feat(split-pane): adds enabled input

fixes #10949

src/components/split-pane/split-pane.ts

@@ -1,6 +1,6 @@
 import { ContentChildren, Directive, ElementRef, EventEmitter, forwardRef, Input, Output, QueryList, NgZone, Renderer } from '@angular/core';
 import { Ion } from '../ion';
-import { assert } from '../../util/util';
+import { isTrueProperty, assert } from '../../util/util';
 import { Config } from '../../config/config';
 import { Platform } from '../../platform/platform';
 
@@ -142,9 +142,10 @@ export abstract class RootNode {
 })
 export class SplitPane extends Ion implements RootNode {
 
-  _rmListener: any;
-  _visible: boolean = false;
   _init: boolean = false;
+  _visible: boolean = false;
+  _isEnabled: boolean = true;
+  _rmListener: any;
   _mediaQuery: string | boolean = QUERY['md'];
   _children: RootNode[];
 
@@ -190,6 +191,19 @@ export class SplitPane extends Ion implements RootNode {
     return this._mediaQuery;
   }
 
+  /**
+   * @input {boolean} If `false`, the split-pane is disabled, ie. the side pane will
+   * never be displayed. Default `true`.
+   */
+  @Input()
+  set enabled(val: boolean) {
+    this._isEnabled = isTrueProperty(val);
+    this._update();
+  }
+  get enabled(): boolean {
+    return this._isEnabled;
+  }
+
   /**
    * @output {any} Expression to be called when the split-pane visibility has changed
    */
@@ -247,6 +261,12 @@ export class SplitPane extends Ion implements RootNode {
     this._rmListener && this._rmListener();
     this._rmListener = null;
 
+    // Check if the split-pane is disabled
+    if (!this._isEnabled) {
+      this._setVisible(false);
+      return;
+    }
+
     const query = this._mediaQuery;
     if (typeof query === 'boolean') {
       this._setVisible(query);