naps2/NAPS2.Sdk/WinForms/FRotate.cs

using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Globalization;
using System.Linq;
using System.Windows.Forms;
using NAPS2.Images;
using NAPS2.Images.Storage;
using NAPS2.Images.Transforms;
using NAPS2.Util;

namespace NAPS2.WinForms
{
    partial class FRotate : ImageForm
    {
        private const int MIN_LINE_DISTANCE = 50;
        private const float LINE_PEN_SIZE = 1;

        private bool guideExists;
        private Point guideStart, guideEnd;

        public FRotate(ImageContext imageContext, BitmapRenderer bitmapRenderer)
            : base(imageContext, bitmapRenderer)
        {
            InitializeComponent();
            txtAngle.Text += '\u00B0';
            ActiveControl = txtAngle;
        }

        public RotationTransform RotationTransform { get; private set; } = new RotationTransform();

        protected override IEnumerable<Transform> Transforms => new[] { RotationTransform };

        protected override PictureBox PictureBox => pictureBox;

        protected override void ResetTransform()
        {
            RotationTransform = new RotationTransform();
            tbAngle.Value = 0;
            txtAngle.Text = (tbAngle.Value / 10.0).ToString("G");
        }

        private void UpdateTransform()
        {
            RotationTransform = new RotationTransform(tbAngle.Value / 10.0);
            UpdatePreviewBox();
        }

        private void txtAngle_TextChanged(object sender, EventArgs e)
        {
            if (double.TryParse(txtAngle.Text.Replace('\u00B0'.ToString(CultureInfo.InvariantCulture), ""), out double valueDouble))
            {
                int value = (int)Math.Round(valueDouble * 10);
                if (value >= tbAngle.Minimum && value <= tbAngle.Maximum)
                {
                    tbAngle.Value = value;
                }
                if (!txtAngle.Text.Contains('\u00B0'))
                {
                    var (ss, sl) = (txtAngle.SelectionStart, txtAngle.SelectionLength);
                    txtAngle.Text += '\u00B0';
                    (txtAngle.SelectionStart, txtAngle.SelectionLength) = (ss, sl);
                }
            }
            UpdateTransform();
        }

        private void tbAngle_Scroll(object sender, EventArgs e)
        {
            txtAngle.Text = (tbAngle.Value / 10.0).ToString("G") + '\u00B0';
            UpdateTransform();
        }

        private void pictureBox_MouseDown(object sender, MouseEventArgs e)
        {
            guideExists = true;
            guideStart = guideEnd = e.Location;
            pictureBox.Invalidate();
        }

        private void pictureBox_MouseUp(object sender, MouseEventArgs e)
        {
            guideExists = false;
            var dx = guideEnd.X - guideStart.X;
            var dy = guideEnd.Y - guideStart.Y;
            var distance = Math.Sqrt(dx * dx + dy * dy);
            if (distance > MIN_LINE_DISTANCE)
            {
                var angle = -Math.Atan2(dy, dx) * 180.0 / Math.PI;
                while (angle > 45.0)
                {
                    angle -= 90.0;
                }
                while (angle < -45.0)
                {
                    angle += 90.0;
                }
                var oldAngle = tbAngle.Value / 10.0;
                var newAngle = angle + oldAngle;
                while (newAngle > 180.0)
                {
                    newAngle -= 360.0;
                }
                while (newAngle < -180.0)
                {
                    newAngle += 360.0;
                }
                tbAngle.Value = (int)Math.Round(newAngle * 10);
                tbAngle_Scroll(null, null);
            }
            pictureBox.Invalidate();
        }

        private void pictureBox_MouseMove(object sender, MouseEventArgs e)
        {
            guideEnd = e.Location;
            pictureBox.Invalidate();
        }

        private void pictureBox_Paint(object sender, PaintEventArgs e)
        {
            if (guideExists)
            {
                var old = e.Graphics.SmoothingMode;
                e.Graphics.SmoothingMode = SmoothingMode.AntiAlias;
                e.Graphics.DrawLine(new Pen(Color.Black, LINE_PEN_SIZE), guideStart, guideEnd);
                e.Graphics.SmoothingMode = old;
            }
        }
    }
}