[UI, TW] IJPL-242950 Remove the Show Toolbar action

Remove the action itself.

Make the TW setToolbarVisible overload no-op,
so the toolbars retain their initial visibility
(and they should be visible by default).

Make the TW overload of isToolbarVisible
always return true to indicate the new behavior.

Reviewed at IJ-CR-209740.

(cherry picked from commit ba486b06af049ad87f3226e44829f6bda5ee7d42)

GitOrigin-RevId: 6955cb859f6e595f95f57c6c911b2320556c20fc

platform/platform-impl/api-dump-unreviewed.txt

@@ -1052,7 +1052,6 @@ f:com.intellij.ide.actions.TogglePresentationModeAction
 f:com.intellij.ide.actions.ToggleToolbarAction
 - s:createAction(java.lang.String,com.intellij.ide.util.PropertiesComponent,java.util.function.Supplier):com.intellij.ide.actions.ToggleToolbarAction
 - s:createToggleToolbarGroup(com.intellij.openapi.project.Project,com.intellij.openapi.wm.ToolWindow):com.intellij.openapi.actionSystem.DefaultActionGroup
-- s:createToolWindowAction(com.intellij.openapi.wm.ToolWindow,com.intellij.ide.util.PropertiesComponent):com.intellij.ide.actions.ToggleToolbarAction
 - getActionUpdateThread():com.intellij.openapi.actionSystem.ActionUpdateThread
 - isSelected(com.intellij.openapi.actionSystem.AnActionEvent):Z
 - s:isToolbarVisible(com.intellij.openapi.wm.ToolWindow):Z
@@ -1066,7 +1065,6 @@ f:com.intellij.ide.actions.ToggleToolbarAction
 - s:setToolbarVisible(java.lang.Iterable,Z):V
 - s:setToolbarVisible(java.lang.String,com.intellij.ide.util.PropertiesComponent,java.lang.Iterable,java.lang.Boolean):V
 - update(com.intellij.openapi.actionSystem.AnActionEvent):V
-- s:updateToolbarVisibility(com.intellij.openapi.wm.ToolWindow,com.intellij.openapi.actionSystem.ActionToolbar,com.intellij.ide.util.PropertiesComponent):V
 c:com.intellij.ide.actions.ToolWindowTabRenameActionBase
 - <init>(java.lang.String,java.lang.String):V
 - actionPerformed(com.intellij.openapi.actionSystem.AnActionEvent,com.intellij.openapi.wm.ToolWindow,com.intellij.ui.content.Content):V

platform/platform-impl/src/com/intellij/ide/actions/ToggleToolbarAction.java

@@ -22,9 +22,6 @@ import com.intellij.openapi.project.Project;
 import com.intellij.openapi.wm.ToolWindow;
 import com.intellij.ui.content.Content;
 import com.intellij.ui.content.ContentManager;
-import com.intellij.ui.content.ContentManagerEvent;
-import com.intellij.ui.content.ContentManagerListener;
-import com.intellij.ui.content.impl.ContentManagerImpl;
 import com.intellij.util.containers.ContainerUtil;
 import com.intellij.util.containers.JBIterable;
 import com.intellij.util.ui.UIUtil;
@@ -44,9 +41,9 @@ import java.util.function.Supplier;
  * @author gregsh
  */
 public final class ToggleToolbarAction extends ToggleAction implements DumbAware {
+  @SuppressWarnings("unused") // published API, can't change the signature
   public static @NotNull DefaultActionGroup createToggleToolbarGroup(@NotNull Project project, @NotNull ToolWindow toolWindow) {
-    return new DefaultActionGroup(new OptionsGroup(toolWindow),
-                                  createToolWindowAction(toolWindow, PropertiesComponent.getInstance(project)));
+    return new DefaultActionGroup(new OptionsGroup(toolWindow));
   }
 
   public static @NotNull ToggleToolbarAction createAction(@NotNull String id,
@@ -55,52 +52,18 @@ public final class ToggleToolbarAction extends ToggleAction implements DumbAware
     return new ToggleToolbarAction(properties, getShowToolbarProperty(id), components);
   }
 
-  public static @NotNull ToggleToolbarAction createToolWindowAction(@NotNull ToolWindow toolWindow,
-                                                                    @NotNull PropertiesComponent properties) {
-    updateToolbarsVisibility(toolWindow, properties);
-    toolWindow.addContentManagerListener(new ContentManagerListener() {
-      @Override
-      public void contentAdded(@NotNull ContentManagerEvent event) {
-        JComponent component = event.getContent().getComponent();
-        setToolbarVisible(Collections.singletonList(component), isToolbarVisible(toolWindow, properties));
-
-        // support nested content managers, e.g. RunnerLayoutUi as content component
-        ContentManager contentManager = ContentManagerImpl.getContentManager(component);
-        if (contentManager != null) {
-          contentManager.addContentManagerListener(this);
-        }
-      }
-
-      @Override
-      public void selectionChanged(@NotNull ContentManagerEvent event) {
-        if (event.getOperation() != ContentManagerEvent.ContentOperation.remove) {
-          updateToolbarsVisibility(toolWindow, properties);
-        }
-      }
-    });
-    return new ToggleToolbarAction(properties, getShowToolbarProperty(toolWindow), () -> {
-      ContentManager manager = toolWindow.getContentManagerIfCreated();
-      return ContainerUtil.createMaybeSingletonList(manager == null ? null : manager.getComponent());
-    });
-  }
-
-  private static void updateToolbarsVisibility(@NotNull ToolWindow toolWindow,
-                                               @NotNull PropertiesComponent properties) {
-    if (toolWindow.getContentManagerIfCreated() == null) return;
-    setToolbarVisible(Collections.singletonList(toolWindow.getComponent()), isToolbarVisible(toolWindow, properties));
-  }
-
-  public static void updateToolbarVisibility(@NotNull ToolWindow toolWindow,
-                                             @NotNull ActionToolbar toolbar,
-                                             @NotNull PropertiesComponent properties) {
-    setToolbarVisible(toolbar, isToolbarVisible(toolWindow, properties));
-  }
-
+  /**
+   * No-op since 2026.3.
+   * @param toolWindow
+   * @param properties
+   * @param visible
+   * @deprecated The Show Toolbar action is dropped in 2026.3, so toolbars are always visible.
+   */
+  @Deprecated
+  @SuppressWarnings("unused") // published API, can't change the signature
   public static void setToolbarVisible(@NotNull ToolWindow toolWindow,
                                        @NotNull PropertiesComponent properties,
                                        @Nullable Boolean visible) {
-    boolean state = visible == null ? isToolbarVisible(toolWindow, properties) : visible;
-    setToolbarVisibleImpl(getShowToolbarProperty(toolWindow), properties, Collections.singletonList(toolWindow.getComponent()), state);
   }
 
   public static void setToolbarVisible(@NotNull String id,
@@ -148,7 +111,7 @@ public final class ToggleToolbarAction extends ToggleAction implements DumbAware
   }
 
   public static boolean isToolbarVisible(@NotNull ToolWindow toolWindow, @NotNull PropertiesComponent properties) {
-    return isSelectedImpl(properties, getShowToolbarProperty(toolWindow));
+    return true;
   }
 
   private final PropertiesComponent myPropertiesComponent;

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

@@ -14,7 +14,6 @@ import com.intellij.ide.actions.ToolWindowMoveAction
 import com.intellij.ide.actions.ToolwindowFusEventFields
 import com.intellij.ide.impl.ContentManagerWatcher
 import com.intellij.ide.ui.UISettings
-import com.intellij.ide.util.PropertiesComponent
 import com.intellij.idea.ActionsBundle
 import com.intellij.internal.statistic.eventLog.events.EventPair
 import com.intellij.openapi.Disposable
@@ -64,7 +63,6 @@ import com.intellij.toolWindow.InternalDecoratorImpl
 import com.intellij.toolWindow.ToolWindowEventSource
 import com.intellij.toolWindow.ToolWindowProperty
 import com.intellij.ui.ClientProperty
-import com.intellij.ui.ComponentTreeWatcher
 import com.intellij.ui.ComponentUtil
 import com.intellij.ui.ExperimentalUI
 import com.intellij.ui.LayeredIcon
@@ -79,7 +77,6 @@ import com.intellij.ui.content.impl.ContentImpl
 import com.intellij.ui.content.impl.ContentManagerImpl
 import com.intellij.ui.content.tabs.TabbedContentAction
 import com.intellij.ui.scale.JBUIScale
-import com.intellij.util.ArrayUtil
 import com.intellij.util.ModalityUiUtil
 import com.intellij.util.SingleAlarm
 import com.intellij.util.cancelOnDispose
@@ -299,15 +296,6 @@ private val LOG = logger<ToolWindowManagerImpl>()
         onMovedOrResized()
       }
     })
-    object : ComponentTreeWatcher(ArrayUtil.EMPTY_CLASS_ARRAY) {
-      override fun processComponent(component: Component) {
-        if (component !is ActionToolbar) return
-        ToggleToolbarAction.updateToolbarVisibility(
-          this@ToolWindowImpl, component, PropertiesComponent.getInstance(project))
-      }
-
-      override fun unprocessComponent(component: Component) = Unit
-    }.register(decorator)
     if (ExperimentalUI.isNewUI()) {
       scrollPaneTracker = ScrollPaneTracker(container = decorator, filter = { true }) {
         updateScrolledState()