samplecode/SampleTextAlpha.cpp

   1
   2 /*
   3  * Copyright 2011 Google Inc.
   4  *
   5  * Use of this source code is governed by a BSD-style license that can be
   6  * found in the LICENSE file.
   7  */
   8 #include "SampleCode.h"
   9 #include "SkBlurMask.h"
  10 #include "SkBlurMaskFilter.h"
  11 #include "SkCanvas.h"
  12 #include "SkDevice.h"
  13 #include "SkGradientShader.h"
  14 #include "SkGraphics.h"
  15 #include "SkImageDecoder.h"
  16 #include "SkPath.h"
  17 #include "SkRandom.h"
  18 #include "SkRegion.h"
  19 #include "SkShader.h"
  20 #include "SkUtils.h"
  21 #include "SkXfermode.h"
  22 #include "SkColorPriv.h"
  23 #include "SkColorFilter.h"
  24 #include "SkTime.h"
  25 #include "SkTypeface.h"
  26 #include "SkView.h"
  27
  28 #include "SkOSFile.h"
  29 #include "SkStream.h"
  30
  31 class TextAlphaView : public SampleView {
  32 public:
  33     TextAlphaView() {
  34         fByte = 0xFF;
  35     }
  36
  37 protected:
  38     // overrides from SkEventSink
  39     bool onQuery(SkEvent* evt) SK_OVERRIDE {
  40         if (SampleCode::TitleQ(*evt)) {
  41             SampleCode::TitleR(evt, "TextAlpha");
  42             return true;
  43         }
  44         return this->INHERITED::onQuery(evt);
  45     }
  46
  47     void onDrawContent(SkCanvas* canvas) SK_OVERRIDE {
  48         const char* str = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
  49         SkPaint paint;
  50         SkScalar    x = SkIntToScalar(10);
  51         SkScalar    y = SkIntToScalar(20);
  52
  53         paint.setFlags(0x105);
  54
  55         paint.setARGB(fByte, 0xFF, 0xFF, 0xFF);
  56
  57         paint.setMaskFilter(SkBlurMaskFilter::Create(kNormal_SkBlurStyle,
  58                                     SkBlurMask::ConvertRadiusToSigma(SkIntToScalar(3))));
  59         paint.getMaskFilter()->unref();
  60
  61         SkRandom rand;
  62
  63         for (int ps = 6; ps <= 35; ps++) {
  64             paint.setColor(rand.nextU() | (0xFF << 24));
  65             paint.setTextSize(SkIntToScalar(ps));
  66             paint.setTextSize(SkIntToScalar(24));
  67             canvas->drawText(str, strlen(str), x, y, paint);
  68             y += paint.getFontMetrics(NULL);
  69         }
  70     }
  71
  72     SkView::Click* onFindClickHandler(SkScalar x, SkScalar y, unsigned) SK_OVERRIDE {
  73         return new Click(this);
  74     }
  75
  76     bool onClick(Click* click) SK_OVERRIDE {
  77         int y = click->fICurr.fY;
  78         if (y < 0) {
  79             y = 0;
  80         } else if (y > 255) {
  81             y = 255;
  82         }
  83         fByte = y;
  84         this->inval(NULL);
  85         return true;
  86     }
  87
  88 private:
  89     int fByte;
  90
  91     typedef SampleView INHERITED;
  92 };
  93
  94 //////////////////////////////////////////////////////////////////////////////
  95
  96 static SkView* MyFactory() { return new TextAlphaView; }
  97 static SkViewRegister reg(MyFactory);