Parasitemia/ParasitemiaUI/GUI.fs

   1 module ParasitemiaUI.GUI
   2
   3 open System
   4 open System.IO
   5 open System.Linq
   6 open System.Windows
   7 open System.Windows.Media
   8 open System.Windows.Markup
   9 open System.Windows.Shapes
  10 open System.Windows.Controls
  11 open System.Diagnostics
  12 open Microsoft.Win32 // For the common dialogs.
  13
  14 open Emgu.CV.WPF
  15
  16 open Logger
  17
  18 open ParasitemiaCore.Config
  19 open ParasitemiaCore.Utils
  20 open Types
  21
  22 let run (defaultConfig: Config) (fileToOpen: string option) =
  23     let app = new Application()
  24     let mainWindow = Views.MainWindow()
  25     let ctrl (name: string): 'a = mainWindow.Root.FindName(name) :?> 'a
  26
  27     let colorRBCHealthy = Brushes.YellowGreen
  28     let colorRBCInfected = Brushes.Red
  29
  30     let state = State.State()
  31     let mutable currentScale = 1.
  32     let mutable displayHealthy = false
  33
  34     let menuExit: MenuItem = ctrl "menuExit"
  35     let menuSaveFile: MenuItem = ctrl "menuSave"
  36     let menuSaveAsFile: MenuItem = ctrl "menuSaveAs"
  37     let menuLoadFile: MenuItem = ctrl "menuOpen"
  38     let menuNewFile: MenuItem = ctrl "menuNew"
  39     let menuAddSourceImage: MenuItem = ctrl "menuAddSourceImage"
  40     let menuAnalysis: MenuItem = ctrl "menuAnalysis"
  41     let menuStartAnalysis: MenuItem = ctrl "menuStartAnalysis"
  42     let menuView: MenuItem = ctrl "menuView"
  43     let menuHightlightRBC: MenuItem = ctrl "menuHightlightRBC"
  44     let menuAbout: MenuItem = ctrl "menuAbout"
  45
  46     let txtDocumentStatus: TextBlock = ctrl "txtDocumentStatus"
  47     let txtMessageStatus: TextBlock = ctrl "txtMessageStatus"
  48
  49     let txtPatient: TextBox = ctrl "txtPatient"
  50     let txtGlobalParasitemia: TextBox = ctrl "txtGlobalParasitemia"
  51
  52     let stackPreviews: StackPanel = ctrl "stackPreviews"
  53
  54     let scrollViewCurrentImage: ScrollViewer = ctrl "scrollViewCurrentImage"
  55     let borderCurrentImage: Border = ctrl "borderCurrentImage"
  56     let canvasCurrentImage: Canvas = ctrl "canvasCurrentImage"
  57     let txtImageInformation1: TextBlock = ctrl "txtImageInformation1"
  58     let txtImageInformation2: TextBlock = ctrl "txtImageInformation2"
  59
  60     let scrollRBC: ScrollViewer = ctrl "scrollRBC"
  61     let stackRBC: StackPanel = ctrl "stackRBC"
  62
  63     // Initializations.
  64     menuHightlightRBC.IsChecked <- displayHealthy
  65
  66     // Utils.
  67     let extractRBCPreview (img: Emgu.CV.Image<Emgu.CV.Structure.Bgr, byte>) (rbc: RBC) : Emgu.CV.Image<Emgu.CV.Structure.Bgr, byte> =
  68         let rbcWidth = rbc.size.Width
  69         let rbcHeight = rbc.size.Height
  70         let x = rbc.center.X - rbcWidth / 2. |> roundInt
  71         let y = rbc.center.Y - rbcHeight / 2. |> roundInt
  72         let w = roundInt rbcWidth
  73         let h = roundInt rbcHeight
  74         img.GetSubRect(System.Drawing.Rectangle(System.Drawing.Point((if x < 0 then 0 else x), (if y < 0 then 0 else y)),
  75                                                 System.Drawing.Size((if x + w >= img.Width then img.Width - x else w),
  76                                                                     (if y + h >= img.Height then img.Height - y else h))))
  77
  78     let setRBCFrameStyle (rbc: RBC) (frame: Views.RBCFrame) =
  79         frame.Opacity <- if displayHealthy || rbc.setManually || rbc.infected then 1. else 0.
  80         let color = if rbc.infected then colorRBCInfected else colorRBCHealthy
  81         frame.manuallyAdded.Visibility <- if rbc.setManually then Visibility.Visible else Visibility.Hidden
  82         frame.manuallyAdded.Fill <- color
  83         frame.border.Stroke <- color
  84
  85     let RBCFrameFromExisting (rbc: RBC) (frame: Views.RBCFrame) : Views.RBCFrame =
  86         frame.Visibility <- Visibility.Visible
  87         frame.Height <- rbc.size.Height
  88         frame.Width <- rbc.size.Width
  89         frame.Tag <- rbc
  90         setRBCFrameStyle rbc frame
  91         frame.border.StrokeThickness <- 1.
  92         frame.txtRBCNumber.Text <- rbc.num.ToString()
  93         frame
  94
  95     let updateDocumentStatus () =
  96         txtDocumentStatus.Text <- if state.FilePath = "" then "<New document>" else state.FilePath
  97
  98     let statusMessageTimer = Threading.DispatcherTimer()
  99     statusMessageTimer.Tick.AddHandler(fun obj args -> statusMessageTimer.Stop(); txtMessageStatus.Text <- "")
 100     statusMessageTimer.Interval <- TimeSpan(0, 0, 2)
 101     let displayStatusMessage (message: string) =
 102         txtMessageStatus.Text <- message
 103         statusMessageTimer.Stop()
 104         statusMessageTimer.Start()
 105
 106     let highlightRBCFrame (frame: Views.RBCFrame) (highlight: bool) =
 107         let rbc = frame.Tag :?> RBC
 108         if highlight
 109         then
 110             frame.border.StrokeThickness <- 3.
 111             if not rbc.infected && not rbc.setManually && not displayHealthy then frame.Opacity <- 1.
 112         else
 113             frame.border.StrokeThickness <- 1.
 114             if not rbc.infected && not rbc.setManually && not displayHealthy then frame.Opacity <- 0.
 115
 116     let zoomToRBC (rbc: RBC) =
 117         scrollViewCurrentImage.ScrollToHorizontalOffset(rbc.center.X * currentScale - scrollViewCurrentImage.ViewportWidth / 2. + borderCurrentImage.BorderThickness.Left)
 118         scrollViewCurrentImage.ScrollToVerticalOffset(rbc.center.Y * currentScale - scrollViewCurrentImage.ViewportHeight / 2. + borderCurrentImage.BorderThickness.Top)
 119
 120     let percentText (nbTotal: int, nb: int) : string =
 121         if nbTotal = 0
 122         then
 123             ""
 124         else
 125             let percent = 100. * (float nb) / (float nbTotal)
 126             sprintf "%.1f %% (%d / %d)" percent nb nbTotal
 127
 128     let updateCurrentImageInformation () =
 129         match state.CurrentImage with
 130         | Some srcImg ->
 131             let parasitemiaStr = percentText (state.ImageParasitemia srcImg)
 132             txtImageInformation1.Inlines.Clear()
 133             txtImageInformation1.Inlines.Add(Documents.Run("Parasitemia: ", FontWeight = FontWeights.Bold))
 134             txtImageInformation1.Inlines.Add(parasitemiaStr)
 135             txtImageInformation1.Inlines.Add(Documents.LineBreak())
 136
 137             txtImageInformation1.Inlines.Add(Documents.Run("Last analysis: ", FontWeight = FontWeights.Bold))
 138             txtImageInformation1.Inlines.Add(Documents.Run(if srcImg.dateLastAnalysis.Ticks = 0L then "<Never>" else srcImg.dateLastAnalysis.ToLocalTime().ToString()))
 139
 140             txtImageInformation2.Inlines.Clear()
 141             let alteredStr = percentText (state.ImageNbAltered srcImg)
 142             txtImageInformation2.Inlines.Add(Documents.Run("Number of erytrocytes manually altered: ", FontWeight = FontWeights.Bold))
 143             txtImageInformation2.Inlines.Add(Documents.Run(alteredStr))
 144             txtImageInformation2.Inlines.Add(Documents.LineBreak())
 145
 146             txtImageInformation2.Inlines.Add(Documents.Run("Average erytrocyte diameter: ", FontWeight = FontWeights.Bold))
 147             txtImageInformation2.Inlines.Add(Documents.Run(srcImg.config.RBCRadius.ToString()))
 148         | _ -> ()
 149
 150     let updateGlobalParasitemia () =
 151         txtGlobalParasitemia.Text <- percentText state.GlobalParasitemia
 152
 153     let updateViewportPreview () =
 154         for preview in stackPreviews.Children |> Seq.cast<Views.ImageSourcePreview> do
 155             let srcImg = preview.Tag :?> SourceImage
 156             if Some srcImg = state.CurrentImage then
 157                 preview.viewport.Visibility <- Visibility.Visible
 158
 159                 let canvasWidth = canvasCurrentImage.ActualWidth * currentScale
 160                 let canvasHeight = canvasCurrentImage.ActualHeight * currentScale
 161                 let previewWidth = (preview.ActualWidth - preview.BorderThickness.Left - preview.BorderThickness.Right)
 162                 let previewHeight = (preview.ActualHeight - preview.BorderThickness.Top - preview.BorderThickness.Bottom)
 163
 164                 let marginLeft = previewWidth * (scrollViewCurrentImage.HorizontalOffset - borderCurrentImage.BorderThickness.Left) / canvasWidth - 2.
 165                 let marginRight = previewWidth * (canvasWidth - (scrollViewCurrentImage.HorizontalOffset - borderCurrentImage.BorderThickness.Right) - scrollViewCurrentImage.ViewportWidth) / canvasWidth - 2.
 166                 let marginTop = previewHeight * (scrollViewCurrentImage.VerticalOffset - borderCurrentImage.BorderThickness.Top) / canvasHeight - 2.
 167                 let marginBottom = previewHeight * (canvasHeight - (scrollViewCurrentImage.VerticalOffset - borderCurrentImage.BorderThickness.Bottom) - scrollViewCurrentImage.ViewportHeight) / canvasHeight - 2.
 168
 169                 preview.viewport.Margin <-
 170                     Thickness(
 171                         marginLeft,
 172                         marginTop,
 173                         marginRight,
 174                         marginBottom)
 175             else
 176                 preview.viewport.Visibility <- Visibility.Hidden
 177
 178     let rec setAsInfected (rbc: RBC) (infected: bool) =
 179         state.SetAsInfected rbc infected
 180         canvasCurrentImage.Children
 181         |> Seq.cast<Views.RBCFrame>
 182         |> Seq.iter
 183             (fun frame ->
 184                 if (frame.Tag :?> RBC) = rbc
 185                 then
 186                     setRBCFrameStyle rbc frame)
 187         updateRBCFramesPreview ()
 188         updateCurrentImageInformation ()
 189         updateGlobalParasitemia ()
 190
 191     and RBCFrame (rbc: RBC) : Views.RBCFrame =
 192         let frame = RBCFrameFromExisting rbc (Views.RBCFrame())
 193         frame.SetValue(Panel.ZIndexProperty, Int32.MaxValue - rbc.num) // To be sure the
 194         frame.menuRBCSetAsHealthy.Click.AddHandler(fun obj args -> setAsInfected (frame.Tag :?> RBC) false)
 195         frame.menuRBCSetAsInfected.Click.AddHandler(fun obj args -> setAsInfected (frame.Tag :?> RBC) true)
 196         frame.ContextMenuOpening.AddHandler(
 197             fun obj args ->
 198                 if (frame.Tag :?> RBC).infected
 199                 then
 200                     frame.menuRBCSetAsHealthy.Visibility <- Visibility.Visible
 201                     frame.menuRBCSetAsInfected.Visibility <- Visibility.Collapsed
 202                 else
 203                     frame.menuRBCSetAsHealthy.Visibility <- Visibility.Collapsed
 204                     frame.menuRBCSetAsInfected.Visibility <- Visibility.Visible)
 205
 206         frame.ContextMenuClosing.AddHandler(fun obj args -> if not frame.IsMouseOver then highlightRBCFrame frame false )
 207         frame.MouseEnter.AddHandler(fun obj args -> highlightRBCFrame frame true)
 208         frame.MouseLeave.AddHandler(fun obj args -> if not frame.grid.ContextMenu.IsOpen then highlightRBCFrame frame false)
 209         frame
 210
 211     and updateRBCFramesPreview () =
 212         match state.CurrentImage with
 213         | Some srcImg ->
 214             let mutable currentPreview = 0
 215             for rbc in srcImg.rbcs |> List.filter (fun rbc -> displayHealthy || rbc.infected) do
 216                 let previewInfected =
 217                     if currentPreview < stackRBC.Children.Count
 218                     then
 219                         RBCFrameFromExisting rbc (stackRBC.Children.[currentPreview] :?> Views.RBCFrame)
 220                     else
 221                         let f = RBCFrame rbc
 222                         f.MouseLeftButtonUp.AddHandler(fun obj args -> zoomToRBC (f.Tag :?> RBC))
 223                         stackRBC.Children.Add(f) |> ignore
 224                         f
 225
 226                 currentPreview <- currentPreview + 1
 227
 228                 previewInfected.Height <- stackRBC.ActualHeight
 229                 previewInfected.Width <- stackRBC.ActualHeight * rbc.size.Width / rbc.size.Height
 230                 previewInfected.border.Fill <- ImageBrush(BitmapSourceConvert.ToBitmapSource(extractRBCPreview srcImg.img rbc))
 231
 232             stackRBC.Children.RemoveRange(currentPreview, stackRBC.Children.Count - currentPreview)
 233         | _ -> ()
 234
 235         updateViewportPreview ()
 236
 237     let updateRBCFramesCurrent () =
 238         match state.CurrentImage with
 239         | Some srcImg ->
 240             let mutable currentCanvas = 0
 241             for rbc in srcImg.rbcs do
 242                 let frame =
 243                     if currentCanvas < canvasCurrentImage.Children.Count
 244                     then
 245                         RBCFrameFromExisting rbc (canvasCurrentImage.Children.[currentCanvas] :?> Views.RBCFrame)
 246                     else
 247                         let f = RBCFrame rbc
 248                         f.Root.Opacity <- 0.7
 249                         canvasCurrentImage.Children.Add(f) |> ignore
 250                         f
 251
 252                 currentCanvas <- currentCanvas + 1
 253
 254                 Canvas.SetLeft(frame, rbc.center.X - rbc.size.Width / 2.)
 255                 Canvas.SetTop(frame, rbc.center.Y - rbc.size.Height / 2.)
 256
 257             for i in currentCanvas .. canvasCurrentImage.Children.Count - 1 do
 258                 canvasCurrentImage.Children.[i].Visibility <- Visibility.Hidden
 259         | _ -> ()
 260
 261     let askDocumentPathToSave () : string option =
 262         let dialog = SaveFileDialog(AddExtension = true, DefaultExt = PiaZ.extension, Filter = PiaZ.filter)
 263
 264         if state.FilePath <> ""
 265         then
 266             dialog.FileName <- FileInfo(state.FilePath).Name
 267         elif state.PatientID <> ""
 268         then
 269             dialog.FileName <- state.PatientID + PiaZ.extension
 270
 271         let res = dialog.ShowDialog()
 272         if res.HasValue && res.Value then
 273             Some dialog.FileName
 274         else
 275             None
 276
 277     let saveCurrentDocument () =
 278         try
 279             if state.FilePath = ""
 280             then
 281                 match askDocumentPathToSave () with
 282                 | Some filepath ->
 283                     state.FilePath <- filepath
 284                     state.Save()
 285                 | _ -> ()
 286             else
 287                 state.Save()
 288             updateDocumentStatus ()
 289             displayStatusMessage "Document saved"
 290         with
 291         | :? IOException as ex ->
 292             Log.Error(ex.ToString())
 293             MessageBox.Show(sprintf "The document cannot be save in '%s'" state.FilePath, "Error saving the document", MessageBoxButton.OK, MessageBoxImage.Error) |> ignore
 294
 295     let saveCurrentDocumentAsNewFile () =
 296         match askDocumentPathToSave () with
 297         | Some filepath ->
 298             state.FilePath <- filepath
 299             saveCurrentDocument ()
 300         | _ -> ()
 301
 302     // Ask the use to save the current document if neccessary.
 303     let askSaveCurrent () =
 304         if state.AlteredSinceLastSave
 305         then
 306             match MessageBox.Show("Would you like to save the current document?", "Saving the current document", MessageBoxButton.YesNo, MessageBoxImage.Question) with
 307             | MessageBoxResult.Yes -> saveCurrentDocument ()
 308             | _ -> ()
 309
 310     let updateCurrentImage () =
 311         match state.CurrentImage with
 312         | Some srcImg ->
 313             // Highlight the preview.
 314             stackPreviews.Children
 315             |> Seq.cast<Views.ImageSourcePreview>
 316             |> Seq.iter (fun preview -> preview.border.BorderThickness <- Thickness(if preview.Tag = (srcImg :> Object) then 3. else 0.))
 317
 318             canvasCurrentImage.Height <- float srcImg.img.Height
 319             canvasCurrentImage.Width <- float srcImg.img.Width
 320             canvasCurrentImage.Background <- ImageBrush(BitmapSourceConvert.ToBitmapSource(srcImg.img))
 321
 322             updateRBCFramesCurrent ()
 323             updateRBCFramesPreview ()
 324             updateCurrentImageInformation ()
 325         | None ->
 326             stackRBC.Children.Clear()
 327             canvasCurrentImage.Children.Clear()
 328             canvasCurrentImage.Background <- Brushes.Black
 329
 330     let setCurrentImage (srcImg: SourceImage) =
 331         if state.CurrentImage.IsNone || state.CurrentImage.Value <> srcImg
 332         then
 333             state.CurrentImage <- Some srcImg
 334             updateCurrentImage ()
 335
 336     let addPreview (srcImg: SourceImage) =
 337         let imgCtrl = Views.ImageSourcePreview(Margin = Thickness(3.))
 338
 339         imgCtrl.menuRemoveImage.Click.AddHandler(fun obj args ->
 340             stackPreviews.Children.Remove(imgCtrl)
 341             let srcImg = imgCtrl.Tag :?> SourceImage
 342             let currentRemoved = Some srcImg = state.CurrentImage
 343             state.RemoveSourceImage srcImg
 344             if currentRemoved
 345             then
 346                 updateCurrentImage()
 347
 348             updateGlobalParasitemia()
 349
 350             // Update image numbers.
 351             stackPreviews.Children |> Seq.cast<Views.ImageSourcePreview> |> Seq.iter (fun imgPreview -> imgPreview.txtImageNumber.Text <- (imgPreview.Tag :?> SourceImage).num.ToString()))
 352
 353         imgCtrl.Tag <- srcImg
 354         imgCtrl.txtImageNumber.Text <- srcImg.num.ToString()
 355         let width = 200
 356         let height = srcImg.img.Height * width / srcImg.img.Width
 357         imgCtrl.imagePreview.Source <- BitmapSourceConvert.ToBitmapSource(srcImg.img.Resize(width, height, Emgu.CV.CvEnum.Inter.Cubic))
 358         stackPreviews.Children.Add(imgCtrl) |> ignore
 359
 360         // Zoom to a mouse position into the control 'imgCtrl'.
 361         let zoomTo (mousePos: Point) =
 362             let canvasW = canvasCurrentImage.ActualWidth * currentScale
 363             let canvasH = canvasCurrentImage.ActualHeight * currentScale
 364             let centerX = (mousePos.X - imgCtrl.BorderThickness.Left) / (imgCtrl.ActualWidth - imgCtrl.BorderThickness.Left) * canvasW
 365             let centerY = (mousePos.Y - imgCtrl.BorderThickness.Top) / (imgCtrl.ActualHeight - imgCtrl.BorderThickness.Top) * canvasH
 366             scrollViewCurrentImage.ScrollToHorizontalOffset(centerX - scrollViewCurrentImage.ViewportWidth / 2. + borderCurrentImage.BorderThickness.Left)
 367             scrollViewCurrentImage.ScrollToVerticalOffset(centerY - scrollViewCurrentImage.ViewportHeight / 2. + borderCurrentImage.BorderThickness.Top)
 368
 369         imgCtrl.MouseLeftButtonDown.AddHandler(fun obj args ->
 370             setCurrentImage (state.SourceImages |> Seq.find (fun srcImg -> (srcImg :> Object) = imgCtrl.Tag))
 371             imgCtrl.UpdateLayout()
 372             zoomTo (args.GetPosition(imgCtrl))
 373             imgCtrl.CaptureMouse() |> ignore)
 374
 375         imgCtrl.MouseMove.AddHandler(fun obj args ->
 376             if imgCtrl.IsMouseCaptured
 377             then
 378                 zoomTo (args.GetPosition(imgCtrl)))
 379
 380         imgCtrl.MouseLeftButtonUp.AddHandler(fun obj args ->
 381             if imgCtrl.IsMouseCaptured
 382             then
 383                 imgCtrl.ReleaseMouseCapture())
 384
 385     let updatePreviews () =
 386         stackPreviews.Children.Clear ()
 387         for srcImg in state.SourceImages do
 388             addPreview srcImg
 389         updateCurrentImage ()
 390
 391     let updateGUI () =
 392         txtPatient.Text <- state.PatientID
 393         updatePreviews ()
 394         updateGlobalParasitemia ()
 395         updateDocumentStatus ()
 396
 397     let loadFile (filepath: string) =
 398         askSaveCurrent ()
 399         let previousFilePath = state.FilePath
 400         try
 401             state.FilePath <- filepath
 402             state.Load()
 403             updateGUI ()
 404         with
 405         | :? IOException as ex ->
 406             Log.Error(ex.ToString())
 407             state.FilePath <- previousFilePath
 408             MessageBox.Show(sprintf "The document cannot be loaded from '%s'" state.FilePath, "Error loading the document", MessageBoxButton.OK, MessageBoxImage.Error) |> ignore
 409
 410     let askLoadFile () =
 411         let dialog = OpenFileDialog(Filter = PiaZ.filter)
 412         let res = dialog.ShowDialog()
 413         if res.HasValue && res.Value
 414         then loadFile dialog.FileName
 415
 416     let newFile () =
 417         askSaveCurrent ()
 418         state.Reset()
 419         updateGUI()
 420
 421     txtPatient.TextChanged.AddHandler(fun obj args -> state.PatientID <- txtPatient.Text)
 422
 423     menuExit.Click.AddHandler(fun obj args -> mainWindow.Root.Close())
 424     menuSaveFile.Click.AddHandler(fun obj args -> saveCurrentDocument ())
 425     menuSaveAsFile.Click.AddHandler(fun obj args -> saveCurrentDocumentAsNewFile ())
 426     menuLoadFile.Click.AddHandler(fun obj args -> askLoadFile ())
 427     menuNewFile.Click.AddHandler(fun obj args -> newFile ())
 428
 429     menuAddSourceImage.Click.AddHandler(fun obj args ->
 430         let dialog = OpenFileDialog(Filter = "Image Files|*.png;*.jpg;*.tif;*.tiff", Multiselect = true)
 431         let res = dialog.ShowDialog()
 432         if res.HasValue && res.Value
 433         then
 434             let noSourceImage = state.SourceImages.Count() = 0
 435
 436             for filename in dialog.FileNames do
 437                 try
 438                     let srcImg = state.AddSourceImage filename defaultConfig
 439                     addPreview srcImg
 440                 with
 441                 | _ as ex ->
 442                     Log.Error(ex.ToString())
 443                     MessageBox.Show(sprintf "Unable to read the image from '%s'" filename, "Error adding an image", MessageBoxButton.OK, MessageBoxImage.Error) |> ignore
 444
 445             updateGlobalParasitemia ()
 446
 447             if noSourceImage
 448             then
 449                 updateCurrentImage ())
 450
 451     menuAnalysis.SubmenuOpened.AddHandler(fun obj args -> menuStartAnalysis.IsEnabled <- state.SourceImages.Count() > 0)
 452
 453     menuStartAnalysis.Click.AddHandler(fun obj args ->
 454         if Analysis.showWindow mainWindow.Root state
 455         then
 456             updateGlobalParasitemia ()
 457             updateCurrentImage ())
 458
 459     menuHightlightRBC.Click.AddHandler(fun obj args ->
 460         displayHealthy <- menuHightlightRBC.IsChecked
 461         updateRBCFramesPreview ()
 462         updateRBCFramesCurrent ())
 463
 464     menuAbout.Click.AddHandler(fun obj args -> About.showWindow mainWindow.Root)
 465
 466     mainWindow.Root.Closing.AddHandler(fun obj args -> askSaveCurrent ())
 467
 468     // Zoom on the current image.
 469     let adjustCurrentImageBorders (deltaX: float) (deltaY: float) =
 470         borderCurrentImage.BorderThickness <-
 471             Thickness(
 472                 (scrollViewCurrentImage.ViewportWidth + deltaX) / 2.,
 473                 (scrollViewCurrentImage.ViewportHeight + deltaY) / 2.,
 474                 (scrollViewCurrentImage.ViewportWidth + deltaX) / 2.,
 475                 (scrollViewCurrentImage.ViewportHeight + deltaY) / 2.)
 476
 477     canvasCurrentImage.SizeChanged.AddHandler(fun obj args ->
 478         let deltaX = args.NewSize.Width - args.PreviousSize.Width
 479         let deltaY = args.NewSize.Height - args.PreviousSize.Height
 480         if deltaX > 0.5 || deltaY > 0.5
 481         then
 482             adjustCurrentImageBorders 0.0 0.0
 483             // Center the view at the center of the image initialy.
 484             scrollViewCurrentImage.UpdateLayout()
 485             scrollViewCurrentImage.ScrollToHorizontalOffset(borderCurrentImage.ActualWidth / 2. - scrollViewCurrentImage.ViewportWidth / 2.)
 486             scrollViewCurrentImage.ScrollToVerticalOffset(borderCurrentImage.ActualHeight / 2. - scrollViewCurrentImage.ViewportHeight / 2.))
 487
 488     scrollViewCurrentImage.SizeChanged.AddHandler(fun obj args ->
 489         let deltaX = args.NewSize.Width - args.PreviousSize.Width
 490         let deltaY = args.NewSize.Height - args.PreviousSize.Height
 491         adjustCurrentImageBorders deltaX deltaY
 492         scrollViewCurrentImage.ScrollToHorizontalOffset(scrollViewCurrentImage.HorizontalOffset + deltaX / 8.)
 493         scrollViewCurrentImage.ScrollToVerticalOffset(scrollViewCurrentImage.VerticalOffset + deltaY / 8.))
 494
 495     let mutable maxScale = 4.
 496     let mutable minScale = 0.25
 497     let currentImageScaleTransform = ScaleTransform()
 498     canvasCurrentImage.LayoutTransform <- currentImageScaleTransform
 499     borderCurrentImage.PreviewMouseWheel.AddHandler(fun obj args ->
 500         let scaleFactor = if args.Delta > 0 then 2.0 else 0.5
 501         if scaleFactor > 1. && currentScale < maxScale || scaleFactor < 1. && currentScale > minScale
 502         then
 503             let previousScale = currentScale
 504             currentScale <-
 505                 let newScale = currentScale * scaleFactor
 506                 if newScale > maxScale then maxScale elif newScale < minScale then minScale else newScale
 507             let realScaleFactor = currentScale / previousScale
 508
 509             let centerX = scrollViewCurrentImage.HorizontalOffset + scrollViewCurrentImage.ViewportWidth / 2. - borderCurrentImage.BorderThickness.Left
 510             let centerY = scrollViewCurrentImage.VerticalOffset + scrollViewCurrentImage.ViewportHeight / 2. - borderCurrentImage.BorderThickness.Top
 511
 512             currentImageScaleTransform.ScaleX <- currentScale
 513             currentImageScaleTransform.ScaleY <- currentScale
 514
 515             scrollViewCurrentImage.ScrollToHorizontalOffset(centerX * realScaleFactor - scrollViewCurrentImage.ViewportWidth / 2. + borderCurrentImage.BorderThickness.Left)
 516             scrollViewCurrentImage.ScrollToVerticalOffset(centerY * realScaleFactor - scrollViewCurrentImage.ViewportHeight / 2. + borderCurrentImage.BorderThickness.Top)
 517
 518         args.Handled <- true)
 519
 520     // Pan on the current image.
 521     let mutable scrollStartPosition = Point(0., 0.)
 522     let mutable scrollStartOffsetX = 0.
 523     let mutable scrollStartOffsetY = 0.
 524     borderCurrentImage.PreviewMouseLeftButtonDown.AddHandler(fun obj args ->
 525         scrollStartPosition <- args.GetPosition(scrollViewCurrentImage)
 526         scrollStartOffsetX <- scrollViewCurrentImage.HorizontalOffset
 527         scrollStartOffsetY <- scrollViewCurrentImage.VerticalOffset
 528         borderCurrentImage.Cursor <- Input.Cursors.ScrollAll
 529         borderCurrentImage.CaptureMouse() |> ignore
 530         args.Handled <- true)
 531
 532     borderCurrentImage.PreviewMouseMove.AddHandler(fun obj args ->
 533         if borderCurrentImage.IsMouseCaptured
 534         then
 535             let position = args.GetPosition(scrollViewCurrentImage)
 536             let deltaX = scrollStartPosition.X - position.X
 537             let deltaY = scrollStartPosition.Y - position.Y
 538             scrollViewCurrentImage.ScrollToHorizontalOffset(deltaX + scrollStartOffsetX)
 539             scrollViewCurrentImage.ScrollToVerticalOffset(deltaY + scrollStartOffsetY)
 540
 541             args.Handled <- true)
 542
 543     borderCurrentImage.PreviewMouseLeftButtonUp.AddHandler(fun obj args ->
 544         if borderCurrentImage.IsMouseCaptured
 545         then
 546             borderCurrentImage.Cursor <- Input.Cursors.Arrow
 547             borderCurrentImage.ReleaseMouseCapture()
 548             args.Handled <- true)
 549
 550     // Shortcuts.
 551     // Save.
 552     mainWindow.Root.InputBindings.Add(
 553         Input.KeyBinding(
 554             FSharp.ViewModule.FunCommand((fun obj -> saveCurrentDocument ()), (fun obj -> true)),
 555             Input.KeyGesture(Input.Key.S, Input.ModifierKeys.Control))) |> ignore
 556
 557     // Save as.
 558     mainWindow.Root.InputBindings.Add(
 559         Input.KeyBinding(
 560             FSharp.ViewModule.FunCommand((fun obj -> saveCurrentDocumentAsNewFile ()), (fun obj -> true)),
 561             Input.KeyGesture(Input.Key.S, Input.ModifierKeys.Control ||| Input.ModifierKeys.Shift))) |> ignore
 562
 563     // Open.
 564     mainWindow.Root.InputBindings.Add(
 565         Input.KeyBinding(
 566             FSharp.ViewModule.FunCommand((fun obj -> askLoadFile ()), (fun obj -> true)),
 567             Input.KeyGesture(Input.Key.O, Input.ModifierKeys.Control))) |> ignore
 568
 569     // New file.
 570     mainWindow.Root.InputBindings.Add(
 571         Input.KeyBinding(
 572             FSharp.ViewModule.FunCommand((fun obj -> newFile ()), (fun obj -> true)),
 573             Input.KeyGesture(Input.Key.N, Input.ModifierKeys.Control))) |> ignore
 574
 575     // Viewport preview.
 576     scrollViewCurrentImage.ScrollChanged.AddHandler(fun obj args -> updateViewportPreview ())
 577
 578     updateDocumentStatus ()
 579
 580     mainWindow.Root.Show()
 581
 582     match fileToOpen with
 583     | Some filepath -> loadFile filepath
 584     | None -> ()
 585
 586     app.Run()