tests/PixelRefTest.cpp

#include "Test.h"
#include "TestClassDef.h"

#include "SkPixelRef.h"
#include "SkMallocPixelRef.h"

namespace {

class TestListener : public SkPixelRef::GenIDChangeListener {
public:
    explicit TestListener(int* ptr) : fPtr(ptr) {}
    void onChange() SK_OVERRIDE { (*fPtr)++; }
private:
    int* fPtr;
};

}  // namespace

DEF_TEST(PixelRef_GenIDChange, r) {
    SkMallocPixelRef pixelRef(NULL, 0, NULL);  // We don't really care about the pixels here.

    // Register a listener.
    int count = 0;
    pixelRef.addGenIDChangeListener(SkNEW_ARGS(TestListener, (&count)));
    REPORTER_ASSERT(r, 0 == count);

    // No one has looked at our pixelRef's generation ID, so invalidating it doesn't make sense.
    // (An SkPixelRef tree falls in the forest but there's nobody around to hear it.  Do we care?)
    pixelRef.notifyPixelsChanged();
    REPORTER_ASSERT(r, 0 == count);

    // Force the generation ID to be calculated.
    REPORTER_ASSERT(r, 0 != pixelRef.getGenerationID());

    // Our listener was dropped in the first call to notifyPixelsChanged().  This is a no-op.
    pixelRef.notifyPixelsChanged();
    REPORTER_ASSERT(r, 0 == count);

    // Force the generation ID to be recalculated, then add a listener.
    REPORTER_ASSERT(r, 0 != pixelRef.getGenerationID());
    pixelRef.addGenIDChangeListener(SkNEW_ARGS(TestListener, (&count)));
    pixelRef.notifyPixelsChanged();
    REPORTER_ASSERT(r, 1 == count);

    // Quick check that NULL is safe.
    REPORTER_ASSERT(r, 0 != pixelRef.getGenerationID());
    pixelRef.addGenIDChangeListener(NULL);
    pixelRef.notifyPixelsChanged();
}