Provide basic support for Android library projects and make the source directories configurable for the user

1 files changed, 64 insertions, 11 deletions

diff --git a/dokka-gradle-plugin/src/main/kotlin/main.kt b/dokka-gradle-plugin/src/main/kotlin/main.kt
index 476f7656..e3275501 100644
--- a/dokka-gradle-plugin/src/main/kotlin/main.kt
+++ b/dokka-gradle-plugin/src/main/kotlin/main.kt
@@ -44,6 +44,10 @@ open class DokkaTask : DefaultTask() {
     var samples: List<Any?> = arrayListOf()
     @Input
     var jdkVersion: Int = 6
+    @Input
+    var sourceDirs: Iterable<File> = emptyList()
+
+    protected open val sdkProvider: SdkProvider? = null
 
     fun linkMapping(closure: Closure<Any?>) {
         val mapping = LinkMapping()
@@ -63,13 +67,15 @@ open class DokkaTask : DefaultTask() {
     @TaskAction
     fun generate() {
         val project = project
+        val sdkProvider = sdkProvider
         val sourceDirectories = getSourceDirectories()
         val allConfigurations = project.configurations
 
         val classpath =
-                processConfigurations
-                .map { allConfigurations?.getByName(it.toString()) ?: throw IllegalArgumentException("No configuration $it found") }
-                .flatMap { it }
+                if (sdkProvider != null && sdkProvider.isValid) sdkProvider.classpath else emptyList<File>() +
+                        processConfigurations
+                                .map { allConfigurations?.getByName(it.toString()) ?: throw IllegalArgumentException("No configuration $it found") }
+                                .flatMap { it }
 
         if (sourceDirectories.isEmpty()) {
             logger.warn("No source directories found: skipping dokka generation")
@@ -89,20 +95,33 @@ open class DokkaTask : DefaultTask() {
         ).generate()
     }
 
-    fun getSourceDirectories(): List<File> {
-        val javaPluginConvention = project.convention.getPlugin(JavaPluginConvention::class.java)
-        val sourceSets = javaPluginConvention.sourceSets?.findByName(SourceSet.MAIN_SOURCE_SET_NAME)
-        return sourceSets?.allSource?.srcDirs?.filter { it.exists() } ?: emptyList()
+    fun getSourceDirectories(): Collection<File> {
+        val provider = sdkProvider
+        val sourceDirs = if (sourceDirs.any()) {
+            logger.info("Dokka: Taking source directories provided by the user")
+            sourceDirs.toSet()
+        } else if (provider != null && provider.isValid) {
+            logger.info("Dokka: Taking source directories from ${provider.name} sdk provider")
+            provider.sourceDirs
+        } else {
+            logger.info("Dokka: Taking source directories from default java plugin")
+            val javaPluginConvention = project.convention.getPlugin(JavaPluginConvention::class.java)
+            val sourceSets = javaPluginConvention.sourceSets?.findByName(SourceSet.MAIN_SOURCE_SET_NAME)
+            sourceSets?.allSource?.srcDirs
+        }
+
+        return sourceDirs?.filter { it.exists() } ?: emptyList()
     }
 
+    @Input
     @InputFiles
     @SkipWhenEmpty
-    fun getInputFiles() : FileCollection = project.files(getSourceDirectories().map { project.fileTree(it) }) +
-        project.files(includes) +
-        project.files(samples)
+    fun getInputFiles(): FileCollection = project.files(getSourceDirectories().map { project.fileTree(it) }) +
+            project.files(includes) +
+            project.files(samples)
 
     @OutputDirectory
-    fun getOutputDirectoryAsFile() : File = project.file(outputDirectory)
+    fun getOutputDirectoryAsFile(): File = project.file(outputDirectory)
 
 }
 
@@ -111,3 +130,37 @@ open class LinkMapping {
     var url: String = ""
     var suffix: String? = null
 }
+
+/**
+ * A provider for SDKs that can be used if a project uses classes that live outside the JDK or uses a
+ * different method to determine the source directories.
+ *
+ * For example an Android library project configures its sources through the Android extension instead
+ * of the basic java convention. Also it has its custom classes located in the SDK installation directory.
+ */
+interface SdkProvider {
+    /**
+     * The name of this provider. Only used for logging purposes.
+     */
+    val name: String
+
+    /**
+     * Checks whether this provider has everything it needs to provide the source directories.
+     */
+    val isValid: Boolean
+
+    /**
+     * Provides additional classpath files where Dokka should search for external classes.
+     * The file list is injected **after** JDK Jars and **before** project dependencies.
+     *
+     * This is only called if [isValid] returns `true`.
+     */
+    val classpath: List<File>
+
+    /**
+     * Provides a list of directories where Dokka should search for source files.
+     *
+     * This is only called if [isValid] returns `true`.
+     */
+    val sourceDirs: Set<File>?
+}