allow GMs to animate

samplecode/SampleDegenerateTwoPtRadials.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"
@@ skipping 19 matching lines @@
                                                          pos, SK_ARRAY_COUNT(pos),
                                                          SkShader::kClamp_TileMode);
     SkPaint paint;
     paint.setShader(s)->unref();
 
     canvas->drawRect(rect, paint);
 }
 
 
 class DegenerateTwoPtRadialsView : public SampleView {
-
 public:
     DegenerateTwoPtRadialsView() {
         fTime = 0;
         this->setBGColor(0xFFDDDDDD);
     }
 
 protected:
-    // overrides from SkEventSink
-    virtual bool onQuery(SkEvent* evt) {
+    bool onQuery(SkEvent* evt) SK_OVERRIDE {
         if (SampleCode::TitleQ(*evt)) {
             SampleCode::TitleR(evt, "DegenerateTwoPtRadials");
             return true;
         }
         return this->INHERITED::onQuery(evt);
     }
 
-    virtual void onDrawContent(SkCanvas* canvas) {
-        fTime += SampleCode::GetAnimSecondsDelta();
+    void onDrawContent(SkCanvas* canvas) SK_OVERRIDE {
         SkScalar delta = fTime / 15.f;
         int intPart = SkScalarFloorToInt(delta);
         delta = delta - SK_Scalar1 * intPart;
         if (intPart % 2) {
             delta = SK_Scalar1 - delta;
         }
         delta -= SK_ScalarHalf;
         static const int DELTA_SCALE = 500;
         delta /= DELTA_SCALE;
 
         SkScalar w = SK_Scalar1 * 500;
         SkScalar h = SK_Scalar1 * 500;
         SkScalar l = SK_Scalar1 * 100;
         SkScalar t = SK_Scalar1 * 100;
         draw_gradient2(canvas, SkRect::MakeXYWH(l, t, w, h), delta);
         SkString txt;
         txt.appendf("gap at \"tangent\" pt = %f", SkScalarToFloat(delta));
         SkPaint paint;
         paint.setAntiAlias(true);
         paint.setColor(SK_ColorBLACK);
         canvas->drawText(txt.c_str(), txt.size(), l + w/2 + w*DELTA_SCALE*delta, t + h + SK_Scalar1 * 10, paint);
-        this->inval(NULL);
+    }
+
+    bool onAnimatePulse(SkMSec curr, SkMSec prev) SK_OVERRIDE {
+        fTime += (curr - prev) * 0.001f;
+        return true;
     }
 
 private:
     SkScalar           fTime;
     typedef SampleView INHERITED;
 };
 
 //////////////////////////////////////////////////////////////////////////////
 
 static SkView* MyFactory() { return new DegenerateTwoPtRadialsView; }
 static SkViewRegister reg(MyFactory);