Unify convergence dock geometry and add invariant test

Introduce shared dock height/reveal constants and use them in folio and taskpanel to keep overlay and exclusion zone aligned. Keep dock backing stationary while only content slides, and add a CTest invariant script to prevent regressions.

components/mobileshell/qml/components/Constants.qml

@@ -31,6 +31,8 @@ QtObject {
         ? 0
         : Kirigami.Units.gridUnit * 2
     readonly property real defaultGesturePanelThickness: Kirigami.Units.gridUnit
+    readonly property real convergenceDockHeight: Kirigami.Units.gridUnit * 3
+    readonly property real convergenceDockRevealHeight: Kirigami.Units.gridUnit
 
     readonly property real navigationPanelThickness: {
         if (!ShellSettings.Settings.navigationPanelEnabled) {

containments/homescreens/folio/qml/FolioHomeScreen.qml

@@ -382,8 +382,8 @@ Item {
                     visible: opacity > 0 && !ShellSettings.Settings.convergenceModeEnabled
 
                     // one is ignored as anchors are set
-                    height: ShellSettings.Settings.convergenceModeEnabled ? Kirigami.Units.gridUnit * 3 : Kirigami.Units.gridUnit * 6
+                    height: ShellSettings.Settings.convergenceModeEnabled ? MobileShell.Constants.convergenceDockHeight : Kirigami.Units.gridUnit * 6
-                    width: ShellSettings.Settings.convergenceModeEnabled ? Kirigami.Units.gridUnit * 3 : Kirigami.Units.gridUnit * 6
+                    width: ShellSettings.Settings.convergenceModeEnabled ? MobileShell.Constants.convergenceDockHeight : Kirigami.Units.gridUnit * 6
 
                     anchors.topMargin: root.topMargin
                     anchors.bottomMargin: ShellSettings.Settings.convergenceModeEnabled ? 0 : root.bottomMargin
@@ -439,7 +439,7 @@ Item {
                             }
                             PropertyChanges {
                                 target: favouritesBar
-                                height: ShellSettings.Settings.convergenceModeEnabled ? Kirigami.Units.gridUnit * 3 : Kirigami.Units.gridUnit * 6
+                                height: ShellSettings.Settings.convergenceModeEnabled ? MobileShell.Constants.convergenceDockHeight : Kirigami.Units.gridUnit * 6
                             }
                         }, State {
                             name: "left"

containments/homescreens/folio/qml/main.qml

@@ -279,7 +279,7 @@ ContainmentItem {
         visible: ShellSettings.Settings.convergenceModeEnabled && !ShellSettings.Settings.gamingModeEnabled
         color: "transparent"
         width: Screen.width
-        height: Kirigami.Units.gridUnit * 3
+        height: MobileShell.Constants.convergenceDockHeight
 
         LayerShell.Window.scope: "dock-overlay"
         LayerShell.Window.layer: LayerShell.Window.LayerTop
@@ -290,11 +290,11 @@ ContainmentItem {
         // Auto-hide: slide dock content off-screen when a window is
         // maximized.  The reveal strip at the screen edge brings it back.
         property real dockOffset: 0
-        readonly property real dockHeight: Kirigami.Units.gridUnit * 3
+        readonly property real dockHeight: MobileShell.Constants.convergenceDockHeight
 
         // Height of the input-receive strip kept at the screen edge when
         // the dock is hidden.  Matches the navigation panel convention.
-        readonly property real revealStripHeight: Kirigami.Units.gridUnit
+        readonly property real revealStripHeight: MobileShell.Constants.convergenceDockRevealHeight
 
         // True once the hover-reveal timer fires; cleared on hover-exit.
         property bool hoverRevealing: false
@@ -353,10 +353,10 @@ ContainmentItem {
 
         Rectangle {
             anchors.fill: parent
+            visible: !dockOverlay.shouldHide || dockOverlay.dockOffset < dockOverlay.dockHeight
             Kirigami.Theme.inherit: false
             Kirigami.Theme.colorSet: Kirigami.Theme.Window
             color: Kirigami.Theme.backgroundColor
-            transform: Translate { y: dockOverlay.dockOffset }
         }
 
         FavouritesBar {
@@ -408,7 +408,7 @@ ContainmentItem {
 
             readonly property real popupWidth: Math.min(Kirigami.Units.gridUnit * 28, parent.width * 0.5)
             readonly property real popupHeight: Math.min(Kirigami.Units.gridUnit * 32, parent.height * 0.7)
-            readonly property real dockHeight: Kirigami.Units.gridUnit * 3
+            readonly property real dockHeight: MobileShell.Constants.convergenceDockHeight
 
             width: popupWidth
             height: popupHeight

containments/taskpanel/qml/main.qml

@@ -166,13 +166,13 @@ ContainmentItem {
         color: "transparent"
         flags: Qt.FramelessWindowHint | Qt.WindowTransparentForInput
         // height is set by layer-shell anchoring; provide a fallback.
-        height: Kirigami.Units.gridUnit * 3
+        height: MobileShell.Constants.convergenceDockHeight
         width: 1 // layer-shell stretches it via AnchorLeft|AnchorRight
 
         LayerShell.Window.scope: "dock-space"
         LayerShell.Window.layer: LayerShell.Window.LayerBottom
         LayerShell.Window.anchors: LayerShell.Window.AnchorBottom | LayerShell.Window.AnchorLeft | LayerShell.Window.AnchorRight
-        LayerShell.Window.exclusionZone: Kirigami.Units.gridUnit * 3
+        LayerShell.Window.exclusionZone: MobileShell.Constants.convergenceDockHeight
         LayerShell.Window.keyboardInteractivity: LayerShell.Window.KeyboardInteractivityNone
     }
 

tests/CMakeLists.txt

@@ -1,4 +1,12 @@
 # SPDX-FileCopyrightText: 2024 Devin Lin <devin@kde.org>
 # SPDX-License-Identifier: GPL-2.0-or-later
 
-add_subdirectory(notificationtest)
+add_subdirectory(notificationtest)
+
+find_program(BASH_EXECUTABLE bash)
+if(BASH_EXECUTABLE)
+    add_test(
+        NAME convergence-dock-invariant
+        COMMAND ${BASH_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/check-convergence-dock-invariant.sh
+    )
+endif()

tests/check-convergence-dock-invariant.sh

@@ -0,0 +1,39 @@
+#!/usr/bin/env bash
+# SPDX-FileCopyrightText: 2026 Marco Allegretti <mightymarco4@gmail.com>
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+set -euo pipefail
+
+repo_root="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+
+constants="$repo_root/components/mobileshell/qml/components/Constants.qml"
+taskpanel="$repo_root/containments/taskpanel/qml/main.qml"
+folio_main="$repo_root/containments/homescreens/folio/qml/main.qml"
+folio_home="$repo_root/containments/homescreens/folio/qml/FolioHomeScreen.qml"
+
+require_line() {
+    local file="$1"
+    local needle="$2"
+
+    if ! grep -Fq "$needle" "$file"; then
+        echo "Missing invariant in ${file#$repo_root/}: $needle" >&2
+        exit 1
+    fi
+}
+
+require_line "$constants" "readonly property real convergenceDockHeight: Kirigami.Units.gridUnit * 3"
+require_line "$constants" "readonly property real convergenceDockRevealHeight: Kirigami.Units.gridUnit"
+
+require_line "$taskpanel" "height: MobileShell.Constants.convergenceDockHeight"
+require_line "$taskpanel" "LayerShell.Window.exclusionZone: MobileShell.Constants.convergenceDockHeight"
+
+require_line "$folio_main" "height: MobileShell.Constants.convergenceDockHeight"
+require_line "$folio_main" "readonly property real dockHeight: MobileShell.Constants.convergenceDockHeight"
+require_line "$folio_main" "readonly property real revealStripHeight: MobileShell.Constants.convergenceDockRevealHeight"
+require_line "$folio_home" "height: ShellSettings.Settings.convergenceModeEnabled ? MobileShell.Constants.convergenceDockHeight : Kirigami.Units.gridUnit * 6"
+
+dock_offset_transforms="$(grep -F "transform: Translate { y: dockOverlay.dockOffset }" "$folio_main" | wc -l)"
+if [[ "$dock_offset_transforms" -ne 1 ]]; then
+    echo "Expected only dock contents to slide with dockOverlay.dockOffset; found $dock_offset_transforms transforms" >&2
+    exit 1
+fi