Revert Layout changes

This reverts commits:
- 974ec92ad6.
- 537e0c12c2.
- 500a3df6e9.

spring-boot-tools/spring-boot-gradle-plugin/src/main/java/org/springframework/boot/gradle/SpringBootPluginExtension.java

@@ -21,13 +21,12 @@ import java.util.Map;
 import java.util.Set;
 
 import groovy.lang.Closure;
-
 import org.gradle.api.Project;
 import org.gradle.api.plugins.JavaPlugin;
 
 import org.springframework.boot.gradle.buildinfo.BuildInfo;
 import org.springframework.boot.loader.tools.Layout;
-import org.springframework.boot.loader.tools.LayoutType;
+import org.springframework.boot.loader.tools.Layouts;
 
 /**
  * Gradle DSL Extension for 'Spring Boot'. Most of the time Spring Boot can guess the
@@ -89,7 +88,7 @@ public class SpringBootPluginExtension {
 	 * the MANIFEST.MF 'Main-Class' to be PropertiesLauncher. Gradle will coerce literal
 	 * String values to the correct type.
 	 */
-	String layout;
+	LayoutType layout;
 
 	/**
 	 * Libraries that must be unpacked from fat jars in order to run. Use Strings in the
@@ -146,7 +145,7 @@ public class SpringBootPluginExtension {
 	 * @return the Layout to use or null if not explicitly set
 	 */
 	public Layout convertLayout() {
-		return (this.layout == null ? null : LayoutType.layout(this.layout));
+		return (this.layout == null ? null : this.layout.layout);
 	}
 
 	public String getMainClass() {
@@ -189,11 +188,11 @@ public class SpringBootPluginExtension {
 		this.backupSource = backupSource;
 	}
 
-	public String getLayout() {
+	public LayoutType getLayout() {
 		return this.layout;
 	}
 
-	public void setLayout(String layout) {
+	public void setLayout(LayoutType layout) {
 		this.layout = layout;
 	}
 
@@ -277,4 +276,29 @@ public class SpringBootPluginExtension {
 		}
 	}
 
+	/**
+	 * Layout Types.
+	 */
+	enum LayoutType {
+
+		JAR(new Layouts.Jar()),
+
+		WAR(new Layouts.War()),
+
+		ZIP(new Layouts.Expanded()),
+
+		DIR(new Layouts.Expanded()),
+
+		MODULE(new Layouts.Module()),
+
+		NONE(new Layouts.None());
+
+		Layout layout;
+
+		LayoutType(Layout layout) {
+			this.layout = layout;
+		}
+
+	}
+
 }