From ff544140e0a7e697e773cf69a1ffa274da1a0546 Mon Sep 17 00:00:00 2001
From: darkerbit <mail.darkerbit@gmail.com>
Date: Sun, 5 Jun 2022 12:27:46 -0700
Subject: [PATCH] add file drop API

---
 src/Game.cs | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/src/Game.cs b/src/Game.cs
index 40e3fe39..643658c6 100644
--- a/src/Game.cs
+++ b/src/Game.cs
@@ -104,6 +104,17 @@ namespace MoonWorks
 		protected abstract void Update(TimeSpan delta);
 		protected abstract void Draw(double alpha);
 
+		// Called when a file is dropped on the game window.
+		protected virtual void DropFile(string filePath) {}
+
+		/* Required to distinguish between multiple files dropped at once
+		 * vs multiple files dropped one at a time.
+		 *
+		 * Called once for every multi-file drop.
+		 */
+		protected virtual void DropBegin() {}
+		protected virtual void DropComplete() {}
+
 		private void Tick()
 		{
 			AdvanceElapsedTime();
@@ -179,6 +190,18 @@ namespace MoonWorks
 					case SDL.SDL_EventType.SDL_MOUSEWHEEL:
 						Inputs.Mouse.Wheel += _event.wheel.y;
 						break;
+
+					case SDL.SDL_EventType.SDL_DROPBEGIN:
+						DropBegin();
+						break;
+
+					case SDL.SDL_EventType.SDL_DROPCOMPLETE:
+						DropComplete();
+						break;
+
+					case SDL.SDL_EventType.SDL_DROPFILE:
+						HandleFileDrop(_event);
+						break;
 				}
 			}
 		}
@@ -211,6 +234,13 @@ namespace MoonWorks
 			}
 		}
 
+		private unsafe void HandleFileDrop(SDL2.SDL.SDL_Event evt)
+		{
+			// Need to do it this way because SDL2 expects you to free the filename string.
+			string filePath = SDL.UTF8_ToManaged(evt.drop.file, true);
+			DropFile(filePath);
+		}
+
 		private TimeSpan AdvanceElapsedTime()
 		{
 			long currentTicks = gameTimer.Elapsed.Ticks;