Better input preview handling

ChatTwo/Ui/InputPreview.cs

@@ -1,8 +1,11 @@
+using System.Numerics;
 using System.Text;
 using ChatTwo.Code;
+using ChatTwo.Resources;
 using ChatTwo.Util;
 using Dalamud.Game.Text;
 using Dalamud.Game.Text.SeStringHandling;
+using Dalamud.Interface.Utility.Raii;
 using Dalamud.Interface.Windowing;
 using ImGuiNET;
 
@@ -12,15 +15,17 @@ public class InputPreview : Window
 {
     private ChatLogWindow LogWindow { get; }
 
-    private float Height;
+    internal float PreviewHeight;
+
+    private int LastLength;
+    private Message? PreviewMessage;
 
     internal InputPreview(ChatLogWindow logWindow) : base("##chat2-inputpreview")
     {
         LogWindow = logWindow;
 
         Flags = ImGuiWindowFlags.NoSavedSettings | ImGuiWindowFlags.NoTitleBar | ImGuiWindowFlags.NoMove |
-                ImGuiWindowFlags.NoResize | ImGuiWindowFlags.NoFocusOnAppearing | ImGuiWindowFlags.NoScrollbar |
-                ImGuiWindowFlags.NoInputs;
+                ImGuiWindowFlags.NoResize | ImGuiWindowFlags.NoFocusOnAppearing | ImGuiWindowFlags.NoScrollbar;
 
         RespectCloseHotkey = false;
         DisableWindowSounds = true;
@@ -32,11 +37,11 @@ public class InputPreview : Window
         var pos = LogWindow.LastWindowPos;
         var size = LogWindow.LastWindowSize;
 
-        Size = size with { Y = Height };
+        Size = size with { Y = PreviewHeight };
 
         var y = Plugin.Config.PreviewPosition switch
         {
-            PreviewPosition.Top => pos.Y - Height,
+            PreviewPosition.Top => pos.Y - PreviewHeight,
             PreviewPosition.Bottom => pos.Y + size.Y,
             _ => throw new ArgumentOutOfRangeException(nameof(Plugin.Config.PreviewPosition), Plugin.Config.PreviewPosition, null)
         };
@@ -52,15 +57,63 @@ public class InputPreview : Window
 
     public override void Draw()
     {
-        var bytes = Encoding.UTF8.GetBytes(LogWindow.Chat.Trim());
-        AutoTranslate.ReplaceWithPayload(Plugin.DataManager, ref bytes);
+        CalculatePreview();
+        DrawPreview();
+    }
 
-        var chunks = ChunkUtil.ToChunks(SeString.Parse(bytes), ChunkSource.Content, ChatType.Say).ToList();
-        var encodedChunks = Message.FakeMessage(chunks, new ChatCode((ushort) XivChatType.Say));
+    internal void CalculatePreview()
+    {
+        // We Pre-draw this once to get the actual height :HideThePain:
+        PreviewHeight = 0;
+        if (!string.IsNullOrEmpty(LogWindow.Chat))
+        {
+            if (PreviewMessage == null || LastLength != LogWindow.Chat.Length)
+            {
+                LastLength = LogWindow.Chat.Length;
 
-        LogWindow.DrawChunks(encodedChunks.Content);
+                var bytes = Encoding.UTF8.GetBytes(LogWindow.Chat.Trim());
+                AutoTranslate.ReplaceWithPayload(ref bytes);
 
-        // WindowPadding applies to top and bottom, so we take it 2 times
-        Height = ImGui.GetCursorPosY() + ImGui.GetStyle().WindowPadding.Y * 2;
+                var chunks = ChunkUtil.ToChunks(SeString.Parse(bytes), ChunkSource.Content, ChatType.Say).ToList();
+                PreviewMessage = Message.FakeMessage(chunks, new ChatCode((ushort)XivChatType.Say));
+                PreviewMessage.DecodeTextParam();
+            }
+
+            var pos = ImGui.GetCursorPos();
+            ImGui.SetCursorPos(new Vector2(-500, -500));
+            var before = ImGui.GetCursorPosY();
+            using (ImRaii.PushStyle(ImGuiStyleVar.ItemSpacing, Vector2.Zero))
+            {
+                ImGui.TextUnformatted(Language.Options_Preview_Header);
+                LogWindow.DrawChunks(PreviewMessage.Content);
+            }
+            var after = ImGui.GetCursorPosY();
+            ImGui.SetCursorPos(pos);
+
+            PreviewHeight = after - before;
+            PreviewHeight += Plugin.Config.PreviewPosition is not PreviewPosition.Inside
+                ? ImGui.GetStyle().WindowPadding.Y * 2
+                : 0;
+        }
+        else
+        {
+            LastLength = 0;
+            PreviewMessage = null;
+        }
+    }
+
+    internal void DrawPreview()
+    {
+        if (PreviewMessage == null)
+            return;
+
+        using (ImRaii.PushStyle(ImGuiStyleVar.ItemSpacing, Vector2.Zero))
+        {
+            ImGui.TextUnformatted(Language.Options_Preview_Header);
+
+            var handler = LogWindow.HandlerLender.Borrow();
+            LogWindow.DrawChunks(PreviewMessage.Content, true, handler);
+            handler.Draw();
+        }
     }
 }