Ignore backspace when appending to the filter string in SampleApp. Fixes a bug on Windows where the…

samplecode/OverView.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "OverView.h"
 #include "SampleCode.h"
 #include "SkCanvas.h"
@@ skipping 41 matching lines @@
     bool onQuery(SkEvent* evt) override {
         if (SampleCode::TitleQ(*evt)) {
             SampleCode::TitleR(evt, "Overview");
             return true;
         }
         if (evt->isType(gIsOverview)) {
             return true;
         }
         SkUnichar uni;
         if (SampleCode::CharQ(*evt, &uni)) {
-            fMatchStr.appendUnichar(uni);
+            if (uni >= ' ') {
+                fMatchStr.appendUnichar(uni);
+            }
             this->inval(nullptr);
             return true;
         }
         return this->INHERITED::onQuery(evt);
     }
 
     void onDraw(SkCanvas* canvas) override;
 
     bool onSendClickToChildren(SkScalar x, SkScalar y, unsigned modi) override {
         return false;
@@ skipping 91 matching lines @@
     SkPoint loc = this->start();
     for (int i = 0; i < fCount; ++i) {
         if (draw_this_name(fNames[i], fMatchStr)) {
             canvas->drawRect(this->bounds(loc), paint);
             canvas->drawText(fNames[i].c_str(), fNames[i].size(), loc.x(), loc.y(), fNamePaint);
             this->next(&loc);
         }
     }
 }