Merge pull request #863 from NativeScript/layout-changes

Layout changes

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

@@ -202,6 +202,22 @@ export class GridLayout extends layouts.LayoutBase implements definition.GridLay
         this.onColumnRemoved(itemSpec, index);
     }
 
+    public removeColumns() {
+        for (var i = 0; i < this._cols.length; i++) {
+            this._cols[i].index = -1;
+        }
+        this._cols.length = 0;
+        this.invalidate();
+    }
+
+    public removeRows() {
+        for (var i = 0; i < this._rows.length; i++) {
+            this._rows[i].index = -1;
+        }
+        this._rows.length = 0;
+        this.invalidate();
+    }
+
     protected onRowChanged(element: view.View, oldValue: number, newValue: number) {
         //
     }

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

@@ -119,23 +119,33 @@
         /**
          * Adds a column specification to a GridLayout.
          */
-        public addColumn(itemSpec: ItemSpec);
+        public addColumn(itemSpec: ItemSpec): void;
 
         /**
          * Adds a row specification to a GridLayout.
          */
-        public addRow(itemSpec: ItemSpec);
+        public addRow(itemSpec: ItemSpec): void;
 
         /**
          * Removes a column specification from a GridLayout.
          */
         public removeColumn(itemSpec: ItemSpec): void;
 
+        /**
+         * Removes all columns specification from a GridLayout.
+         */
+        public removeColumns(): void;
+
         /**
          * Removes a row specification from a GridLayout.
          */
         public removeRow(itemSpec: ItemSpec): void;
 
+        /**
+         * Removes all rows specification from a GridLayout.
+         */
+        public removeRows(): void;
+
         /**
          * Gets array of column specifications defined on this instance of GridLayout. 
          */

ui/layouts/layout-base.d.ts

@@ -30,20 +30,25 @@
          * Adds the view to children array.
          * @param view The view to be added to the end of the children array.
          */
-        addChild(view: view.View);
+        addChild(view: view.View): void;
 
         /**
          * Inserts the view to children array at the specified index.
          * @param view The view to be added to the end of the children array.
          * @param atIndex The insertion index.
          */
-        insertChild(child: view.View, atIndex: number);
+        insertChild(child: view.View, atIndex: number): void;
 
         /**
          * Removes the specified view from the children array.
          * @param view The view to remove from the children array.
          */
-        removeChild(view: view.View);
+        removeChild(view: view.View): void;
+
+        /**
+         * Removes all views in this layout.
+         */
+        removeChildren(): void;
 
         /**
          * Gets or sets padding style property.

ui/layouts/layout-base.ts

@@ -37,18 +37,18 @@ export class LayoutBase extends view.CustomLayoutView implements definition.Layo
         return view.getViewById(this, id);
     }
 
-    public addChild(child: view.View) {
+    public addChild(child: view.View): void {
         // TODO: Do we need this method since we have the core logic in the View implementation?
         this._addView(child);
         this._subViews.push(child);
     }
 
-    public insertChild(child: view.View, atIndex: number) {
+    public insertChild(child: view.View, atIndex: number): void {
         this._addView(child, atIndex);
         this._subViews.splice(atIndex, 0, child);
     }
 
-    public removeChild(child: view.View) {
+    public removeChild(child: view.View): void {
         this._removeView(child);
 
         // TODO: consider caching the index on the child.
@@ -56,7 +56,13 @@ export class LayoutBase extends view.CustomLayoutView implements definition.Layo
         this._subViews.splice(index, 1);
     }
 
-    public _eachChildView(callback: (child: view.View) => boolean) {
+    public removeChildren(): void {
+        while (this.getChildrenCount() !== 0) {
+            this.removeChild(this._subViews[this.getChildrenCount() - 1]);
+        }
+    }
+
+    public _eachChildView(callback: (child: view.View) => boolean): void {
         var i;
         var length = this._subViews.length;
         var retVal: boolean;