From 3ff013b47baac1ac421a2148c39cd0c8f2eb811e Mon Sep 17 00:00:00 2001
From: moWerk <mo@mowerk.net>
Date: Thu, 14 May 2026 13:42:20 +0200
Subject: [PATCH] Fix Application_p zero size on Qt6 Wayland by syncing to
 window geometry

- In Qt5, the Wayland platform set the root QQuickItem dimensions synchronously before QML evaluation, so anchors.fill: parent on Application_p correctly resolved to the screen size at startup
- In Qt6, the Wayland xdg_toplevel configure handshake is asynchronous and the QQuickWindow geometry arrives after QML component completion, leaving Application_p at 0x0 until a layout pass occurs
- This caused LayerStack to calculate sub-page x positions as depth * 0 = 0 at push() time, stacking all pages at the origin with no slide animation, and the FlatMesh tutorial off-screen positions to resolve to 0 instead of the screen width
- Fix: override itemChange in Application_p to detect ItemSceneChange and immediately call setWidth/setHeight from the QQuickWindow dimensions, then stay connected to widthChanged and heightChanged for any subsequent resize
- The initial ItemSceneChange fires before the window is sized (0x0), so the guard w->width() > 0 skips that first call; the widthChanged signal fires moments later with the correct 321x321 geometry and the size is applied then
- Diagnosed via Component.onCompleted logging in asteroid-settings confirming Application width reported as 0 at startup, and itemChange qDebug output confirming the two-phase size arrival sequence on sparrow
- Confirmed on sparrow (catfish TicWatch Pro 2020): LayerStack sub-pages now animate in correctly with the slide transition
---
 src/controls/src/application_p.cpp | 17 +++++++++++++++++
 src/controls/src/application_p.h   |  3 +++
 2 files changed, 20 insertions(+)

diff --git a/src/controls/src/application_p.cpp b/src/controls/src/application_p.cpp
index b329c82..0fb191b 100644
--- a/src/controls/src/application_p.cpp
+++ b/src/controls/src/application_p.cpp
@@ -51,3 +51,20 @@ bool Application_p::overridesSystemGestures()
 {
     return m_overridesSystemGestures;
 }
+
+void Application_p::itemChange(ItemChange change, const ItemChangeData &data)
+{
+    QQuickItem::itemChange(change, data);
+    if (change == ItemSceneChange && data.window) {
+        auto syncSize = [this]() {
+            QQuickWindow *w = window();
+            if (w && w->width() > 0) {
+                setWidth(w->width());
+                setHeight(w->height());
+            }
+        };
+        syncSize();
+        connect(data.window, &QQuickWindow::widthChanged, this, syncSize);
+        connect(data.window, &QQuickWindow::heightChanged, this, syncSize);
+    }
+}
diff --git a/src/controls/src/application_p.h b/src/controls/src/application_p.h
index 414db5a..1cfede6 100644
--- a/src/controls/src/application_p.h
+++ b/src/controls/src/application_p.h
@@ -47,6 +47,9 @@ class Application_p : public QQuickItem
 private:
     bool m_overridesSystemGestures;
 
+protected:
+    void itemChange(ItemChange change, const ItemChangeData &data) override;
+
 signals:
     void overridesSystemGesturesChanged();
 };