Register ProxyViewContainer children with parent layout.

- Fixes a crash when used in a GridLayout on iOS since the layout needs to be
notified of any layout children changes.
- Adds a _parentChanged hook for all views.

apps/tests/ui/proxy-view-container/proxy-view-container-tests.ts

@@ -6,7 +6,7 @@ import color = require("color");
 import platform = require("platform");
 
 import {ProxyViewContainer} from "ui/proxy-view-container";
-import {View, Button, StackLayout} from "ui";
+import {View, Button, LayoutBase, StackLayout, GridLayout} from "ui";
 
 export function test_add_children_to_attached_proxy() {
     var outer = new StackLayout();
@@ -27,6 +27,34 @@ export function test_add_children_to_attached_proxy() {
     helper.buildUIAndRunTest(outer, testAction);
 }
 
+export function test_children_immediately_registered_in_parent_grid_layout() {
+    var outer = new GridLayout();
+    var proxy = new ProxyViewContainer();
+
+    function testAction(views: Array<viewModule.View>) {
+        outer.addChild(proxy);
+        proxy.addChild(createBtn("1"));
+
+        assertNativeChildren(outer, ["1"]);
+    };
+
+    helper.buildUIAndRunTest(outer, testAction);
+}
+
+export function test_children_registered_in_parent_grid_layout_on_attach() {
+    var outer = new GridLayout();
+    var proxy = new ProxyViewContainer();
+
+    function testAction(views: Array<viewModule.View>) {
+        proxy.addChild(createBtn("1"));
+        outer.addChild(proxy);
+
+        assertNativeChildren(outer, ["1"]);
+    };
+
+    helper.buildUIAndRunTest(outer, testAction);
+}
+
 export function test_add_children_to_detached_proxy() {
     var outer = new StackLayout();
     var proxy = new ProxyViewContainer();
@@ -139,16 +167,16 @@ function createBtn(text: string): Button {
     return b;
 }
 
-function assertNativeChildren(stack: StackLayout, arr: Array<string>) {
-    if (stack.android) {
-        let android: org.nativescript.widgets.StackLayout = stack.android;
+function assertNativeChildren(layout: LayoutBase, arr: Array<string>) {
+    if (layout.android) {
+        let android: org.nativescript.widgets.LayoutBase = layout.android;
         TKUnit.assertEqual(android.getChildCount(), arr.length, "Native children");
         for (let i = 0; i < arr.length; i++) {
             let nativeBtn = <android.widget.Button>android.getChildAt(i);
             TKUnit.assertEqual(nativeBtn.getText(), arr[i]);
         }
-    } else if (stack.ios) {
-        let ios: UIView = stack.ios;
+    } else if (layout.ios) {
+        let ios: UIView = layout.ios;
         TKUnit.assertEqual(ios.subviews.count, arr.length, "Native children");
         for (let i = 0; i < arr.length; i++) {
             let nativeBtn = <UIButton>ios.subviews[i];

ui/core/view-common.ts

@@ -961,6 +961,7 @@ export class View extends ProxyObject implements definition.View {
 
         view._parent = this;
         this._addViewCore(view, atIndex);
+        view._parentChanged(null);
 
         trace.write("called _addView on view " + this._domId + " for a child " + view._domId, trace.categories.ViewHierarchy);
     }
@@ -1014,6 +1015,7 @@ export class View extends ProxyObject implements definition.View {
 
         this._removeViewCore(view);
         view._parent = undefined;
+        view._parentChanged(this);
 
         trace.write("called _removeView on view " + this._domId + " for a child " + view._domId, trace.categories.ViewHierarchy);
     }
@@ -1045,6 +1047,10 @@ export class View extends ProxyObject implements definition.View {
         view._eachSetProperty(inheritablePropertiesSetCallback);
     }
 
+    public _parentChanged(oldParent: View): void {
+        //Overridden
+    }
+
     /**
      * Method is intended to be overridden by inheritors and used as "protected".
      */

ui/core/view.d.ts

@@ -509,6 +509,7 @@ declare module "ui/core/view" {
 
         // TODO: Implement logic for stripping these lines out
         //@private
+        _parentChanged(oldParent: View): void;
         _gestureObservers: any;
         _isInheritedChange(): boolean;
         _domId: number;

ui/layouts/grid-layout/grid-layout.ios.ts

@@ -35,24 +35,12 @@ export class GridLayout extends common.GridLayout {
         this.helper.columns.splice(index, 1);
     }
 
-    public addChild(child: View): void {
-        super.addChild(child);
+    public _registerLayoutChild(child: View) {
         this.addToMap(child);
     }
 
-    public insertChild(child: View, atIndex: number): void {
-        super.insertChild(child, atIndex);
-        this.addToMap(child);
-    }
-
-    public removeChild(child: View): void {
+    public _unregisterLayoutChild(child: View) {
         this.removeFromMap(child);
-        super.removeChild(child);
-    }
-
-    public removeChildren(): void {
-        this.map.clear();
-        super.removeChildren();
     }
 
     private getColumnIndex(view: View): number {

ui/layouts/layout-base.d.ts

@@ -50,6 +50,16 @@
          */
         removeChildren(): void;
 
+        /**
+         * INTERNAL. Used by the layout system.
+         */
+        _registerLayoutChild(child: view.View): void;
+
+        /**
+         * INTERNAL. Used by the layout system.
+         */
+        _unregisterLayoutChild(child: view.View): void;
+
         /**
          * Calls the callback for each child that should be laid out.
          * @param callback The callback

ui/layouts/layout-base.ts

@@ -40,15 +40,25 @@ export class LayoutBase extends view.CustomLayoutView implements definition.Layo
         return view.getViewById(this, id);
     }
 
+    public _registerLayoutChild(child: view.View) {
+        //Overridden
+    }
+
+    public _unregisterLayoutChild(child: view.View) {
+        //Overridden
+    }
+
     public addChild(child: view.View): void {
         // TODO: Do we need this method since we have the core logic in the View implementation?
         this._subViews.push(child);
         this._addView(child);
+        this._registerLayoutChild(child);
     }
 
     public insertChild(child: view.View, atIndex: number): void {
         this._subViews.splice(atIndex, 0, child);
         this._addView(child, atIndex);
+        this._registerLayoutChild(child);
     }
 
     public removeChild(child: view.View): void {
@@ -57,6 +67,7 @@ export class LayoutBase extends view.CustomLayoutView implements definition.Layo
         // TODO: consider caching the index on the child.
         var index = this._subViews.indexOf(child);
         this._subViews.splice(index, 1);
+        this._unregisterLayoutChild(child);
     }
 
     public removeChildren(): void {

ui/proxy-view-container/proxy-view-container.ts

@@ -1,8 +1,8 @@
 import types = require("utils/types");
-import view = require("ui/core/view");
+import {View} from "ui/core/view";
 import definition = require("ui/proxy-view-container");
 import trace = require("trace");
-import layout = require("ui/layouts/layout-base");
+import {LayoutBase} from "ui/layouts/layout-base";
 /**
  * Proxy view container that adds all its native children directly to the parent. 
  * To be used as a logical grouping container of views.
@@ -16,7 +16,7 @@ import layout = require("ui/layouts/layout-base");
 // * Proxy (with children) is removed form the DOM.
 //   - IOS: Handled in _removeFromSuperview - when the proxy is removed, it removes all its children from its parent.
 //   - Android: _onDetached calls _removeViewFromNativeVisualTree recursively when the proxy is removed from its parent.
-export class ProxyViewContainer extends layout.LayoutBase implements definition.ProxyViewContainer {
+export class ProxyViewContainer extends LayoutBase implements definition.ProxyViewContainer {
     // No native view for proxy container.
     get ios(): any { 
         return null; 
@@ -51,15 +51,15 @@ export class ProxyViewContainer extends layout.LayoutBase implements definition.
         });
     }
 
-    public _addViewToNativeVisualTree(child: view.View, atIndex?: number): boolean {
-        trace.write("ViewContainer._addViewToNativeVisualTree for a child " + view + " ViewContainer.parent: " + this.parent, trace.categories.ViewHierarchy);
+    public _addViewToNativeVisualTree(child: View, atIndex?: number): boolean {
+        trace.write("ViewContainer._addViewToNativeVisualTree for a child " + child + " ViewContainer.parent: " + this.parent, trace.categories.ViewHierarchy);
         super._addViewToNativeVisualTree(child);
 
         var parent = this.parent;
         if (parent) {
             let baseIndex = 0;
             let insideIndex = 0;
-            if (parent instanceof layout.LayoutBase) {
+            if (parent instanceof LayoutBase) {
                 // Get my index in parent and convert it to native index.
                 baseIndex = parent._childIndexToNativeChildIndex(parent.getChildIndex(this));
             }
@@ -78,8 +78,8 @@ export class ProxyViewContainer extends layout.LayoutBase implements definition.
         return false;
     }
 
-    public _removeViewFromNativeVisualTree(child: view.View): void {
-        trace.write("ProxyViewContainer._removeViewFromNativeVisualTree for a child " + view + " ViewContainer.parent: " + this.parent, trace.categories.ViewHierarchy);
+    public _removeViewFromNativeVisualTree(child: View): void {
+        trace.write("ProxyViewContainer._removeViewFromNativeVisualTree for a child " + child + " ViewContainer.parent: " + this.parent, trace.categories.ViewHierarchy);
         super._removeViewFromNativeVisualTree(child);
 
         var parent = this.parent;
@@ -108,4 +108,43 @@ export class ProxyViewContainer extends layout.LayoutBase implements definition.
             return true;
         });
     }
+
+    /*
+     * Some layouts (e.g. GridLayout) need to get notified when adding and
+     * removing children, so that they can update private measure data.
+     *
+     * We register our children with the parent to avoid breakage.
+     */
+    public _registerLayoutChild(child: View) {
+        if (this.parent instanceof LayoutBase) {
+            (<LayoutBase>this.parent)._registerLayoutChild(child);
+        }
+    }
+
+    public _unregisterLayoutChild(child: View) {
+        if (this.parent instanceof LayoutBase) {
+            (<LayoutBase>this.parent)._unregisterLayoutChild(child);
+        }
+    }
+
+    /*
+     * Register/unregister existing children with the parent layout.
+     */
+    public _parentChanged(oldParent: View): void {
+        const addingToParent = this.parent && !oldParent;
+        const newLayout = <LayoutBase>this.parent;
+        const oldLayout = <LayoutBase>oldParent;
+
+        if (addingToParent && newLayout instanceof LayoutBase) {
+            this._eachChildView((child) => {
+                newLayout._registerLayoutChild(child);
+                return true;
+            });
+        } else if (oldLayout instanceof LayoutBase) {
+            this._eachChildView((child) => {
+                oldLayout._unregisterLayoutChild(child);
+                return true;
+            });
+        }
+    }
 }