Add state save for Fragments

activitystarter-compiler/src/main/java/activitystarter/compiler/generation/ClassGeneration.kt

@@ -56,7 +56,7 @@ internal abstract class ClassGeneration(val classModel: ClassModel) {
         val bundleValue = (if (arg.paramType.typeUsedBySupertype()) "(\$T) " else "") +
                 arg.addUnwrapper { getBundleGetter(bundleName, arg.saveParamType, fieldName) }
         val bundleValueSetter = arg.accessor.makeSetter(bundleValue)
-        if (checkIfSet) addCode("if(${getBundlePredicate(bundleName, fieldName)}) ")
+        if (checkIfSet) addCode("if($bundleName != null && ${getBundlePredicate(bundleName, fieldName)}) ")
         addStatement("$className.$bundleValueSetter", arg.typeName)
     }
 

activitystarter-compiler/src/main/java/activitystarter/compiler/generation/FragmentGeneration.kt

@@ -5,19 +5,40 @@ import activitystarter.compiler.model.param.ArgumentModel
 import activitystarter.compiler.utils.BUNDLE
 import activitystarter.compiler.utils.doIf
 import com.squareup.javapoet.MethodSpec
+import com.squareup.javapoet.TypeSpec
 
 internal class FragmentGeneration(classModel: ClassModel) : ClassGeneration(classModel) {
 
     override fun createFillFieldsMethod() = getBasicFillMethodBuilder()
             .addParameter(classModel.targetTypeName, "fragment")
-            .doIf(classModel.argumentModels.isNotEmpty()) { addStatement("\$T arguments = fragment.getArguments()", BUNDLE) }
-            .addBundleSetters("arguments", "fragment", true)
+            .addParameter(BUNDLE, "savedInstanceState")
+            .doIf(classModel.argumentModels.isNotEmpty()) {
+                addFieldSettersCode()
+            }
             .build()!!
 
+    private fun MethodSpec.Builder.addFieldSettersCode() {
+        addStatement("\$T arguments = fragment.getArguments()", BUNDLE)
+        if (classModel.savable) {
+            for (arg in classModel.argumentModels) {
+                val bundleName = "savedInstanceState"
+                val bundlePredicate = getBundlePredicate(bundleName, arg.fieldName)
+                addCode("if($bundleName != null && $bundlePredicate) {\n")
+                addBundleSetter(arg, bundleName, "fragment", false)
+                addCode("} else ")
+                addBundleSetter(arg, "arguments", "fragment", true)
+            }
+        } else {
+            addBundleSetters("arguments", "fragment", true)
+        }
+    }
     override fun createStarters(variant: List<ArgumentModel>): List<MethodSpec> = listOf(
             createGetFragmentMethod(variant)
     )
 
+    override fun TypeSpec.Builder.addExtraToClass() = this
+            .addMethod(createSaveMethod())
+
     private fun createGetFragmentMethod(variant: List<ArgumentModel>) = builderWithCreationBasicFieldsNoContext("newInstance")
             .addArgParameters(variant)
             .returns(classModel.targetTypeName)
@@ -32,4 +53,13 @@ internal class FragmentGeneration(classModel: ClassModel) : ClassGeneration(clas
                 addStatement("fragment.setArguments(args)")
             }
             .addStatement("return fragment")
+
+    private fun createSaveMethod(): MethodSpec = this
+            .builderWithCreationBasicFieldsNoContext("save")
+            .addParameter(classModel.targetTypeName, "fragment")
+            .addParameter(BUNDLE, "bundle")
+            .doIf(classModel.savable) {
+                addSaveBundleStatements("bundle", classModel.argumentModels, { "fragment.${it.accessor.getFieldValue()}" })
+            }
+            .build()
 }

activitystarter-compiler/src/main/java/activitystarter/compiler/processing/ArgumentFactory.kt

@@ -56,4 +56,14 @@ class ArgumentFactory(val enclosingElement: TypeElement, val config: ProjectConf
     private fun showProcessingError(element: Element, text: String) {
         error(enclosingElement, "@%s %s $text (%s)", Arg::class.java.simpleName, enclosingElement.qualifiedName, element.simpleName)
     }
+
+class ProcessingError(override val message: String): Throwable(message)
+
+fun processElement(element: Element) {
+    fun throwError(message: String): Nothing
+            = throw ProcessingError("Error in element $element: $message")
+
+val enclosingElement = element.enclosingElement ?: throwError("Lack of enclosing element")
+}
+
 }

activitystarter/src/main/java/activitystarter/ActivityStarter.java

@@ -23,11 +23,19 @@ public static void fill(@NonNull Activity target, @Nullable Bundle savedInstance
     }
 
     public static void fill(@NonNull Fragment target) {
-        innerFill(target);
+        innerFill(target, null, Bundle.class);
+    }
+
+    public static void fill(@NonNull Fragment target, @Nullable Bundle savedInstanceState) {
+        innerFill(target, savedInstanceState, Bundle.class);
     }
 
     public static void fill(@NonNull android.support.v4.app.Fragment target) {
-        innerFill(target);
+        innerFill(target, null, Bundle.class);
+    }
+
+    public static void fill(@NonNull android.support.v4.app.Fragment target, @Nullable Bundle savedInstanceState) {
+        innerFill(target, savedInstanceState, Bundle.class);
     }
 
     public static void fill(@NonNull Service target, @NonNull Intent intent) {
@@ -47,6 +55,24 @@ public static void save(@NonNull Activity target, Bundle bundle) {
         invokeMethod(method, target, bundle);
     }
 
+    public static void save(@NonNull Fragment target, Bundle bundle) {
+        Class<?> targetClass = target.getClass();
+        Class<?> starterClass = getStarterClass(targetClass);
+        if (starterClass == null) return;
+        Method method = getMethod(starterClass, "save", targetClass, Bundle.class);
+        if (method == null) return;
+        invokeMethod(method, target, bundle);
+    }
+
+    public static void save(@NonNull android.support.v4.app.Fragment target, Bundle bundle) {
+        Class<?> targetClass = target.getClass();
+        Class<?> starterClass = getStarterClass(targetClass);
+        if (starterClass == null) return;
+        Method method = getMethod(starterClass, "save", targetClass, Bundle.class);
+        if (method == null) return;
+        invokeMethod(method, target, bundle);
+    }
+
     private static void innerFill(@NonNull Object target) {
         Class<?> targetClass = target.getClass();
         Class<?> starterClass = getStarterClass(targetClass);

build.gradle

@@ -46,7 +46,7 @@ subprojects { project ->
             maven { url "https://plugins.gradle.org/m2/" }
         }
         dependencies {
-            classpath 'com.android.tools.build:gradle:2.3.2'
+            classpath 'com.android.tools.build:gradle:2.3.3'
             classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlinVersion"
         }
     }

sample/app/src/main/java/com/example/activitystarter/fragment/TabbedPlaceholderFragment.java

@@ -21,9 +21,22 @@ public TabbedPlaceholderFragment() {}
     @Override
     public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
         View rootView = inflater.inflate(R.layout.fragment_tabbed, container, false);
-        ActivityStarter.fill(this);
-        TextView textView = (TextView) rootView.findViewById(R.id.section_label);
+        ActivityStarter.fill(this, savedInstanceState);
+        final TextView textView = (TextView) rootView.findViewById(R.id.section_label);
+        textView.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                ++sectionNumber;
+                textView.setText(getString(R.string.section_format, sectionNumber));
+            }
+        });
         textView.setText(getString(R.string.section_format, sectionNumber));
         return rootView;
     }
+
+    @Override
+    public void onSaveInstanceState(Bundle outState) {
+        super.onSaveInstanceState(outState);
+        ActivityStarter.save(this, outState);
+    }
 }