XplorePlane/XP.Camera/Calibration/Controls/ImageCanvasControl.xaml.cs

using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;

namespace XP.Camera.Calibration.Controls;

/// <summary>
/// 图像画布控件 - 提供图像显示、缩放、平移功能
/// </summary>
public partial class ImageCanvasControl : UserControl
{
    private Point mouseDownPoint = new Point();

    #region Dependency Properties

    public static readonly DependencyProperty ZoomScaleProperty =
        DependencyProperty.Register("ZoomScale", typeof(double), typeof(ImageCanvasControl), new PropertyMetadata(1.0));

    public static readonly DependencyProperty ZoomCenterProperty =
        DependencyProperty.Register("ZoomCenter", typeof(Point), typeof(ImageCanvasControl), new PropertyMetadata(new Point()));

    public static readonly DependencyProperty PanningOffsetXProperty =
        DependencyProperty.Register("PanningOffsetX", typeof(double), typeof(ImageCanvasControl), new PropertyMetadata(0.0));

    public static readonly DependencyProperty PanningOffsetYProperty =
        DependencyProperty.Register("PanningOffsetY", typeof(double), typeof(ImageCanvasControl), new PropertyMetadata(0.0));

    public static readonly DependencyProperty ReferenceImageProperty =
        DependencyProperty.Register("ReferenceImage", typeof(BitmapSource), typeof(ImageCanvasControl),
            new UIPropertyMetadata(null, ReferenceImageChanged));

    public static readonly DependencyProperty ImageScaleFactorProperty =
        DependencyProperty.Register("ImageScaleFactor", typeof(double), typeof(ImageCanvasControl), new PropertyMetadata(1.0));

    public static readonly DependencyProperty MaxImageWidthProperty =
        DependencyProperty.Register("MaxImageWidth", typeof(int), typeof(ImageCanvasControl), new PropertyMetadata(0));

    public static readonly DependencyProperty MaxImageHeightProperty =
        DependencyProperty.Register("MaxImageHeight", typeof(int), typeof(ImageCanvasControl), new PropertyMetadata(0));

    public static readonly DependencyProperty EnablePanningProperty =
        DependencyProperty.Register("EnablePanning", typeof(bool), typeof(ImageCanvasControl), new PropertyMetadata(true));

    #endregion

    #region Properties

    public double ZoomScale
    {
        get => (double)GetValue(ZoomScaleProperty);
        set => SetValue(ZoomScaleProperty, value);
    }

    public Point ZoomCenter
    {
        get => (Point)GetValue(ZoomCenterProperty);
        set => SetValue(ZoomCenterProperty, value);
    }

    public double PanningOffsetX
    {
        get => (double)GetValue(PanningOffsetXProperty);
        set => SetValue(PanningOffsetXProperty, value);
    }

    public double PanningOffsetY
    {
        get => (double)GetValue(PanningOffsetYProperty);
        set => SetValue(PanningOffsetYProperty, value);
    }

    public BitmapSource? ReferenceImage
    {
        get => (BitmapSource?)GetValue(ReferenceImageProperty);
        set => SetValue(ReferenceImageProperty, value);
    }

    public double ImageScaleFactor
    {
        get => (double)GetValue(ImageScaleFactorProperty);
        set => SetValue(ImageScaleFactorProperty, value);
    }

    public int MaxImageWidth
    {
        get => (int)GetValue(MaxImageWidthProperty);
        set => SetValue(MaxImageWidthProperty, value);
    }

    public int MaxImageHeight
    {
        get => (int)GetValue(MaxImageHeightProperty);
        set => SetValue(MaxImageHeightProperty, value);
    }

    public bool EnablePanning
    {
        get => (bool)GetValue(EnablePanningProperty);
        set => SetValue(EnablePanningProperty, value);
    }

    private Canvas roiCanvas = new Canvas();
    public Canvas RoiCanvas
    {
        get => roiCanvas;
        set => roiCanvas = value;
    }

    #endregion

    #region Events

    public event EventHandler<MouseButtonEventArgs>? CanvasRightMouseUp;
    public event EventHandler<MouseButtonEventArgs>? CanvasRightMouseDown;
    public event EventHandler<MouseButtonEventArgs>? CanvasLeftMouseDown;
    public event EventHandler<MouseEventArgs>? CanvasMouseMove;
    public event EventHandler<MouseWheelEventArgs>? CanvasMouseWheel;

    #endregion

    public ImageCanvasControl()
    {
        InitializeComponent();
    }

    #region Private Methods

    private static void ReferenceImageChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        (d as ImageCanvasControl)?.OnReferenceImageChanged(e.NewValue as BitmapSource);
    }

    private void OnReferenceImageChanged(BitmapSource? bitmapSource)
    {
        if (bitmapSource != null)
        {
            ImageBrush brush = new ImageBrush { ImageSource = bitmapSource, Stretch = Stretch.Uniform };
            RoiCanvas.Background = brush;
            RoiCanvas.Height = bitmapSource.Height;
            RoiCanvas.Width = bitmapSource.Width;
        }
        else
        {
            RoiCanvas.Height = MaxImageHeight > 0 ? MaxImageHeight : 600;
            RoiCanvas.Width = MaxImageWidth > 0 ? MaxImageWidth : 800;
            RoiCanvas.Background = Brushes.LightGray;
        }
    }

    private double CalculateScaleFactor()
    {
        if (ActualWidth <= 0) return 1;
        double scaleFactor = Math.Max(RoiCanvas.Width / ActualWidth, RoiCanvas.Height / ActualHeight);
        if (scaleFactor < 0)
            scaleFactor = Math.Min(RoiCanvas.Width / ActualWidth, RoiCanvas.Height / ActualHeight);
        return scaleFactor;
    }

    #endregion

    #region Event Handlers

    private void Canvas_MouseEnter(object sender, MouseEventArgs e)
    {
        if (e.LeftButton == MouseButtonState.Pressed)
            mouseDownPoint = e.GetPosition(RoiCanvas);
    }

    private void Canvas_MouseMove(object sender, MouseEventArgs e)
    {
        CanvasMouseMove?.Invoke(sender, e);
        if (EnablePanning && e.LeftButton == MouseButtonState.Pressed)
        {
            Point mousePoint = e.GetPosition(RoiCanvas);
            double mouseMoveLength = Point.Subtract(mousePoint, mouseDownPoint).Length;
            if (mouseMoveLength > (10 * CalculateScaleFactor()) / ZoomScale)
            {
                PanningOffsetX += mousePoint.X - mouseDownPoint.X;
                PanningOffsetY += mousePoint.Y - mouseDownPoint.Y;
            }
        }
    }

    private void Canvas_MouseLeftButtonUp(object sender, MouseButtonEventArgs e) { }

    private void Canvas_MouseRightButtonUp(object sender, MouseButtonEventArgs e)
    {
        CanvasRightMouseUp?.Invoke(sender, e);
    }

    private void Canvas_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
    {
        mouseDownPoint = e.GetPosition(RoiCanvas);
        CanvasLeftMouseDown?.Invoke(sender, e);
        if (EnablePanning && e.ClickCount == 2)
        {
            ResetView();
            e.Handled = true;
        }
    }

    private void Canvas_MouseRightButtonDown(object sender, MouseButtonEventArgs e)
    {
        CanvasRightMouseDown?.Invoke(sender, e);
        e.Handled = true;
    }

    private void Adorner_MouseWheel(object sender, MouseWheelEventArgs e)
    {
        CanvasMouseWheel?.Invoke(sender, e);
    }

    private void ContentPresenter_SizeChanged(object sender, SizeChangedEventArgs e)
    {
        ImageScaleFactor = CalculateScaleFactor();
    }

    private void ResetView()
    {
        ZoomScale = 1.0;
        PanningOffsetX = 0.0;
        PanningOffsetY = 0.0;
        ZoomCenter = new Point(0, 0);
    }

    #endregion
}