First commit. Version 0.1.0

src/draw/chrome.rs

@@ -0,0 +1,102 @@
+// SPDX-License-Identifier: LGPL-2.1-only
+// Copyright (C) 2026 Liberux Labs, S. L. <info@liberux.net>
+
+//! Surface chrome: the client-side title bar and the Wayland input
+//! region. Both are backend-agnostic — the software and GPU draw
+//! paths call them with a `&mut Canvas` / a `&WlSurface` and get back
+//! the geometry they need for hit testing + commit.
+
+use smithay_client_toolkit::compositor::{ CompositorState, Region };
+use smithay_client_toolkit::reexports::client::protocol::wl_surface::WlSurface;
+
+use crate::render::Canvas;
+use crate::types::{ Color, Rect };
+
+/// Paint the client-side title bar (close button, divider, title text).
+///
+/// Returns the close button rect in physical pixels so the caller can
+/// store it for hit testing. Returns `Rect::default()` when `tb_h <=
+/// 0` — overlays / layer-shell surfaces have no title bar.
+pub( crate ) fn draw_titlebar( canvas: &mut Canvas, title: &str, pw: u32, tb_h: f32, sf: f32 ) -> Rect
+{
+	if tb_h <= 0.0 { return Rect::default(); }
+	let tb_rect = Rect { x: 0.0, y: 0.0, width: pw as f32, height: tb_h };
+	canvas.fill_rect( tb_rect, Color::rgb( 0.15, 0.15, 0.18 ), 0.0 );
+
+	let title_size = 15.0;
+	// `Canvas::draw_text` interprets `y` as the baseline. Match the
+	// vertical-centring formula used by `Button::draw_text_button` so
+	// chrome and content text lines line up at the same optical height.
+	let title_y    = ( tb_h + title_size * sf ) / 2.0 - 2.0;
+	let title_w    = canvas.measure_text( title, title_size );
+	let title_x    = ( pw as f32 - title_w ) / 2.0;
+	canvas.draw_text( title, title_x, title_y, title_size, Color::WHITE );
+
+	let btn_size = tb_h - 8.0 * sf;
+	let btn_x    = pw as f32 - btn_size - 8.0 * sf;
+	let btn_y    = 4.0 * sf;
+	let close_rect_phys = Rect { x: btn_x, y: btn_y, width: btn_size, height: btn_size };
+	canvas.fill_rect( close_rect_phys, Color::rgba( 1.0, 1.0, 1.0, 0.1 ), 4.0 * sf );
+
+	let cx  = btn_x + btn_size / 2.0;
+	let cy  = btn_y + btn_size / 2.0;
+	let arm = btn_size * 0.25;
+	canvas.draw_line( cx - arm, cy - arm, cx + arm, cy + arm, Color::WHITE, 2.0 * sf );
+	canvas.draw_line( cx + arm, cy - arm, cx - arm, cy + arm, Color::WHITE, 2.0 * sf );
+
+	canvas.draw_line( 0.0, tb_h - 0.5, pw as f32, tb_h - 0.5, Color::rgba( 1.0, 1.0, 1.0, 0.15 ), 1.0 );
+
+	close_rect_phys
+}
+
+/// Stamp a red warning banner at the top of the surface when the
+/// active theme came from the in-memory B/W fallback (i.e.
+/// [`crate::theme::is_fallback_active`] returned `true`). Gives the
+/// user a clear visual cue that `ltk-theme-default` is missing.
+///
+/// Paints a thin red strip across the top of the surface (24 px
+/// logical) with the install-instruction text. When the fallback is
+/// not active this is a no-op.
+pub( crate ) fn draw_fallback_banner(
+	canvas: &mut Canvas,
+	pw:     u32,
+	sf:     f32,
+)
+{
+	if !crate::theme::is_fallback_active() { return; }
+
+	let banner_h = 24.0 * sf;
+	let rect = Rect { x: 0.0, y: 0.0, width: pw as f32, height: banner_h };
+	canvas.fill_rect( rect, Color::rgb( 0.75, 0.10, 0.10 ), 0.0 );
+
+	let msg  = "ltk: fallback theme — install `ltk-theme-default`";
+	let size = 12.0;
+	let msg_w = canvas.measure_text( msg, size );
+	let x     = ( ( pw as f32 - msg_w ) / 2.0 ).max( 6.0 * sf );
+	let y     = ( banner_h - size * sf ) / 2.0;
+	canvas.draw_text( msg, x, y, size, Color::WHITE );
+}
+
+/// Apply or clear the surface's input region (set by
+/// `App::input_region`). `None` restores the default of "receive
+/// input everywhere"; `Some(&[])` makes the surface pointer-through.
+pub( crate ) fn apply_input_region(
+	wl_surface:   &WlSurface,
+	compositor:   &CompositorState,
+	input_region: Option<&[Rect]>,
+)
+{
+	if let Some( regions ) = input_region
+	{
+		if let Ok( region ) = Region::new( compositor )
+		{
+			for r in regions
+			{
+				region.add( r.x as i32, r.y as i32, r.width as i32, r.height as i32 );
+			}
+			wl_surface.set_input_region( Some( region.wl_region() ) );
+		}
+	} else {
+		wl_surface.set_input_region( None );
+	}
+}