feat(modal-view-ios): handle iOS 13 dismiss modal gesture (#8024)

* feat(modal-view): introduce cancelable property on ShowModalOptions

* fix(modal-view): handle iOS 13 modal dismiss gesture

* chore: address PR comments

nativescript-core/ui/core/view-base/view-base.d.ts

@@ -83,10 +83,15 @@ export interface ShowModalOptions {
     }
     android?: {
         /**
+        * @deprecated Use ShowModalOptions.cancelable instead.
         * An optional parameter specifying whether the modal view can be dismissed when not in full-screen mode.
         */
         cancelable?: boolean
     }
+    /**
+    * An optional parameter specifying whether the modal view can be dismissed when not in full-screen mode.
+    */
+    cancelable?: boolean
 }
 
 export abstract class ViewBase extends Observable {

nativescript-core/ui/core/view/view.android.ts

@@ -640,12 +640,21 @@ export class View extends ViewCommon {
         args.putInt(DOMID, this._domId);
         df.setArguments(args);
 
+        let cancelable = true;
+
+        if (options.android && (<any>options).android.cancelable !== undefined) {
+            cancelable = !!(<any>options).android.cancelable;
+            console.log("ShowModalOptions.android.cancelable is deprecated. Use ShowModalOptions.cancelable instead.");
+        }
+
+        cancelable = options.cancelable !== undefined ? !!options.cancelable : cancelable;
+
         const dialogOptions: DialogOptions = {
             owner: this,
             fullscreen: !!options.fullscreen,
             animated: !!options.animated,
             stretched: !!options.stretched,
-            cancelable: options.android ? !!options.android.cancelable : true,
+            cancelable: cancelable,
             shownCallback: () => this._raiseShownModallyEvent(),
             dismissCallback: () => this.closeModal()
         };

nativescript-core/ui/core/view/view.ios.ts

@@ -30,6 +30,7 @@ export class View extends ViewCommon {
     nativeViewProtected: UIView;
     viewController: UIViewController;
     private _popoverPresentationDelegate: ios.UIPopoverPresentationControllerDelegateImp;
+    private _adaptivePresentationDelegate: ios.UIAdaptivePresentationControllerDelegateImp;
 
     private _isLaidOut = false;
     private _hasTransfrom = false;
@@ -422,14 +423,19 @@ export class View extends ViewCommon {
             controller.modalPresentationStyle = presentationStyle;
 
             if (presentationStyle === UIModalPresentationStyle.Popover) {
-                const popoverPresentationController = controller.popoverPresentationController;
+                this._setupPopoverControllerDelegate(controller, parent);
-                this._popoverPresentationDelegate = ios.UIPopoverPresentationControllerDelegateImp.initWithOwnerAndCallback(new WeakRef(this), this._closeModalCallback);
+            }
-                popoverPresentationController.delegate = this._popoverPresentationDelegate;
+        }
-                const view = parent.nativeViewProtected;
+
-                // Note: sourceView and sourceRect are needed to specify the anchor location for the popover.
+        const cancelable = options.cancelable !== undefined ? !!options.cancelable : true;
-                // Note: sourceView should be the button triggering the modal. If it the Page the popover might appear "behind" the page content
+
-                popoverPresentationController.sourceView = view;
+        if (majorVersion >= 13) {
-                popoverPresentationController.sourceRect = CGRectMake(0, 0, view.frame.size.width, view.frame.size.height);
+            if (cancelable) {
+                // Listen for dismiss modal callback.
+                this._setupAdaptiveControllerDelegate(controller);
+            } else {
+                // Prevent users from dismissing the modal.
+                (<any>controller).modalInPresentation = true;
             }
         }
 
@@ -644,6 +650,22 @@ export class View extends ViewCommon {
             backgroundInternal.hasBorderWidth() ||
             backgroundInternal.hasBorderRadius();
     }
+
+    private _setupPopoverControllerDelegate(controller: UIViewController, parent: View) {
+        const popoverPresentationController = controller.popoverPresentationController;
+        this._popoverPresentationDelegate = ios.UIPopoverPresentationControllerDelegateImp.initWithOwnerAndCallback(new WeakRef(this), this._closeModalCallback);
+        popoverPresentationController.delegate = this._popoverPresentationDelegate;
+        const view = parent.nativeViewProtected;
+        // Note: sourceView and sourceRect are needed to specify the anchor location for the popover.
+        // Note: sourceView should be the button triggering the modal. If it the Page the popover might appear "behind" the page content
+        popoverPresentationController.sourceView = view;
+        popoverPresentationController.sourceRect = CGRectMake(0, 0, view.frame.size.width, view.frame.size.height);
+    }
+
+    private _setupAdaptiveControllerDelegate(controller: UIViewController) {
+        this._adaptivePresentationDelegate = ios.UIAdaptivePresentationControllerDelegateImp.initWithOwnerAndCallback(new WeakRef(this), this._closeModalCallback);
+        controller.presentationController.delegate = this._adaptivePresentationDelegate;
+    }
 }
 View.prototype._nativeBackgroundState = "unset";
 
@@ -1019,6 +1041,28 @@ export namespace ios {
         }
     }
 
+    export class UIAdaptivePresentationControllerDelegateImp extends NSObject implements UIAdaptivePresentationControllerDelegate {
+        public static ObjCProtocols = [UIAdaptivePresentationControllerDelegate];
+
+        private owner: WeakRef<View>;
+        private closedCallback: Function;
+
+        public static initWithOwnerAndCallback(owner: WeakRef<View>, whenClosedCallback: Function): UIAdaptivePresentationControllerDelegateImp {
+            const instance = <UIAdaptivePresentationControllerDelegateImp>super.new();
+            instance.owner = owner;
+            instance.closedCallback = whenClosedCallback;
+
+            return instance;
+        }
+
+        public presentationControllerDidDismiss(presentationController: UIPresentationController) {
+            const owner = this.owner.get();
+            if (owner && typeof this.closedCallback === "function") {
+                this.closedCallback();
+            }
+        }
+    }
+
     export class UIPopoverPresentationControllerDelegateImp extends NSObject implements UIPopoverPresentationControllerDelegate {
         public static ObjCProtocols = [UIPopoverPresentationControllerDelegate];