Merge 2b67ebf466 into ac2d522415

Dalamud/Interface/Windowing/IWindow.cs

@@ -0,0 +1,216 @@
+using System.Collections.Generic;
+using System.Numerics;
+
+using Dalamud.Bindings.ImGui;
+
+namespace Dalamud.Interface.Windowing;
+
+/// <summary>
+/// Represents a ImGui window for use with the built-in <see cref="WindowSystem"/>.
+/// </summary>
+public interface IWindow
+{
+    /// <summary>
+    /// Gets or sets the namespace of the window.
+    /// </summary>
+    string? Namespace { get; set; }
+
+    /// <summary>
+    /// Gets or sets the name of the window.
+    /// If you have multiple windows with the same name, you will need to
+    /// append an unique ID to it by specifying it after "###" behind the window title.
+    /// </summary>
+    string WindowName { get; set; }
+
+    /// <summary>
+    /// Gets or sets a value indicating whether the window is focused.
+    /// </summary>
+    bool IsFocused { get; set; }
+
+    /// <summary>
+    /// Gets or sets a value indicating whether this window is to be closed with a hotkey, like Escape, and keep game addons open in turn if it is closed.
+    /// </summary>
+    bool RespectCloseHotkey { get; set; }
+
+    /// <summary>
+    /// Gets or sets a value indicating whether this window should not generate sound effects when opening and closing.
+    /// </summary>
+    bool DisableWindowSounds { get; set; }
+
+    /// <summary>
+    /// Gets or sets a value representing the sound effect id to be played when the window is opened.
+    /// </summary>
+    uint OnOpenSfxId { get; set; }
+
+    /// <summary>
+    /// Gets or sets a value representing the sound effect id to be played when the window is closed.
+    /// </summary>
+    uint OnCloseSfxId { get; set; }
+
+    /// <summary>
+    /// Gets or sets a value indicating whether this window should not fade in and out, regardless of the users'
+    /// preference.
+    /// </summary>
+    bool DisableFadeInFadeOut { get; set; }
+
+    /// <summary>
+    /// Gets or sets the position of this window.
+    /// </summary>
+    Vector2? Position { get; set; }
+
+    /// <summary>
+    /// Gets or sets the condition that defines when the position of this window is set.
+    /// </summary>
+    ImGuiCond PositionCondition { get; set; }
+
+    /// <summary>
+    /// Gets or sets the size of the window. The size provided will be scaled by the global scale.
+    /// </summary>
+    Vector2? Size { get; set; }
+
+    /// <summary>
+    /// Gets or sets the condition that defines when the size of this window is set.
+    /// </summary>
+    ImGuiCond SizeCondition { get; set; }
+
+    /// <summary>
+    /// Gets or sets the size constraints of the window. The size constraints provided will be scaled by the global scale.
+    /// </summary>
+    WindowSizeConstraints? SizeConstraints { get; set; }
+
+    /// <summary>
+    /// Gets or sets a value indicating whether this window is collapsed.
+    /// </summary>
+    bool? Collapsed { get; set; }
+
+    /// <summary>
+    /// Gets or sets the condition that defines when the collapsed state of this window is set.
+    /// </summary>
+    ImGuiCond CollapsedCondition { get; set; }
+
+    /// <summary>
+    /// Gets or sets the window flags.
+    /// </summary>
+    ImGuiWindowFlags Flags { get; set; }
+
+    /// <summary>
+    /// Gets or sets a value indicating whether this ImGui window will be forced to stay inside the main game window.
+    /// </summary>
+    bool ForceMainWindow { get; set; }
+
+    /// <summary>
+    /// Gets or sets this window's background alpha value.
+    /// </summary>
+    float? BgAlpha { get; set; }
+
+    /// <summary>
+    /// Gets or sets a value indicating whether this ImGui window should display a close button in the title bar.
+    /// </summary>
+    bool ShowCloseButton { get; set; }
+
+    /// <summary>
+    /// Gets or sets a value indicating whether this window should offer to be pinned via the window's titlebar context menu.
+    /// </summary>
+    bool AllowPinning { get; set; }
+
+    /// <summary>
+    /// Gets or sets a value indicating whether this window should offer to be made click-through via the window's titlebar context menu.
+    /// </summary>
+    bool AllowClickthrough { get; set; }
+
+    /// <summary>
+    /// Gets a value indicating whether this window is pinned.
+    /// </summary>
+    public bool IsPinned { get; set; }
+
+    /// <summary>
+    /// Gets a value indicating whether this window is click-through.
+    /// </summary>
+    public bool IsClickthrough { get; set; }
+
+    /// <summary>
+    /// Gets or sets a list of available title bar buttons.
+    ///
+    /// If <see cref="AllowPinning"/> or <see cref="AllowClickthrough"/> are set to true, and this features is not
+    /// disabled globally by the user, an internal title bar button to manage these is added when drawing, but it will
+    /// not appear in this collection. If you wish to remove this button, set both of these values to false.
+    /// </summary>
+    List<TitleBarButton> TitleBarButtons { get; set; }
+
+    /// <summary>
+    /// Gets or sets a value indicating whether this window will stay open.
+    /// </summary>
+    bool IsOpen { get; set; }
+
+    /// <summary>
+    /// Gets or sets a value indicating whether this window will request focus from the window system next frame.
+    /// </summary>
+    public bool RequestFocus { get; set; }
+
+    /// <summary>
+    /// Toggle window is open state.
+    /// </summary>
+    void Toggle();
+
+    /// <summary>
+    /// Bring this window to the front.
+    /// </summary>
+    void BringToFront();
+
+    /// <summary>
+    /// Code to always be executed before the open-state of the window is checked.
+    /// </summary>
+    void PreOpenCheck();
+
+    /// <summary>
+    /// Additional conditions for the window to be drawn, regardless of its open-state.
+    /// </summary>
+    /// <returns>
+    /// True if the window should be drawn, false otherwise.
+    /// </returns>
+    /// <remarks>
+    /// Not being drawn due to failing this condition will not change focus or trigger OnClose.
+    /// This is checked before PreDraw, but after Update.
+    /// </remarks>
+    bool DrawConditions();
+
+    /// <summary>
+    /// Code to be executed before conditionals are applied and the window is drawn.
+    /// </summary>
+    void PreDraw();
+
+    /// <summary>
+    /// Code to be executed after the window is drawn.
+    /// </summary>
+    void PostDraw();
+
+    /// <summary>
+    /// Code to be executed every time the window renders.
+    /// </summary>
+    /// <remarks>
+    /// In this method, implement your drawing code.
+    /// You do NOT need to ImGui.Begin your window.
+    /// </remarks>
+    void Draw();
+
+    /// <summary>
+    /// Code to be executed when the window is opened.
+    /// </summary>
+    void OnOpen();
+
+    /// <summary>
+    /// Code to be executed when the window is closed.
+    /// </summary>
+    void OnClose();
+
+    /// <summary>
+    /// Code to be executed when the window is safe to be disposed or removed from the window system.
+    /// Doing so in <see cref="IWindow.OnClose"/> may result in animations not playing correctly.
+    /// </summary>
+    void OnSafeToRemove();
+
+    /// <summary>
+    /// Code to be executed every frame, even when the window is collapsed.
+    /// </summary>
+    void Update();
+}

Dalamud/Interface/Windowing/IWindowSystem.cs

@@ -0,0 +1,51 @@
+using System.Collections.Generic;
+
+namespace Dalamud.Interface.Windowing;
+
+/// <summary>
+/// Class running a WindowSystem using <see cref="IWindow"/> implementations to simplify ImGui windowing.
+/// </summary>
+public interface IWindowSystem
+{
+    /// <summary>
+    /// Gets a read-only list of all <see cref="IWindow"/>s in this <see cref="WindowSystem"/>.
+    /// </summary>
+    IReadOnlyList<IWindow> Windows { get; }
+
+    /// <summary>
+    /// Gets a value indicating whether any window in this <see cref="WindowSystem"/> has focus and is
+    /// not marked to be excluded from consideration.
+    /// </summary>
+    bool HasAnyFocus { get; }
+
+    /// <summary>
+    /// Gets or sets the name/ID-space of this <see cref="WindowSystem"/>.
+    /// </summary>
+    string? Namespace { get; set; }
+
+    /// <summary>
+    /// Add a window to this <see cref="WindowSystem"/>.
+    /// The window system doesn't own your window, it just renders it
+    /// You need to store a reference to it to use it later.
+    /// </summary>
+    /// <param name="window">The window to add.</param>
+    void AddWindow(IWindow window);
+
+    /// <summary>
+    /// Remove a window from this <see cref="WindowSystem"/>.
+    /// Will not dispose your window, if it is disposable.
+    /// </summary>
+    /// <param name="window">The window to remove.</param>
+    void RemoveWindow(IWindow window);
+
+    /// <summary>
+    /// Remove all windows from this <see cref="WindowSystem"/>.
+    /// Will not dispose your windows, if they are disposable.
+    /// </summary>
+    void RemoveAllWindows();
+
+    /// <summary>
+    /// Draw all registered windows using ImGui.
+    /// </summary>
+    void Draw();
+}

Dalamud/Interface/Windowing/TitleBarButton.cs

@@ -0,0 +1,45 @@
+using System.Numerics;
+
+using Dalamud.Bindings.ImGui;
+
+namespace Dalamud.Interface.Windowing;
+
+/// <summary>
+/// Structure describing a title bar button.
+/// </summary>
+public class TitleBarButton
+{
+    /// <summary>
+    /// Gets or sets the icon of the button.
+    /// </summary>
+    public FontAwesomeIcon Icon { get; set; }
+
+    /// <summary>
+    /// Gets or sets a vector by which the position of the icon within the button shall be offset.
+    /// Automatically scaled by the global font scale for you.
+    /// </summary>
+    public Vector2 IconOffset { get; set; }
+
+    /// <summary>
+    /// Gets or sets an action that is called when a tooltip shall be drawn.
+    /// May be null if no tooltip shall be drawn.
+    /// </summary>
+    public Action? ShowTooltip { get; set; }
+
+    /// <summary>
+    /// Gets or sets an action that is called when the button is clicked.
+    /// </summary>
+    public Action<ImGuiMouseButton> Click { get; set; }
+
+    /// <summary>
+    /// Gets or sets the priority the button shall be shown in.
+    /// Lower = closer to ImGui default buttons.
+    /// </summary>
+    public int Priority { get; set; }
+
+    /// <summary>
+    /// Gets or sets a value indicating whether the button shall be clickable
+    /// when the respective window is set to clickthrough.
+    /// </summary>
+    public bool AvailableClickthrough { get; set; }
+}

Dalamud/Interface/Windowing/WindowHost.cs

@@ -0,0 +1,721 @@
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Linq;
+using System.Numerics;
+using System.Threading.Tasks;
+
+using CheapLoc;
+using Dalamud.Bindings.ImGui;
+using Dalamud.Game.ClientState.Keys;
+using Dalamud.Interface.Colors;
+using Dalamud.Interface.Components;
+using Dalamud.Interface.Internal;
+using Dalamud.Interface.Textures.Internal;
+using Dalamud.Interface.Textures.TextureWraps;
+using Dalamud.Interface.Utility;
+using Dalamud.Interface.Utility.Internal;
+using Dalamud.Interface.Utility.Raii;
+using Dalamud.Interface.Windowing.Persistence;
+using Dalamud.Logging.Internal;
+
+using FFXIVClientStructs.FFXIV.Client.UI;
+
+namespace Dalamud.Interface.Windowing;
+
+/// <summary>
+/// Base class you can use to implement an ImGui window for use with the built-in <see cref="WindowSystem"/>.
+/// </summary>
+public class WindowHost
+{
+    private const float FadeInOutTime = 0.072f;
+
+    private static readonly ModuleLog Log = new("WindowSystem");
+
+    private static bool wasEscPressedLastFrame = false;
+
+    private bool internalLastIsOpen = false;
+    private bool didPushInternalAlpha = false;
+    private float? internalAlpha = null;
+
+    private bool hasInitializedFromPreset = false;
+    private PresetModel.PresetWindow? presetWindow;
+    private bool presetDirty = false;
+
+    private bool pushedFadeInAlpha = false;
+    private float fadeInTimer = 0f;
+    private float fadeOutTimer = 0f;
+    private IDrawListTextureWrap? fadeOutTexture = null;
+    private Vector2 fadeOutSize = Vector2.Zero;
+    private Vector2 fadeOutOrigin = Vector2.Zero;
+
+    private bool hasError = false;
+    private Exception? lastError;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="WindowHost"/> class.
+    /// </summary>
+    /// <param name="window">A plugin provided window.</param>
+    internal WindowHost(IWindow window)
+    {
+        this.Window = window;
+    }
+
+    /// <summary>
+    /// Flags to control window behavior.
+    /// </summary>
+    [Flags]
+    internal enum WindowDrawFlags
+    {
+        /// <summary>
+        /// Nothing.
+        /// </summary>
+        None = 0,
+
+        /// <summary>
+        /// Enable window opening/closing sound effects.
+        /// </summary>
+        UseSoundEffects = 1 << 0,
+
+        /// <summary>
+        /// Hook into the game's focus management.
+        /// </summary>
+        UseFocusManagement = 1 << 1,
+
+        /// <summary>
+        /// Enable the built-in "additional options" menu on the title bar.
+        /// </summary>
+        UseAdditionalOptions = 1 << 2,
+
+        /// <summary>
+        /// Do not draw non-critical animations.
+        /// </summary>
+        IsReducedMotion = 1 << 3,
+    }
+
+    /// <summary>
+    /// Gets or sets the backing window provided by the plugin.
+    /// </summary>
+    public IWindow Window { get; set; }
+
+    private bool CanShowCloseButton => this.Window.ShowCloseButton && !this.Window.IsClickthrough;
+
+    /// <summary>
+    /// Draw the window via ImGui.
+    /// </summary>
+    /// <param name="internalDrawFlags">Flags controlling window behavior.</param>
+    /// <param name="persistence">Handler for window persistence data.</param>
+    internal void DrawInternal(WindowDrawFlags internalDrawFlags, WindowSystemPersistence? persistence)
+    {
+        this.Window.PreOpenCheck();
+        var doFades = !internalDrawFlags.HasFlag(WindowDrawFlags.IsReducedMotion) && !this.Window.DisableFadeInFadeOut;
+
+        if (!this.Window.IsOpen)
+        {
+            if (this.Window.IsOpen != this.internalLastIsOpen)
+            {
+                this.internalLastIsOpen = this.Window.IsOpen;
+                this.Window.OnClose();
+
+                this.Window.IsFocused = false;
+
+                if (internalDrawFlags.HasFlag(WindowDrawFlags.UseSoundEffects) && !this.Window.DisableWindowSounds)
+                    UIGlobals.PlaySoundEffect(this.Window.OnCloseSfxId);
+            }
+
+            if (this.fadeOutTexture != null)
+            {
+                this.fadeOutTimer -= ImGui.GetIO().DeltaTime;
+                if (this.fadeOutTimer <= 0f)
+                {
+                    this.fadeOutTexture.Dispose();
+                    this.fadeOutTexture = null;
+                    this.Window.OnSafeToRemove();
+                }
+                else
+                {
+                    this.DrawFakeFadeOutWindow();
+                }
+            }
+
+            this.fadeInTimer = doFades ? 0f : FadeInOutTime;
+            return;
+        }
+
+        this.fadeInTimer += ImGui.GetIO().DeltaTime;
+        if (this.fadeInTimer > FadeInOutTime)
+            this.fadeInTimer = FadeInOutTime;
+
+        this.Window.Update();
+        if (!this.Window.DrawConditions())
+            return;
+
+        var hasNamespace = !string.IsNullOrEmpty(this.Window.Namespace);
+
+        if (hasNamespace)
+            ImGui.PushID(this.Window.Namespace);
+
+        this.PreHandlePreset(persistence);
+
+        if (this.internalLastIsOpen != this.Window.IsOpen && this.Window.IsOpen)
+        {
+            this.internalLastIsOpen = this.Window.IsOpen;
+            this.Window.OnOpen();
+
+            if (internalDrawFlags.HasFlag(WindowDrawFlags.UseSoundEffects) && !this.Window.DisableWindowSounds)
+                UIGlobals.PlaySoundEffect(this.Window.OnOpenSfxId);
+        }
+
+        // TODO: We may have to allow for windows to configure if they should fade
+        if (this.internalAlpha.HasValue)
+        {
+            ImGui.PushStyleVar(ImGuiStyleVar.Alpha, this.internalAlpha.Value);
+            this.didPushInternalAlpha = true;
+        }
+
+        this.Window.PreDraw();
+        this.ApplyConditionals();
+
+        if (this.Window.ForceMainWindow)
+            ImGuiHelpers.ForceNextWindowMainViewport();
+
+        var wasFocused = this.Window.IsFocused;
+        if (wasFocused)
+        {
+            var style = ImGui.GetStyle();
+            var focusedHeaderColor = style.Colors[(int)ImGuiCol.TitleBgActive];
+            ImGui.PushStyleColor(ImGuiCol.TitleBgCollapsed, focusedHeaderColor);
+        }
+
+        if (this.Window.RequestFocus)
+        {
+            ImGui.SetNextWindowFocus();
+            this.Window.RequestFocus = false;
+        }
+
+        var flags = this.Window.Flags;
+
+        if (this.Window.IsPinned || this.Window.IsClickthrough)
+            flags |= ImGuiWindowFlags.NoMove | ImGuiWindowFlags.NoResize;
+
+        if (this.Window.IsClickthrough)
+            flags |= ImGuiWindowFlags.NoInputs | ImGuiWindowFlags.NoNav | ImGuiWindowFlags.NoCollapse | ImGuiWindowFlags.NoScrollWithMouse | ImGuiWindowFlags.NoMouseInputs;
+
+        var isWindowOpen = this.Window.IsOpen;
+
+        if (this.CanShowCloseButton ? ImGui.Begin(this.Window.WindowName, ref isWindowOpen, flags) : ImGui.Begin(this.Window.WindowName, flags))
+        {
+            if (this.Window.IsOpen != isWindowOpen)
+            {
+                this.Window.IsOpen = isWindowOpen;
+            }
+
+            var context = ImGui.GetCurrentContext();
+            if (!context.IsNull)
+            {
+                ImGuiP.GetCurrentWindow().InheritNoInputs = this.Window.IsClickthrough;
+            }
+
+            // Not supported yet on non-main viewports
+            if ((this.Window.IsPinned || this.Window.IsClickthrough || this.internalAlpha.HasValue) &&
+                ImGui.GetWindowViewport().ID != ImGui.GetMainViewport().ID)
+            {
+                this.internalAlpha = null;
+                this.Window.IsPinned = false;
+                this.Window.IsClickthrough = false;
+                this.presetDirty = true;
+            }
+
+            // Draw the actual window contents
+            if (this.hasError)
+            {
+                this.DrawErrorMessage();
+            }
+            else
+            {
+                // Draw the actual window contents
+                try
+                {
+                    this.Window.Draw();
+                }
+                catch (Exception ex)
+                {
+                    Log.Error(ex, "Error during Draw(): {WindowName}", this.Window.WindowName);
+
+                    this.hasError = true;
+                    this.lastError = ex;
+                }
+            }
+        }
+
+        const string additionsPopupName = "WindowSystemContextActions";
+        var flagsApplicableForTitleBarIcons = !flags.HasFlag(ImGuiWindowFlags.NoDecoration) &&
+                                              !flags.HasFlag(ImGuiWindowFlags.NoTitleBar);
+        var showAdditions = (this.Window.AllowPinning || this.Window.AllowClickthrough) &&
+                            internalDrawFlags.HasFlag(WindowDrawFlags.UseAdditionalOptions) &&
+                            flagsApplicableForTitleBarIcons;
+        var printWindow = false;
+        if (showAdditions)
+        {
+            ImGui.PushStyleVar(ImGuiStyleVar.Alpha, 1f);
+
+            if (ImGui.BeginPopup(additionsPopupName, ImGuiWindowFlags.NoMove))
+            {
+                var isAvailable = ImGuiHelpers.CheckIsWindowOnMainViewport();
+
+                if (!isAvailable)
+                    ImGui.BeginDisabled();
+
+                if (this.Window.IsClickthrough)
+                    ImGui.BeginDisabled();
+
+                if (this.Window.AllowPinning)
+                {
+                    var showAsPinned = this.Window.IsPinned || this.Window.IsClickthrough;
+                    if (ImGui.Checkbox(Loc.Localize("WindowSystemContextActionPin", "Pin Window"), ref showAsPinned))
+                    {
+                        this.Window.IsPinned = showAsPinned;
+                        this.presetDirty = true;
+                    }
+
+                    ImGuiComponents.HelpMarker(
+                        Loc.Localize("WindowSystemContextActionPinHint", "Pinned windows will not move or resize when you click and drag them, nor will they close when escape is pressed."));
+                }
+
+                if (this.Window.IsClickthrough)
+                    ImGui.EndDisabled();
+
+                if (this.Window.AllowClickthrough)
+                {
+                    var isClickthrough = this.Window.IsClickthrough;
+                    if (ImGui.Checkbox(
+                            Loc.Localize("WindowSystemContextActionClickthrough", "Make clickthrough"),
+                            ref isClickthrough))
+                    {
+                        this.Window.IsClickthrough = isClickthrough;
+                        this.presetDirty = true;
+                    }
+
+                    ImGuiComponents.HelpMarker(
+                        Loc.Localize("WindowSystemContextActionClickthroughHint", "Clickthrough windows will not receive mouse input, move or resize. They are completely inert."));
+                }
+
+                var alpha = (this.internalAlpha ?? ImGui.GetStyle().Alpha) * 100f;
+                if (ImGui.SliderFloat(Loc.Localize("WindowSystemContextActionAlpha", "Opacity"), ref alpha, 20f,
+                                      100f))
+                {
+                    this.internalAlpha = Math.Clamp(alpha / 100f, 0.2f, 1f);
+                    this.presetDirty = true;
+                }
+
+                ImGui.SameLine();
+                if (ImGui.Button(Loc.Localize("WindowSystemContextActionReset", "Reset")))
+                {
+                    this.internalAlpha = null;
+                    this.presetDirty = true;
+                }
+
+                if (isAvailable)
+                {
+                    ImGui.TextColored(ImGuiColors.DalamudGrey,
+                                      Loc.Localize("WindowSystemContextActionClickthroughDisclaimer",
+                                                   "Open this menu again by clicking the three dashes to disable clickthrough."));
+                }
+                else
+                {
+                    ImGui.TextColored(ImGuiColors.DalamudGrey,
+                                      Loc.Localize("WindowSystemContextActionViewportDisclaimer",
+                                                   "These features are only available if this window is inside the game window."));
+                }
+
+                if (!isAvailable)
+                    ImGui.EndDisabled();
+
+                if (ImGui.Button(Loc.Localize("WindowSystemContextActionPrintWindow", "Print window")))
+                    printWindow = true;
+
+                ImGui.EndPopup();
+            }
+
+            ImGui.PopStyleVar();
+        }
+
+        unsafe
+        {
+            var window = ImGuiP.GetCurrentWindow();
+
+            ImRect outRect;
+            ImGuiP.TitleBarRect(&outRect, window);
+
+            var additionsButton = new TitleBarButton
+            {
+                Icon = FontAwesomeIcon.Bars,
+                IconOffset = new Vector2(2.5f, 1),
+                Click = _ =>
+                {
+                    this.Window.IsClickthrough = false;
+                    this.presetDirty = false;
+                    ImGui.OpenPopup(additionsPopupName);
+                },
+                Priority = int.MinValue,
+                AvailableClickthrough = true,
+            };
+
+            if (flagsApplicableForTitleBarIcons)
+            {
+                this.DrawTitleBarButtons(window, flags, outRect,
+                                         showAdditions
+                                             ? this.Window.TitleBarButtons.Append(additionsButton)
+                                             : this.Window.TitleBarButtons);
+            }
+        }
+
+        if (wasFocused)
+        {
+            ImGui.PopStyleColor();
+        }
+
+        this.Window.IsFocused = ImGui.IsWindowFocused(ImGuiFocusedFlags.RootAndChildWindows);
+
+        if (internalDrawFlags.HasFlag(WindowDrawFlags.UseFocusManagement) && !this.Window.IsPinned)
+        {
+            var escapeDown = Service<KeyState>.Get()[VirtualKey.ESCAPE];
+            if (escapeDown && this.Window.IsFocused && !wasEscPressedLastFrame && this.Window.RespectCloseHotkey)
+            {
+                this.Window.IsOpen = false;
+                wasEscPressedLastFrame = true;
+            }
+            else if (!escapeDown && wasEscPressedLastFrame)
+            {
+                wasEscPressedLastFrame = false;
+            }
+        }
+
+        this.fadeOutSize = ImGui.GetWindowSize();
+        this.fadeOutOrigin = ImGui.GetWindowPos();
+        var isCollapsed = ImGui.IsWindowCollapsed();
+        var isDocked = ImGui.IsWindowDocked();
+
+        ImGui.End();
+
+        if (this.pushedFadeInAlpha)
+        {
+            ImGui.PopStyleVar();
+            this.pushedFadeInAlpha = false;
+        }
+
+        // TODO: No fade-out if the window is collapsed. We could do this if we knew the "FullSize" of the window
+        // from the internal ImGuiWindow, but I don't want to mess with that here for now. We can do this a lot
+        // easier with the new bindings.
+        // TODO: No fade-out if docking is enabled and the window is docked, since this makes them "unsnap".
+        // Ideally we should get rid of this "fake window" thing and just insert a new drawlist at the correct spot.
+        if (!this.Window.IsOpen && this.fadeOutTexture == null && doFades && !isCollapsed && !isDocked)
+        {
+            this.fadeOutTexture = Service<TextureManager>.Get().CreateDrawListTexture(
+                "WindowFadeOutTexture");
+            Log.Verbose("Attempting to fade out {WindowName}", this.Window.WindowName);
+            this.fadeOutTexture.ResizeAndDrawWindow(this.Window.WindowName, Vector2.One);
+            this.fadeOutTimer = FadeInOutTime;
+        }
+
+        if (printWindow)
+        {
+            var tex = Service<TextureManager>.Get().CreateDrawListTexture(
+                Loc.Localize("WindowSystemContextActionPrintWindow", "Print window"));
+            tex.ResizeAndDrawWindow(this.Window.WindowName, Vector2.One);
+            _ = Service<DevTextureSaveMenu>.Get().ShowTextureSaveMenuAsync(
+                this.Window.WindowName,
+                this.Window.WindowName,
+                Task.FromResult<IDalamudTextureWrap>(tex));
+        }
+
+        if (this.didPushInternalAlpha)
+        {
+            ImGui.PopStyleVar();
+            this.didPushInternalAlpha = false;
+        }
+
+        this.Window.PostDraw();
+
+        this.PostHandlePreset(persistence);
+
+        if (hasNamespace)
+            ImGui.PopID();
+    }
+
+    private unsafe void ApplyConditionals()
+    {
+        if (this.Window.Position.HasValue)
+        {
+            var pos = this.Window.Position.Value;
+
+            if (this.Window.ForceMainWindow)
+                pos += ImGuiHelpers.MainViewport.Pos;
+
+            ImGui.SetNextWindowPos(pos, this.Window.PositionCondition);
+        }
+
+        if (this.Window.Size.HasValue)
+        {
+            ImGui.SetNextWindowSize(this.Window.Size.Value * ImGuiHelpers.GlobalScale, this.Window.SizeCondition);
+        }
+
+        if (this.Window.Collapsed.HasValue)
+        {
+            ImGui.SetNextWindowCollapsed(this.Window.Collapsed.Value, this.Window.CollapsedCondition);
+        }
+
+        if (this.Window.SizeConstraints.HasValue)
+        {
+            var (min, max) = this.GetValidatedConstraints(this.Window.SizeConstraints.Value);
+            ImGui.SetNextWindowSizeConstraints(
+                min * ImGuiHelpers.GlobalScale,
+                max * ImGuiHelpers.GlobalScale);
+        }
+
+        var maxBgAlpha = this.internalAlpha ?? this.Window.BgAlpha;
+        var fadeInAlpha = this.fadeInTimer / FadeInOutTime;
+        if (fadeInAlpha < 1f)
+        {
+            maxBgAlpha = maxBgAlpha.HasValue ?
+                             Math.Clamp(maxBgAlpha.Value * fadeInAlpha, 0f, 1f) :
+                             (*ImGui.GetStyleColorVec4(ImGuiCol.WindowBg)).W * fadeInAlpha;
+            ImGui.PushStyleVar(ImGuiStyleVar.Alpha, ImGui.GetStyle().Alpha * fadeInAlpha);
+            this.pushedFadeInAlpha = true;
+        }
+
+        if (maxBgAlpha.HasValue)
+        {
+            ImGui.SetNextWindowBgAlpha(maxBgAlpha.Value);
+        }
+    }
+
+    private (Vector2 Min, Vector2 Max) GetValidatedConstraints(WindowSizeConstraints constraints)
+    {
+        var min = constraints.MinimumSize;
+        var max = constraints.MaximumSize;
+
+        // If max < min, treat as "no constraint" (float.MaxValue)
+        if (max.X < min.X || max.Y < min.Y)
+            max = new Vector2(float.MaxValue);
+
+        return (min, max);
+    }
+
+    private void PreHandlePreset(WindowSystemPersistence? persistence)
+    {
+        if (persistence == null || this.hasInitializedFromPreset)
+            return;
+
+        var id = ImGui.GetID(this.Window.WindowName);
+        this.presetWindow = persistence.GetWindow(id);
+
+        this.hasInitializedFromPreset = true;
+
+        // Fresh preset - don't apply anything
+        if (this.presetWindow == null)
+        {
+            this.presetWindow = new PresetModel.PresetWindow();
+            this.presetDirty = true;
+            return;
+        }
+
+        this.Window.IsPinned = this.presetWindow.IsPinned;
+        this.Window.IsClickthrough = this.presetWindow.IsClickThrough;
+        this.internalAlpha = this.presetWindow.Alpha;
+    }
+
+    private void PostHandlePreset(WindowSystemPersistence? persistence)
+    {
+        if (persistence == null)
+            return;
+
+        Debug.Assert(this.presetWindow != null, "this.presetWindow != null");
+
+        if (this.presetDirty)
+        {
+            this.presetWindow.IsPinned = this.Window.IsPinned;
+            this.presetWindow.IsClickThrough = this.Window.IsClickthrough;
+            this.presetWindow.Alpha = this.internalAlpha;
+
+            var id = ImGui.GetID(this.Window.WindowName);
+            persistence.SaveWindow(id, this.presetWindow!);
+            this.presetDirty = false;
+
+            Log.Verbose("Saved preset for {WindowName}", this.Window.WindowName);
+        }
+    }
+
+    private unsafe void DrawTitleBarButtons(ImGuiWindowPtr window, ImGuiWindowFlags flags, ImRect titleBarRect, IEnumerable<TitleBarButton> buttons)
+    {
+        ImGui.PushClipRect(ImGui.GetWindowPos(), ImGui.GetWindowPos() + ImGui.GetWindowSize(), false);
+
+        var style = ImGui.GetStyle();
+        var fontSize = ImGui.GetFontSize();
+        var drawList = ImGui.GetWindowDrawList();
+
+        var padR = 0f;
+        var buttonSize = ImGui.GetFontSize();
+
+        var numNativeButtons = 0;
+        if (this.CanShowCloseButton)
+            numNativeButtons++;
+
+        if (!flags.HasFlag(ImGuiWindowFlags.NoCollapse) && style.WindowMenuButtonPosition == ImGuiDir.Right)
+            numNativeButtons++;
+
+        // If there are no native buttons, pad from the right to make some space
+        if (numNativeButtons == 0)
+            padR += style.FramePadding.X;
+
+        // Pad to the left, to get out of the way of the native buttons
+        padR += numNativeButtons * (buttonSize + style.ItemInnerSpacing.X);
+
+        Vector2 GetCenter(ImRect rect) => new((rect.Min.X + rect.Max.X) * 0.5f, (rect.Min.Y + rect.Max.Y) * 0.5f);
+
+        var numButtons = 0;
+        bool DrawButton(TitleBarButton button, Vector2 pos)
+        {
+            var id = ImGui.GetID($"###CustomTbButton{numButtons}");
+            numButtons++;
+
+            var max = pos + new Vector2(fontSize, fontSize);
+            ImRect bb = new(pos, max);
+            var isClipped = !ImGuiP.ItemAdd(bb, id, null, 0);
+            bool hovered, held;
+            var pressed = false;
+
+            if (this.Window.IsClickthrough)
+            {
+                hovered = false;
+                held = false;
+
+                // ButtonBehavior does not function if the window is clickthrough, so we have to do it ourselves
+                if (ImGui.IsMouseHoveringRect(pos, max))
+                {
+                    hovered = true;
+
+                    // We can't use ImGui native functions here, because they don't work with clickthrough
+                    if ((global::Windows.Win32.PInvoke.GetKeyState((int)VirtualKey.LBUTTON) & 0x8000) != 0)
+                    {
+                        held = true;
+                        pressed = true;
+                    }
+                }
+            }
+            else
+            {
+                pressed = ImGuiP.ButtonBehavior(bb, id, &hovered, &held, ImGuiButtonFlags.None);
+            }
+
+            if (isClipped)
+                return pressed;
+
+            // Render
+            var bgCol = ImGui.GetColorU32((held && hovered) ? ImGuiCol.ButtonActive : hovered ? ImGuiCol.ButtonHovered : ImGuiCol.Button);
+            var textCol = ImGui.GetColorU32(ImGuiCol.Text);
+            if (hovered || held)
+                drawList.AddCircleFilled(GetCenter(bb) + new Vector2(0.0f, -0.5f), (fontSize * 0.5f) + 1.0f, bgCol);
+
+            var offset = button.IconOffset * ImGuiHelpers.GlobalScale;
+            drawList.AddText(InterfaceManager.IconFont, (float)(fontSize * 0.8), new Vector2(bb.Min.X + offset.X, bb.Min.Y + offset.Y), textCol, button.Icon.ToIconString());
+
+            if (hovered)
+                button.ShowTooltip?.Invoke();
+
+            // Switch to moving the window after mouse is moved beyond the initial drag threshold
+            if (ImGui.IsItemActive() && ImGui.IsMouseDragging(ImGuiMouseButton.Left) && !this.Window.IsClickthrough)
+                ImGuiP.StartMouseMovingWindow(window);
+
+            return pressed;
+        }
+
+        foreach (var button in buttons.OrderBy(x => x.Priority))
+        {
+            if (this.Window.IsClickthrough && !button.AvailableClickthrough)
+                return;
+
+            Vector2 position = new(titleBarRect.Max.X - padR - buttonSize, titleBarRect.Min.Y + style.FramePadding.Y);
+            padR += buttonSize + style.ItemInnerSpacing.X;
+
+            if (DrawButton(button, position))
+                button.Click?.Invoke(ImGuiMouseButton.Left);
+        }
+
+        ImGui.PopClipRect();
+    }
+
+    private void DrawFakeFadeOutWindow()
+    {
+        // Draw a fake window to fade out, so that the fade out texture stays in the right place in the
+        // focus order
+        ImGui.SetNextWindowPos(this.fadeOutOrigin);
+        ImGui.SetNextWindowSize(this.fadeOutSize);
+
+        using var style = ImRaii.PushStyle(ImGuiStyleVar.WindowPadding, Vector2.Zero);
+        style.Push(ImGuiStyleVar.WindowBorderSize, 0);
+        style.Push(ImGuiStyleVar.FrameBorderSize, 0);
+
+        const ImGuiWindowFlags flags = ImGuiWindowFlags.NoInputs | ImGuiWindowFlags.NoNav |
+                                           ImGuiWindowFlags.NoScrollWithMouse | ImGuiWindowFlags.NoMouseInputs |
+                                           ImGuiWindowFlags.NoDecoration | ImGuiWindowFlags.NoBackground;
+        if (ImGui.Begin(this.Window.WindowName, flags))
+        {
+            var dl = ImGui.GetWindowDrawList();
+            dl.AddImage(
+                this.fadeOutTexture!.Handle,
+                this.fadeOutOrigin,
+                this.fadeOutOrigin + this.fadeOutSize,
+                Vector2.Zero,
+                Vector2.One,
+                ImGui.ColorConvertFloat4ToU32(new(1f, 1f, 1f, Math.Clamp(this.fadeOutTimer / FadeInOutTime, 0f, 1f))));
+        }
+
+        ImGui.End();
+    }
+
+    private void DrawErrorMessage()
+    {
+        // TODO: Once window systems are services, offer to reload the plugin
+        ImGui.TextColoredWrapped(ImGuiColors.DalamudRed,Loc.Localize("WindowSystemErrorOccurred", "An error occurred while rendering this window. Please contact the developer for details."));
+
+        ImGuiHelpers.ScaledDummy(5);
+
+        if (ImGui.Button(Loc.Localize("WindowSystemErrorRecoverButton", "Attempt to retry")))
+        {
+            this.hasError = false;
+            this.lastError = null;
+        }
+
+        ImGui.SameLine();
+
+        if (ImGui.Button(Loc.Localize("WindowSystemErrorClose", "Close Window")))
+        {
+            this.Window.IsOpen = false;
+            this.hasError = false;
+            this.lastError = null;
+        }
+
+        ImGuiHelpers.ScaledDummy(10);
+
+        if (this.lastError != null)
+        {
+            using var child = ImRaii.Child("##ErrorDetails", new Vector2(0, 200 * ImGuiHelpers.GlobalScale), true);
+            using (ImRaii.PushColor(ImGuiCol.Text, ImGuiColors.DalamudGrey))
+            {
+                ImGui.TextWrapped(Loc.Localize("WindowSystemErrorDetails", "Error Details:"));
+                ImGui.Separator();
+                ImGui.TextWrapped(this.lastError.ToString());
+            }
+
+            var childWindowSize = ImGui.GetWindowSize();
+            var copyText = Loc.Localize("WindowSystemErrorCopy", "Copy");
+            var buttonWidth = ImGuiComponents.GetIconButtonWithTextWidth(FontAwesomeIcon.Copy, copyText);
+            ImGui.SetCursorPos(new Vector2(childWindowSize.X - buttonWidth - ImGui.GetStyle().FramePadding.X,
+                                           ImGui.GetStyle().FramePadding.Y));
+            if (ImGuiComponents.IconButtonWithText(FontAwesomeIcon.Copy, copyText))
+            {
+                ImGui.SetClipboardText(this.lastError.ToString());
+            }
+        }
+    }
+}

Dalamud/Interface/Windowing/WindowSizeConstraints.cs

@@ -0,0 +1,26 @@
+using System.Numerics;
+
+namespace Dalamud.Interface.Windowing;
+
+/// <summary>
+/// Structure detailing the size constraints of a window.
+/// </summary>
+public struct WindowSizeConstraints
+{
+    /// <summary>
+    /// Initializes a new instance of the <see cref="WindowSizeConstraints"/> struct.
+    /// </summary>
+    public WindowSizeConstraints()
+    {
+    }
+
+    /// <summary>
+    /// Gets or sets the minimum size of the window.
+    /// </summary>
+    public Vector2 MinimumSize { get; set; }
+
+    /// <summary>
+    /// Gets or sets the maximum size of the window.
+    /// </summary>
+    public Vector2 MaximumSize { get; set; }
+}

Dalamud/Interface/Windowing/WindowSystem.cs

@@ -8,14 +8,12 @@ using Serilog;
 
 namespace Dalamud.Interface.Windowing;
 
-/// <summary>
-/// Class running a WindowSystem using <see cref="Window"/> implementations to simplify ImGui windowing.
-/// </summary>
-public class WindowSystem
+/// <inheritdoc/>
+public class WindowSystem : IWindowSystem
 {
     private static DateTimeOffset lastAnyFocus;
 
-    private readonly List<Window> windows = new();
+    private readonly List<WindowHost> windows = new();
 
     private string lastFocusedWindowName = string.Empty;
 
@@ -29,7 +27,7 @@ public class WindowSystem
     }
 
     /// <summary>
-    /// Gets a value indicating whether any <see cref="WindowSystem"/> contains any <see cref="Window"/>
+    /// Gets a value indicating whether any <see cref="WindowSystem"/> contains any <see cref="IWindow"/>
     /// that has focus and is not marked to be excluded from consideration.
     /// </summary>
     public static bool HasAnyWindowSystemFocus { get; internal set; } = false;
@@ -44,20 +42,13 @@ public class WindowSystem
     /// </summary>
     public static TimeSpan TimeSinceLastAnyFocus => DateTimeOffset.Now - lastAnyFocus;
 
-    /// <summary>
-    /// Gets a read-only list of all <see cref="Window"/>s in this <see cref="WindowSystem"/>.
-    /// </summary>
-    public IReadOnlyList<Window> Windows => this.windows;
+    /// <inheritdoc/>
+    public IReadOnlyList<IWindow> Windows => this.windows.Select(c => c.Window).ToList();
 
-    /// <summary>
-    /// Gets a value indicating whether any window in this <see cref="WindowSystem"/> has focus and is
-    /// not marked to be excluded from consideration.
-    /// </summary>
+    /// <inheritdoc/>
     public bool HasAnyFocus { get; private set; }
 
-    /// <summary>
-    /// Gets or sets the name/ID-space of this <see cref="WindowSystem"/>.
-    /// </summary>
+    /// <inheritdoc/>
     public string? Namespace { get; set; }
 
     /// <summary>
@@ -66,42 +57,28 @@ public class WindowSystem
     /// </summary>
     internal static bool ShouldInhibitAtkCloseEvents { get; set; }
 
-    /// <summary>
-    /// Add a window to this <see cref="WindowSystem"/>.
-    /// The window system doesn't own your window, it just renders it
-    /// You need to store a reference to it to use it later.
-    /// </summary>
-    /// <param name="window">The window to add.</param>
-    public void AddWindow(Window window)
+    /// <inheritdoc/>
+    public void AddWindow(IWindow window)
     {
-        if (this.windows.Any(x => x.WindowName == window.WindowName))
+        if (this.windows.Any(x => x.Window.WindowName == window.WindowName))
             throw new ArgumentException("A window with this name/ID already exists.");
 
-        this.windows.Add(window);
+        this.windows.Add(new WindowHost(window));
     }
 
-    /// <summary>
-    /// Remove a window from this <see cref="WindowSystem"/>.
-    /// Will not dispose your window, if it is disposable.
-    /// </summary>
-    /// <param name="window">The window to remove.</param>
-    public void RemoveWindow(Window window)
+    /// <inheritdoc/>
+    public void RemoveWindow(IWindow window)
     {
-        if (!this.windows.Contains(window))
+        if (this.windows.All(c => c.Window != window))
             throw new ArgumentException("This window is not registered on this WindowSystem.");
 
-        this.windows.Remove(window);
+        this.windows.RemoveAll(c => c.Window == window);
     }
 
-    /// <summary>
-    /// Remove all windows from this <see cref="WindowSystem"/>.
-    /// Will not dispose your windows, if they are disposable.
-    /// </summary>
+    /// <inheritdoc/>
     public void RemoveAllWindows() => this.windows.Clear();
 
-    /// <summary>
-    /// Draw all registered windows using ImGui.
-    /// </summary>
+    /// <inheritdoc/>
     public void Draw()
     {
         var hasNamespace = !string.IsNullOrEmpty(this.Namespace);
@@ -113,19 +90,19 @@ public class WindowSystem
         var config = Service<DalamudConfiguration>.GetNullable();
         var persistence = Service<WindowSystemPersistence>.GetNullable();
 
-        var flags = Window.WindowDrawFlags.None;
+        var flags = WindowHost.WindowDrawFlags.None;
 
         if (config?.EnablePluginUISoundEffects ?? false)
-            flags |= Window.WindowDrawFlags.UseSoundEffects;
+            flags |= WindowHost.WindowDrawFlags.UseSoundEffects;
 
         if (config?.EnablePluginUiAdditionalOptions ?? false)
-            flags |= Window.WindowDrawFlags.UseAdditionalOptions;
+            flags |= WindowHost.WindowDrawFlags.UseAdditionalOptions;
 
         if (config?.IsFocusManagementEnabled ?? false)
-            flags |= Window.WindowDrawFlags.UseFocusManagement;
+            flags |= WindowHost.WindowDrawFlags.UseFocusManagement;
 
         if (config?.ReduceMotions ?? false)
-            flags |= Window.WindowDrawFlags.IsReducedMotion;
+            flags |= WindowHost.WindowDrawFlags.IsReducedMotion;
 
         // Shallow clone the list of windows so that we can edit it without modifying it while the loop is iterating
         foreach (var window in this.windows.ToArray())
@@ -136,15 +113,15 @@ public class WindowSystem
             window.DrawInternal(flags, persistence);
         }
 
-        var focusedWindow = this.windows.FirstOrDefault(window => window.IsFocused);
+        var focusedWindow = this.windows.FirstOrDefault(window => window.Window.IsFocused);
         this.HasAnyFocus = focusedWindow != default;
 
         if (this.HasAnyFocus)
         {
-            if (this.lastFocusedWindowName != focusedWindow.WindowName)
+            if (this.lastFocusedWindowName != focusedWindow.Window.WindowName)
             {
-                Log.Verbose($"WindowSystem \"{this.Namespace}\" Window \"{focusedWindow.WindowName}\" has focus now");
-                this.lastFocusedWindowName = focusedWindow.WindowName;
+                Log.Verbose($"WindowSystem \"{this.Namespace}\" Window \"{focusedWindow.Window.WindowName}\" has focus now");
+                this.lastFocusedWindowName = focusedWindow.Window.WindowName;
             }
 
             HasAnyWindowSystemFocus = true;
@@ -161,10 +138,10 @@ public class WindowSystem
             }
         }
 
-        ShouldInhibitAtkCloseEvents |= this.windows.Any(w => w.IsFocused &&
-                                                            w.RespectCloseHotkey &&
-                                                            !w.IsPinned &&
-                                                            !w.IsClickthrough);
+        ShouldInhibitAtkCloseEvents |= this.windows.Any(w => w.Window.IsFocused &&
+                                                            w.Window.RespectCloseHotkey &&
+                                                            !w.Window.IsPinned &&
+                                                            !w.Window.IsClickthrough);
 
         if (hasNamespace)
             ImGui.PopID();