ToolTip: fixed positioning of huge tooltips (issue #333)

CHANGELOG.md

@@ -7,6 +7,7 @@ FlatLaf Change Log
 
 - Fixed white lines at bottom and right side of window (in dark themes on HiDPI
   screens with scaling enabled).
+- ToolTip: Fixed positioning of huge tooltips. (issue #333)
 
 
 ## 1.2

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

@@ -20,12 +20,16 @@ import java.awt.Color;
 import java.awt.Component;
 import java.awt.Container;
 import java.awt.Dimension;
+import java.awt.GraphicsConfiguration;
+import java.awt.GraphicsDevice;
+import java.awt.GraphicsEnvironment;
 import java.awt.Insets;
 import java.awt.MouseInfo;
 import java.awt.Panel;
 import java.awt.Point;
 import java.awt.PointerInfo;
 import java.awt.Rectangle;
+import java.awt.Toolkit;
 import java.awt.Window;
 import java.awt.event.ComponentEvent;
 import java.awt.event.ComponentListener;
@@ -63,7 +67,7 @@ public class FlatPopupFactory
 	public Popup getPopup( Component owner, Component contents, int x, int y )
 		throws IllegalArgumentException
 	{
-		Point pt = fixToolTipLocation( contents, x, y );
+		Point pt = fixToolTipLocation( owner, contents, x, y );
 		if( pt != null ) {
 			x = pt.x;
 			y = pt.y;
@@ -207,13 +211,13 @@ public class FlatPopupFactory
 	/**
 	 * Usually ToolTipManager places a tooltip at (mouseLocation.x, mouseLocation.y + 20).
 	 * In case that the tooltip would be partly outside of the screen,
-	 * ToolTipManagerthe changes the location so that the entire tooltip fits on screen.
+	 * the ToolTipManager changes the location so that the entire tooltip fits on screen.
 	 * But this can place the tooltip under the mouse location and hide the owner component.
 	 * <p>
 	 * This method checks whether the current mouse location is within tooltip bounds
 	 * and corrects the y-location so that the tooltip is placed above the mouse location.
 	 */
-	private Point fixToolTipLocation( Component contents, int x, int y ) {
+	private Point fixToolTipLocation( Component owner, Component contents, int x, int y ) {
 		if( !(contents instanceof JToolTip) || !wasInvokedFromToolTipManager() )
 			return null;
 
@@ -229,8 +233,30 @@ public class FlatPopupFactory
 		if( !tipBounds.contains( mouseLocation ) )
 			return null;
 
-		// place tooltip above mouse location
+		// find GraphicsConfiguration at mouse location (similar to ToolTipManager.getDrawingGC())
-		return new Point( x, mouseLocation.y - tipSize.height - UIScale.scale( 20 ) );
+		GraphicsConfiguration gc = null;
+		for( GraphicsDevice device : GraphicsEnvironment.getLocalGraphicsEnvironment().getScreenDevices() ) {
+			GraphicsConfiguration dgc = device.getDefaultConfiguration();
+			if( dgc.getBounds().contains( mouseLocation ) ) {
+				gc = dgc;
+				break;
+			}
+		}
+		if( gc == null )
+			gc = owner.getGraphicsConfiguration();
+		if( gc == null )
+			return null;
+
+		Rectangle screenBounds = gc.getBounds();
+		Insets screenInsets = Toolkit.getDefaultToolkit().getScreenInsets( gc );
+		int screenTop = screenBounds.y + screenInsets.top;
+
+		// place tooltip above mouse location if there is enough space
+		int newY =  mouseLocation.y - tipSize.height - UIScale.scale( 20 );
+		if( newY < screenTop )
+			return null;
+
+		return new Point( x, newY );
 	}
 
 	private boolean wasInvokedFromToolTipManager() {