Round normal window decorations

Reserve side and bottom decoration borders for normal windows and draw a rounded decoration frame so windows match the convergence workspace shape. Add static guards for the decoration and existing workspace-frame corner geometry.

kwin/decorations/org.shift.decoration/contents/ui/main.qml

@@ -2,6 +2,7 @@
 // SPDX-License-Identifier: EUPL-1.2
 
 import QtQuick
+import QtQuick.Shapes
 import org.kde.kwin.decoration
 import org.kde.plasma.private.mobileshell as MobileShell
 import org.kde.plasma.private.mobileshell.shellsettingsplugin as ShellSettings
@@ -20,7 +21,9 @@ Decoration {
     readonly property int btnSize:       16
     readonly property int btnSpacing:     8
     readonly property int btnSideMargin: 12
-    readonly property int cornerRadius:  decoration.client.maximized ? 0 : 8
+    readonly property int normalCornerRadius: 8
+    readonly property int cornerRadius:  decoration.client.maximized ? 0 : normalCornerRadius
+    readonly property int frameThickness: decoration.client.maximized ? 0 : normalCornerRadius
     readonly property int shortAnimationDuration: MobileShell.Motion.duration(MobileShell.Motion.EffectsFast)
     readonly property bool windowMenuAllowed: !ShellSettings.Settings.convergenceModeEnabled
                                            || ShellSettings.Settings.gamingModeEnabled
@@ -28,9 +31,9 @@ Decoration {
 
     Component.onCompleted: {
         borders.top    = barHeight;
-        borders.left   = 0;
+        borders.left   = normalCornerRadius;
-        borders.right  = 0;
+        borders.right  = normalCornerRadius;
-        borders.bottom = 0;
+        borders.bottom = normalCornerRadius;
 
         // Keep titlebar controls available for maximized windows in desktop
         // convergence mode. Mobile mode uses noBorder=true and bypasses this.
@@ -45,6 +48,36 @@ Decoration {
         deco: decoration
     }
 
+    readonly property color frameColor: decoration.client.active ? root.activeBar : root.inactiveBar
+
+    Shape {
+        anchors.fill: parent
+        visible: !decoration.client.maximized
+
+        ShapePath {
+            fillColor: root.frameColor
+            fillRule: ShapePath.OddEvenFill
+            strokeWidth: 0
+
+            startX: root.cornerRadius
+            startY: 0
+            PathLine { x: root.width - root.cornerRadius; y: 0 }
+            PathArc { x: root.width; y: root.cornerRadius; radiusX: root.cornerRadius; radiusY: root.cornerRadius }
+            PathLine { x: root.width; y: root.height - root.cornerRadius }
+            PathArc { x: root.width - root.cornerRadius; y: root.height; radiusX: root.cornerRadius; radiusY: root.cornerRadius }
+            PathLine { x: root.cornerRadius; y: root.height }
+            PathArc { x: 0; y: root.height - root.cornerRadius; radiusX: root.cornerRadius; radiusY: root.cornerRadius }
+            PathLine { x: 0; y: root.cornerRadius }
+            PathArc { x: root.cornerRadius; y: 0; radiusX: root.cornerRadius; radiusY: root.cornerRadius }
+
+            PathMove { x: root.frameThickness; y: root.barHeight }
+            PathLine { x: root.width - root.frameThickness; y: root.barHeight }
+            PathLine { x: root.width - root.frameThickness; y: root.height - root.frameThickness }
+            PathLine { x: root.frameThickness; y: root.height - root.frameThickness }
+            PathLine { x: root.frameThickness; y: root.barHeight }
+        }
+    }
+
     // ── Faint window outline ─────────────────────────────────────────────────
     Rectangle {
         anchors.fill: parent

tests/check-convergence-dock-invariant.sh

@@ -53,6 +53,10 @@ require_line "$folio_main" "readonly property real workAreaY: topReservedHeight
 require_line "$folio_main" "readonly property real workAreaWidth: Math.max(0, width - frameThickness * 2)"
 require_line "$folio_main" "readonly property real workAreaHeight: Math.max(0, height - topReservedHeight - bottomReservedHeight - frameThickness * 2)"
 require_line "$folio_main" "fillRule: ShapePath.OddEvenFill"
+require_line "$folio_main" "PathLine { x: workspaceFrame.width; y: workspaceFrame.height - workspaceFrame.bottomReservedHeight }"
+require_line "$folio_main" "PathLine { x: 0; y: workspaceFrame.height - workspaceFrame.bottomReservedHeight }"
+require_line "$folio_main" "PathArc { x: workspaceFrame.workAreaX + workspaceFrame.workAreaWidth - workspaceFrame.frameRadius; y: workspaceFrame.workAreaY + workspaceFrame.workAreaHeight; radiusX: workspaceFrame.frameRadius; radiusY: workspaceFrame.frameRadius }"
+require_line "$folio_main" "PathArc { x: workspaceFrame.workAreaX; y: workspaceFrame.workAreaY + workspaceFrame.workAreaHeight - workspaceFrame.frameRadius; radiusX: workspaceFrame.frameRadius; radiusY: workspaceFrame.frameRadius }"
 require_line "$folio_main" "readonly property real popupTopY: MobileShell.Constants.topPanelHeight"
 require_line "$folio_main" "+ MobileShell.Constants.convergenceWorkspaceFrameThickness"
 require_line "$folio_main" "readonly property real popupBottomY: parent.height"

tests/check-dynamic-tiles-motion.sh

@@ -118,6 +118,12 @@ require_line "$decoration_qml" "readonly property bool windowMenuAllowed: !Shell
 require_line "$decoration_qml" "return root.windowMenuAllowed;"
 require_line "$decoration_qml" "enabled: !root.windowMenuAllowed"
 require_line "$decoration_qml" "acceptedButtons: Qt.RightButton"
+require_line "$decoration_qml" "readonly property int frameThickness: decoration.client.maximized ? 0 : normalCornerRadius"
+require_line "$decoration_qml" "borders.left   = normalCornerRadius;"
+require_line "$decoration_qml" "borders.right  = normalCornerRadius;"
+require_line "$decoration_qml" "borders.bottom = normalCornerRadius;"
+require_line "$decoration_qml" "PathArc { x: root.width - root.cornerRadius; y: root.height; radiusX: root.cornerRadius; radiusY: root.cornerRadius }"
+require_line "$decoration_qml" "PathArc { x: 0; y: root.height - root.cornerRadius; radiusX: root.cornerRadius; radiusY: root.cornerRadius }"
 
 reject_line "$tiling_script" "targetKey = lastLeafKey(rootNode)"
 reject_line "$tiling_script" "function lastLeafKey(node)"