use Make instead of Create to return a shared shader

samplecode/SampleShaders.cpp

-
 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
+
 #include "SampleCode.h"
 #include "SkView.h"
 #include "SkCanvas.h"
 #include "SkGradientShader.h"
 #include "SkGraphics.h"
 #include "SkImageDecoder.h"
 #include "SkPath.h"
 #include "SkRegion.h"
 #include "SkShader.h"
 #include "SkUtils.h"
 #include "SkXfermode.h"
 #include "SkColorPriv.h"
 #include "SkColorFilter.h"
 #include "SkTime.h"
 #include "SkTypeface.h"
 
-static SkShader* make_bitmapfade(const SkBitmap& bm)
+static sk_sp<SkShader> make_bitmapfade(const SkBitmap& bm)
 {
     SkPoint pts[2];
     SkColor colors[2];
 
     pts[0].set(0, 0);
     pts[1].set(0, SkIntToScalar(bm.height()));
     colors[0] = SK_ColorBLACK;
     colors[1] = SkColorSetARGB(0, 0, 0, 0);
-    SkShader* shaderA = SkGradientShader::CreateLinear(pts, colors, nullptr, 2, SkShader::kClamp_TileMode);
+    auto shaderA = SkGradientShader::MakeLinear(pts, colors, nullptr, 2, SkShader::kClamp_TileMode);
 
-    SkShader* shaderB = SkShader::CreateBitmapShader(bm,
+    auto shaderB = SkShader::MakeBitmapShader(bm,
                         SkShader::kClamp_TileMode, SkShader::kClamp_TileMode);
 
-    SkXfermode* mode = SkXfermode::Create(SkXfermode::kDstIn_Mode);
+    SkAutoTUnref<SkXfermode> mode(SkXfermode::Create(SkXfermode::kDstIn_Mode));
 
-    SkShader* shader = SkShader::CreateComposeShader(shaderB, shaderA, mode);
-    shaderA->unref();
-    shaderB->unref();
-    mode->unref();
-
-    return shader;
+    return SkShader::MakeComposeShader(shaderB, shaderA, mode);

[f(malita), 2016/03/08 15:50:35]

prolly not important for a sample, but I'm trying to condition myself:

return SkShader::MakeComposeShader(std::move(shaderB), std::move(shaderA),
mode);

[reed1, 2016/03/08 20:17:15]

Done.

 }
 
 class ShaderView : public SampleView {
 public:
-    SkShader*   fShader;
-    SkBitmap    fBitmap;
+    sk_sp<SkShader> fShader;
+    SkBitmap        fBitmap;
 
     ShaderView() {
         SkImageDecoder::DecodeFile("/skimages/logo.gif", &fBitmap);
 
         SkPoint pts[2];
         SkColor colors[2];
 
         pts[0].set(0, 0);
         pts[1].set(SkIntToScalar(100), 0);
         colors[0] = SK_ColorRED;
         colors[1] = SK_ColorBLUE;
-        SkShader* shaderA = SkGradientShader::CreateLinear(pts, colors, nullptr, 2, SkShader::kClamp_TileMode);
+        auto shaderA = SkGradientShader::MakeLinear(pts, colors, nullptr, 2, SkShader::kClamp_TileMode);
 
         pts[0].set(0, 0);
         pts[1].set(0, SkIntToScalar(100));
         colors[0] = SK_ColorBLACK;
         colors[1] = SkColorSetARGB(0x80, 0, 0, 0);
-        SkShader* shaderB = SkGradientShader::CreateLinear(pts, colors, nullptr, 2, SkShader::kClamp_TileMode);
+        auto shaderB = SkGradientShader::MakeLinear(pts, colors, nullptr, 2, SkShader::kClamp_TileMode);
 
-        SkXfermode* mode = SkXfermode::Create(SkXfermode::kDstIn_Mode);
+        SkAutoTUnref<SkXfermode> mode(SkXfermode::Create(SkXfermode::kDstIn_Mode));
 
-        fShader = SkShader::CreateComposeShader(shaderA, shaderB, mode);
-        shaderA->unref();
-        shaderB->unref();
-        mode->unref();
-    }
-    virtual ~ShaderView() {
-        SkSafeUnref(fShader);
+        fShader = SkShader::MakeComposeShader(shaderA, shaderB, mode);

[f(malita), 2016/03/08 15:50:35]

same

[reed1, 2016/03/08 20:17:15]

Done.

     }
 
 protected:
     // overrides from SkEventSink
     bool onQuery(SkEvent* evt) override {
         if (SampleCode::TitleQ(*evt)) {
             SampleCode::TitleR(evt, "Shaders");
             return true;
         }
         return this->INHERITED::onQuery(evt);
@@ skipping 15 matching lines @@
         canvas->translate(SkIntToScalar(110), 0);
 
         int w = fBitmap.width();
         int h = fBitmap.height();
         w = 120;
         h = 80;
         r.set(0, 0, SkIntToScalar(w), SkIntToScalar(h));
 
         paint.setShader(nullptr);
         canvas->drawRect(r, paint);
-        paint.setShader(make_bitmapfade(fBitmap))->unref();
+        paint.setShader(make_bitmapfade(fBitmap));
         canvas->drawRect(r, paint);
     }
 
     SkView::Click* onFindClickHandler(SkScalar x, SkScalar y, unsigned modi) override {
         this->inval(nullptr);
         return this->INHERITED::onFindClickHandler(x, y, modi);
     }
 
     bool onClick(Click* click)  override {
         return this->INHERITED::onClick(click);
     }
 
 private:
     typedef SampleView INHERITED;
 };
 
 //////////////////////////////////////////////////////////////////////////////
 
 static SkView* MyFactory() { return new ShaderView; }
 static SkViewRegister reg(MyFactory);