List and Tree: Hide cell focus indicator (black rectangle) by default. Can be enabled with List.showCellFocusIndicator=true / Tree.showCellFocusIndicator=true, but then the cell focus indicator is shown only if more than one item is selected.

Table: Hide cell focus indicator (black rectangle) by default if none of the selected cells is editable. Can be show always with `Table.showCellFocusIndicator=true`.

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatListCellBorder.java

@@ -23,8 +23,9 @@ import javax.swing.SwingUtilities;
 import javax.swing.UIManager;
 
 /**
- * Cell border for {@link javax.swing.DefaultListCellRenderer}.
- *
+ * Cell border for {@link javax.swing.DefaultListCellRenderer}
+ * (used by {@link javax.swing.JList}).
+ * <p>
  * Uses separate cell margins from UI defaults to allow easy customizing.
  *
  * @author Karl Tauber
@@ -32,23 +33,31 @@ import javax.swing.UIManager;
 public class FlatListCellBorder
 	extends FlatLineBorder
 {
+	final boolean showCellFocusIndicator = UIManager.getBoolean( "List.showCellFocusIndicator" );
+
 	protected FlatListCellBorder() {
 		super( UIManager.getInsets( "List.cellMargins" ), UIManager.getColor( "List.cellFocusColor" ) );
 	}
 
 	//---- class Default ------------------------------------------------------
 
+	/**
+	 * Border for unselected cell that uses margins, but does not paint focus indicator border.
+	 */
 	public static class Default
 		extends FlatListCellBorder
 	{
 		@Override
 		public void paintBorder( Component c, Graphics g, int x, int y, int width, int height ) {
-			// do not paint border
+			// do not paint focus indicator border
 		}
 	}
 
 	//---- class Focused ------------------------------------------------------
 
+	/**
+	 * Border for focused unselected cell that uses margins and paints focus indicator border.
+	 */
 	public static class Focused
 		extends FlatListCellBorder
 	{
@@ -56,12 +65,19 @@ public class FlatListCellBorder
 
 	//---- class Selected -----------------------------------------------------
 
+	/**
+	 * Border for selected cell that uses margins and paints focus indicator border
+	 * if enabled (List.showCellFocusIndicator=true) and exactly one item is selected.
+	 */
 	public static class Selected
 		extends FlatListCellBorder
 	{
 		@Override
 		public void paintBorder( Component c, Graphics g, int x, int y, int width, int height ) {
-			// paint border only if exactly one item is selected
+			if( !showCellFocusIndicator )
+				return;
+
+			// paint focus indicator border only if exactly one item is selected
 			JList<?> list = (JList<?>) SwingUtilities.getAncestorOfClass( JList.class, c );
 			if( list != null && list.getMinSelectionIndex() == list.getMaxSelectionIndex() )
 				return;

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatListUI.java

@@ -56,6 +56,7 @@ import javax.swing.plaf.basic.BasicListUI;
  *
  * @uiDefault List.cellMargins						Insets
  * @uiDefault List.cellFocusColor					Color
+ * @uiDefault List.showCellFocusIndicator			boolean
  *
  * @author Karl Tauber
  */

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatTableCellBorder.java

@@ -0,0 +1,115 @@
+/*
+ * Copyright 2019 FormDev Software GmbH
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.formdev.flatlaf.ui;
+
+import java.awt.Component;
+import java.awt.Graphics;
+import javax.swing.JTable;
+import javax.swing.SwingUtilities;
+import javax.swing.UIManager;
+
+/**
+ * Cell border for {@link javax.swing.table.DefaultTableCellRenderer}
+ * (used by {@link javax.swing.JTable}).
+ * <p>
+ * Uses separate cell margins from UI defaults to allow easy customizing.
+ *
+ * @author Karl Tauber
+ */
+public class FlatTableCellBorder
+	extends FlatLineBorder
+{
+	final boolean showCellFocusIndicator = UIManager.getBoolean( "Table.showCellFocusIndicator" );
+
+	protected FlatTableCellBorder() {
+		super( UIManager.getInsets( "Table.cellMargins" ), UIManager.getColor( "Table.cellFocusColor" ) );
+	}
+
+	//---- class Default ------------------------------------------------------
+
+	/**
+	 * Border for unselected cell that uses margins, but does not paint focus indicator border.
+	 */
+	public static class Default
+		extends FlatTableCellBorder
+	{
+		@Override
+		public void paintBorder( Component c, Graphics g, int x, int y, int width, int height ) {
+			// do not paint focus indicator border
+		}
+	}
+
+	//---- class Focused ------------------------------------------------------
+
+	/**
+	 * Border for focused unselected cell that uses margins and paints focus indicator border.
+	 */
+	public static class Focused
+		extends FlatTableCellBorder
+	{
+	}
+
+	//---- class Selected -----------------------------------------------------
+
+	/**
+	 * Border for selected cell that uses margins and paints focus indicator border
+	 * if enabled (Table.showCellFocusIndicator=true) or at least one selected cell is editable.
+	 */
+	public static class Selected
+		extends FlatTableCellBorder
+	{
+		@Override
+		public void paintBorder( Component c, Graphics g, int x, int y, int width, int height ) {
+			if( !showCellFocusIndicator ) {
+				JTable table = (JTable) SwingUtilities.getAncestorOfClass( JTable.class, c );
+				if( table != null && !isSelectionEditable( table ) )
+					return;
+			}
+
+			super.paintBorder( c, g, x, y, width, height );
+		}
+
+		/**
+		 * Checks whether at least one selected cell is editable.
+		 */
+		private boolean isSelectionEditable( JTable table ) {
+			if( table.getRowSelectionAllowed() ) {
+				int columnCount = table.getColumnCount();
+				int[] selectedRows = table.getSelectedRows();
+				for( int selectedRow : selectedRows ) {
+					for( int column = 0; column < columnCount; column++ ) {
+						if( table.isCellEditable( selectedRow, column ) )
+							return true;
+					}
+				}
+			}
+
+			if( table.getColumnSelectionAllowed() ) {
+				int rowCount = table.getRowCount();
+				int[] selectedColumns = table.getSelectedColumns();
+				for( int selectedColumn : selectedColumns ) {
+					for( int row = 0; row < rowCount; row++ ) {
+						if( table.isCellEditable( row, selectedColumn ) )
+							return true;
+					}
+				}
+			}
+
+			return false;
+		}
+	}
+}

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatTableUI.java

@@ -55,11 +55,17 @@ import com.formdev.flatlaf.util.UIScale;
  *
  * <!-- FlatTableUI -->
  *
- * @uiDefault Table.rowHeight						int
- * @uiDefault Table.showGrid						boolean
- * @uiDefault Table.intercellSpacing				Dimension
- * @uiDefault Table.selectionInactiveBackground		Color
- * @uiDefault Table.selectionInactiveForeground		Color
+ * @uiDefault Table.rowHeight							int
+ * @uiDefault Table.showGrid							boolean
+ * @uiDefault Table.intercellSpacing					Dimension
+ * @uiDefault Table.selectionInactiveBackground			Color
+ * @uiDefault Table.selectionInactiveForeground			Color
+ *
+ * <!-- FlatTableCellBorder -->
+ *
+ * @uiDefault Table.cellMargins							Insets
+ * @uiDefault Table.cellFocusColor						Color
+ * @uiDefault Table.showCellFocusIndicator				boolean
  *
  * @author Karl Tauber
  */

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatTreeUI.java

@@ -83,6 +83,7 @@ import com.formdev.flatlaf.util.UIScale;
  * @uiDefault Tree.selectionInactiveBackground		Color
  * @uiDefault Tree.selectionInactiveForeground		Color
  * @uiDefault Tree.wideSelection					boolean
+ * @uiDefault Tree.showCellFocusIndicator			boolean
  *
  * @author Karl Tauber
  */
@@ -95,6 +96,7 @@ public class FlatTreeUI
 	protected Color selectionInactiveForeground;
 	protected Color selectionBorderColor;
 	protected boolean wideSelection;
+	protected boolean showCellFocusIndicator;
 
 	public static ComponentUI createUI( JComponent c ) {
 		return new FlatTreeUI();
@@ -112,6 +114,7 @@ public class FlatTreeUI
 		selectionInactiveForeground = UIManager.getColor( "Tree.selectionInactiveForeground" );
 		selectionBorderColor = UIManager.getColor( "Tree.selectionBorderColor" );
 		wideSelection = UIManager.getBoolean( "Tree.wideSelection" );
+		showCellFocusIndicator = UIManager.getBoolean( "Tree.showCellFocusIndicator" );
 
 		// scale
 		int rowHeight = FlatUIUtils.getUIInt( "Tree.rowHeight", 16 );
@@ -217,9 +220,7 @@ public class FlatTreeUI
 	protected void paintRow( Graphics g, Rectangle clipBounds, Insets insets, Rectangle bounds,
 		TreePath path, int row, boolean isExpanded, boolean hasBeenExpanded, boolean isLeaf )
 	{
-		if( editingComponent != null && editingRow == row )
-			return;
-
+		boolean isEditing = (editingComponent != null && editingRow == row);
 		boolean hasFocus = tree.hasFocus();
 		boolean cellHasFocus = hasFocus && (row == getLeadSelectionRow());
 		boolean isSelected = tree.isRowSelected( row );
@@ -240,6 +241,9 @@ public class FlatTreeUI
 			}
 		}
 
+		if( isEditing )
+			return;
+
 		// get renderer component
 		Component rendererComponent = currentCellRenderer.getTreeCellRendererComponent( tree,
 			path.getLastPathComponent(), isSelected, isExpanded, isLeaf, row, cellHasFocus );
@@ -262,10 +266,10 @@ public class FlatTreeUI
 				rendererComponent.setForeground( selectionInactiveForeground );
 		}
 
-		// remove selection border if exactly one item is selected
+		// remove focus selection border if exactly one item is selected
 		Color oldBorderSelectionColor = null;
 		if( isSelected && hasFocus &&
-			tree.getMinSelectionRow() == tree.getMaxSelectionRow() &&
+			(!showCellFocusIndicator || tree.getMinSelectionRow() == tree.getMaxSelectionRow()) &&
 			rendererComponent instanceof DefaultTreeCellRenderer )
 		{
 			DefaultTreeCellRenderer renderer = (DefaultTreeCellRenderer) rendererComponent;

flatlaf-core/src/main/resources/com/formdev/flatlaf/FlatLaf.properties

@@ -375,8 +375,11 @@ Table.scrollPaneBorder=com.formdev.flatlaf.ui.FlatBorder
 Table.ascendingSortIcon=com.formdev.flatlaf.icons.FlatAscendingSortIcon
 Table.descendingSortIcon=com.formdev.flatlaf.icons.FlatDescendingSortIcon
 Table.sortIconColor=@icon
-Table.cellNoFocusBorder=2,3,2,3
-Table.focusSelectedCellHighlightBorder=2,3,2,3,@cellFocusColor
+Table.cellMargins=2,3,2,3
+Table.cellFocusColor=@cellFocusColor
+Table.cellNoFocusBorder=com.formdev.flatlaf.ui.FlatTableCellBorder$Default
+Table.focusCellHighlightBorder=com.formdev.flatlaf.ui.FlatTableCellBorder$Focused
+Table.focusSelectedCellHighlightBorder=com.formdev.flatlaf.ui.FlatTableCellBorder$Selected
 Table.selectionInactiveBackground=@selectionInactiveBackground
 Table.selectionInactiveForeground=@selectionInactiveForeground
 Table.dropCellBackground=@dropCellBackground