修复一些问题

lib/pen.js

@@ -456,7 +456,6 @@ export default class Painter {
         } else {
           this.ctx.fillText(text, x, y, measuredWith);
         }
-        const fontSize = view.css.fontSize.toPx();
         if (view.css.textDecoration) {
           this.ctx.beginPath();
           this.ctx.moveTo(...this.callbackInfo.textDecoration.moveTo);

painter.js

@@ -279,7 +279,8 @@ Component({
         if (isDelete) {
           this.triggerEvent('touchEnd', {
             view: this.currentPalette.views[deleteIndex],
-            index: deleteIndex
+            index: deleteIndex,
+            type: 'delete'
           })
           this.doAction()
         } else if (this.findedIndex < 0) {
@@ -461,6 +462,16 @@ Component({
           height,
           views: []
         }).paint()
+        new Pen(this.bottomContext, {
+          width,
+          height,
+          views: []
+        }).paint()
+        new Pen(this.topContext, {
+          width,
+          height,
+          views: []
+        }).paint()
       });
     },