Compose NavGen

Generate helper methods for compose navigation using KSP.

? You can try it now, but it’s still under development. ?

TODO

  • Support default value and nullable.
  • Support argument types.
  • Support animation navigation.
  • Add unit test.
  • Add Github Actions.

Usage

Add @NavGen annotation to each compose screen.

@NavGen("list")
@Composable
fun ListScreen(navController: NavController) {
    // ...
}

@NavGen("detail")
@Composable
fun DetailScreen(data: String, navController: NavController) {
    // ...
}

When build, the processor generates helper methods from @NavGen.

Generated code 

// list
fun NavGraphBuilder.list(navController: NavController) {
  composable("list") {
    ListScreen(navController)
  }
}
public fun NavController.list(): Unit {
  navigate("list")
}

// detail
fun NavGraphBuilder.detail(navController: NavController) {
  composable(
  "detail/{data}",
    arguments = listOf(navArgument("data") { type = NavType.StringType })
  ) { backStackEntry ->
    DetailScreen(
      backStackEntry.arguments!!.getString("data")!!,
      navController,
    )
  }
}
fun NavController.detail(`data`: String) {
  navigate("detail/$data")
}

You can use generated code for compose navigation.

val navController = rememberNavController()
NavHost(navController = navController, startDestination = NavGenRoutes.list) {
    list(navController) // Add route 'list'
    detail(navController) // Add route 'detail/{data}'
}

// navigate to next screen
navController.detail(data) // Call NavController.navigate("detail/$data")

Set srcDirs

Android Studio does not automatically index generated codes by KSP. You have to add sourceSets manually.

Ref: https://github.com/google/ksp/issues/37

  • build.gradle.kts

android {
    // ...
    applicationVariants.all {
        val variantName = name
        sourceSets {
            getByName("main") {
                java.srcDir(File("build/generated/ksp/$variantName/kotlin"))
            }
        }
    }
}
  • build.gradle

android {
    // ...
    applicationVariants.all { variant ->
        variant.sourceSets.java.each {
            it.srcDirs += "build/generated/ksp/${variant.name}/kotlin"
        }
    }
}

Download

plugins {
    id("com.google.devtools.ksp") version "1.5.30-1.0.0"
}

dependencies {
    implementation("androidx.navigation:navigation-compose:2.4.0-alpha10")

    implementation("com.star-zero:compose-navgen:1.0.0-alpha01")
    ksp("com.star-zero:compose-navgen-processor:1.0.0-alpha01")
}

License

Copyright 2021 Kenji Abe

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

GitHub

https://github.com/STAR-ZERO/compose-navgen