layout: Refactor to support window decorations, add border and fullscreen backdrop

Windows are now wrapped in Tiles, which keep track of window-specific
decorations. Particularly, I implemented a black fullscreen backdrop,
which finally brings fullscreened windows smaller than the screen in
line with how the Wayland protocol says they should look—centered in a
black rectangle. I also implemented window borders, which are similar to
the focus ring, but always visible (and hence affect the layout and
sizing).

1 files changed, 267 insertions, 0 deletions

diff --git a/src/layout/tile.rs b/src/layout/tile.rs
new file mode 100644
index 00000000..2e8dcd90
--- /dev/null
+++ b/src/layout/tile.rs
@@ -0,0 +1,267 @@
+use std::cmp::max;
+use std::rc::Rc;
+use std::time::Duration;
+
+use smithay::backend::renderer::element::solid::{SolidColorBuffer, SolidColorRenderElement};
+use smithay::backend::renderer::element::utils::{Relocate, RelocateRenderElement};
+use smithay::backend::renderer::element::Kind;
+use smithay::backend::renderer::{ImportAll, Renderer};
+use smithay::utils::{Logical, Point, Scale, Size};
+
+use super::focus_ring::FocusRing;
+use super::workspace::WorkspaceRenderElement;
+use super::{LayoutElement, Options};
+
+/// Toplevel window with decorations.
+#[derive(Debug)]
+pub struct Tile<W: LayoutElement> {
+    /// The toplevel window itself.
+    window: W,
+
+    /// The border around the window.
+    border: FocusRing,
+
+    /// Whether this tile is fullscreen.
+    ///
+    /// This will update only when the `window` actually goes fullscreen, rather than right away,
+    /// to avoid black backdrop flicker before the window has had a chance to resize.
+    is_fullscreen: bool,
+
+    /// The black backdrop for fullscreen windows.
+    fullscreen_backdrop: SolidColorBuffer,
+
+    /// The size we were requested to fullscreen into.
+    fullscreen_size: Size<i32, Logical>,
+
+    /// Configurable properties of the layout.
+    options: Rc<Options>,
+}
+
+impl<W: LayoutElement> Tile<W> {
+    pub fn new(window: W, options: Rc<Options>) -> Self {
+        Self {
+            window,
+            border: FocusRing::new(options.border),
+            is_fullscreen: false, // FIXME: up-to-date fullscreen right away, but we need size.
+            fullscreen_backdrop: SolidColorBuffer::new((0, 0), [0., 0., 0., 1.]),
+            fullscreen_size: Default::default(),
+            options,
+        }
+    }
+
+    pub fn update_config(&mut self, options: Rc<Options>) {
+        self.border.update_config(options.border);
+        self.options = options;
+    }
+
+    pub fn advance_animations(&mut self, _current_time: Duration, is_active: bool) {
+        let width = self.border.width();
+        self.border.update(
+            (width, width).into(),
+            self.window.size(),
+            self.window.has_ssd(),
+        );
+        self.border.set_active(is_active);
+
+        // FIXME: remove when we can get a fullscreen size right away.
+        if self.fullscreen_size != Size::from((0, 0)) {
+            self.is_fullscreen = self.window.is_fullscreen();
+        }
+    }
+
+    pub fn window(&self) -> &W {
+        &self.window
+    }
+
+    pub fn into_window(self) -> W {
+        self.window
+    }
+
+    /// Returns `None` if the border is hidden and `Some(width)` if it should be shown.
+    fn effective_border_width(&self) -> Option<i32> {
+        if self.is_fullscreen {
+            return None;
+        }
+
+        if self.border.is_off() {
+            return None;
+        }
+
+        Some(self.border.width())
+    }
+
+    /// Returns the location of the window's visual geometry within this Tile.
+    fn window_loc(&self) -> Point<i32, Logical> {
+        let mut loc = Point::from((0, 0));
+
+        // In fullscreen, center the window in the given size.
+        if self.is_fullscreen {
+            let window_size = self.window.size();
+            let target_size = self.fullscreen_size;
+
+            // Windows aren't supposed to be larger than the fullscreen size, but in case we get
+            // one, leave it at the top-left as usual.
+            if window_size.w < target_size.w {
+                loc.x += (target_size.w - window_size.w) / 2;
+            }
+            if window_size.h < target_size.h {
+                loc.y += (target_size.h - window_size.h) / 2;
+            }
+        }
+
+        if let Some(width) = self.effective_border_width() {
+            loc += (width, width).into();
+        }
+
+        loc
+    }
+
+    pub fn tile_size(&self) -> Size<i32, Logical> {
+        let mut size = self.window.size();
+
+        if self.is_fullscreen {
+            // Normally we'd just return the fullscreen size here, but this makes things a bit
+            // nicer if a fullscreen window is bigger than the fullscreen size for some reason.
+            size.w = max(size.w, self.fullscreen_size.w);
+            size.h = max(size.h, self.fullscreen_size.h);
+            return size;
+        }
+
+        if let Some(width) = self.effective_border_width() {
+            size += (width * 2, width * 2).into();
+        }
+
+        size
+    }
+
+    pub fn window_size(&self) -> Size<i32, Logical> {
+        self.window.size()
+    }
+
+    pub fn buf_loc(&self) -> Point<i32, Logical> {
+        let mut loc = Point::from((0, 0));
+        loc += self.window_loc();
+        loc += self.window.buf_loc();
+        loc
+    }
+
+    pub fn is_in_input_region(&self, mut point: Point<f64, Logical>) -> bool {
+        point -= self.window_loc().to_f64();
+        self.window.is_in_input_region(point)
+    }
+
+    pub fn request_tile_size(&mut self, mut size: Size<i32, Logical>) {
+        // Can't go through effective_border_width() because we might be fullscreen.
+        if !self.border.is_off() {
+            let width = self.border.width();
+            size.w = max(1, size.w - width * 2);
+            size.h = max(1, size.h - width * 2);
+        }
+
+        self.window.request_size(size);
+    }
+
+    pub fn tile_width_for_window_width(&self, size: i32) -> i32 {
+        if self.border.is_off() {
+            size
+        } else {
+            size + self.border.width() * 2
+        }
+    }
+
+    pub fn tile_height_for_window_height(&self, size: i32) -> i32 {
+        if self.border.is_off() {
+            size
+        } else {
+            size + self.border.width() * 2
+        }
+    }
+
+    pub fn window_height_for_tile_height(&self, size: i32) -> i32 {
+        if self.border.is_off() {
+            size
+        } else {
+            size - self.border.width() * 2
+        }
+    }
+
+    pub fn request_fullscreen(&mut self, size: Size<i32, Logical>) {
+        self.fullscreen_backdrop.resize(size);
+        self.fullscreen_size = size;
+        self.window.request_fullscreen(size);
+    }
+
+    pub fn min_size(&self) -> Size<i32, Logical> {
+        let mut size = self.window.min_size();
+
+        if let Some(width) = self.effective_border_width() {
+            size.w = max(1, size.w);
+            size.h = max(1, size.h);
+            size += (width * 2, width * 2).into();
+        }
+
+        size
+    }
+
+    pub fn max_size(&self) -> Size<i32, Logical> {
+        let mut size = self.window.max_size();
+
+        if let Some(width) = self.effective_border_width() {
+            if size.w > 0 {
+                size.w += width * 2;
+            }
+            if size.h > 0 {
+                size.h += width * 2;
+            }
+        }
+
+        size
+    }
+
+    pub fn has_ssd(&self) -> bool {
+        self.effective_border_width().is_some() || self.window.has_ssd()
+    }
+
+    pub fn render<R: Renderer + ImportAll>(
+        &self,
+        renderer: &mut R,
+        location: Point<i32, Logical>,
+        scale: Scale<f64>,
+    ) -> Vec<WorkspaceRenderElement<R>>
+    where
+        <R as Renderer>::TextureId: 'static,
+    {
+        let mut rv = Vec::new();
+
+        let window_pos = location + self.window_loc();
+        rv.extend(self.window.render(renderer, window_pos, scale));
+
+        if self.effective_border_width().is_some() {
+            rv.extend(
+                self.border
+                    .render(scale)
+                    .map(|elem| {
+                        RelocateRenderElement::from_element(
+                            elem,
+                            location.to_physical_precise_round(scale),
+                            Relocate::Relative,
+                        )
+                    })
+                    .map(Into::into),
+            );
+        }
+
+        if self.is_fullscreen {
+            let elem = SolidColorRenderElement::from_buffer(
+                &self.fullscreen_backdrop,
+                location.to_physical_precise_round(scale),
+                scale,
+                1.,
+                Kind::Unspecified,
+            );
+            rv.push(elem.into());
+        }
+
+        rv
+    }
+}