From 85fe9eb4ecf91ec431c067055936f61acb3e5a9c Mon Sep 17 00:00:00 2001
From: Eugene Pankov <john.pankov@gmail.com>
Date: Tue, 27 Jul 2021 20:27:03 +0200
Subject: [PATCH] don't show drop hints when dragging the tab onto itself

---
 tabby-core/src/components/splitTab.component.ts      |  1 +
 .../src/components/splitTabDropZone.component.ts     | 12 +++++++++---
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/tabby-core/src/components/splitTab.component.ts b/tabby-core/src/components/splitTab.component.ts
index 43aa88e0..7482310c 100644
--- a/tabby-core/src/components/splitTab.component.ts
+++ b/tabby-core/src/components/splitTab.component.ts
@@ -147,6 +147,7 @@ export interface SplitDropZoneInfo {
         ></split-tab-spanner>
         <split-tab-drop-zone
             *ngFor='let dropZone of _dropZones'
+            [parent]='this'
             [dropZone]='dropZone'
             (tabDropped)='onTabDropped($event, dropZone)'
         >
diff --git a/tabby-core/src/components/splitTabDropZone.component.ts b/tabby-core/src/components/splitTabDropZone.component.ts
index f2621d0d..f784acee 100644
--- a/tabby-core/src/components/splitTabDropZone.component.ts
+++ b/tabby-core/src/components/splitTabDropZone.component.ts
@@ -22,6 +22,7 @@ import { SplitDropZoneInfo } from './splitTab.component'
 })
 export class SplitTabDropZoneComponent extends SelfPositioningComponent {
     @Input() dropZone: SplitDropZoneInfo
+    @Input() parent: BaseTabComponent
     @Output() tabDropped = new EventEmitter<BaseTabComponent>()
     @HostBinding('class.active') isActive = false
     @HostBinding('class.highlighted') isHighlighted = false
@@ -32,8 +33,8 @@ export class SplitTabDropZoneComponent extends SelfPositioningComponent {
         app: AppService,
     ) {
         super(element)
-        this.subscribeUntilDestroyed(app.tabDragActive$, active => {
-            this.isActive = active
+        this.subscribeUntilDestroyed(app.tabDragActive$, tab => {
+            this.isActive = !!tab && tab !== this.parent
             this.layout()
         })
     }
@@ -43,7 +44,12 @@ export class SplitTabDropZoneComponent extends SelfPositioningComponent {
     }
 
     layout () {
-        const tabElement: HTMLElement = this.dropZone.relativeToTab.viewContainerEmbeddedRef?.rootNodes[0]
+        const tabElement: HTMLElement|undefined = this.dropZone.relativeToTab.viewContainerEmbeddedRef?.rootNodes[0]
+
+        if (!tabElement) {
+            // being destroyed
+            return
+        }
 
         const args = {
             t: [0, 0, tabElement.clientWidth, tabElement.clientHeight / 5],