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      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 "SkView.h"
     10 #include "SkCanvas.h"
     11 #include "SkGradientShader.h"
     12 #include "SkGraphics.h"
     13 #include "SkImageDecoder.h"
     14 #include "SkPath.h"
     15 #include "SkRegion.h"
     16 #include "SkShader.h"
     17 #include "SkUtils.h"
     18 #include "SkXfermode.h"
     19 #include "SkComposeShader.h"
     20 #include "SkColorPriv.h"
     21 #include "SkColorFilter.h"
     22 #include "SkTime.h"
     23 #include "SkTransparentShader.h"
     24 #include "SkTypeface.h"
     25 
     26 static SkShader* make_bitmapfade(const SkBitmap& bm)
     27 {
     28     SkPoint pts[2];
     29     SkColor colors[2];
     30 
     31     pts[0].set(0, 0);
     32     pts[1].set(0, SkIntToScalar(bm.height()));
     33     colors[0] = SK_ColorBLACK;
     34     colors[1] = SkColorSetARGB(0, 0, 0, 0);
     35     SkShader* shaderA = SkGradientShader::CreateLinear(pts, colors, NULL, 2, SkShader::kClamp_TileMode);
     36 
     37     SkShader* shaderB = SkShader::CreateBitmapShader(bm,
     38                         SkShader::kClamp_TileMode, SkShader::kClamp_TileMode);
     39 
     40     SkXfermode* mode = SkXfermode::Create(SkXfermode::kDstIn_Mode);
     41 
     42     SkShader* shader = new SkComposeShader(shaderB, shaderA, mode);
     43     shaderA->unref();
     44     shaderB->unref();
     45     mode->unref();
     46 
     47     return shader;
     48 }
     49 
     50 class ShaderView : public SampleView {
     51 public:
     52     SkShader*   fShader;
     53     SkBitmap    fBitmap;
     54 
     55     ShaderView() {
     56         SkImageDecoder::DecodeFile("/skimages/logo.gif", &fBitmap);
     57 
     58         SkPoint pts[2];
     59         SkColor colors[2];
     60 
     61         pts[0].set(0, 0);
     62         pts[1].set(SkIntToScalar(100), 0);
     63         colors[0] = SK_ColorRED;
     64         colors[1] = SK_ColorBLUE;
     65         SkShader* shaderA = SkGradientShader::CreateLinear(pts, colors, NULL, 2, SkShader::kClamp_TileMode);
     66 
     67         pts[0].set(0, 0);
     68         pts[1].set(0, SkIntToScalar(100));
     69         colors[0] = SK_ColorBLACK;
     70         colors[1] = SkColorSetARGB(0x80, 0, 0, 0);
     71         SkShader* shaderB = SkGradientShader::CreateLinear(pts, colors, NULL, 2, SkShader::kClamp_TileMode);
     72 
     73         SkXfermode* mode = SkXfermode::Create(SkXfermode::kDstIn_Mode);
     74 
     75         fShader = new SkComposeShader(shaderA, shaderB, mode);
     76         shaderA->unref();
     77         shaderB->unref();
     78         mode->unref();
     79     }
     80     virtual ~ShaderView() {
     81         SkSafeUnref(fShader);
     82     }
     83 
     84 protected:
     85     // overrides from SkEventSink
     86     virtual bool onQuery(SkEvent* evt) {
     87         if (SampleCode::TitleQ(*evt)) {
     88             SampleCode::TitleR(evt, "Shaders");
     89             return true;
     90         }
     91         return this->INHERITED::onQuery(evt);
     92     }
     93 
     94     virtual void onDrawContent(SkCanvas* canvas) {
     95         canvas->drawBitmap(fBitmap, 0, 0);
     96 
     97         canvas->translate(SkIntToScalar(20), SkIntToScalar(120));
     98 
     99         SkPaint paint;
    100         SkRect  r;
    101 
    102         paint.setColor(SK_ColorGREEN);
    103         canvas->drawRectCoords(0, 0, SkIntToScalar(100), SkIntToScalar(100), paint);
    104         paint.setShader(fShader);
    105         canvas->drawRectCoords(0, 0, SkIntToScalar(100), SkIntToScalar(100), paint);
    106 
    107         canvas->translate(SkIntToScalar(110), 0);
    108 
    109         int w = fBitmap.width();
    110         int h = fBitmap.height();
    111         w = 120;
    112         h = 80;
    113         r.set(0, 0, SkIntToScalar(w), SkIntToScalar(h));
    114 
    115         paint.setShader(NULL);
    116         canvas->drawRect(r, paint);
    117         paint.setShader(make_bitmapfade(fBitmap))->unref();
    118         canvas->drawRect(r, paint);
    119 
    120         paint.setShader(new SkTransparentShader)->unref();
    121         canvas->drawRect(r, paint);
    122     }
    123 
    124     virtual SkView::Click* onFindClickHandler(SkScalar x, SkScalar y,
    125                                               unsigned modi) SK_OVERRIDE {
    126         this->inval(NULL);
    127         return this->INHERITED::onFindClickHandler(x, y, modi);
    128     }
    129 
    130     virtual bool onClick(Click* click) {
    131         return this->INHERITED::onClick(click);
    132     }
    133 
    134 private:
    135     typedef SampleView INHERITED;
    136 };
    137 
    138 //////////////////////////////////////////////////////////////////////////////
    139 
    140 static SkView* MyFactory() { return new ShaderView; }
    141 static SkViewRegister reg(MyFactory);
    142