From 1304ba3997951a93939b04b9ad1df1e0a0c146eb Mon Sep 17 00:00:00 2001
From: Jan Grulich <jgrulich@redhat.com>
Date: Tue, 19 Nov 2024 19:15:08 +0100
Subject: [PATCH] Adwaita decorations: improve border painting

This is a backport of two changes pushed to QAdwaitaDecorations upstream
that further improve painting of border around the application window.
Using the 0.5px adjustment makes the border to look better as the line
better aligns. Also the separator between window and title doesn't need
to be painted separately. Co-authored with Lorenzo Bertini.

Pick-to: 6.8
Change-Id: Ib841073884dee58e599a173c259547416d2ed8ce
---

diff --git a/src/plugins/decorations/adwaita/qwaylandadwaitadecoration.cpp b/src/plugins/decorations/adwaita/qwaylandadwaitadecoration.cpp
index 2d3575b..c32ab4a 100644
--- a/src/plugins/decorations/adwaita/qwaylandadwaitadecoration.cpp
+++ b/src/plugins/decorations/adwaita/qwaylandadwaitadecoration.cpp
@@ -46,7 +46,6 @@
 static constexpr int ceShadowsWidth = 10;
 static constexpr int ceTitlebarHeight = 38;
 static constexpr int ceWindowBorderWidth = 1;
-static constexpr qreal ceTitlebarSeperatorWidth = 0.5;
 
 static QMap<QWaylandAdwaitaDecoration::ButtonIcon, QString> buttonMap = {
     { QWaylandAdwaitaDecoration::CloseIcon, "window-close-symbolic"_L1 },
@@ -129,36 +128,29 @@
     /*
      * Titlebar and window border
      */
-    const int titleBarWidth = surfaceRect.width() - margins().left() - margins().right();
     QPainterPath path;
+    const QPointF topLeft = { margins(ShadowsOnly).left() + 0.5,
+                              margins(ShadowsOnly).top() - 0.5 };
+    const int titleBarWidth = surfaceRect.width() - margins(ShadowsOnly).left()
+            - margins(ShadowsOnly).right() - 0.5;
+    const int borderRectHeight =
+            surfaceRect.height() - margins().top() - margins().bottom() + 0.5;
 
     // Maximized or tiled won't have rounded corners
     if (waylandWindow()->windowStates() & Qt::WindowMaximized
         || waylandWindow()->toplevelWindowTilingStates() != QWaylandWindow::WindowNoState)
-        path.addRect(margins().left(), margins().bottom(), titleBarWidth, margins().top());
+        path.addRect(QRectF(topLeft, QSizeF(titleBarWidth, margins().top())));
     else
-        path.addRoundedRect(margins().left(), margins().bottom(), titleBarWidth,
-                            margins().top() + ceCornerRadius, ceCornerRadius, ceCornerRadius);
+        path.addRoundedRect(QRectF(topLeft, QSizeF(titleBarWidth, margins().top() + ceCornerRadius)),
+                            ceCornerRadius, ceCornerRadius);
 
     p.save();
     p.setPen(color(Border));
     p.fillPath(path.simplified(), color(Background));
     p.drawPath(path);
-    p.drawRect(margins().left(), margins().top(), titleBarWidth, surfaceRect.height() - margins().top() - margins().bottom());
+    p.drawRect(QRectF(topLeft.x(), margins().top(), titleBarWidth, borderRectHeight));
     p.restore();
 
-
-    /*
-     * Titlebar separator
-     */
-    p.save();
-    p.setPen(color(Border));
-    p.drawLine(QLineF(margins().left(), margins().top() - ceTitlebarSeperatorWidth,
-                        surfaceRect.width() - margins().right(),
-                        margins().top() - ceTitlebarSeperatorWidth));
-    p.restore();
-
-
     /*
      * Window title
      */