A sketch dialog and the Sketch Palette on screen at the same time (#791)

A command dialog opened while sketching no longer hides the Sketch Palette: the dialog docks at the left of the viewport and the palette keeps the right. A view too narrow for both keeps the dialog alone.

crates/ui-egui/src/frame.rs

@@ -3,6 +3,8 @@
 //! other file creates an `egui::Window`, and that every dialog stays within the limits).
 //!
 //! - [`docked`]: command dialogs and command panels, flush to the right edge of the viewport.
+//! - [`docked_on`]: the same, against either edge ([`Side`]), with [`dock_frame`] for its
+//!   chrome. A dialog opened while the Sketch Palette holds the right edge takes the left.
 //! - [`window`]: floating windows (Preferences, Parameters, prompts…), centred by default.
 //! - [`right_aligned`]: right-align a row's last items without widening the window (a
 //!   right-to-left layout would stretch it to its maximum width).
@@ -28,17 +30,60 @@ pub enum Width {
     Wide,
 }
 
+/// Which edge of the viewport a docked panel sits against. The Sketch Palette holds the right
+/// edge while a sketch is open, so a dialog started there takes the left.
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum Side {
+    Right,
+    Left,
+}
+
+impl Side {
+    /// The x of the viewport edge this side docks against.
+    pub fn anchor_x(self, viewport: egui::Rect) -> f32 {
+        match self {
+            Side::Right => viewport.right(),
+            Side::Left => viewport.left(),
+        }
+    }
+}
+
+/// The window frame of a docked panel: the two corners away from its edge are rounded, and the
+/// shadow falls the same way, so a left dock mirrors a right one.
+pub fn dock_frame(ctx: &egui::Context, side: Side) -> egui::Frame {
+    let t = crate::theme::Tokens::get();
+    let (corner_radius, shadow_x) = match side {
+        Side::Right => (egui::CornerRadius { nw: 4, sw: 4, ne: 0, se: 0 }, -2),
+        Side::Left => (egui::CornerRadius { nw: 0, sw: 0, ne: 4, se: 4 }, 2),
+    };
+    egui::Frame::window(&ctx.global_style())
+        .fill(t.dialog_bg)
+        .stroke(egui::Stroke::new(1.0, t.dialog_border))
+        .corner_radius(corner_radius)
+        .shadow(egui::Shadow { offset: [shadow_x, 2], blur: 8, spread: 0, color: egui::Color32::from_black_alpha(40) })
+}
+
 /// A command dialog docked at `anchor` (its top right corner), shrink-wrapped to its content.
 pub fn docked<'a>(title: impl Into<WidgetText>, id: egui::Id, anchor: Pos2, max_height: f32, width: Width) -> egui::Window<'a> {
+    docked_on(title, id, anchor, max_height, width, Side::Right)
+}
+
+/// A command dialog docked against `side` at `anchor` (its top corner on that side),
+/// shrink-wrapped to its content.
+pub fn docked_on<'a>(title: impl Into<WidgetText>, id: egui::Id, anchor: Pos2, max_height: f32, width: Width, side: Side) -> egui::Window<'a> {
     let max = match width {
         Width::Normal => DIALOG_MAX_W,
         Width::Wide => DIALOG_WIDE_MAX_W,
     };
+    let pivot = match side {
+        Side::Right => Align2::RIGHT_TOP,
+        Side::Left => Align2::LEFT_TOP,
+    };
     egui::Window::new(title)
         .enabled(!crate::issue_report::cad_input_blocked())
         .id(id)
         .title_bar(false)
-        .pivot(Align2::RIGHT_TOP)
+        .pivot(pivot)
         .fixed_pos(anchor)
         .constrain(false)
         .auto_sized()