IDEA-101642 Floating windows disappear/change positions on dual monitor

platform/platform-api/src/com/intellij/ui/ScreenUtil.java

@@ -24,6 +24,7 @@ import org.jetbrains.annotations.Nullable;
 
 import javax.swing.*;
 import java.awt.*;
+import java.awt.geom.Area;
 import java.util.Map;
 
 /**
@@ -79,6 +80,15 @@ public class ScreenUtil {
     return result;
   }
 
+  public static Shape getAllScreensShape() {
+    Rectangle[] rectangles = getAllScreenBounds();
+    Area area = new Area();
+    for (Rectangle rectangle : rectangles) {
+      area.add(new Area(rectangle));
+    }
+    return area;
+  }
+
   public static Rectangle getScreenRectangle(@NotNull Point p) {
     double distance = -1;
     Rectangle answer = null;

platform/platform-impl/src/com/intellij/openapi/wm/impl/WindowManagerImpl.java

@@ -98,11 +98,6 @@ public final class WindowManagerImpl extends WindowManagerEx implements Applicat
 
   private final EventDispatcher<WindowManagerListener> myEventDispatcher = EventDispatcher.create(WindowManagerListener.class);
 
-  /**
-   * Union of bounds of all available default screen devices.
-   */
-  private final Rectangle myScreenBounds;
-
   private final CommandProcessor myCommandProcessor;
   private final WindowWatcher myWindowWatcher;
   /**
@@ -164,18 +159,6 @@ public final class WindowManagerImpl extends WindowManagerEx implements Applicat
     myDialogsToDispose = new HashMap<Project, Set<JDialog>>();
     myFrameExtendedState = Frame.NORMAL;
 
-    // Calculate screen bounds.
-
-    Rectangle screenBounds = new Rectangle();
-    if (!application.isHeadlessEnvironment()) {
-      final GraphicsEnvironment env = GraphicsEnvironment.getLocalGraphicsEnvironment();
-      final GraphicsDevice[] devices = env.getScreenDevices();
-      for (final GraphicsDevice device : devices) {
-        screenBounds = screenBounds.union(device.getDefaultConfiguration().getBounds());
-      }
-    }
-    myScreenBounds = screenBounds;
-
     myActivationListener = new WindowAdapter() {
       @Override
       public void windowActivated(WindowEvent e) {
@@ -245,7 +228,7 @@ public final class WindowManagerImpl extends WindowManagerEx implements Applicat
 
   @Override
   public final Rectangle getScreenBounds() {
-    return myScreenBounds;
+    return ScreenUtil.getAllScreensShape().getBounds();
   }
 
   @Override
@@ -265,16 +248,12 @@ public final class WindowManagerImpl extends WindowManagerEx implements Applicat
 
   @Override
   public final boolean isInsideScreenBounds(final int x, final int y, final int width) {
-    return
-      x >= myScreenBounds.x + 50 - width &&
-      y >= myScreenBounds.y - 50 &&
-      x <= myScreenBounds.x + myScreenBounds.width - 50 &&
-      y <= myScreenBounds.y + myScreenBounds.height - 50;
+    return ScreenUtil.getAllScreensShape().contains(x, y, width, 1);
   }
 
   @Override
   public final boolean isInsideScreenBounds(final int x, final int y) {
-    return myScreenBounds.contains(x, y);
+    return ScreenUtil.getAllScreensShape().contains(x, y);
   }
 
   @Override