refactor: split every monolithic module into focused submodules

Each source file that had grown beyond a single concern is replaced by an identically-named directory containing focused submodules. `src/event_loop/mod.rs` (878 lines) becomes a directory with clipboard, context_menu, cursor_shape, drag, focus, handlers, invalidation, overlays_reconcile, repeat, run, surface, text_editing, and tooltip. Every widget, input handler, and theme component follows the same split. Public interfaces are unchanged — only the internal file layout moves.
image bumped from 0.25.2 to 0.25.9.

src/widget/viewport/mod.rs

@@ -0,0 +1,109 @@
+// SPDX-License-Identifier: LGPL-2.1-only
+// Copyright (C) 2026 Liberux Labs, S. L. <info@liberux.net>
+
+use crate::render::Canvas;
+use crate::widget::Element;
+
+/// A non-scrollable clipped viewport for revealing only part of a child tree.
+///
+/// Unlike `Scroll`, this widget does not own
+/// any gesture state. It simply renders its child into an off-screen canvas
+/// and blits the result into the allocated rect, clipping anything outside.
+pub struct Viewport<Msg: Clone>
+{
+	/// The child element to render inside the viewport.
+	pub child: Box<Element<Msg>>,
+	/// Optional fixed width in logical pixels. When omitted the
+	/// viewport reports `max_width` as its preferred width — i.e. it
+	/// stretches to fill whatever horizontal slice the parent layout
+	/// gives it. Set explicitly when the viewport has to coexist with
+	/// `flex` siblings (the flex would otherwise lose every pixel to
+	/// the viewport's `max_width` claim) or whenever the inner content
+	/// has its own intrinsic width and the viewport is just a vertical
+	/// clip.
+	pub width: Option<f32>,
+	/// Optional fixed height in logical pixels. When omitted the viewport
+	/// reports the child's natural height.
+	pub height: Option<f32>,
+	/// Logical pixels at the bottom edge that fade to transparent during the
+	/// blit. Zero leaves the bottom hard-edged. Useful for slide-in panels so
+	/// the leading edge of the animation does not knife-cut against the layer
+	/// below it.
+	pub fade_bottom: f32,
+}
+
+impl<Msg: Clone> Viewport<Msg>
+{
+	pub fn new( child: impl Into<Element<Msg>> ) -> Self
+	{
+		Self { child: Box::new( child.into() ), width: None, height: None, fade_bottom: 0.0 }
+	}
+
+	/// Set a fixed viewport width in logical pixels. Mirrors
+	/// [`Self::height`]: with an explicit value the viewport
+	/// reports `w` as its preferred width and the child is laid
+	/// out against `w` rather than the parent-supplied `max_width`.
+	pub fn width( mut self, w: f32 ) -> Self
+	{
+		self.width = Some( w.max( 0.0 ) );
+		self
+	}
+
+	/// Set a fixed viewport height in logical pixels.
+	pub fn height( mut self, h: f32 ) -> Self
+	{
+		self.height = Some( h.max( 0.0 ) );
+		self
+	}
+
+	/// Feather the bottom `px` rows of the viewport so its lower edge dissolves
+	/// to transparent. Drawn by the GLES blit shader as a linear alpha ramp
+	/// over the bottom band; the software backend currently renders a hard
+	/// edge regardless.
+	pub fn fade_bottom( mut self, px: f32 ) -> Self
+	{
+		self.fade_bottom = px.max( 0.0 );
+		self
+	}
+
+	pub fn preferred_size( &self, max_width: f32, canvas: &Canvas ) -> ( f32, f32 )
+	{
+		let inner_w = self.width.unwrap_or( max_width );
+		let child_h = self.child.preferred_size( inner_w, canvas ).1;
+		( self.width.unwrap_or( max_width ), self.height.unwrap_or( child_h ) )
+	}
+
+	/// No-op — rendering is handled by `layout_and_draw` in `draw.rs`.
+	pub fn draw( &self ) {}
+
+	pub( crate ) fn map_msg<U>( self, f: &super::MapFn<Msg, U> ) -> Viewport<U>
+	where
+		U: Clone + 'static,
+		Msg: 'static,
+	{
+		Viewport
+		{
+			child:       Box::new( self.child.map_arc( f ) ),
+			width:       self.width,
+			height:      self.height,
+			fade_bottom: self.fade_bottom,
+		}
+	}
+}
+
+impl<Msg: Clone + 'static> From<Viewport<Msg>> for Element<Msg>
+{
+	fn from( v: Viewport<Msg> ) -> Self
+	{
+		Element::Viewport( v )
+	}
+}
+
+/// Create a clipped viewport wrapping `child`.
+pub fn viewport<Msg: Clone>( child: impl Into<Element<Msg>> ) -> Viewport<Msg>
+{
+	Viewport::new( child )
+}
+
+#[ cfg( test ) ]
+mod tests;

src/widget/viewport/tests.rs

@@ -0,0 +1,75 @@
+// SPDX-License-Identifier: LGPL-2.1-only
+// Copyright (C) 2026 Liberux Labs, S. L. <info@liberux.net>
+
+use super::*;
+use crate::layout::spacer::spacer;
+use crate::render::Canvas;
+
+fn make_canvas() -> Canvas { Canvas::new( 800, 600 ) }
+
+#[ test ]
+fn new_defaults_are_unset_dimensions_and_no_fade()
+{
+	let v = Viewport::<()>::new( spacer() );
+	assert!( v.width.is_none() );
+	assert!( v.height.is_none() );
+	assert_eq!( v.fade_bottom, 0.0 );
+}
+
+#[ test ]
+fn width_builder_clamps_negative_to_zero()
+{
+	let v = Viewport::<()>::new( spacer() ).width( -50.0 );
+	assert_eq!( v.width, Some( 0.0 ) );
+}
+
+#[ test ]
+fn height_builder_clamps_negative_to_zero()
+{
+	let v = Viewport::<()>::new( spacer() ).height( -10.0 );
+	assert_eq!( v.height, Some( 0.0 ) );
+}
+
+#[ test ]
+fn fade_bottom_clamps_negative_to_zero()
+{
+	let v = Viewport::<()>::new( spacer() ).fade_bottom( -1.0 );
+	assert_eq!( v.fade_bottom, 0.0 );
+}
+
+#[ test ]
+fn fade_bottom_accepts_positive_pixel_count()
+{
+	let v = Viewport::<()>::new( spacer() ).fade_bottom( 16.0 );
+	assert_eq!( v.fade_bottom, 16.0 );
+}
+
+#[ test ]
+fn explicit_dimensions_override_child_intrinsic_size()
+{
+	let v = Viewport::<()>::new( spacer().width( 99.0 ).height( 99.0 ) )
+		.width( 200.0 )
+		.height( 80.0 );
+	let canvas = make_canvas();
+	let ( w, h ) = v.preferred_size( 600.0, &canvas );
+	assert_eq!( w, 200.0 );
+	assert_eq!( h,  80.0 );
+}
+
+#[ test ]
+fn unset_width_falls_through_to_max_width()
+{
+	let v = Viewport::<()>::new( spacer().height( 40.0 ) );
+	let canvas = make_canvas();
+	let ( w, _ ) = v.preferred_size( 400.0, &canvas );
+	assert_eq!( w, 400.0 );
+}
+
+#[ test ]
+fn unset_height_falls_through_to_child_intrinsic_height()
+{
+	let v = Viewport::<()>::new( spacer().height( 75.0 ) );
+	let canvas = make_canvas();
+	let ( _, h ) = v.preferred_size( 400.0, &canvas );
+	assert_eq!( h, 75.0 );
+}