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      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 "Sample.h"
      8 
      9 #include "SkBlurMaskFilter.h"
     10 #include "SkCanvas.h"
     11 #include "SkColorFilter.h"
     12 #include "SkColorPriv.h"
     13 #include "SkColorShader.h"
     14 #include "SkGradientShader.h"
     15 #include "SkGraphics.h"
     16 #include "SkOSFile.h"
     17 #include "SkPath.h"
     18 #include "SkRandom.h"
     19 #include "SkRegion.h"
     20 #include "SkShader.h"
     21 #include "SkShaper.h"
     22 #include "SkStream.h"
     23 #include "SkTextBlob.h"
     24 #include "SkTime.h"
     25 #include "SkTypeface.h"
     26 #include "SkUTF.h"
     27 
     28 static const char gText[] =
     29     "When in the Course of human events it becomes necessary for one people "
     30     "to dissolve the political bands which have connected them with another "
     31     "and to assume among the powers of the earth, the separate and equal "
     32     "station to which the Laws of Nature and of Nature's God entitle them, "
     33     "a decent respect to the opinions of mankind requires that they should "
     34     "declare the causes which impel them to the separation.";
     35 
     36 class TextBoxView : public Sample {
     37 public:
     38     TextBoxView() : fShaper(SkShaper::Make()) {}
     39 
     40 protected:
     41     bool onQuery(Sample::Event* evt) override {
     42         if (Sample::TitleQ(*evt)) {
     43             Sample::TitleR(evt, "TextBox");
     44             return true;
     45         }
     46         return this->INHERITED::onQuery(evt);
     47     }
     48 
     49     void drawTest(SkCanvas* canvas, SkScalar w, SkScalar h, SkColor fg, SkColor bg) {
     50         SkAutoCanvasRestore acr(canvas, true);
     51 
     52         canvas->clipRect(SkRect::MakeWH(w, h));
     53         canvas->drawColor(bg);
     54 
     55         SkScalar margin = 20;
     56 
     57         SkPaint paint;
     58         paint.setColor(fg);
     59 
     60         for (int i = 9; i < 24; i += 2) {
     61             SkTextBlobBuilderRunHandler builder(gText);
     62             SkFont font(nullptr, SkIntToScalar(i));
     63             font.setEdging(SkFont::Edging::kSubpixelAntiAlias);
     64 
     65             SkPoint end = fShaper->shape(&builder, font, gText, strlen(gText), true,
     66                                          { margin, margin }, w - margin);
     67             canvas->drawTextBlob(builder.makeBlob(), 0, 0, paint);
     68 
     69             canvas->translate(0, end.y());
     70         }
     71     }
     72 
     73     void onDrawContent(SkCanvas* canvas) override {
     74         SkScalar width = this->width() / 3;
     75         drawTest(canvas, width, this->height(), SK_ColorBLACK, SK_ColorWHITE);
     76         canvas->translate(width, 0);
     77         drawTest(canvas, width, this->height(), SK_ColorWHITE, SK_ColorBLACK);
     78         canvas->translate(width, 0);
     79         drawTest(canvas, width, this->height()/2, SK_ColorGRAY, SK_ColorWHITE);
     80         canvas->translate(0, this->height()/2);
     81         drawTest(canvas, width, this->height()/2, SK_ColorGRAY, SK_ColorBLACK);
     82     }
     83 
     84 private:
     85     std::unique_ptr<SkShaper> fShaper;
     86     typedef Sample INHERITED;
     87 };
     88 
     89 //////////////////////////////////////////////////////////////////////////////
     90 
     91 DEF_SAMPLE( return new TextBoxView(); )
     92