add documentation to Imagen Editing

Author: David Motsonashvili

firebase-ai/src/main/kotlin/com/google/firebase/ai/ImagenModel.kt

@@ -83,6 +83,13 @@ internal constructor(
       throw FirebaseAIException.from(e)
     }
 
+  /**
+   * Generates an image, based on both a prompt, and input image, returning the result directly to
+   * the caller.
+   *
+   * @param prompt The input(s) given to the model as a prompt.
+   * @param config The editing config given to the model.
+   */
   public suspend fun editImage(
     prompt: String,
     config: ImagenEditingConfig

firebase-ai/src/main/kotlin/com/google/firebase/ai/type/ImagenEditMode.kt

@@ -1,10 +1,39 @@
+/*
+ * Copyright 2025 Google LLC
+ *
+ * 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.
+ */
+
 package com.google.firebase.ai.type
 
+/** Represents the edit mode for this imagen editing config */
 public class ImagenEditMode private constructor(internal val value: String) {
 
   public companion object {
+    /**
+     * Inpainting insertion is an edit mode where you mask off an area of the image, and use the
+     * prompt to add new elements to the image.
+     */
     public val INPAINT_INSERTION: ImagenEditMode = ImagenEditMode("EDIT_MODE_INPAINT_INSERTION")
+    /**
+     * Inpainting removal is an edit mode where you mask off an area of the image, and use the
+     * prompt to remove elements from the image.
+     */
     public val INPAINT_REMOVAL: ImagenEditMode = ImagenEditMode("EDIT_MODE_INPAINT_REMOVAL")
+    /**
+     * Outpainting is an edit mode where your mask is larger than the image, and expands the
+     * boundaries of the image by continuing the background. The prompt can guide this process.
+     */
     public val OUTPAINT: ImagenEditMode = ImagenEditMode("EDIT_MODE_OUTPAINT")
   }
 }

firebase-ai/src/main/kotlin/com/google/firebase/ai/type/ImagenEditingConfig.kt

@@ -1,7 +1,31 @@
+/*
+ * Copyright 2025 Google LLC
+ *
+ * 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.
+ */
+
 package com.google.firebase.ai.type
 
 import kotlinx.serialization.Serializable
 
+/**
+ * Configuration parameters to use for imagen editing.
+ * @property image the base image to be edited.
+ * @property editMode specifies the edititing mode for this request.
+ * @property mask the mask to specify which sections of the base image can be edited.
+ * @property maskDilation a percentage by which to shrink the mask to allow some edge blending.
+ * @property editSteps the number of intermediate steps for the edit to take.
+ */
 @PublicPreviewAPI
 public class ImagenEditingConfig(
   public val image: ImagenInlineImage,
@@ -14,6 +38,18 @@ public class ImagenEditingConfig(
     public fun builder(): Builder = Builder()
   }
 
+  /**
+   * Builder for creating a [ImagenEditingConfig].
+   *
+   * Mainly intended for Java interop. Kotlin consumers should use [imagenEditingConfig] for a more
+   * idiomatic experience.
+   *
+   * @property image see [ImagenEditingConfig.image]
+   * @property editMode see [ImagenEditingConfig.editMode]
+   * @property mask see [ImagenEditingConfig.mask]
+   * @property maskDilation see [ImagenEditingConfig.maskDilation]
+   * @property editSteps see [ImagenEditingConfig.editSteps]
+   */
   public class Builder {
     @JvmField public var image: ImagenInlineImage? = null
     @JvmField public var editMode: ImagenEditMode? = null
@@ -33,6 +69,7 @@ public class ImagenEditingConfig(
 
     public fun setEditSteps(editSteps: Int): Builder = apply { this.editSteps = editSteps }
 
+    /** Creates a new [ImagenEditingConfig] with the attached arguments */
     public fun build(): ImagenEditingConfig {
       if (image == null) {
         throw IllegalStateException("ImagenEditingConfig must contain an image")
@@ -60,6 +97,19 @@ public class ImagenEditingConfig(
   )
 }
 
+/**
+ * Helper method to construct a [ImagenEditingConfig] in a DSL-like manner.
+ *
+ * Example Usage:
+ * ```
+ * imagenEditingConfig {
+ *   image = baseImage
+ *   mask = imageMask
+ *   editMode = ImagenEditMode.INPAINTING_REMOVAL
+ *   maskDilation = 0.05
+ * }
+ * ```
+ */
 @PublicPreviewAPI
 public fun imagenEditingConfig(init: ImagenEditingConfig.Builder.() -> Unit): ImagenEditingConfig {
   val builder = ImagenEditingConfig.builder()