protobufs finally are functional

zcash-android-wallet-app/app/build.gradle.kts

@@ -27,7 +27,7 @@ android {
 // Note: we use string primitives for dependencies rather than something fancy (like buildSrc
 // variables) so that we can leverage the built-in lint check that alerts us about new versions
 dependencies {
-    compile(kotlin("stdlib-jdk7", KotlinCompilerVersion.VERSION))
+    implementation(kotlin("stdlib-jdk7", KotlinCompilerVersion.VERSION))
     implementation(project(":zcash-android-welding"))
     implementation(fileTree(mapOf("dir" to "libs", "include" to listOf("*.jar"))))
     implementation("androidx.appcompat:appcompat:1.0.0")

zcash-android-wallet-app/zcash-android-welding/build.gradle.kts

@@ -1,5 +1,7 @@
 import org.jetbrains.kotlin.config.KotlinCompilerVersion
 
+apply(from = "custom-tasks.gradle.kts")
+
 plugins {
     id("com.android.library")
     id("kotlin-android-extensions")
@@ -24,17 +26,15 @@ android {
         }
     }
 
+    sourceSets["main"].java.srcDirs("build/generated/source/wire")
 }
 
 dependencies {
-    compile(kotlin("stdlib-jdk7", KotlinCompilerVersion.VERSION))
+    implementation(kotlin("stdlib-jdk7", KotlinCompilerVersion.VERSION))
+    implementation("com.squareup.wire:wire-runtime:2.3.0-RC1")
     implementation(fileTree(mapOf("dir" to "libs", "include" to listOf("*.jar"))))
     implementation("com.android.support:appcompat-v7:28.0.0")
     testImplementation("junit:junit:4.12")
     androidTestImplementation("com.android.support.test:runner:1.0.2")
     androidTestImplementation("com.android.support.test.espresso:espresso-core:3.0.2")
-}
-
-repositories {
-    mavenCentral()
-}
+}

zcash-android-wallet-app/zcash-android-welding/custom-tasks.gradle.kts

@@ -0,0 +1,64 @@
+val protoSrcDir = "src/main/proto"
+val protoDestDir = "build/generated/source/wire"
+val jniSrcDir = "src/main/rust"
+val jniDestDir = "build/rust/target"
+
+
+fun fileTreeWith(dir: String, vararg include: String): ConfigurableFileTree {
+    return fileTree(mapOf("dir" to dir, "include" to include))
+}
+
+buildscript {
+    dependencies {
+        classpath("com.squareup.wire:wire-compiler:2.3.0-RC1")
+    }
+
+    repositories {
+        mavenCentral()
+    }
+
+}
+
+val generateProtobufClasses: TaskProvider<Task> = tasks.register("generateProtobufClasses").apply {
+    configure {
+        doFirst {
+            println("**** CREATING PROTOS ****")
+            delete(protoDestDir)
+            mkdir(protoDestDir)
+        }
+        description = "Generate Java classes from protocol buffer (.proto) schema files for use with Square's Wire library"
+
+        fileTreeWith(protoSrcDir, "**/*.proto").forEach { file ->
+            doLast {
+                javaexec {
+                    main = "com.squareup.wire.WireCompiler"
+                    classpath = buildscript.configurations.getByName("classpath")
+                    args = listOf("--proto_path=$protoSrcDir", "--java_out=$protoDestDir", file.path)
+                }
+            }
+        }
+        inputs.files(fileTreeWith(protoSrcDir, "**/*.proto"))
+        outputs.files(fileTreeWith(protoDestDir, "**"))
+    }
+}
+
+val generateJniLibs: TaskProvider<Task> = tasks.register("generateJniLibs").apply {
+    configure {
+        doFirst {
+            println("**** CREATING JNI LIBS ****")
+            delete(jniDestDir)
+            mkdir(jniDestDir)
+        }
+        description = "Generate *.so files for connecting to the Rust wallet logic through the JNI"
+        doLast {
+            exec {
+                commandLine("./build-rust.sh")
+            }
+        }
+        inputs.files(fileTreeWith(jniSrcDir, "**/*"))
+        outputs.files(fileTreeWith(jniDestDir, "**/*.so"))
+    }
+}
+
+tasks["preBuild"]!!.dependsOn(generateProtobufClasses)
+tasks["preBuild"]!!.dependsOn(generateJniLibs)

zcash-android-wallet-app/zcash-android-welding/src/main/proto/WalletData.proto

@@ -0,0 +1,6 @@
+package cash.z.wallet.sdk.proto;
+message WalletData {
+  required string name = 1;
+  required int32 id = 2;
+  optional string emails = 3;
+}

zcash-android-wallet-app/zcash-android-welding/src/main/rust/lib.rs

@@ -7,7 +7,6 @@ pub extern "C" fn test_response(input: *const c_char) -> c_int {
     magic_number
 }
 
-
 /// JNI interface
 #[cfg(target_os="android")]
 #[allow(non_snake_case)]