@SmallTest
public void testComputeScrollOffsetForFling() throws Exception {
class TestData extends Parameter {
final int velocity;
final float decayRate;
final int expectedScrollPosition;
TestData(int velocity, float decayRate, int expectedScrollPosition) {
this.velocity = velocity;
this.decayRate = decayRate;
this.expectedScrollPosition = expectedScrollPosition;
}
}
int scrollPosition = 50;
TestData[] testDataList = {
new TestData(0, 0f, 50),
// Decay rate is 0 so scroll animation happens only once.
new TestData(+1000, 0f, 60),
// Decay rate is 1 so scroll animation happens repeatedly until
// reaching the maximum boundary.
new TestData(+1000, 1f, 90),
// Check boundary value.
new TestData(Integer.MAX_VALUE, 1f, 90),
};
SnapScroller.TimestampCalculator timestampCalculator =
createMock(SnapScroller.TimestampCalculator.class);
SnapScroller scroller = new SnapScroller(timestampCalculator);
scroller.setContentSize(110);
scroller.setPageSize(10);
scroller.setViewSize(20);
scroller.setMinimumVelocity(0);
for (TestData testData : testDataList) {
resetAll();
expect(timestampCalculator.getTimestamp())
.andStubAnswer(
new IAnswer<Long>() {
long counter = 0;
@Override
public Long answer() throws Throwable {
return counter += 100;
}
});
replayAll();
scroller.setDecayRate(testData.decayRate);
scroller.scrollTo(scrollPosition);
scroller.fling(testData.velocity);
while (scroller.isScrolling()) {
scroller.computeScrollOffset();
}
assertEquals(testData.toString(), testData.expectedScrollPosition, scroller.scrollPosition);
}
}
