- **Fix JSON-RPC**: Corrected method name to message/send and fixed serialization logic to handle polymorphic ServerPart correctly.
- **Fix UI Rendering**:
    - Implemented IconRenderer with reflection to support all Material Icons dynamically.
    - Added DividerRenderer to support separator lines.
    - Integrated Coil for image loading and added localhost->10.0.2.2 URL rewriting for emulator.
- **Stability**:
    - Increased OKHttp timeout to 90s.
    - Increased Gradle JVM heap size to 4GB to prevent OOM during build.
- **Documentation**:
    - Updated Android client README with setup instructions.
    - Cleaned up build logs.

Author: divyanshsaraswat

.idea/.name

@@ -1,6 +1,7 @@
 plugins {
     alias(libs.plugins.android.library)
     alias(libs.plugins.jetbrains.kotlin.android)
+    alias(libs.plugins.kotlin.serialization)
 }
 
 android {
@@ -31,7 +32,7 @@ android {
         compose = true
     }
     composeOptions {
-        kotlinCompilerExtensionVersion = "1.5.1"
+        kotlinCompilerExtensionVersion = "1.5.11"
     }
 }
 
@@ -46,6 +47,10 @@ dependencies {
     implementation(libs.androidx.ui.graphics)
     implementation(libs.androidx.ui.tooling.preview)
     implementation(libs.androidx.material3)
+    implementation(libs.androidx.compose.material.icons.extended)
+    implementation(libs.kotlinx.serialization.json)
+    implementation("io.coil-kt:coil-compose:2.6.0")
+    implementation(kotlin("reflect"))
 
     testImplementation(libs.junit)
     androidTestImplementation(libs.androidx.junit)

.idea/deploymentTargetSelector.xml

@@ -3,10 +3,11 @@ package com.google.a2ui.compose
 import com.google.a2ui.core.model.Action
 import com.google.a2ui.core.model.BoundValue
 import com.google.a2ui.core.state.SurfaceState
+import kotlinx.serialization.json.JsonElement
 
 data class A2UIContext(
     val state: SurfaceState,
-    val onUserAction: (Action, String) -> Unit // action, sourceId
+    val onUserAction: (Action, String, Map<String, JsonElement>) -> Unit // action, sourceId, context
 ) {
     fun resolve(boundValue: BoundValue?): Any? {
         return state.resolve(boundValue)
@@ -19,4 +20,8 @@ data class A2UIContext(
     fun resolveBoolean(boundValue: BoundValue?): Boolean {
         return resolve(boundValue) as? Boolean ?: false
     }
+
+    fun resolveNumber(boundValue: BoundValue?): Double {
+        return (resolve(boundValue) as? Number)?.toDouble() ?: 0.0
+    }
 }

.idea/kotlinc.xml

@@ -5,6 +5,7 @@ import androidx.compose.runtime.CompositionLocalProvider
 import androidx.compose.runtime.staticCompositionLocalOf
 import com.google.a2ui.core.model.Action
 import com.google.a2ui.core.state.SurfaceState
+import kotlinx.serialization.json.JsonElement
 
 val LocalA2UIContext = staticCompositionLocalOf<A2UIContext> {
     error("No A2UIContext provided")
@@ -14,7 +15,7 @@ val LocalA2UIContext = staticCompositionLocalOf<A2UIContext> {
 fun A2UISurface(
     surfaceId: String,
     state: SurfaceState,
-    onUserAction: (Action, String) -> Unit
+    onUserAction: (Action, String, Map<String, JsonElement>) -> Unit
 ) {
     val context = A2UIContext(
         state = state,

.idea/migrations.xml

@@ -14,6 +14,8 @@ import com.google.a2ui.compose.components.TabsRenderer
 import com.google.a2ui.compose.components.TextFieldRenderer
 import com.google.a2ui.compose.components.TextRenderer
 import com.google.a2ui.compose.components.VideoRenderer
+import com.google.a2ui.compose.components.IconRenderer
+import com.google.a2ui.compose.components.DividerRenderer
 import com.google.a2ui.core.model.ComponentWrapper
 
 typealias ComponentRenderer = @Composable (ComponentWrapper, A2UIContext) -> Unit
@@ -38,6 +40,8 @@ object ComponentRegistry {
         register("Modal") { wrapper, ctx -> ModalRenderer(wrapper.Modal!!, ctx) }
         register("DateTimeInput") { wrapper, ctx -> DateTimeRenderer(wrapper.DateTimeInput!!, ctx) }
         register("Video") { wrapper, ctx -> VideoRenderer(wrapper.Video!!, ctx) }
+        register("Icon") { wrapper, ctx -> IconRenderer.Render(wrapper, ctx) }
+        register("Divider") { wrapper, ctx -> DividerRenderer(wrapper.Divider!!, ctx) }
     }
 
     fun register(type: String, renderer: ComponentRenderer) {
@@ -68,7 +72,9 @@ object ComponentRegistry {
             wrapper.Modal != null -> "Modal"
             wrapper.DateTimeInput != null -> "DateTimeInput"
             wrapper.Video != null -> "Video"
-            wrapper.Audio != null -> "Audio" // Audio maps to Video/Media renderer usually or separate
+            wrapper.Audio != null -> "Audio"
+            wrapper.Icon != null -> "Icon"
+            wrapper.Divider != null -> "Divider"
             else -> null
         }
     }

ANDROID_GUIDE.md

@@ -27,15 +27,18 @@ fun ButtonRenderer(
             // To fix this properly, I should pass the ID to the renderer.
             // But let's stick to current plan and fix registry separately.
             // I'll emit "unknown" for now and fix later.
-            context.onUserAction(action, "unknown_source_id") 
+            context.onUserAction(action, "unknown_source_id", emptyMap())
         }
+        Unit
     }
 
     Button(onClick = onClick) {
         if (properties.label != null) {
             Text(text = context.resolveString(properties.label))
-        } else if (properties.child != null) {
-            A2UIComponent(id = properties.child, context = context)
+        } else {
+            properties.child?.let { childId ->
+                A2UIComponent(id = childId, context = context)
+            }
         }
     }
 }