feat(ios): added layoutChanged event support to Page (NativeScript#10707)

Author: CatchABus

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

@@ -1034,6 +1034,10 @@ export abstract class View extends ViewCommon {
 	 * @private
 	 */
 	_goToVisualState(state: string);
+	/**
+	 * @private
+	 */
+	_modifyNativeViewFrame(nativeView: any, frame: any): void;
 	/**
 	 * @private
 	 */

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

@@ -202,42 +202,52 @@ export class View extends ViewCommon implements ViewDefinition {
 		//
 	}
 
+	public _modifyNativeViewFrame(nativeView: UIView, frame: CGRect): void {
+		let transform: CATransform3D;
+
+		if (this._isTransformed) {
+			// Always set identity transform before setting frame
+			transform = nativeView.layer.transform;
+			nativeView.layer.transform = CATransform3DIdentity;
+		} else {
+			transform = null;
+		}
+
+		nativeView.frame = frame;
+
+		const adjustedFrame = this.applySafeAreaInsets(frame);
+		if (adjustedFrame) {
+			nativeView.frame = adjustedFrame;
+		}
+
+		if (transform != null) {
+			// Re-apply the transform after the frame is adjusted
+			nativeView.layer.transform = transform;
+		}
+
+		const boundsOrigin = nativeView.bounds.origin;
+		const boundsFrame = adjustedFrame || frame;
+
+		nativeView.bounds = CGRectMake(boundsOrigin.x, boundsOrigin.y, boundsFrame.size.width, boundsFrame.size.height);
+		nativeView.layoutIfNeeded();
+	}
+
 	public _setNativeViewFrame(nativeView: UIView, frame: CGRect): void {
 		const oldFrame = this._cachedFrame || nativeView.frame;
+
 		if (!CGRectEqualToRect(oldFrame, frame)) {
 			if (Trace.isEnabled()) {
 				Trace.write(this + ' :_setNativeViewFrame: ' + JSON.stringify(IOSHelper.getPositionFromFrame(frame)), Trace.categories.Layout);
 			}
-			this._cachedFrame = frame;
-			let adjustedFrame = null;
-			let transform = null;
-			if (this._isTransformed) {
-				// Always set identity transform before setting frame;
-				transform = nativeView.layer.transform;
-				nativeView.layer.transform = CATransform3DIdentity;
-				nativeView.frame = frame;
-			} else {
-				nativeView.frame = frame;
-			}
-
-			adjustedFrame = this.applySafeAreaInsets(frame);
-			if (adjustedFrame) {
-				nativeView.frame = adjustedFrame;
-			}
 
-			if (this._isTransformed) {
-				// re-apply the transform after the frame is adjusted
-				nativeView.layer.transform = transform;
-			}
-
-			const boundsOrigin = nativeView.bounds.origin;
-			const boundsFrame = adjustedFrame || frame;
-			nativeView.bounds = CGRectMake(boundsOrigin.x, boundsOrigin.y, boundsFrame.size.width, boundsFrame.size.height);
-			nativeView.layoutIfNeeded();
+			this._cachedFrame = frame;
+			this._modifyNativeViewFrame(nativeView, frame);
 
 			this._raiseLayoutChangedEvent();
 			this._isLaidOut = true;
 		} else if (!this._isLaidOut) {
+			this._cachedFrame = frame;
+
 			// Rects could be equal on the first layout and an event should be raised.
 			this._raiseLayoutChangedEvent();
 			// But make sure event is raised only once if rects are equal on the first layout as

packages/core/ui/core/view/view-common.ts

@@ -1176,6 +1176,10 @@ export abstract class ViewCommon extends ViewBase implements ViewDefinition {
 		super.resetNativeView();
 	}
 
+	public _modifyNativeViewFrame(nativeView: any, frame: any) {
+		//
+	}
+
 	public _setNativeViewFrame(nativeView: any, frame: any) {
 		//
 	}

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

@@ -424,10 +424,19 @@ export class Page extends PageBase {
 	}
 
 	public layoutNativeView(left: number, top: number, right: number, bottom: number): void {
-		//
+		const nativeView = this.nativeViewProtected;
+		if (!nativeView) {
+			return;
+		}
+
+		const currentFrame = nativeView.frame;
+		// Create a copy of current view frame
+		const newFrame = CGRectMake(currentFrame.origin.x, currentFrame.origin.y, currentFrame.size.width, currentFrame.size.height);
+
+		this._setNativeViewFrame(nativeView, newFrame);
 	}
 
-	public _setNativeViewFrame(nativeView: UIView, frame: CGRect) {
+	public _modifyNativeViewFrame(nativeView: UIView, frame: CGRect) {
 		//
 	}