added documentation in the code

example/lib/main.dart

@@ -41,6 +41,9 @@ class _ImagePickerExampleHomePageState
   final ImagePicker imagePicker = ImagePicker();
   final double whiteSpace = 20;
   final double imageWidth = 300;
+  final String placeholder = 'assets/images/placeholder.png';
+  final String imageAlreadyDisplayedMessage =
+      'Selected image is already being displayed!';
 
   @override
   Widget build(BuildContext context) {
@@ -56,7 +59,7 @@ class _ImagePickerExampleHomePageState
               Column(children: [
                 if (image == null) ...[
                   Image.asset(
-                    'assets/images/placeholder.png',
+                    placeholder,
                     width: imageWidth,
                     height: imageWidth,
                   )
@@ -83,6 +86,14 @@ class _ImagePickerExampleHomePageState
     );
   }
 
+  /// The [pickImage] function is used to show the usage of the Image Picker Package.
+  /// The most important part is the [showImagePickerDialog] function call.
+  /// The only required parameter is the [context] of the application.
+  /// There are multiple optional parameters that can be included to customize the Image Picker Dialog.
+  /// You can add an optional parameter by for example adding [title: "Image Picker"] to the function call after the context parameter.
+  /// Check the README for all possible optional parameters you can add.
+  /// This function saves the image in a variable and if it's different than the current image it will get displayed in the application.
+  /// When the same image is chosen there will be a snackbar popping up to let you know it's already being displayed.
   void pickImage() async {
     Uint8List? imageInBytes = await imagePicker.showImagePickerDialog(context);
     if (imageInBytes != null) {
@@ -91,9 +102,9 @@ class _ImagePickerExampleHomePageState
           image = imageInBytes;
         });
       } else {
+        if (!mounted) return;
         ScaffoldMessenger.of(context).showSnackBar(
-          const SnackBar(
+          SnackBar(content: Text(imageAlreadyDisplayedMessage)),
-              content: Text('Selected image is already being displayed!')),
         );
       }
     }

lib/image_picker.dart

@@ -5,14 +5,31 @@ import 'src/models/image_picker_settings.dart';
 import 'src/ui/image_picker_ui.dart';
 
 class ImagePicker {
+  /// [showImagePickerDialog] is the function that gets called by the user of the package.
+  /// With this function the Image Picker Dialog gets shown and can be used to pick an image.
+  /// The image gets returned as a [Uint8List] and can be used in the application.
+  /// It can also return null when there is no image selected.
+  /// The function has one required parameter and multiple optional parameters to customize the Image Picker Dialog.
+  /// The only required parameter is [context] which is the [BuildContext] of the application.
+  /// Then you can give the following optional parameters to customize the Image Picker Dialog:
+  /// [title] expects a [String] that is used as the title of the Image Picker Dialog and will be showed at the top of it.
+  /// [titleTextSize] is the font size of the [title].
+  /// [iconSize] is the size of each icon shown in the Image Picker Dialog.
+  /// [iconTextSize] is the size of the text that's show underneath the icon.
+  /// [spaceBetweenIcons] is the size of the space that's between the two icons in the Image Picker Dialog.
+  /// [makePhotoIcon] is the icon as [IconData] that's shown for the make photo button of the Image Picker Dialog.
+  /// [makePhotoText] is the text that's shown underneath the make photo button in the Image Picker Dialog.
+  /// [selectImageIcon] is the icon as [IconData] that's shown for the select image button of the Image Picker Dialog.
+  /// [selectImageText] is the text that's shown underneath the select image button in the Image Picker Dialog.
+  /// [closeButtonText] is the text that's shown on the close dialog button on the bottom of the Image Picker Dialog.
   Future<Uint8List?> showImagePickerDialog(BuildContext context,
       {String title = ImagePickerDefaultParameters.title,
       double titleTextSize = ImagePickerDefaultParameters.titleTextSize,
       double iconSize = ImagePickerDefaultParameters.iconSize,
       double iconTextSize = ImagePickerDefaultParameters.iconTextSize,
       double spaceBetweenIcons = ImagePickerDefaultParameters.spaceBetweenIcons,
-      String makePhotoText = ImagePickerDefaultParameters.makePhotoText,
       IconData makePhotoIcon = ImagePickerDefaultParameters.makePhotoIcon,
+      String makePhotoText = ImagePickerDefaultParameters.makePhotoText,
       IconData selectImageIcon = ImagePickerDefaultParameters.selectImageIcon,
       String selectImageText = ImagePickerDefaultParameters.selectImageText,
       String closeButtonText = ImagePickerDefaultParameters.closeButtonText}) {

lib/src/models/image_picker_settings.dart

@@ -1,5 +1,7 @@
 import 'package:flutter/material.dart';
 
+/// Default values for all the possible optional parameters to be included in the function call when opening the Image Picker Dialog.
+/// When the function call has no optional parameters included these values will be used.
 class ImagePickerDefaultParameters {
   static const String title = "Upload Image";
   static const double titleTextSize = 20;

lib/src/services/image_picker_service.dart

@@ -4,6 +4,9 @@ import 'package:image_picker/image_picker.dart';
 class ImagePickerService {
   final ImagePicker _imagePicker = ImagePicker();
 
+  /// [pickImage] is the function that picks the image and returns it when the Image Picker Dialog gets closed.
+  /// The function requires [source], an [ImageSource] that's the method of how the image needs to be picked, for example gallery or camera.
+  /// It also requires [context], the [BuildContext] which is needed to be able to return the image when the Image Picker Dialog gets closed.
   void pickImage(ImageSource source, BuildContext context) async {
     var image =
         await (await _imagePicker.pickImage(source: source))?.readAsBytes();

lib/src/ui/image_picker_ui.dart

@@ -7,6 +7,13 @@ import 'package:image_picker/image_picker.dart';
 class ImagePickerUI {
   final ImagePickerService _imagePickerService = ImagePickerService();
 
+  /// [pickImageDialog] returns a [ModalBottomSheet] widget that displays two icons.
+  /// When clicked on the left icon the user can pick an image from their documents on their phone.
+  /// When clicked on the right icon the user can make a photo with the camera on their phone.
+  /// The function gets all the parameters from the [image_picker] class where a function provides them all.
+  /// See that function for a description of each parameter.
+  /// The [pickImageDialog] function can return a [Uint8List] that is the picked image as a bytes list.
+  /// It can also return null when no image gets chosen.
   Future<Uint8List?> pickImageDialog(
       BuildContext context,
       String title,
@@ -35,12 +42,12 @@ class ImagePickerUI {
             Row(
               mainAxisAlignment: MainAxisAlignment.center,
               children: [
-                generateIconButtonWithText(context, selectImageIcon, iconSize,
+                _generateIconButtonWithText(context, selectImageIcon, iconSize,
                     iconTextSize, ImageSource.gallery, selectImageText),
                 SizedBox(
                   width: spaceBetweenIcons,
                 ),
-                generateIconButtonWithText(context, makePhotoIcon, iconSize,
+                _generateIconButtonWithText(context, makePhotoIcon, iconSize,
                     iconTextSize, ImageSource.camera, makePhotoText),
               ],
             ),
@@ -65,7 +72,15 @@ class ImagePickerUI {
     );
   }
 
-  Column generateIconButtonWithText(
+  /// The [_generateIconButtonWithText] function returns a column that includes an [IconButton] and [Text].
+  /// The function requires the following parameters to be able to generate an icon with text:
+  /// [context] The build context that is required to make the [pickImage] function in [_imagePickerService] work.
+  /// [icon] The icon that needs to be displayed, requires an [IconData] as value to be used.
+  /// [iconSize] The size of the icon.
+  /// [iconTextSize] The size of the text that's displayed underneath the icon.
+  /// [imageSource] The type of [ImageSource] to be used to pick an image when pressed on the icon.
+  /// [bottomText] The text that's displayed underneath the icon.
+  Column _generateIconButtonWithText(
       BuildContext context,
       IconData icon,
       double iconSize,