BeatLyrics/BeatLyrics.Tool/Dialogs/ContextDialog.cs

using System;
using System.Drawing;
using System.Windows.Forms;

namespace BeatLyrics.Tool.Dialogs
{
    internal class ContextDialog
    {
        public static void PopTextBox(Point screenPoint, string orig, Action<DialogResult, string> ret)
        {
            var form = new Form
            {
                FormBorderStyle = FormBorderStyle.None,
                StartPosition = FormStartPosition.Manual,
                Location = screenPoint,
                ShowInTaskbar = false,
            };
            var textBox = new TextBox
            {
                Left = 0,
                Top = 0,
            };

            form.Controls.Add(textBox);

            var closed = false;
            textBox.PreviewKeyDown += delegate (object sender, PreviewKeyDownEventArgs args)
            {
                if (closed) return;
                if (args.KeyCode == Keys.Escape)
                {
                    form.DialogResult = DialogResult.Cancel;
                    form.Close();
                }

                if (args.KeyCode == Keys.Enter)
                {
                    form.DialogResult = DialogResult.OK;
                    form.Close();
                }
            };
            textBox.LostFocus += delegate
            {
                if (closed) return;
                form.DialogResult = DialogResult.OK;
                form.Close();
            };

            form.FormClosed += delegate { closed = true; ret(form.DialogResult, textBox.Text); };

            form.Show();
            form.Height = textBox.Height;
            textBox.Text = orig;
            textBox.SelectAll();
            var tw = TextRenderer.MeasureText(orig, textBox.Font).Width;
            if (tw > textBox.Width) textBox.Width = tw;
            form.Width = textBox.Width;
        }
    }
}