// If the cropping rectangle's size changed significantly, change the
// view's center and scale according to the cropping rectangle.
private void CenterBasedOnHighlightView(HighlightView hv)
{
var drawRect = hv.DrawRect;
float width = drawRect.Width();
float height = drawRect.Height();
float thisWidth = Width;
float thisHeight = Height;
var z1 = thisWidth / width * .6F;
var z2 = thisHeight / height * .6F;
var zoom = Math.Min(z1, z2);
zoom = zoom * GetScale();
zoom = Math.Max(1F, zoom);
if ((Math.Abs(zoom - GetScale()) / zoom) > .1)
{
float[] coordinates =
{
hv.CropRect.CenterX(),
hv.CropRect.CenterY()
};
ImageMatrix.MapPoints(coordinates);
ZoomTo(zoom, coordinates[0], coordinates[1], 300F);
}
EnsureVisible(hv);
}
// Pan the displayed image to make sure the cropping rectangle is visible.
private void EnsureVisible(HighlightView hv)
{
var r = hv.DrawRect;
var panDeltaX1 = Math.Max(0, IvLeft - r.Left);
var panDeltaX2 = Math.Min(0, IvRight - r.Right);
var panDeltaY1 = Math.Max(0, IvTop - r.Top);
var panDeltaY2 = Math.Min(0, IvBottom - r.Bottom);
var panDeltaX = panDeltaX1 != 0 ? panDeltaX1 : panDeltaX2;
var panDeltaY = panDeltaY1 != 0 ? panDeltaY1 : panDeltaY2;
if (panDeltaX != 0 || panDeltaY != 0)
{
PanBy(panDeltaX, panDeltaY);
}
}
private void AddHighlightView()
{
Crop = new HighlightView(_imageView);
var width = _bitmap.Width;
var height = _bitmap.Height;
var imageRect = new Rect(0, 0, width, height);
// make the default size about 4/5 of the width or height
var cropWidth = Math.Min(width, height) * 4 / 5;
var cropHeight = cropWidth;
if (_aspectX != 0 && _aspectY != 0)
{
if (_aspectX > _aspectY)
{
cropHeight = cropWidth * _aspectY / _aspectX;
}
else
{
cropWidth = cropHeight * _aspectX / _aspectY;
}
}
var x = (width - cropWidth) / 2;
var y = (height - cropHeight) / 2;
var cropRect = new RectF(x, y, x + cropWidth, y + cropHeight);
Crop.Setup(_imageView.ImageMatrix, imageRect, cropRect, _aspectX != 0 && _aspectY != 0);
_imageView.ClearHighlightViews();
Crop.Focused = true;
_imageView.AddHighlightView(Crop);
}
public void AddHighlightView(HighlightView hv)
{
_hightlightViews.Add(hv);
Invalidate();
}
public override bool OnTouchEvent(MotionEvent ev)
{
var cropImage = (CropImage)_context;
if (cropImage.Saving)
{
return(false);
}
switch (ev.Action)
{
case MotionEventActions.Down:
foreach (var hv in _hightlightViews)
{
var edge = hv.GetHit(ev.GetX(), ev.GetY());
if (edge != HighlightView.HitPosition.None)
{
_motionEdge = edge;
_mMotionHighlightView = hv;
_mLastX = ev.GetX();
_mLastY = ev.GetY();
_mMotionHighlightView.Mode =
(edge == HighlightView.HitPosition.Move)
? HighlightView.ModifyMode.Move
: HighlightView.ModifyMode.Grow;
break;
}
}
break;
case MotionEventActions.Up:
if (_mMotionHighlightView != null)
{
CenterBasedOnHighlightView(_mMotionHighlightView);
_mMotionHighlightView.Mode = HighlightView.ModifyMode.None;
}
_mMotionHighlightView = null;
break;
case MotionEventActions.Move:
if (_mMotionHighlightView != null)
{
_mMotionHighlightView.HandleMotion(_motionEdge,
ev.GetX() - _mLastX,
ev.GetY() - _mLastY);
_mLastX = ev.GetX();
_mLastY = ev.GetY();
if (true)
{
// This section of code is optional. It has some user
// benefit in that moving the crop rectangle against
// the edge of the screen causes scrolling but it means
// that the crop rectangle is no longer fixed under
// the user's finger.
EnsureVisible(_mMotionHighlightView);
}
}
break;
}
switch (ev.Action)
{
case MotionEventActions.Up:
Center(true, true);
break;
case MotionEventActions.Move:
// if we're not zoomed then there's no point in even allowing
// the user to move the image around. This call to center puts
// it back to the normalized location (with false meaning don't
// animate).
if (Math.Abs(GetScale() - 1F) < double.Epsilon)
{
Center(true, true);
}
break;
}
return(true);
}