private static int CalculateMaxPointCountToDisplay()
{
const int oneMlnPointsRequirement = 8 + 16 + 4 + 8;
var memorySize = GetMaxMemorySize() - 40;
var maxPointCount = memorySize / oneMlnPointsRequirement * 1000000;
return((int)Math.Round(maxPointCount / 3));
}
void SnapScroll()
{
var roughIndex = (float)_scrollView.ScrollX / _scrollView.Width;
var targetIndex =
_deltaX < 0 ? Math.Floor(roughIndex)
: _deltaX > 0 ? Math.Ceil(roughIndex)
: Math.Round(roughIndex);
ScrollToIndex((int)targetIndex);
}
private Color ShadeColor(Color color, double percent)
{
var hex = $"#{(0xFFFFFF & color):6x}";
var f = Long.ParseLong(hex.Substring(1), 16);
double t = percent < 0 ? 0 : 255;
var p = percent < 0 ? percent * -1 : percent;
var r = f >> 16;
var g = f >> 8 & 0x00FF;
var b = f & 0x0000FF;
var alpha = Color.GetAlphaComponent(color);
var red = (int)(Math.Round((t - r) * p) + r);
var green = (int)(Math.Round((t - g) * p) + g);
var blue = (int)(Math.Round((t - b) * p) + b);
return(Color.Argb(alpha, red, green, blue));
}
void SnapScroll()
{
try
{
var roughIndex = (float)_scrollView.ScrollX / _scrollView.Width;
var targetIndex =
_deltaX < 0 ? System.Math.Floor(roughIndex)
: _deltaX > 0 ? Math.Ceil(roughIndex)
: Math.Round(roughIndex);
ScrollToIndex((int)targetIndex);
}
catch (System.Exception ex)
{
}
}
public override bool OnTouchEvent(MotionEvent ev)
{
if (mIsVerbose)
{
Log.Verbose(TAG, "onTouchEvent: " + ((int)ev.Action & MotionEventCompat.ActionMask));
}
if (mVelocityTracker == null)
{
mVelocityTracker = VelocityTracker.Obtain();
}
mVelocityTracker.AddMovement(ev);
var action = ev.Action;
switch ((int)action & MotionEventCompat.ActionMask)
{
case (int)MotionEventActions.Down:
// If being flinged and user touches, stop the fling. isFinished
// will be false if being flinged.
if (!mScroller.IsFinished)
{
mScroller.AbortAnimation();
}
// Remember where the motion event started
mDownMotionX = ev.GetX();
mDownMotionY = ev.GetY();
mDownScrollX = ScrollX;
mActivePointerId = MotionEventCompat.GetPointerId(ev, 0);
break;
case (int)MotionEventActions.Move:
if (mIsVerbose)
{
Log.Verbose(TAG, "mTouchState=" + mTouchState);
}
if (mTouchState == TOUCH_STATE_SCROLLING)
{
// Scroll to follow the motion event
int pointerIndex = MotionEventCompat.FindPointerIndex(ev, mActivePointerId);
float x = MotionEventCompat.GetX(ev, pointerIndex);
View lastChild = GetChildAt(ChildCount - 1);
int maxScrollX = lastChild.Right - Width;
ScrollTo(Math.Max(0, Math.Min(maxScrollX,
(int)(mDownScrollX + mDownMotionX - x
))), 0);
if (mOnScrollListener != null)
{
mOnScrollListener.OnScroll(GetCurrentScreenFraction());
}
}
else if (mTouchState == TOUCH_STATE_REST)
{
if (mLocked)
{
// we're locked on the current screen, don't allow moving
break;
}
/*
* Locally do absolute value. mLastMotionX is set to the y value
* of the down event.
*/
int pointerIndex = MotionEventCompat.FindPointerIndex(ev, mActivePointerId);
float x = MotionEventCompat.GetX(ev, pointerIndex);
float y = MotionEventCompat.GetY(ev, pointerIndex);
int xDiff = (int)Math.Abs(x - mDownMotionX);
int yDiff = (int)Math.Abs(y - mDownMotionY);
bool xPaged = xDiff > mPagingTouchSlop;
bool xMoved = xDiff > mTouchSlop;
bool yMoved = yDiff > mTouchSlop;
if (xMoved || yMoved)
{
if (xPaged)
{
// Scroll if the user moved far enough along the X axis
mTouchState = TOUCH_STATE_SCROLLING;
}
// Either way, cancel any pending longpress
if (mAllowLongPress)
{
mAllowLongPress = false;
// Try canceling the long press. It could also have been scheduled
// by a distant descendant, so use the mAllowLongPress flag to block
// everything
View currentScreen = GetScreenAt(mCurrentScreen);
if (currentScreen != null)
{
currentScreen.CancelLongPress();
}
}
}
}
break;
case (int)MotionEventActions.Up:
if (mTouchState == TOUCH_STATE_SCROLLING)
{
int activePointerId = mActivePointerId;
int pointerIndex = MotionEventCompat.FindPointerIndex(ev, activePointerId);
float x = MotionEventCompat.GetX(ev, pointerIndex);
VelocityTracker velocityTracker = mVelocityTracker;
velocityTracker.ComputeCurrentVelocity(1000, mMaximumVelocity);
//TODO(minsdk8): int velocityX = (int) MotionEventUtils.getXVelocity(velocityTracker, activePointerId);
int velocityX = (int)velocityTracker.XVelocity;
bool isFling = Math.Abs(mDownMotionX - x) > MIN_LENGTH_FOR_FLING;
float scrolledPos = GetCurrentScreenFraction();
int whichScreen = Math.Round(scrolledPos);
if (isFling && mIsVerbose)
{
Log.Verbose(TAG, "isFling, whichScreen=" + whichScreen
+ " scrolledPos=" + scrolledPos
+ " mCurrentScreen=" + mCurrentScreen
+ " velocityX=" + velocityX);
}
if (isFling && velocityX > SNAP_VELOCITY && mCurrentScreen > 0)
{
// Fling hard enough to move left
// Don't fling across more than one screen at a time.
int bound = scrolledPos <= whichScreen ?
mCurrentScreen - 1 : mCurrentScreen;
SnapToScreen(Math.Min(whichScreen, bound));
}
else if (isFling && velocityX < -SNAP_VELOCITY &&
mCurrentScreen < ChildCount - 1)
{
// Fling hard enough to move right
// Don't fling across more than one screen at a time.
int bound = scrolledPos >= whichScreen ?
mCurrentScreen + 1 : mCurrentScreen;
SnapToScreen(Math.Max(whichScreen, bound));
}
else
{
SnapToDestination();
}
}
else
{
PerformClick();
}
mTouchState = TOUCH_STATE_REST;
mActivePointerId = INVALID_POINTER;
// Can't do this -> // Intentially fall through to cancel
mTouchState = TOUCH_STATE_REST;
mActivePointerId = INVALID_POINTER;
if (mVelocityTracker != null)
{
mVelocityTracker.Recycle();
mVelocityTracker = null;
}
break;
case (int)MotionEventActions.Cancel:
mTouchState = TOUCH_STATE_REST;
mActivePointerId = INVALID_POINTER;
if (mVelocityTracker != null)
{
mVelocityTracker.Recycle();
mVelocityTracker = null;
}
break;
case (int)MotionEventCompat.ActionPointerUp:
OnSecondaryPointerUp(ev);
break;
}
return(true);
}
