skia2/samplecode/SampleCowboy.cpp

/*
 * Copyright 2017 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 "Resources.h"
#include "SkCanvas.h"
#include "SkDOM.h"
#include "SkOSFile.h"
#include "SkOSPath.h"
#include "SkRect.h"
#include "SkStream.h"
#include "SkSVGDOM.h"
#include "SkView.h"

namespace {

class CowboyView : public SampleView {
public:
    CowboyView()
        : fLabel("SampleCowboy")
        , fState(kZoomIn)
        , fAnimationLoop(kAnimationIterations)
        , fDelta(1) {}
    ~CowboyView() override = default;

protected:
    static constexpr auto kAnimationIterations = 5;
    
    enum State {
        kZoomIn,
        kScroll,
        kZoomOut
    };
    
    void onOnceBeforeDraw() override {
        fPath = GetResourcePath("Cowboy.svg");
        SkFILEStream svgStream(fPath.c_str());
        if (!svgStream.isValid()) {
            SkDebugf("file not found: \"path\"\n", fPath.c_str());
            return;
        }

        SkDOM xmlDom;
        if (!xmlDom.build(svgStream)) {
            SkDebugf("XML parsing failed: \"path\"\n", fPath.c_str());
            return;
        }

        fDom = SkSVGDOM::MakeFromDOM(xmlDom);
        if (fDom) {
            fDom->setContainerSize(SkSize::Make(this->width(), this->height()));
        }
    }

    void onDrawContent(SkCanvas* canvas) override {
        if (fDom) {
            canvas->setMatrix(SkMatrix::MakeScale(3));
            canvas->clipRect(SkRect::MakeLTRB(0, 0, 400, 400));
            switch (fState) {
                case kZoomIn:
                    fDelta += 0.2f;
                    canvas->concat(SkMatrix::MakeScale(fDelta));
                    break;
                case kScroll:
                    if (fAnimationLoop > kAnimationIterations/2) {
                        fDelta += 80.f;
                    } else {
                        fDelta -= 80.f;
                    }
                    canvas->concat(SkMatrix::MakeScale(fDelta));
                    canvas->translate(fDelta, 0);
                    break;
                case kZoomOut:
                    fDelta += 0.2f;
                    canvas->concat(SkMatrix::MakeScale(fDelta));
                    break;
            }
            
            fDom->render(canvas);
        }
    }

    void onSizeChange() override {
        if (fDom) {
            fDom->setContainerSize(SkSize::Make(this->width(), this->height()));
        }

        this->INHERITED::onSizeChange();
    }

    bool onQuery(SkEvent* evt) override {
        if (SampleCode::TitleQ(*evt)) {
            SampleCode::TitleR(evt, fLabel.c_str());
            return true;
        }

        return this->INHERITED::onQuery(evt);
    }
    
    bool onAnimate(const SkAnimTimer& timer) override {
        if (!fDom) {
            return false;
        }
        
        --fAnimationLoop;
        if (fAnimationLoop == 0) {
            fAnimationLoop = kAnimationIterations;
            switch (fState) {
                case kZoomIn:
                    fState = kScroll;
                    fDelta = 0;
                    break;
                case kScroll:
                    fState = kZoomOut;
                    fDelta = 2;
                    break;
                case kZoomOut:
                    fState = kZoomIn;
                    fDelta = 1;
                    break;
            }
        }
        return true;
    }
    
private:
    sk_sp<SkSVGDOM> fDom;
    SkString        fPath;
    SkString        fLabel;
    State           fState;
    int             fAnimationLoop;
    SkScalar        fDelta;

    typedef SampleView INHERITED;
};

} // anonymous namespace

DEF_SAMPLE( return new CowboyView(); )