From 6909bb4b0378086a2d84e5fa0bb8d54ec4737bb4 Mon Sep 17 00:00:00 2001
From: Karl Tauber <karl@jformdesigner.com>
Date: Wed, 31 Mar 2021 20:56:17 +0200
Subject: [PATCH] Native window decorations: removed superfluous pixel-line at
 top of screen when window is maximized (issue #296)

---
 CHANGELOG.md                                           |  2 ++
 .../java/com/formdev/flatlaf/ui/FlatTitlePane.java     | 10 ++++++++--
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4b649dae..a14f29bb 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,8 @@ FlatLaf Change Log
 #### Fixed bugs
 
 - Fixed crash when running in Webswing. (issue #290)
+- Native window decorations: Removed superfluous pixel-line at top of screen
+  when window is maximized. (issue #296)
 
 
 ## 1.1.1
diff --git a/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatTitlePane.java b/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatTitlePane.java
index 845c1aa0..05a0cb1c 100644
--- a/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatTitlePane.java
+++ b/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatTitlePane.java
@@ -803,7 +803,7 @@ debug*/
 			} else if( borderColor != null && (rootPane.getJMenuBar() == null || !rootPane.getJMenuBar().isVisible()) )
 				insets.bottom += UIScale.scale( 1 );
 
-			if( hasNativeCustomDecoration() )
+			if( hasNativeCustomDecoration() && !isWindowMaximized( c ) )
 				insets = FlatUIUtils.addInsets( insets, WindowTopBorder.getInstance().getBorderInsets() );
 
 			return insets;
@@ -822,7 +822,7 @@ debug*/
 				FlatUIUtils.paintFilledRectangle( g, borderColor, x, y + height - lineHeight, width, lineHeight );
 			}
 
-			if( hasNativeCustomDecoration() )
+			if( hasNativeCustomDecoration() && !isWindowMaximized( c ) )
 				WindowTopBorder.getInstance().paintBorder( c, g, x, y, width, height );
 		}
 
@@ -830,6 +830,12 @@ debug*/
 			JMenuBar menuBar = rootPane.getJMenuBar();
 			return hasVisibleEmbeddedMenuBar( menuBar ) ? menuBar.getBorder() : null;
 		}
+
+		protected boolean isWindowMaximized( Component c ) {
+			return window instanceof Frame
+				? (((Frame)window).getExtendedState() & Frame.MAXIMIZED_BOTH) != 0
+				: false;
+		}
 	}
 
 	//---- class FlatTitleLabelUI ---------------------------------------------