samplecode/SampleTextBox.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 "SkBlurMaskFilter.h"
  10 #include "SkCanvas.h"
  11 #include "SkColorShader.h"
  12 #include "SkGradientShader.h"
  13 #include "SkGraphics.h"
  14 #include "SkPath.h"
  15 #include "SkRandom.h"
  16 #include "SkRegion.h"
  17 #include "SkShader.h"
  18 #include "SkUtils.h"
  19 #include "SkColorPriv.h"
  20 #include "SkColorFilter.h"
  21 #include "SkTime.h"
  22 #include "SkTypeface.h"
  23 #include "SkTextBox.h"
  24 #include "SkOSFile.h"
  25 #include "SkStream.h"
  26 #include "SkKey.h"
  27
  28 extern void skia_set_text_gamma(float blackGamma, float whiteGamma);
  29
  30 #if defined(SK_BUILD_FOR_WIN) && defined(SK_FONTHOST_WIN_GDI)
  31 extern SkTypeface* SkCreateTypefaceFromLOGFONT(const LOGFONT&);
  32 #endif
  33
  34 static const char gText[] =
  35     "When in the Course of human events it becomes necessary for one people "
  36     "to dissolve the political bands which have connected them with another "
  37     "and to assume among the powers of the earth, the separate and equal "
  38     "station to which the Laws of Nature and of Nature's God entitle them, "
  39     "a decent respect to the opinions of mankind requires that they should "
  40     "declare the causes which impel them to the separation.";
  41
  42 class TextBoxView : public SampleView {
  43 public:
  44     TextBoxView() {
  45 #if defined(SK_BUILD_FOR_WIN) && defined(SK_FONTHOST_WIN_GDI)
  46         LOGFONT lf;
  47         sk_bzero(&lf, sizeof(lf));
  48         lf.lfHeight = 9;
  49         SkTypeface* tf0 = SkCreateTypefaceFromLOGFONT(lf);
  50         lf.lfHeight = 12;
  51         SkTypeface* tf1 = SkCreateTypefaceFromLOGFONT(lf);
  52         // we assert that different sizes should not affect which face we get
  53         SkASSERT(tf0 == tf1);
  54         tf0->unref();
  55         tf1->unref();
  56 #endif
  57     }
  58
  59 protected:
  60     // overrides from SkEventSink
  61     virtual bool onQuery(SkEvent* evt)  {
  62         if (SampleCode::TitleQ(*evt)) {
  63             SampleCode::TitleR(evt, "TextBox");
  64             return true;
  65         }
  66         return this->INHERITED::onQuery(evt);
  67     }
  68
  69     void drawTest(SkCanvas* canvas, SkScalar w, SkScalar h, SkColor fg, SkColor bg) {
  70         SkAutoCanvasRestore acr(canvas, true);
  71
  72         canvas->clipRect(SkRect::MakeWH(w, h));
  73         canvas->drawColor(bg);
  74         SkScalar margin = 20;
  75         SkTextBox tbox;
  76         tbox.setMode(SkTextBox::kLineBreak_Mode);
  77         tbox.setBox(margin, margin,
  78                     w - margin, h - margin);
  79         tbox.setSpacing(SkIntToScalar(3)/3, 0);
  80
  81         SkPaint paint;
  82         paint.setAntiAlias(true);
  83         paint.setLCDRenderText(true);
  84         paint.setColor(fg);
  85         tbox.setText(gText, strlen(gText), paint);
  86
  87         for (int i = 9; i < 24; i += 2) {
  88             paint.setTextSize(SkIntToScalar(i));
  89             tbox.draw(canvas);
  90             canvas->translate(0, tbox.getTextHeight() + paint.getFontSpacing());
  91         }
  92     }
  93
  94     virtual void onDrawContent(SkCanvas* canvas) {
  95         SkScalar width = this->width() / 3;
  96         drawTest(canvas, width, this->height(), SK_ColorBLACK, SK_ColorWHITE);
  97         canvas->translate(width, 0);
  98         drawTest(canvas, width, this->height(), SK_ColorWHITE, SK_ColorBLACK);
  99         canvas->translate(width, 0);
 100         drawTest(canvas, width, this->height()/2, SK_ColorGRAY, SK_ColorWHITE);
 101         canvas->translate(0, this->height()/2);
 102         drawTest(canvas, width, this->height()/2, SK_ColorGRAY, SK_ColorBLACK);
 103     }
 104
 105 private:
 106     typedef SampleView INHERITED;
 107 };
 108
 109 //////////////////////////////////////////////////////////////////////////////
 110
 111 static SkView* MyFactory() { return new TextBoxView; }
 112 static SkViewRegister reg(MyFactory);