mod(mouse): fix input.Mouse.in method

Pass through mouse events where they actually match the corresponding
`Container`. Adopt mouse event accordingly in `Scrollable` `Element`
trait when passing through the mouse event to the scrollable
`Container`.

src/container.zig

@@ -387,6 +387,10 @@ pub fn Container(comptime Event: type) type {
                         try element.handle(.{ .resize = element_size });
                     }
                 },
+                .mouse => |mouse| if (mouse.in(this.size)) {
+                    try this.element.handle(event);
+                    for (this.elements.items) |*element| try element.handle(event);
+                },
                 else => {
                     try this.element.handle(event);
                     for (this.elements.items) |*element| try element.handle(event);

src/element.zig

@@ -112,6 +112,17 @@ pub fn Scrollable(Event: type) type {
                     // TODO: not just pass through the given size, but rather the size that is necessary for scrollable content
                     try this.container.handle(.{ .resize = size });
                 },
+                .mouse => |mouse| {
+                    std.log.debug("mouse event detected in scrollable element {any}", .{mouse.in(this.size)});
+                    try this.container.handle(.{
+                        .mouse = .{
+                            .col = mouse.col + this.anchor.col,
+                            .row = mouse.row + this.anchor.row,
+                            .button = mouse.button,
+                            .kind = mouse.kind,
+                        },
+                    });
+                },
                 else => try this.container.handle(event),
             }
         }

src/input.zig

@@ -36,8 +36,8 @@ pub const Mouse = packed struct {
     }
 
     pub fn in(this: @This(), size: Size) bool {
-        return this.col >= size.anchor.col and this.col <= size.cols -| size.anchor.col and
-            this.row >= size.anchor.row and this.row <= size.rows -| size.anchor.row;
+        return this.col >= size.anchor.col and this.col <= size.cols + size.anchor.col and
+            this.row >= size.anchor.row and this.row <= size.rows + size.anchor.row;
     }
 };