From 7ea1eed8bf34cf9d277e47883677d25b71f230ab Mon Sep 17 00:00:00 2001
From: Damocles <damocles@darkest.space>
Date: Sun, 12 Apr 2026 23:20:38 +0200
Subject: [PATCH] overview backdrop: test pattern, niri layer-rule in hm-module

---
 modules/OverviewBackdrop.qml | 78 ++++++++++++++++++++++++++++++++++++
 modules/qmldir               |  1 +
 nix/hm-module.nix            |  8 ++++
 shell.qml                    |  4 ++
 4 files changed, 91 insertions(+)
 create mode 100644 modules/OverviewBackdrop.qml

diff --git a/modules/OverviewBackdrop.qml b/modules/OverviewBackdrop.qml
new file mode 100644
index 0000000..fdb3c0f
--- /dev/null
+++ b/modules/OverviewBackdrop.qml
@@ -0,0 +1,78 @@
+import QtQuick
+import Quickshell
+import Quickshell.Wayland
+import "." as M
+
+// Rendered in niri's overview backdrop via place-within-backdrop layer rule.
+// Visible between workspace rows during overview.
+PanelWindow {
+    id: root
+
+    required property var screen
+
+    color: "transparent"
+
+    WlrLayershell.layer: WlrLayer.Background
+    WlrLayershell.exclusiveZone: -1
+    WlrLayershell.namespace: "nova-overview-backdrop"
+    mask: Region {}
+
+    anchors.top: true
+    anchors.left: true
+    anchors.right: true
+    anchors.bottom: true
+
+    // Test pattern — diagonal gradient with centered label
+    Rectangle {
+        anchors.fill: parent
+        gradient: Gradient {
+            orientation: Gradient.Horizontal
+            GradientStop {
+                position: 0
+                color: Qt.rgba(M.Theme.base0C.r, M.Theme.base0C.g, M.Theme.base0C.b, 0.15)
+            }
+            GradientStop {
+                position: 0.5
+                color: Qt.rgba(M.Theme.base0E.r, M.Theme.base0E.g, M.Theme.base0E.b, 0.1)
+            }
+            GradientStop {
+                position: 1
+                color: Qt.rgba(M.Theme.base09.r, M.Theme.base09.g, M.Theme.base09.b, 0.15)
+            }
+        }
+    }
+
+    // Grid of dots as a test pattern
+    Grid {
+        anchors.fill: parent
+        columns: Math.floor(width / 80)
+        rows: Math.floor(height / 80)
+
+        Repeater {
+            model: parent.columns * parent.rows
+            Rectangle {
+                width: 80
+                height: 80
+                color: "transparent"
+                Rectangle {
+                    anchors.centerIn: parent
+                    width: 4
+                    height: 4
+                    radius: 2
+                    color: M.Theme.base0D
+                    opacity: 0.2
+                }
+            }
+        }
+    }
+
+    Text {
+        anchors.centerIn: parent
+        text: "nova-shell overview backdrop"
+        color: M.Theme.base05
+        opacity: 0.3
+        font.pixelSize: 24
+        font.family: M.Theme.fontFamily
+        font.letterSpacing: 6
+    }
+}
diff --git a/modules/qmldir b/modules/qmldir
index e7839d9..0fc1e6e 100644
--- a/modules/qmldir
+++ b/modules/qmldir
@@ -34,3 +34,4 @@ Notifications 1.0 Notifications.qml
 Power 1.0 Power.qml
 Privacy 1.0 Privacy.qml
 BackgroundOverlay 1.0 BackgroundOverlay.qml
+OverviewBackdrop 1.0 OverviewBackdrop.qml
diff --git a/nix/hm-module.nix b/nix/hm-module.nix
index 35a0447..b186191 100644
--- a/nix/hm-module.nix
+++ b/nix/hm-module.nix
@@ -192,6 +192,14 @@ in
       in
       (pkgs.formats.json { }).generate "nova-shell-theme.json" finalTheme;
 
+    # Niri layer rules for backdrop placement (requires niri-flake hm module)
+    programs.niri.settings.layer-rules = lib.mkIf (config ? programs && config.programs ? niri) [
+      {
+        matches = [ { namespace = "^nova-overview-backdrop$"; } ];
+        place-within-backdrop = true;
+      }
+    ];
+
     systemd.user.services.nova-shell = lib.mkIf cfg.systemd.enable {
       Unit = {
         Description = "nova-shell Quickshell bar";
diff --git a/shell.qml b/shell.qml
index ec9007c..d6826f1 100644
--- a/shell.qml
+++ b/shell.qml
@@ -23,6 +23,10 @@ ShellRoot {
                 screen: scope.modelData
             }
 
+            OverviewBackdrop {
+                screen: scope.modelData
+            }
+
             ScreenCorners {
                 screen: scope.modelData
             }