inabox/inabox.wpf/DigitalForms/Designer/Controls/Fields/DFEmbeddedImageControl.cs

using InABox.Core;
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media.Imaging;
using System.Windows.Media;
using InABox.WPF;
using Color = System.Drawing.Color;
using Image = System.Windows.Controls.Image;
using System.Diagnostics.CodeAnalysis;
using System.IO;
using Microsoft.Win32;

namespace InABox.DynamicGrid
{
    public static class EmbeddedImageUtilities
    {
        private static BitmapImage? EmptyImage;
        private static BitmapImage? EmptySignature;
        public static ImageSource CreateEmptyImage()
        {
            EmptyImage ??= new Bitmap(256, 256).WatermarkImage("No Image", Color.Gray).AsBitmapImage();
            return EmptyImage;
        }
        public static ImageSource CreateEmptySignature()
        {
            EmptySignature ??= new Bitmap(400, 400).WatermarkImage("No Signature", Color.Gray).AsBitmapImage();
            return EmptySignature;
        }

        public static bool SelectImageFile([NotNullWhen(true)] out byte[]? data)
        {
            var dlg = new OpenFileDialog();
            dlg.Filter = "Image Files (*.jpg;*.png;*.bmp)|*.png;*.jpg;*.jpeg;*.bmp";
            if (dlg.ShowDialog() == true)
            {
                var filename = Path.GetFileName(dlg.FileName).ToLower();
                var timestamp = new FileInfo(dlg.FileName).LastWriteTime;
                data = File.ReadAllBytes(dlg.FileName);
                return true;
            }
            data = null;
            return false;
        }
        public static byte[]? SaveImageToBytes(Image? image, bool isEmpty, BitmapEncoder encoder)
        {
            if (image == null
                || image.Source is not BitmapImage bmpimg) return null;
            if (isEmpty) return null;

            byte[] data;
            encoder.Frames.Add(BitmapFrame.Create(bmpimg));
            using (var ms = new MemoryStream())
            {
                encoder.Save(ms);
                ms.Seek(0, SeekOrigin.Begin);
                data = ms.ToArray();
            }

            return data;
        }
        public static string SaveImageToString(Image? image, bool isEmpty, BitmapEncoder encoder)
        {
            var data = SaveImageToBytes(image, isEmpty, encoder);
            return data != null ? Convert.ToBase64String(data) : "";
        }
        /// <summary>
        /// Loads a value into an Image object.
        /// </summary>
        /// <param name="image"></param>
        /// <param name="value"></param>
        /// <param name="defImage"></param>
        /// <returns><see langword="false"/> if the image is empty.</returns>
        public static bool LoadImageFromData(Image? image, object? value, Func<ImageSource>? defImage = null)
        {
            if (image == null) return false;

            BitmapImage? source = null;
            try
            {
                if (value is string str)
                {
                    source = ImageUtils.BitmapImageFromBase64(str);
                }
                else if (value is byte[] data)
                {
                    source = ImageUtils.BitmapImageFromBytes(data);
                }
            }
            catch (Exception e)
            {
                Logger.Send(LogType.Error, "", string.Format("*** Unknown Error: {0}\n{1}", e.Message, e.StackTrace));
            }

            if (source != null)
            {
                image.Source = source;
                return true;
            }
            else
            {
                image.Source = defImage?.Invoke() ?? CreateEmptyImage();
                return false;
            }
        }
    }

    public class DFEmbeddedImageControl : DynamicFormFieldControl<DFLayoutEmbeddedImage, DFLayoutEmbeddedImageProperties, byte[]>
    {
        private Grid Grid = null!; // Late-initialised
        private Image Image = null!; // Late-initialised

        private bool _isEmpty = true;

        protected override FrameworkElement Create()
        {
            Grid = new Grid();
            Grid.ColumnDefinitions.Add(new ColumnDefinition { Width = new GridLength(1, GridUnitType.Star) });
            Grid.ColumnDefinitions.Add(new ColumnDefinition { Width = GridLength.Auto });
            Grid.ColumnDefinitions.Add(new ColumnDefinition { Width = GridLength.Auto });

            Grid.RowDefinitions.Add(new RowDefinition { Height = new GridLength(1, GridUnitType.Star) });
            Grid.RowDefinitions.Add(new RowDefinition { Height = GridLength.Auto });

            Image = new Image();
            Image.StretchDirection = StretchDirection.DownOnly;
            Image.Source = EmbeddedImageUtilities.CreateEmptyImage();

            var clearButton = new Button
            {
                Content = "Clear",
                Margin = new Thickness(0, 5, 5, 0),
                Width = 60,
                Height = 35
            };
            clearButton.Click += EmbeddedImageClear_Click;

            var selectButton = new Button
            {
                Content = "Select",
                Margin = new Thickness(0, 5, 0, 0),
                Width = 60,
                Height = 35
            };
            selectButton.Click += EmbeddedImageSelect_Click;

            Image.SetGridPosition(0, 0, 1, 3);
            clearButton.SetGridPosition(1, 1, 1, 1);
            selectButton.SetGridPosition(1, 2, 1, 1);
            Grid.Children.Add(Image);
            Grid.Children.Add(clearButton);
            Grid.Children.Add(selectButton);

            return Grid;
        }

        public override byte[] GetValue()
        {
            return EmbeddedImageUtilities.SaveImageToBytes(Image, _isEmpty, new JpegBitmapEncoder()) ?? Array.Empty<byte>();
        }

        public override void SetValue(byte[]? value)
        {
            _isEmpty = !EmbeddedImageUtilities.LoadImageFromData(Image, value);
        }

        private void EmbeddedImageClear_Click(object sender, RoutedEventArgs e)
        {
            if (!_isEmpty)
            {
                Image.Source = EmbeddedImageUtilities.CreateEmptyImage();
                _isEmpty = true;
                ChangeField();
            }
        }

        private void EmbeddedImageSelect_Click(object sender, RoutedEventArgs e)
        {
            if (EmbeddedImageUtilities.SelectImageFile(out var data))
            {
                var img = ImageUtils.BitmapImageFromBytes(data);
                var empty = img == null;
                if (_isEmpty != empty)
                {
                    _isEmpty = empty;

                    if (empty)
                        Image.Source = EmbeddedImageUtilities.CreateEmptyImage();
                    else
                        Image.Source = img;

                    ChangeField();
                }
            }
        }

        protected override void OnPropertyChanged(DependencyPropertyChangedEventArgs e)
        {
            base.OnPropertyChanged(e);
            if(e.Property == IsEnabledProperty)
            {
                Grid.RowDefinitions[1].Height = (bool)e.NewValue
                    ? GridLength.Auto
                    : new GridLength(0);
            }
        }
        protected override bool IsEmpty() => _isEmpty;
    }
}