@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);
}
}
@SmallTest
public void testScrollTo() {
class TestData extends Parameter {
final int toPosition;
final int expected;
TestData(int toPosition, int expected) {
this.toPosition = toPosition;
this.expected = expected;
}
}
TestData[] testDataList = {
new TestData(-1, 0),
new TestData(0, 0),
new TestData(1, 1),
new TestData(90, 90),
new TestData(91, 90),
new TestData(80, 80),
};
SnapScroller scroller = new SnapScroller();
scroller.setContentSize(100);
scroller.setViewSize(10);
for (TestData testData : testDataList) {
scroller.scrollTo(testData.toPosition);
assertEquals(testData.toString(), testData.expected, scroller.getScrollPosition());
assertFalse(testData.toString(), scroller.isScrolling());
}
// Widen view size.
scroller.setViewSize(50);
testDataList =
new TestData[] {
new TestData(81, 80),
new TestData(70, 70),
new TestData(71, 70),
new TestData(1, 1),
new TestData(50, 50),
new TestData(51, 50),
};
for (TestData testData : testDataList) {
scroller.scrollTo(testData.toPosition);
assertEquals(testData.toString(), testData.expected, scroller.getScrollPosition());
assertFalse(testData.toString(), scroller.isScrolling());
}
}
@SmallTest
public void testFling() {
class TestData extends Parameter {
final int velocity;
final int mimimumVelocity;
final int scrollPosition;
final int expectedEndScrollPosition;
final boolean expectedIsScrolling;
TestData(
int velocity,
int mimimumVelocity,
int scrollPosition,
int expectedEndScrollPosition,
boolean expectedIsScrolling) {
this.velocity = velocity;
this.mimimumVelocity = mimimumVelocity;
this.scrollPosition = scrollPosition;
this.expectedEndScrollPosition = expectedEndScrollPosition;
this.expectedIsScrolling = expectedIsScrolling;
}
}
int pageSize = 10;
int viewSize = 20;
int contentSize = 110;
final long timestamp = 12345;
TestData[] testDataList = {
// Velocity is 0 so scroll animation does not start.
new TestData(0, 0, 0, 0, false),
// Usual situation to start scroll.
new TestData(-1, 1, 5, 0, true),
new TestData(+1, 1, 5, 10, true),
// Velocity is lower than mininum velocity so animation does not start.
new TestData(-1, 2, 5, 0, false),
new TestData(+1, 2, 5, 0, false),
// Animation starts on the page edge position.
new TestData(-1, 1, 10, 0, true),
new TestData(+1, 1, 10, 20, true),
// Minimum and maximum boundary check.
new TestData(-1, 1, 0, 0, false),
new TestData(+1, 1, 100, 90, false),
};
SnapScroller scroller =
new SnapScroller(
new SnapScroller.TimestampCalculator() {
@Override
public long getTimestamp() {
return timestamp;
}
});
scroller.setContentSize(contentSize);
scroller.setPageSize(pageSize);
scroller.setViewSize(viewSize);
for (TestData testData : testDataList) {
scroller.scrollTo(testData.scrollPosition);
scroller.setMinimumVelocity(testData.mimimumVelocity);
scroller.fling(testData.velocity);
assertEquals(testData.toString(), testData.expectedIsScrolling, scroller.isScrolling());
if (scroller.isScrolling()) {
assertEquals(
testData.toString(), testData.scrollPosition, scroller.getStartScrollPosition());
assertEquals(
testData.toString(),
testData.expectedEndScrollPosition,
scroller.getEndScrollPosition());
assertEquals(testData.toString(), timestamp, scroller.getStartScrollTime());
}
}
}