Fixed theming bug in button and button group.

lib/pixi/buttongroup.js

@@ -113,8 +113,8 @@ export default class ButtonGroup extends PIXI.Container {
                 strokeActive: theme.strokeActive,
                 strokeActiveWidth: theme.strokeActiveWidth,
                 strokeActiveAlpha: theme.strokeActiveAlpha,
-                textStyle: theme.textStyle,
-                textStyleActive: theme.textStyleActive,
+                textStyle: {},
+                textStyleActive: {},
                 style: 'default',
                 radius: theme.radius,
                 disabled: null,
@@ -127,6 +127,9 @@ export default class ButtonGroup extends PIXI.Container {
             opts
         )
 
+        this.opts.textStyle = Object.assign({}, theme.textStyle, this.opts.textStyle)
+        this.opts.textStyleActive = Object.assign({}, theme.textStyleActive, this.opts.textStyleActive)
+
         this.buttons = []
 
         this._disabled = null
@@ -440,8 +443,10 @@ export default class ButtonGroup extends PIXI.Container {
      * @param {*} event
      */
     onStart(event) {
-
-        if ((this.opts.maxWidth != null && this.__initWidth > this.opts.maxWidth) || (this.opts.maxHeight != null && this.__initHeight > this.opts.maxHeight)) {
+        if (
+            (this.opts.maxWidth != null && this.__initWidth > this.opts.maxWidth) ||
+            (this.opts.maxHeight != null && this.__initHeight > this.opts.maxHeight)
+        ) {
             this.__dragging = true
 
             this.capture(event)
@@ -509,7 +514,7 @@ export default class ButtonGroup extends PIXI.Container {
                     // stack!
                     const distanceToTop = this.container.y
                     const distanceToBottom = this.opts.maxHeight - this.container.y - this.__initHeight
-                    
+
                     if (distanceToTop > 0) {
                         throwProps.y.end = 0
                     } else if (distanceToBottom > 0) {
@@ -549,8 +554,10 @@ export default class ButtonGroup extends PIXI.Container {
      * @param {*} event
      */
     onScroll(event) {
-
-        if ((this.opts.maxWidth != null && this.__initWidth > this.opts.maxWidth) || (this.opts.maxHeight != null && this.__initHeight > this.opts.maxHeight)) {
+        if (
+            (this.opts.maxWidth != null && this.__initWidth > this.opts.maxWidth) ||
+            (this.opts.maxHeight != null && this.__initHeight > this.opts.maxHeight)
+        ) {
             this.capture(event)
 
             if (this.opts.orientation === 'horizontal') {