fix(core): improve loaded/unloaded handling

packages/core/ui/action-bar/index.android.ts

@@ -177,7 +177,9 @@ export class ActionBar extends ActionBarBase {
 	}
 
 	public disposeNativeView() {
-		(<any>this.nativeViewProtected).menuItemClickListener.owner = null;
+		if ((<any>this.nativeViewProtected)?.menuItemClickListener) {
+			(<any>this.nativeViewProtected).menuItemClickListener.owner = null;
+		}
 		super.disposeNativeView();
 	}
 

packages/core/ui/button/index.android.ts

@@ -95,7 +95,7 @@ export class Button extends ButtonBase {
 	}
 
 	public disposeNativeView() {
-		if (this.nativeViewProtected) {
+		if ((<any>this.nativeViewProtected)?.clickListener) {
 			(<any>this.nativeViewProtected).clickListener.owner = null;
 		}
 		super.disposeNativeView();

packages/core/ui/core/view/index.android.ts

@@ -476,7 +476,6 @@ export class View extends ViewCommon {
 	}
 
 	public disposeNativeView(): void {
-		super.disposeNativeView();
 		if (this.touchListenerIsSet) {
 			this.touchListenerIsSet = false;
 			if (this.nativeViewProtected) {
@@ -485,8 +484,12 @@ export class View extends ViewCommon {
 		}
 		if (this.layoutChangeListenerIsSet) {
 			this.layoutChangeListenerIsSet = false;
-			this.nativeViewProtected.removeOnLayoutChangeListener(this.layoutChangeListener);
+			if (this.nativeViewProtected) {
+				this.nativeViewProtected.removeOnLayoutChangeListener(this.layoutChangeListener);
+				this.layoutChangeListener = null;
+			}
 		}
+		super.disposeNativeView();
 	}
 
 	setOnTouchListener() {

packages/core/ui/date-picker/index.android.ts

@@ -91,7 +91,9 @@ export class DatePicker extends DatePickerBase {
 		if (this.timePicker) {
 			this.timePicker.disposeNativeView();
 		}
-		(<any>this.nativeViewProtected).listener.owner = null;
+		if ((<any>this.nativeViewProtected)?.listener) {
+			(<any>this.nativeViewProtected).listener.owner = null;
+		}
 		super.disposeNativeView();
 	}
 

packages/core/ui/image/index.android.ts

@@ -67,7 +67,9 @@ export class Image extends ImageBase {
 	}
 
 	public disposeNativeView() {
-		(<any>this.nativeViewProtected).listener.owner = null;
+		if ((<any>this.nativeViewProtected)?.listener) {
+			(<any>this.nativeViewProtected).listener.owner = null;
+		}
 		super.disposeNativeView();
 	}
 

packages/core/ui/image/index.ios.ts

@@ -39,13 +39,12 @@ export class Image extends ImageBase {
 	}
 
 	public disposeNativeView(): void {
-		super.disposeNativeView();
-
 		if (this.nativeViewProtected?.image) {
 			this.nativeViewProtected.image = null;
 		}
 
 		this.disposeImageSource();
+		super.disposeNativeView();
 	}
 
 	private setTintColor(value: Color) {

packages/core/ui/layouts/root-layout/index.android.ts

@@ -16,17 +16,19 @@ export class RootLayout extends RootLayoutBase {
 		super.insertChild(view, atIndex);
 		if (!view.hasGestureObservers()) {
 			// block tap events from going through to layers behind the view
-			view.nativeViewProtected.setOnTouchListener(
-				new android.view.View.OnTouchListener({
-					onTouch: function (view, event) {
-						return true;
-					},
-				})
-			);
+			if (view.nativeViewProtected) {
+				view.nativeViewProtected.setOnTouchListener(
+					new android.view.View.OnTouchListener({
+						onTouch: function (view, event) {
+							return true;
+						},
+					})
+				);
+			}
 		}
 	}
 	removeChild(view: View): void {
-		if (view.hasGestureObservers()) {
+		if (view.hasGestureObservers() && view.nativeViewProtected) {
 			view.nativeViewProtected.setOnTouchListener(null);
 		}
 		super.removeChild(view);

packages/core/ui/list-picker/index.android.ts

@@ -131,8 +131,12 @@ export class ListPicker extends ListPickerBase {
 
 	public disposeNativeView() {
 		const nativeView = this.nativeViewProtected;
-		(<any>nativeView).formatter.owner = null;
-		(<any>nativeView).valueChangedListener.owner = null;
+		if ((<any>nativeView)?.formatter) {
+			(<any>nativeView).formatter.owner = null;
+		}
+		if ((<any>nativeView)?.valueChangedListener) {
+			(<any>nativeView).valueChangedListener.owner = null;
+		}
 		super.disposeNativeView();
 	}
 

packages/core/ui/list-view/index.android.ts

@@ -153,8 +153,12 @@ export class ListView extends ListViewBase {
 	public disposeNativeView() {
 		const nativeView = this.nativeViewProtected;
 		nativeView.setAdapter(null);
-		(<any>nativeView).itemClickListener.owner = null;
-		(<any>nativeView).adapter.owner = null;
+		if ((<any>nativeView).itemClickListener) {
+			(<any>nativeView).itemClickListener.owner = null;
+		}
+		if ((<any>nativeView).adapter) {
+			(<any>nativeView).adapter.owner = null;
+		}
 		this.clearRealizedCells();
 		super.disposeNativeView();
 	}

packages/core/ui/scroll-view/index.android.ts

@@ -166,8 +166,8 @@ export class ScrollView extends ScrollViewBase {
 	}
 
 	disposeNativeView() {
-		super.disposeNativeView();
 		this.removeNativeListener();
+		super.disposeNativeView();
 	}
 
 	public _onOrientationChanged() {

packages/core/ui/scroll-view/index.ios.ts

@@ -50,6 +50,7 @@ export class ScrollView extends ScrollViewBase {
 	}
 
 	disposeNativeView() {
+		this.removeNativeListener();
 		this._delegate = null;
 		super.disposeNativeView();
 	}

packages/core/ui/search-bar/index.android.ts

@@ -150,8 +150,12 @@ export class SearchBar extends SearchBarBase {
 
 	public disposeNativeView() {
 		const nativeView: any = this.nativeViewProtected;
-		nativeView.closeListener.owner = null;
-		nativeView.queryTextListener.owner = null;
+		if (nativeView.closeListener) {
+			nativeView.closeListener.owner = null;
+		}
+		if (nativeView.queryTextListener) {
+			nativeView.queryTextListener.owner = null;
+		}
 		this._searchPlate = null;
 		this._searchTextView = null;
 		super.disposeNativeView();

packages/core/ui/segmented-bar/index.android.ts

@@ -238,7 +238,9 @@ export class SegmentedBar extends SegmentedBarBase {
 
 	public disposeNativeView() {
 		const nativeView: any = this.nativeViewProtected;
-		nativeView.listener.owner = null;
+		if (nativeView?.listener) {
+			nativeView.listener.owner = null;
+		}
 		super.disposeNativeView();
 	}
 

packages/core/ui/switch/index.android.ts

@@ -52,7 +52,9 @@ export class Switch extends SwitchBase {
 
 	public disposeNativeView() {
 		const nativeView: any = this.nativeViewProtected;
-		nativeView.listener.owner = null;
+		if (nativeView.listener) {
+			nativeView.listener.owner = null;
+		}
 		super.disposeNativeView();
 	}
 

packages/core/ui/tab-view/index.android.ts

@@ -350,8 +350,8 @@ export class TabViewItem extends TabViewItemBase {
 	}
 
 	public disposeNativeView(): void {
-		super.disposeNativeView();
 		(<TabViewItemDefinition>this).canBeLoaded = false;
+		super.disposeNativeView();
 	}
 
 	public createNativeView() {

packages/core/ui/web-view/index.android.ts

@@ -123,10 +123,12 @@ export class WebView extends WebViewBase {
 	public disposeNativeView() {
 		const nativeView = this.nativeViewProtected;
 		if (nativeView) {
+			if ((<any>nativeView).client) {
+				(<any>nativeView).client.owner = null;
+			}
 			nativeView.destroy();
 		}
 
-		(<any>nativeView).client.owner = null;
 		super.disposeNativeView();
 	}
 

packages/core/ui/web-view/index.ios.ts

@@ -208,10 +208,10 @@ export class WebView extends WebViewBase {
 	}
 
 	disposeNativeView() {
-		super.disposeNativeView();
 		this._delegate = null;
 		this._scrollDelegate = null;
 		this._uiDelegate = null;
+		super.disposeNativeView();
 	}
 
 	// @ts-ignore