More IO events

src/termio/message.zig

@@ -1,8 +1,11 @@
+const std = @import("std");
 const renderer = @import("../renderer.zig");
 const terminal = @import("../terminal/main.zig");
 
 /// The messages that can be sent to an IO thread.
 pub const IO = union(enum) {
+    pub const SmallWriteArray = [22]u8;
+
     /// Resize the window.
     resize: struct {
         grid_size: renderer.GridSize,
@@ -11,7 +14,19 @@ pub const IO = union(enum) {
 
     /// Clear the selection
     clear_selection: void,
-    //
-    // /// Scroll the viewport
-    // scroll_viewport: terminal.Terminal.ScrollViewport,
+
+    /// Scroll the viewport
+    scroll_viewport: terminal.Terminal.ScrollViewport,
+
+    /// Write where the data fits in the union.
+    small_write: struct {
+        data: [22]u8,
+        len: u8,
+    },
 };
+
+test {
+    // Ensure we don't grow our IO message size without explicitly wanting to.
+    const testing = std.testing;
+    try testing.expectEqual(@as(usize, 24), @sizeOf(IO));
+}