Coverage Summary for Class: SurferPaneRole (com.georgeci.moneysurfer.uikit.window)

 package com.georgeci.moneysurfer.uikit.window
 
 import androidx.compose.runtime.Immutable
 import androidx.compose.runtime.ProvidableCompositionLocal
 import androidx.compose.runtime.compositionLocalOf
 
 /** Which pane of the host layout a screen is currently composing into. */
 enum class SurferPaneRole {
     /**
      * The screen is the only thing on screen — every compact-width window, and every route the
      * pane host does not lay out side by side. Chrome behaves exactly as it always has.
      */
     Single,
 
     /** The list pane of a two-pane layout. Owns the section's top app bar and its FAB. */
     List,
 
     /**
      * The detail pane of a two-pane layout, displayed *next to* its list pane. The list pane is
      * already drawing the section's top app bar and FAB, so this one must not draw its own.
      */
     Detail,
 
     /**
      * The extra pane of a three-pane layout — the design's inline "add" panel, displayed to the
      * right of the detail pane it was opened from (issue #391). Like the detail pane it draws no
      * section chrome; the list pane on the far side still owns the top app bar and the FAB.
      */
     Extra,
 }
 
 /**
  * How the pane host is displaying the screen currently composing, published through
  * [LocalSurferPane].
  *
  * A screen reads this instead of measuring the window itself: whether a sibling pane is on screen
  * is a fact about the *back stack* as much as about the width, and only the host knows both. See
  * `SurferPaneSceneStrategy` in `:navigation` for where the value comes from.
  *
  * @param role which pane the screen occupies.
  * @param hasPaneBackStack whether a back affordance on this screen still leads somewhere inside
  *   the two-pane layout rather than merely swapping the detail pane for its placeholder — either
  *   an earlier entry of the same pane to return to (a settings sub-screen that opened another,
  *   About → Licenses) or an entry stacked above this one (a list route pushed from a detail, which
  *   leaves the detail beside a list that is not its own). A detail opened straight from its list
  *   has neither, and is the one case that drops the affordance. An [SurferPaneRole.Extra] panel
  *   always has one: dismissing it leaves the list and the detail it was opened from in place.
  */
 @Immutable
 data class SurferPane(
     val role: SurferPaneRole = SurferPaneRole.Single,
     val hasPaneBackStack: Boolean = false,
 ) {
     /**
      * Whether this screen draws the section's top app bar and floating action button. Only the
      * panes displayed *beside* a list pane give them up — that list pane is already drawing both.
      */
     val ownsSectionChrome: Boolean
         get() = role == SurferPaneRole.Single || role == SurferPaneRole.List
 
     /** Whether a back affordance on this screen still has somewhere to go. */
     val showsBackNavigation: Boolean get() = ownsSectionChrome || hasPaneBackStack
 }
 
 /** The [SurferPane] the current composition sits in. Defaults to a plain full-window screen. */
 val LocalSurferPane: ProvidableCompositionLocal<SurferPane> = compositionLocalOf { SurferPane() }