perf(button): no reflows on button onInit

ionic/components/button/button.ts

@@ -1,30 +1,64 @@
-import {Directive} from 'angular2/angular2';
+import {Directive, ElementRef, Renderer} from 'angular2/angular2';
+
+import {IonicConfig} from '../../config/config';
 
 
 /**
  * TODO
  */
 @Directive({
-  selector: 'button,[button]',
-  host: {
-    '[class.icon-left]': 'iconLeft',
-    '[class.icon-right]': 'iconRight',
-    '[class.icon-only]': 'iconOnly'
-  }
+  selector: 'button,[button]'
 })
 export class Button {
 
-  constructor() {
+  constructor(
+    config: IonicConfig,
+    elementRef: ElementRef,
+    renderer: Renderer
+  ) {
     this.iconLeft = this.iconRight = this.iconOnly = false;
+
+    if (config.setting('hoverCSS') === false) {
+      renderer.setElementClass(elementRef, 'disable-hover', true);
     }
 
-  /**
-   * TODO
-   * @param {TODO} icon  TODO
-   */
-  registerIcon(icon) {
-    this.iconLeft = icon.iconLeft;
-    this.iconRight = icon.iconRight;
-    this.iconOnly = icon.iconOnly;
+    // figure out if and where the icon lives in the button
+    let childNodes = elementRef.nativeElement.childNodes;
+    let childNode;
+    let nodes = [];
+    for (let i = 0, l = childNodes.length; i < l; i++) {
+      childNode = childNodes[i];
+      if (childNode.nodeType === 3) {
+        // text node
+        if (childNode.textContent.trim() !== '') {
+          nodes.push(TEXT);
         }
+
+      } else if (childNode.nodeName === 'ICON') {
+        // element node
+        nodes.push(ICON);
+
+      } else {
+        // element other than an <icon>
+        nodes.push(TEXT);
+
+      }
+    }
+
+    if (nodes.length > 1) {
+      if (nodes[0] === ICON && nodes[1] === TEXT) {
+        renderer.setElementClass(elementRef, 'icon-left', true);
+
+      } else if (nodes[0] === TEXT && nodes[1] === ICON) {
+        renderer.setElementClass(elementRef, 'icon-right', true);
+      }
+    } else if (nodes.length === 1 && nodes[0] === ICON) {
+      renderer.setElementClass(elementRef, 'icon-only', true);
+    }
+
+  }
+
 }
+
+const TEXT = 1;
+const ICON = 2;

ionic/components/icon/icon.ts

@@ -1,9 +1,6 @@
-import {Directive, View, NgClass, ElementRef, Optional, Host, Attribute, Renderer} from 'angular2/angular2';
+import {Directive, ElementRef, Attribute, Renderer} from 'angular2/angular2';
 
 import {IonicConfig} from '../../config/config';
-import {IonicComponent} from '../../config/decorators';
-import {Ion} from '../ion';
-import {Button} from '../button/button';
 
 
 /**
@@ -19,7 +16,6 @@ import {Button} from '../button/button';
   ],
   host: {
     '[attr.aria-label]': 'label',
-    '[attr.aria-hidden]': 'ariaHidden',
     'role': 'img'
   }
 })
@@ -27,24 +23,18 @@ export class Icon {
   /**
    * TODO
    * @param {ElementRef} elementRef  TODO
-   * @param {Button} hostButton  TODO
    * @param {IonicConfig} config  TODO
    * @param {Renderer} renderer  TODO
    */
   constructor(
     private elementRef: ElementRef,
-    @Optional() @Host() hostButton: Button,
     config: IonicConfig,
     private renderer: Renderer
   ) {
     this.eleRef = elementRef;
-    this.hostButton = hostButton;
     this.config = config;
 
     this.mode = config.setting('iconMode');
-
-    this.iconLeft = this.iconRight = this.iconOnly = false;
-    this.ariaHidden = true;
   }
 
   /**
@@ -78,29 +68,6 @@ export class Icon {
       this.name = 'ion-' + this.mode + '-' + this.name;
     }
 
-    if (this.hostButton) {
-      // check if there is a sibling element (that's not aria hidden)
-      let hasPreviousSiblingElement = !!ele.previousElementSibling;
-      let hasNextSiblingElement = ele.nextElementSibling && ele.nextElementSibling.getAttribute('aria-hidden') !== 'true';
-
-      if (!hasPreviousSiblingElement && !hasNextSiblingElement) {
-        // this icon is within a button, and doesn't have a sibling element
-        // check for text nodes to the right and left of this icon element
-        this.iconLeft = (ele.nextSibling && ele.nextSibling.textContent || '').trim() !== '';
-        this.iconRight = (ele.previousSibling && ele.previousSibling.textContent || '').trim() !== '';
-        this.iconOnly = !this.iconLeft && !this.iconRight;
-      }
-
-      // tell the button there's a child icon
-      // the button will set the correct css classes on itself
-      this.hostButton.registerIcon(this);
-    }
-
-
-    // hide the icon when it's within a button
-    // and the button isn't an icon only button
-    this.ariaHidden = (this.hostButton && !this.iconOnly);
-
     this.update();
   }
 
@@ -113,7 +80,6 @@ export class Icon {
     this.update();
   }
 
-
   update() {
     if (this.name && this.mode == 'ios') {
 
@@ -135,12 +101,8 @@ export class Icon {
       this._name = this.name;
       this.renderer.setElementClass(this.elementRef, this.name, true);
 
-      if (!this.ariaHidden) {
-        // the icon is either not within a button
-        // or the icon is within a button, and its an icon only button
       this.label = this.name.replace('ion-', '').replace('ios-', '').replace('md-', '').replace('-', ' ');
     }
   }
-  }
 
 }