IDEA-344769 Account for invisible insets for tool window floating bounds

Now that we have a separate property for external decorator bounds,
implement it for both decorators to account for invisible insets.

As there seems to be no API for getting those invisible insets,
we use guesswork: the top inset is usually the window header,
and it's visible; the other insets are usually invisible drag zones.

Insets aren't available until the window is connected to an actual display
(the peer is created), so the new property will work incorrectly before
the window is shown for the first time, but thankfully we already have
a helper class to fix the insets after the window is shown, so it works
as expected, even though it's still a dirty hack and not a proper fix.

GitOrigin-RevId: efd75de13d070a6873bda05898803cc533259194

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

@@ -18,6 +18,7 @@ import com.intellij.ui.*;
 import com.intellij.ui.paint.LinePainter2D;
 import com.intellij.util.Alarm;
 import com.intellij.util.MathUtil;
+import com.intellij.util.ui.JBInsets;
 import kotlin.Unit;
 import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.NotNull;
@@ -200,13 +201,17 @@ public final class FloatingDecorator extends JDialog implements FloatingDecorato
   @NotNull
   @Override
   public Rectangle getVisibleWindowBounds() {
-    return getBounds();
+    var result = getBounds();
+    JBInsets.removeFrom(result, ToolWindowExternalDecoratorKt.getInvisibleInsets(this));
+    return result;
   }
 
   @Override
   public void setVisibleWindowBounds(@NotNull Rectangle r) {
     myBoundsHelper.setBounds(r);
-    super.setBounds(r);
+    var newBounds = new Rectangle(r);
+    JBInsets.addTo(newBounds, ToolWindowExternalDecoratorKt.getInvisibleInsets(this));
+    super.setBounds(newBounds);
   }
 
   @NotNull

platform/platform-impl/src/com/intellij/openapi/wm/impl/ToolWindowExternalDecorator.kt

@@ -6,6 +6,7 @@ import com.intellij.openapi.util.Key
 import com.intellij.openapi.wm.ToolWindowType
 import com.intellij.openapi.wm.WindowInfo
 import java.awt.Component
+import java.awt.Insets
 import java.awt.Rectangle
 import java.awt.Window
 
@@ -32,3 +33,7 @@ internal interface ToolWindowExternalDecorator {
   }
 
 }
+
+internal val Window.invisibleInsets: Insets
+  // guesswork: the top inset is typically visible (window header), others are typically invisible drag zones
+  get() = insets.apply { top = 0 }

platform/platform-impl/src/com/intellij/openapi/wm/impl/WindowedDecorator.kt

@@ -11,6 +11,7 @@ import com.intellij.openapi.wm.WindowInfo
 import com.intellij.openapi.wm.impl.ToolWindowExternalDecorator.Companion.DECORATOR_PROPERTY
 import com.intellij.toolWindow.InternalDecoratorImpl
 import com.intellij.ui.ClientProperty
+import com.intellij.util.ui.JBInsets
 import java.awt.Component
 import java.awt.Rectangle
 import java.awt.Window
@@ -71,10 +72,16 @@ internal class WindowedDecorator(
   }
 
   override var visibleWindowBounds: Rectangle
-    get() = getFrame().bounds
+    get() {
+      val result = getFrame().bounds
+      JBInsets.removeFrom(result, getFrame().invisibleInsets)
+      return result
+    }
     set(value) {
       boundsHelper.bounds = value
-      getFrame().bounds = value
+      val newBounds = Rectangle(value)
+      JBInsets.addTo(newBounds, getFrame().invisibleInsets)
+      getFrame().bounds = newBounds
     }
 
   override fun log(): Logger = LOG