TweetDuck/Core/Other/FormMessage.cs

using System;
using System.Drawing;
using System.Windows.Forms;
using TweetDuck.Core.Controls;
using TweetDuck.Core.Utils;

namespace TweetDuck.Core.Other{
    [Flags]
    enum ControlType{
        None = 0,
        Accept = 1, // triggered by pressing enter when a non-button is focused
        Cancel = 2, // triggered by closing the dialog without pressing a button
        Focused = 4 // active control after the dialog is showed
    }

    sealed partial class FormMessage : Form{
        public const string OK = "OK";
        public const string Yes = "Yes";
        public const string No = "No";
        public const string Cancel = "Cancel";
        public const string Retry = "Retry";
        public const string Ignore = "Ignore";
        public const string Exit = "Exit";

        public static bool Information(string caption, string text, string buttonAccept, string buttonCancel = null){
            return Show(caption, text, MessageBoxIcon.Information, buttonAccept, buttonCancel);
        }

        public static bool Warning(string caption, string text, string buttonAccept, string buttonCancel = null){
            return Show(caption, text, MessageBoxIcon.Warning, buttonAccept, buttonCancel);
        }

        public static bool Error(string caption, string text, string buttonAccept, string buttonCancel = null){
            return Show(caption, text, MessageBoxIcon.Error, buttonAccept, buttonCancel);
        }

        public static bool Question(string caption, string text, string buttonAccept, string buttonCancel = null){
            return Show(caption, text, MessageBoxIcon.Question, buttonAccept, buttonCancel);
        }

        public static bool Show(string caption, string text, MessageBoxIcon icon, string button){
            return Show(caption, text, icon, button, null);
        }

        public static bool Show(string caption, string text, MessageBoxIcon icon, string buttonAccept, string buttonCancel){
            using(FormMessage message = new FormMessage(caption, text, icon)){
                if (buttonCancel == null){
                    message.AddButton(buttonAccept, DialogResult.OK, ControlType.Cancel | ControlType.Focused);
                }
                else{
                    message.AddButton(buttonCancel, DialogResult.Cancel, ControlType.Cancel);
                    message.AddButton(buttonAccept, DialogResult.OK, ControlType.Accept | ControlType.Focused);
                }

                return message.ShowDialog() == DialogResult.OK;
            }
        }

        // Instance

        public Button ClickedButton { get; private set; }

        public bool HasIcon => icon != null;
        public int ActionPanelY => panelActions.Location.Y;

        private int ClientWidth{
            get => ClientSize.Width;
            set => ClientSize = new Size(value, ClientSize.Height);
        }

        private int ButtonDistance{
            get => BrowserUtils.Scale(96, dpiScale);
        }

        private readonly Icon icon;
        private readonly bool isReady;
        private readonly float dpiScale;

        private int realFormWidth, minFormWidth;
        private int buttonCount;
        private int prevLabelWidth, prevLabelHeight;
        private bool wasLabelMultiline;

        public FormMessage(string caption, string text, MessageBoxIcon messageIcon){
            InitializeComponent();

            this.dpiScale = this.GetDPIScale();

            this.prevLabelWidth = labelMessage.Width;
            this.prevLabelHeight = labelMessage.Height;
            this.minFormWidth = BrowserUtils.Scale(42, dpiScale);

            switch(messageIcon){
                case MessageBoxIcon.Information:
                    icon = SystemIcons.Information;
                    break;

                case MessageBoxIcon.Warning:
                    icon = SystemIcons.Warning;
                    break;
                    
                case MessageBoxIcon.Error:
                    icon = SystemIcons.Error;
                    break;

                case MessageBoxIcon.Question:
                    icon = SystemIcons.Question;
                    break;

                default:
                    icon = null;
                    labelMessage.Location = new Point(BrowserUtils.Scale(19, dpiScale), labelMessage.Location.Y); // 19 instead of 9 due to larger height
                    break;
            }

            this.isReady = true;

            this.Text = caption;
            this.labelMessage.Text = text.Replace("\r", "").Replace("\n", Environment.NewLine);
        }

        private void FormMessage_SizeChanged(object sender, EventArgs e){
            RecalculateButtonLocation();
        }

        public Button AddButton(string title, ControlType type){
            return AddButton(title, DialogResult.OK, type);
        }

        public Button AddButton(string title, DialogResult result = DialogResult.OK, ControlType type = ControlType.None){
            Button button = new Button{
                Anchor = AnchorStyles.Bottom,
                Font = SystemFonts.MessageBoxFont,
                Location = new Point(0, 12),
                Size = new Size(BrowserUtils.Scale(88, dpiScale), BrowserUtils.Scale(26, dpiScale)),
                TabIndex = 256-buttonCount,
                Text = title,
                UseVisualStyleBackColor = true
            };

            button.Click += (sender, args) => {
                ClickedButton = (Button)sender;
                DialogResult = result;
                Close();
            };

            panelActions.Controls.Add(button);
            ++buttonCount;

            minFormWidth += ButtonDistance;
            ClientWidth = Math.Max(realFormWidth, minFormWidth);
            RecalculateButtonLocation();

            if (type.HasFlag(ControlType.Accept)){
                AcceptButton = button;
            }

            if (type.HasFlag(ControlType.Cancel)){
                CancelButton = button;
            }

            if (type.HasFlag(ControlType.Focused)){
                ActiveControl = button;
            }

            return button;
        }

        public void AddActionControl(Control control){
            panelActions.Controls.Add(control);
            
            control.Size = new Size(BrowserUtils.Scale(control.Width, dpiScale), BrowserUtils.Scale(control.Height, dpiScale));

            minFormWidth += control.Width+control.Margin.Horizontal;
            ClientWidth = Math.Max(realFormWidth, minFormWidth);
        }
        
        private void RecalculateButtonLocation(){
            int dist = ButtonDistance;
            int start = ClientWidth-dist;

            for(int index = 0; index < buttonCount; index++){
                Control control = panelActions.Controls[index];
                control.Location = new Point(start-index*dist, control.Location.Y);
            }
        }

        private void labelMessage_SizeChanged(object sender, EventArgs e){
            if (!isReady){
                return;
            }

            bool isMultiline = labelMessage.Height > labelMessage.MinimumSize.Height;
            int labelOffset = BrowserUtils.Scale(8, dpiScale);

            if (isMultiline && !wasLabelMultiline){
                labelMessage.Location = new Point(labelMessage.Location.X, labelMessage.Location.Y-labelOffset);
                prevLabelHeight += labelOffset;
            }
            else if (!isMultiline && wasLabelMultiline){
                labelMessage.Location = new Point(labelMessage.Location.X, labelMessage.Location.Y+labelOffset);
                prevLabelHeight -= labelOffset;
            }

            realFormWidth = ClientWidth-(icon == null ? BrowserUtils.Scale(50, dpiScale) : 0)+labelMessage.Width-prevLabelWidth;
            ClientWidth = Math.Max(realFormWidth, minFormWidth);
            Height += labelMessage.Height-prevLabelHeight;

            prevLabelWidth = labelMessage.Width;
            prevLabelHeight = labelMessage.Height;
            wasLabelMultiline = isMultiline;
        }

        protected override void OnPaint(PaintEventArgs e){
            if (icon != null){
                e.Graphics.DrawIcon(icon, BrowserUtils.Scale(25, dpiScale), 1+BrowserUtils.Scale(25, dpiScale));
            }

            base.OnPaint(e);
        }
    }
}