public SelectRectangleViewModel()
{
MouseDownPoint = new ReactivePropertySlim <Point>(mode: ReactivePropertyMode.None).AddTo(CompositeDisposable);
MouseUpPoint = new ReactivePropertySlim <Point>(mode: ReactivePropertyMode.None).AddTo(CompositeDisposable);
MouseMovePoint = new ReactivePropertySlim <Point>().AddTo(CompositeDisposable);
ViewImageSize = new ReactivePropertySlim <Size>().AddTo(CompositeDisposable);
IsFinishedSelectingRectangle = new ReactivePropertySlim <bool>().AddTo(CompositeDisposable);
SelectedRectangle = new ReactivePropertySlim <Rect>().AddTo(CompositeDisposable);
FixedRectangle = new ReactivePropertySlim <Rect>().AddTo(CompositeDisposable);
// マウス操作中に移動量を流す + 操作完了時に枠位置を通知する
MouseMovePoint
.Select(movePoint => (startPoint: MouseDownPoint.Value, latestPoint: movePoint))
.SkipUntil(MouseDownPoint.ToUnit())
.TakeUntil(MouseUpPoint.ToUnit())
.Finally(() =>
{
var(startPoint, latestPoint) = (MouseDownPoint.Value, MouseUpPoint.Value);
if (startPoint == latestPoint)
{
return;
}
// 実画像の座標系に変換
var viewRect = ClipRectangle(new Rect(startPoint, latestPoint), ViewImageSize.Value);
var imagePixelSize = new Size(MyImage.PixelWidth, MyImage.PixelHeight);
var imagePixelRect = ConvertCoordinate(viewRect, ViewImageSize.Value, imagePixelSize);
FixedRectangle.Value = imagePixelRect;
IsFinishedSelectingRectangle.Value = true;
})
.Repeat()
.Subscribe(x =>
{
SelectedRectangle.Value = ClipRectangle(new Rect(x.startPoint, x.latestPoint), ViewImageSize.Value);
IsFinishedSelectingRectangle.Value = false;
})
.AddTo(CompositeDisposable);
// Viewのサイズ変更に枠サイズを追従
ViewImageSize
.Pairwise()
.Where(x => x.OldItem.Width != 0 && x.OldItem.Height != 0)
.Select(x => (X: x.NewItem.Width / x.OldItem.Width, Y: x.NewItem.Height / x.OldItem.Height))
.Subscribe(ratio => SelectedRectangle.Value = MultipleRectangle(SelectedRectangle.Value, ratio.X, ratio.Y))
.AddTo(CompositeDisposable);
}