samplecode/SampleDash.cpp

   1 /*
   2  * Copyright 2011 Google Inc.
   3  *
   4  * Use of this source code is governed by a BSD-style license that can be
   5  * found in the LICENSE file.
   6  */
   7 #include "SampleCode.h"
   8 #include "SkView.h"
   9 #include "SkCanvas.h"
  10 #include "SkGraphics.h"
  11 #include "SkRandom.h"
  12 #include "SkDashPathEffect.h"
  13 #include "SkShader.h"
  14
  15 static void setBitmapDash(SkPaint* paint, int width) {
  16     SkColor c = paint->getColor();
  17
  18     SkBitmap bm;
  19     bm.allocN32Pixels(2, 1);
  20     bm.lockPixels();
  21     *bm.getAddr32(0, 0) = SkPreMultiplyARGB(0xFF, SkColorGetR(c),
  22                                             SkColorGetG(c), SkColorGetB(c));
  23     *bm.getAddr32(1, 0) = 0;
  24     bm.unlockPixels();
  25
  26     SkMatrix matrix;
  27     matrix.setScale(SkIntToScalar(width), SK_Scalar1);
  28
  29     SkShader* s = SkShader::CreateBitmapShader(bm, SkShader::kRepeat_TileMode,
  30                                                SkShader::kClamp_TileMode, &matrix);
  31
  32     paint->setShader(s)->unref();
  33 }
  34
  35 class DashView : public SampleView {
  36 public:
  37     DashView() {
  38         this->setBGColor(0xFFDDDDDD);
  39     }
  40
  41 protected:
  42     // overrides from SkEventSink
  43     virtual bool onQuery(SkEvent* evt) {
  44         if (SampleCode::TitleQ(*evt)) {
  45             SampleCode::TitleR(evt, "Dash");
  46             return true;
  47         }
  48         return this->INHERITED::onQuery(evt);
  49     }
  50
  51     virtual void onDrawContent(SkCanvas* canvas) {
  52         static const char* gStr[] = {
  53             "11",
  54             "44",
  55             "112233",
  56             "411327463524",
  57         };
  58
  59         SkPaint paint;
  60         paint.setStrokeWidth(SkIntToScalar(1));
  61
  62         SkScalar x0 = SkIntToScalar(10);
  63         SkScalar y0 = SkIntToScalar(10);
  64         SkScalar x1 = x0 + SkIntToScalar(1000);
  65         for (size_t i = 0; i < SK_ARRAY_COUNT(gStr); i++) {
  66             SkScalar interval[12];
  67             size_t len = SkMin32(strlen(gStr[i]), SK_ARRAY_COUNT(interval));
  68             for (size_t j = 0; j < len; j++) {
  69                 interval[j] = SkIntToScalar(gStr[i][j] - '0');
  70             }
  71
  72             SkDashPathEffect dash(interval, len, 0);
  73             paint.setPathEffect(&dash);
  74             canvas->drawLine(x0, y0, x1, y0, paint);
  75             paint.setPathEffect(nullptr);
  76
  77             y0 += paint.getStrokeWidth() * 3;
  78         }
  79
  80         setBitmapDash(&paint, 3);
  81         canvas->drawLine(x0, y0, x1, y0, paint);
  82     }
  83
  84 private:
  85     typedef SampleView INHERITED;
  86 };
  87
  88 //////////////////////////////////////////////////////////////////////////////
  89
  90 static SkView* MyFactory() { return new DashView; }
  91 static SkViewRegister reg(MyFactory);