+ win.Closing.AddHandler (fun obj args -> askSaveCurrent ())
+
+ // Zoom on the current image.
+ let adjustCurrentImageBorders (deltaX : float) (deltaY : float) =
+ win.borderCurrentImage.BorderThickness <-
+ Thickness (
+ (win.scrollViewCurrentImage.ViewportWidth + deltaX) / 2.,
+ (win.scrollViewCurrentImage.ViewportHeight + deltaY) / 2.,
+ (win.scrollViewCurrentImage.ViewportWidth + deltaX) / 2.,
+ (win.scrollViewCurrentImage.ViewportHeight + deltaY) / 2.
+ )
+
+ win.canvasCurrentImage.SizeChanged.AddHandler (
+ fun obj args ->
+ let deltaX = args.NewSize.Width - args.PreviousSize.Width
+ let deltaY = args.NewSize.Height - args.PreviousSize.Height
+ if deltaX > 0.5 || deltaY > 0.5 then
+ adjustCurrentImageBorders 0.0 0.0
+ // Center the view at the center of the image initialy.
+ win.scrollViewCurrentImage.UpdateLayout ()
+ win.scrollViewCurrentImage.ScrollToHorizontalOffset (win.borderCurrentImage.ActualWidth / 2. - win.scrollViewCurrentImage.ViewportWidth / 2.)
+ win.scrollViewCurrentImage.ScrollToVerticalOffset (win.borderCurrentImage.ActualHeight / 2. - win.scrollViewCurrentImage.ViewportHeight / 2.)
+ )
+
+ win.scrollViewCurrentImage.SizeChanged.AddHandler (
+ fun obj args ->
+ let deltaX = args.NewSize.Width - args.PreviousSize.Width
+ let deltaY = args.NewSize.Height - args.PreviousSize.Height
+ adjustCurrentImageBorders deltaX deltaY
+ win.scrollViewCurrentImage.ScrollToHorizontalOffset (win.scrollViewCurrentImage.HorizontalOffset + deltaX / 8.)
+ win.scrollViewCurrentImage.ScrollToVerticalOffset (win.scrollViewCurrentImage.VerticalOffset + deltaY / 8.)
+ )
+
+ let mutable maxScale = 4.
+ let mutable minScale = 0.25
+ let currentImageScaleTransform = ScaleTransform ()
+ win.canvasCurrentImage.LayoutTransform <- currentImageScaleTransform
+ win.borderCurrentImage.PreviewMouseWheel.AddHandler (
+ fun _obj args ->
+ let scaleFactor = if args.Delta > 0 then 2.0 else 0.5
+ if scaleFactor > 1. && currentScale < maxScale || scaleFactor < 1. && currentScale > minScale then
+ let previousScale = currentScale
+ currentScale <-
+ let newScale = currentScale * scaleFactor
+ if newScale > maxScale then maxScale elif newScale < minScale then minScale else newScale
+ let realScaleFactor = currentScale / previousScale
+
+ let centerX = win.scrollViewCurrentImage.HorizontalOffset + win.scrollViewCurrentImage.ViewportWidth / 2. - win.borderCurrentImage.BorderThickness.Left
+ let centerY = win.scrollViewCurrentImage.VerticalOffset + win.scrollViewCurrentImage.ViewportHeight / 2. - win.borderCurrentImage.BorderThickness.Top
+
+ currentImageScaleTransform.ScaleX <- currentScale
+ currentImageScaleTransform.ScaleY <- currentScale
+
+ win.scrollViewCurrentImage.ScrollToHorizontalOffset (centerX * realScaleFactor - win.scrollViewCurrentImage.ViewportWidth / 2. + win.borderCurrentImage.BorderThickness.Left)
+ win.scrollViewCurrentImage.ScrollToVerticalOffset (centerY * realScaleFactor - win.scrollViewCurrentImage.ViewportHeight / 2. + win.borderCurrentImage.BorderThickness.Top)
+
+ args.Handled <- true
+ )