PDFOffice_Windows_exe/PDF Office/CustomControl/ScanViewControl/CustomPanel.cs

using PDF_Office.Helper;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using System.Windows.Media.Imaging;

namespace PDF_Office.CustomControl.ScanViewControl
{
    class CustomPanel: Panel
    {
        public SolidColorBrush CoverBrush { get; set; } = new SolidColorBrush(Color.FromArgb(0xA0, 0xFF, 0xFF, 0xFF));
        public bool DrawCover { get; set; } = false;

        private WriteableBitmap BackgroundImage = null;
        private int BackgroundWidth = 0;
        private int BackgroundHeight = 0;
        private Point OffsetPos = new Point(0, 0);
        private double ScaleRate = 1;
        private CustomDraw HoverChild = null;
        public TextBlock ParentBlock;
        private int RawWidth = 0;
        private int RawHeight = 0;

        private List<CustomDraw> VisualControlList = new List<CustomDraw>();
        protected override int VisualChildrenCount => VisualControlList.Count;
        protected override Visual GetVisualChild(int index)
        {
            return VisualControlList[index];
        }
        protected override void OnRender(DrawingContext dc)
        {
            Rect drawRect = new Rect(0, 0, ActualWidth, ActualHeight);
            dc.DrawRectangle(Brushes.LightGray, null, drawRect);
            DrawBackground(dc);
        }

        protected override void OnRenderSizeChanged(SizeChangedInfo sizeInfo)
        {
            double scale = Math.Min(sizeInfo.NewSize.Width / BackgroundWidth, sizeInfo.NewSize.Height / BackgroundHeight);
            scale = Math.Min(scale, 1);
            int drawWidth = (int)(scale * BackgroundWidth);
            int drawHeight = (int)(scale * BackgroundHeight);
            if (drawWidth < 10 || drawHeight < 10)
            {
                return;
            }

            int offsetX = (int)((sizeInfo.NewSize.Width - drawWidth) / 2);
            int offsetY = (int)((sizeInfo.NewSize.Height - drawHeight) / 2);
            foreach (CustomDraw drawVisual in VisualControlList)
            {
                Rect paintRect = drawVisual.RawRect;
                drawVisual.PaintRect = new Rect((int)(paintRect.Left * scale + offsetX),
                   (int)(paintRect.Top * scale + offsetY),
                   (int)(paintRect.Width * scale),
                   (int)(paintRect.Height * scale));
                drawVisual.Draw();
            }
        }

        private void DrawBackground(DrawingContext dc)
        {
            if (BackgroundImage != null && BackgroundWidth > 0 && BackgroundHeight > 0)
            {
                double scale = Math.Min(ActualWidth / BackgroundWidth, ActualHeight / BackgroundHeight);
                scale = Math.Min(scale, 1);
                int drawWidth = (int)(scale * BackgroundWidth);
                int drawHeight = (int)(scale * BackgroundHeight);
                if (drawWidth < 10 || drawHeight < 10)
                {
                    return;
                }
                ScaleRate = scale;
                OffsetPos.X = (int)((ActualWidth - drawWidth) / 2);
                OffsetPos.Y = (int)((ActualHeight - drawHeight) / 2);
                Rect drawRect = new Rect(OffsetPos.X, OffsetPos.Y, drawWidth, drawHeight);
                dc.DrawImage(BackgroundImage, drawRect);
                if (DrawCover)
                {
                    dc.DrawRectangle(CoverBrush, null, drawRect);
                }
            }
        }

        private void CleanChild()
        {
            foreach (DrawingVisual child in VisualControlList)
            {
                RemoveLogicalChild(child);
                RemoveVisualChild(child);
            }
            VisualControlList.Clear();
        }

        public void SetBackgroundImage(WriteableBitmap bgImage)
        {
            DrawCover = false;
            BackgroundImage = bgImage;
            BackgroundWidth = 0;
            BackgroundHeight = 0;
            RawWidth = 0;
            RawHeight = 0;
            OffsetPos = new Point(0, 0);
            CleanChild();
            if (BackgroundImage != null && BackgroundImage.PixelHeight > 0 && BackgroundImage.PixelWidth > 0)
            {
                RawWidth = BackgroundImage.PixelWidth;
                RawHeight = BackgroundImage.PixelHeight;
                BackgroundWidth = DpiHelpers.GetDpiUnrelatedNum(BackgroundImage.PixelWidth);
                BackgroundHeight = DpiHelpers.GetDpiUnrelatedNum(BackgroundImage.PixelHeight);
                InvalidateVisual();
            }
        }

        public int GetBackgroundImageWidth()
        {
            if (BackgroundImage != null)
            {
                return RawWidth;
            }
            return 0;
        }

        public int GetBackgroundImageHeight()
        {
            if (BackgroundImage != null)
            {
                return RawHeight;
            }
            return 0;
        }

        public void SetTextsRects(List<KeyValuePair<Rect, string>> textsRect)
        {
            CleanChild();
            foreach (KeyValuePair<Rect, string> textRect in textsRect)
            {
                CustomDraw drawVisual = new CustomDraw();
                drawVisual.PaintText = textRect.Value;
                Rect paintRect = DpiHelpers.GetDpiUnrelatedRect(textRect.Key);
                drawVisual.RawRect = paintRect;
                drawVisual.PaintRect = new Rect((int)(paintRect.Left * ScaleRate + OffsetPos.X),
                    (int)(paintRect.Top * ScaleRate + OffsetPos.Y),
                    (int)(paintRect.Width * ScaleRate),
                    (int)(paintRect.Height * ScaleRate));
                drawVisual.Draw();
                VisualControlList.Add(drawVisual);
                AddLogicalChild(drawVisual);
                AddVisualChild(drawVisual);
            }
        }

        public void RePaint()
        {
            InvalidateVisual();
        }
    }
}