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     let imgLogos: Border = ctrl "imgLogos"
  64
  65     // Initializations.
  66     let canvasCurrentImageColor = canvasCurrentImage.Background
  67     menuHightlightRBC.IsChecked <- displayHealthy
  68
  69     // Utils.
  70     let extractRBCPreview (img: Emgu.CV.Image<Emgu.CV.Structure.Bgr, byte>) (rbc: RBC) : Emgu.CV.Image<Emgu.CV.Structure.Bgr, byte> =
  71         let rbcWidth = rbc.size.Width
  72         let rbcHeight = rbc.size.Height
  73         let x = rbc.center.X - rbcWidth / 2. |> roundInt
  74         let y = rbc.center.Y - rbcHeight / 2. |> roundInt
  75         let w = roundInt rbcWidth
  76         let h = roundInt rbcHeight
  77         img.GetSubRect(System.Drawing.Rectangle(System.Drawing.Point((if x < 0 then 0 else x), (if y < 0 then 0 else y)),
  78                                                 System.Drawing.Size((if x + w >= img.Width then img.Width - x else w),
  79                                                                     (if y + h >= img.Height then img.Height - y else h))))
  80
  81     let setRBCFrameStyle (rbc: RBC) (frame: Views.RBCFrame) =
  82         frame.Opacity <- if displayHealthy || rbc.setManually || rbc.infected then 1. else 0.
  83         let color = if rbc.infected then colorRBCInfected else colorRBCHealthy
  84         frame.manuallyAdded.Visibility <- if rbc.setManually then Visibility.Visible else Visibility.Hidden
  85         frame.manuallyAdded.Fill <- color
  86         frame.border.Stroke <- color
  87
  88     let RBCFrameFromExisting (rbc: RBC) (frame: Views.RBCFrame) : Views.RBCFrame =
  89         frame.Visibility <- Visibility.Visible
  90         frame.Height <- rbc.size.Height
  91         frame.Width <- rbc.size.Width
  92         frame.Tag <- rbc
  93         setRBCFrameStyle rbc frame
  94         frame.border.StrokeThickness <- 1.
  95         frame.txtRBCNumber.Text <- rbc.num.ToString()
  96         frame
  97
  98     let updateDocumentStatus () =
  99         txtDocumentStatus.Text <- if state.FilePath = "" then "<New document>" else state.FilePath
 100
 101     let statusMessageTimer = Threading.DispatcherTimer()
 102     statusMessageTimer.Tick.AddHandler(fun obj args -> statusMessageTimer.Stop(); txtMessageStatus.Text <- "")
 103     statusMessageTimer.Interval <- TimeSpan(0, 0, 2)
 104     let displayStatusMessage (message: string) =
 105         txtMessageStatus.Text <- message
 106         statusMessageTimer.Stop()
 107         statusMessageTimer.Start()
 108
 109     let highlightRBCFrame (frame: Views.RBCFrame) (highlight: bool) =
 110         let rbc = frame.Tag :?> RBC
 111         if highlight
 112         then
 113             frame.border.StrokeThickness <- 3.
 114             if not rbc.infected && not rbc.setManually && not displayHealthy then frame.Opacity <- 1.
 115         else
 116             frame.border.StrokeThickness <- 1.
 117             if not rbc.infected && not rbc.setManually && not displayHealthy then frame.Opacity <- 0.
 118
 119     let zoomToRBC (rbc: RBC) =
 120         scrollViewCurrentImage.ScrollToHorizontalOffset(rbc.center.X * currentScale - scrollViewCurrentImage.ViewportWidth / 2. + borderCurrentImage.BorderThickness.Left)
 121         scrollViewCurrentImage.ScrollToVerticalOffset(rbc.center.Y * currentScale - scrollViewCurrentImage.ViewportHeight / 2. + borderCurrentImage.BorderThickness.Top)
 122
 123     let percentText (nbTotal: int, nb: int) : string =
 124         if nbTotal = 0
 125         then
 126             ""
 127         else
 128             let percent = 100. * (float nb) / (float nbTotal)
 129             sprintf "%.1f %% (%d / %d)" percent nb nbTotal
 130
 131     let updateCurrentImageInformation () =
 132         txtImageInformation1.Inlines.Clear()
 133         txtImageInformation2.Inlines.Clear()
 134
 135         match state.CurrentImage with
 136         | Some srcImg ->
 137             let parasitemiaStr = percentText (state.ImageParasitemia srcImg)
 138             txtImageInformation1.Inlines.Add(Documents.Run("Parasitemia: ", FontWeight = FontWeights.Bold))
 139             txtImageInformation1.Inlines.Add(parasitemiaStr)
 140             txtImageInformation1.Inlines.Add(Documents.LineBreak())
 141
 142             txtImageInformation1.Inlines.Add(Documents.Run("Last analysis: ", FontWeight = FontWeights.Bold))
 143             txtImageInformation1.Inlines.Add(Documents.Run(if srcImg.dateLastAnalysis.Ticks = 0L then "<Never>" else srcImg.dateLastAnalysis.ToLocalTime().ToString()))
 144
 145             let alteredStr = percentText (state.ImageNbAltered srcImg)
 146             txtImageInformation2.Inlines.Add(Documents.Run("Number of erytrocytes manually altered: ", FontWeight = FontWeights.Bold))
 147             txtImageInformation2.Inlines.Add(Documents.Run(alteredStr))
 148             txtImageInformation2.Inlines.Add(Documents.LineBreak())
 149
 150             txtImageInformation2.Inlines.Add(Documents.Run("Average erytrocyte diameter: ", FontWeight = FontWeights.Bold))
 151             txtImageInformation2.Inlines.Add(Documents.Run(srcImg.config.RBCRadius.ToString()))
 152         | _ -> ()
 153
 154     let updateGlobalParasitemia () =
 155         txtGlobalParasitemia.Text <- percentText state.GlobalParasitemia
 156
 157     let updateViewportPreview () =
 158         for preview in stackPreviews.Children |> Seq.cast<Views.ImageSourcePreview> do
 159             let srcImg = preview.Tag :?> SourceImage
 160             if Some srcImg = state.CurrentImage then
 161                 preview.viewport.Visibility <- Visibility.Visible
 162
 163                 let canvasWidth = canvasCurrentImage.ActualWidth * currentScale
 164                 let canvasHeight = canvasCurrentImage.ActualHeight * currentScale
 165                 let previewWidth = (preview.ActualWidth - preview.BorderThickness.Left - preview.BorderThickness.Right)
 166                 let previewHeight = (preview.ActualHeight - preview.BorderThickness.Top - preview.BorderThickness.Bottom)
 167
 168                 let marginLeft = previewWidth * (scrollViewCurrentImage.HorizontalOffset - borderCurrentImage.BorderThickness.Left) / canvasWidth - 2.
 169                 let marginRight = previewWidth * (canvasWidth - (scrollViewCurrentImage.HorizontalOffset - borderCurrentImage.BorderThickness.Right) - scrollViewCurrentImage.ViewportWidth) / canvasWidth - 2.
 170                 let marginTop = previewHeight * (scrollViewCurrentImage.VerticalOffset - borderCurrentImage.BorderThickness.Top) / canvasHeight - 2.
 171                 let marginBottom = previewHeight * (canvasHeight - (scrollViewCurrentImage.VerticalOffset - borderCurrentImage.BorderThickness.Bottom) - scrollViewCurrentImage.ViewportHeight) / canvasHeight - 2.
 172
 173                 preview.viewport.Margin <-
 174                     Thickness(
 175                         marginLeft,
 176                         marginTop,
 177                         marginRight,
 178                         marginBottom)
 179             else
 180                 preview.viewport.Visibility <- Visibility.Hidden
 181
 182     let rec setAsInfected (rbc: RBC) (infected: bool) =
 183         state.SetAsInfected rbc infected
 184         canvasCurrentImage.Children
 185         |> Seq.cast<Views.RBCFrame>
 186         |> Seq.iter
 187             (fun frame ->
 188                 if (frame.Tag :?> RBC) = rbc
 189                 then
 190                     setRBCFrameStyle rbc frame)
 191         updateRBCFramesPreview ()
 192         updateCurrentImageInformation ()
 193         updateGlobalParasitemia ()
 194
 195     and RBCFrame (rbc: RBC) : Views.RBCFrame =
 196         let frame = RBCFrameFromExisting rbc (Views.RBCFrame())
 197         frame.SetValue(Panel.ZIndexProperty, Int32.MaxValue - rbc.num) // To be sure the
 198         frame.menuRBCSetAsHealthy.Click.AddHandler(fun obj args -> setAsInfected (frame.Tag :?> RBC) false)
 199         frame.menuRBCSetAsInfected.Click.AddHandler(fun obj args -> setAsInfected (frame.Tag :?> RBC) true)
 200         frame.ContextMenuOpening.AddHandler(
 201             fun obj args ->
 202                 if (frame.Tag :?> RBC).infected
 203                 then
 204                     frame.menuRBCSetAsHealthy.Visibility <- Visibility.Visible
 205                     frame.menuRBCSetAsInfected.Visibility <- Visibility.Collapsed
 206                 else
 207                     frame.menuRBCSetAsHealthy.Visibility <- Visibility.Collapsed
 208                     frame.menuRBCSetAsInfected.Visibility <- Visibility.Visible)
 209
 210         frame.ContextMenuClosing.AddHandler(fun obj args -> if not frame.IsMouseOver then highlightRBCFrame frame false )
 211         frame.MouseEnter.AddHandler(fun obj args -> highlightRBCFrame frame true)
 212         frame.MouseLeave.AddHandler(fun obj args -> if not frame.grid.ContextMenu.IsOpen then highlightRBCFrame frame false)
 213         frame
 214
 215     and updateRBCFramesPreview () =
 216         match state.CurrentImage with
 217         | Some srcImg ->
 218             let mutable currentPreview = 0
 219             for rbc in srcImg.rbcs |> List.filter (fun rbc -> displayHealthy || rbc.infected) do
 220                 let previewInfected =
 221                     if currentPreview < stackRBC.Children.Count
 222                     then
 223                         RBCFrameFromExisting rbc (stackRBC.Children.[currentPreview] :?> Views.RBCFrame)
 224                     else
 225                         let f = RBCFrame rbc
 226                         f.MouseLeftButtonUp.AddHandler(fun obj args -> zoomToRBC (f.Tag :?> RBC))
 227                         stackRBC.Children.Add(f) |> ignore
 228                         f
 229
 230                 currentPreview <- currentPreview + 1
 231
 232                 previewInfected.Height <- stackRBC.ActualHeight
 233                 previewInfected.Width <- stackRBC.ActualHeight * rbc.size.Width / rbc.size.Height
 234                 previewInfected.border.Fill <- ImageBrush(BitmapSourceConvert.ToBitmapSource(extractRBCPreview srcImg.img rbc))
 235
 236             stackRBC.Children.RemoveRange(currentPreview, stackRBC.Children.Count - currentPreview)
 237         | _ -> ()
 238
 239         updateViewportPreview ()
 240
 241     let updateRBCFramesCurrent () =
 242         match state.CurrentImage with
 243         | Some srcImg ->
 244             let mutable currentCanvas = 0
 245             for rbc in srcImg.rbcs do
 246                 let frame =
 247                     if currentCanvas < canvasCurrentImage.Children.Count
 248                     then
 249                         RBCFrameFromExisting rbc (canvasCurrentImage.Children.[currentCanvas] :?> Views.RBCFrame)
 250                     else
 251                         let f = RBCFrame rbc
 252                         f.Root.Opacity <- 0.7
 253                         canvasCurrentImage.Children.Add(f) |> ignore
 254                         f
 255
 256                 currentCanvas <- currentCanvas + 1
 257
 258                 Canvas.SetLeft(frame, rbc.center.X - rbc.size.Width / 2.)
 259                 Canvas.SetTop(frame, rbc.center.Y - rbc.size.Height / 2.)
 260
 261             for i in currentCanvas .. canvasCurrentImage.Children.Count - 1 do
 262                 canvasCurrentImage.Children.[i].Visibility <- Visibility.Hidden
 263         | _ -> ()
 264
 265     let askDocumentPathToSave () : string option =
 266         let dialog = SaveFileDialog(AddExtension = true, DefaultExt = PiaZ.extension, Filter = PiaZ.filter)
 267
 268         if state.FilePath <> ""
 269         then
 270             dialog.FileName <- FileInfo(state.FilePath).Name
 271         elif state.PatientID <> ""
 272         then
 273             dialog.FileName <- state.PatientID + PiaZ.extension
 274
 275         let res = dialog.ShowDialog()
 276         if res.HasValue && res.Value then
 277             Some dialog.FileName
 278         else
 279             None
 280
 281     let saveCurrentDocument () =
 282         try
 283             if state.FilePath = ""
 284             then
 285                 match askDocumentPathToSave () with
 286                 | Some filepath ->
 287                     state.FilePath <- filepath
 288                     state.Save()
 289                 | _ -> ()
 290             else
 291                 state.Save()
 292             updateDocumentStatus ()
 293             displayStatusMessage "Document saved"
 294         with
 295         | :? IOException as ex ->
 296             Log.Error(ex.ToString())
 297             MessageBox.Show(sprintf "The document cannot be save in '%s'" state.FilePath, "Error saving the document", MessageBoxButton.OK, MessageBoxImage.Error) |> ignore
 298
 299     let saveCurrentDocumentAsNewFile () =
 300         match askDocumentPathToSave () with
 301         | Some filepath ->
 302             state.FilePath <- filepath
 303             saveCurrentDocument ()
 304         | _ -> ()
 305
 306     // Ask the use to save the current document if neccessary.
 307     let askSaveCurrent () =
 308         if state.AlteredSinceLastSave
 309         then
 310             match MessageBox.Show("Would you like to save the current document?", "Saving the current document", MessageBoxButton.YesNo, MessageBoxImage.Question) with
 311             | MessageBoxResult.Yes -> saveCurrentDocument ()
 312             | _ -> ()
 313
 314     let updateCurrentImage () =
 315         match state.CurrentImage with
 316         | Some srcImg ->
 317             imgLogos.Visibility <- Visibility.Collapsed
 318
 319             // Highlight the preview.
 320             stackPreviews.Children
 321             |> Seq.cast<Views.ImageSourcePreview>
 322             |> Seq.iter (fun preview -> preview.border.BorderThickness <- Thickness(if preview.Tag = (srcImg :> Object) then 3. else 0.))
 323
 324             canvasCurrentImage.Height <- float srcImg.img.Height
 325             canvasCurrentImage.Width <- float srcImg.img.Width
 326             canvasCurrentImage.Background <- ImageBrush(BitmapSourceConvert.ToBitmapSource(srcImg.img))
 327
 328             updateRBCFramesCurrent ()
 329             updateRBCFramesPreview ()
 330         | None ->
 331             imgLogos.Visibility <- Visibility.Visible
 332             stackRBC.Children.Clear()
 333             canvasCurrentImage.Children.Clear()
 334             canvasCurrentImage.Background <- canvasCurrentImageColor
 335
 336         updateCurrentImageInformation ()
 337
 338     let setCurrentImage (srcImg: SourceImage) =
 339         if state.CurrentImage.IsNone || state.CurrentImage.Value <> srcImg
 340         then
 341             state.CurrentImage <- Some srcImg
 342             updateCurrentImage ()
 343
 344     let addPreview (srcImg: SourceImage) =
 345         let imgCtrl = Views.ImageSourcePreview(Margin = Thickness(3.))
 346
 347         imgCtrl.menuRemoveImage.Click.AddHandler(fun obj args ->
 348             stackPreviews.Children.Remove(imgCtrl)
 349             let srcImg = imgCtrl.Tag :?> SourceImage
 350             let currentRemoved = Some srcImg = state.CurrentImage
 351             state.RemoveSourceImage srcImg
 352             if currentRemoved
 353             then
 354                 updateCurrentImage()
 355
 356             updateGlobalParasitemia()
 357
 358             // Update image numbers.
 359             stackPreviews.Children |> Seq.cast<Views.ImageSourcePreview> |> Seq.iter (fun imgPreview -> imgPreview.txtImageNumber.Text <- (imgPreview.Tag :?> SourceImage).num.ToString()))
 360
 361         imgCtrl.Tag <- srcImg
 362         imgCtrl.txtImageNumber.Text <- srcImg.num.ToString()
 363         let width = 200
 364         let height = srcImg.img.Height * width / srcImg.img.Width
 365         imgCtrl.imagePreview.Source <- BitmapSourceConvert.ToBitmapSource(srcImg.img.Resize(width, height, Emgu.CV.CvEnum.Inter.Cubic))
 366         stackPreviews.Children.Add(imgCtrl) |> ignore
 367
 368         // Zoom to a mouse position into the control 'imgCtrl'.
 369         let zoomTo (mousePos: Point) =
 370             let canvasW = canvasCurrentImage.ActualWidth * currentScale
 371             let canvasH = canvasCurrentImage.ActualHeight * currentScale
 372             let centerX = (mousePos.X - imgCtrl.BorderThickness.Left) / (imgCtrl.ActualWidth - imgCtrl.BorderThickness.Left) * canvasW
 373             let centerY = (mousePos.Y - imgCtrl.BorderThickness.Top) / (imgCtrl.ActualHeight - imgCtrl.BorderThickness.Top) * canvasH
 374             scrollViewCurrentImage.ScrollToHorizontalOffset(centerX - scrollViewCurrentImage.ViewportWidth / 2. + borderCurrentImage.BorderThickness.Left)
 375             scrollViewCurrentImage.ScrollToVerticalOffset(centerY - scrollViewCurrentImage.ViewportHeight / 2. + borderCurrentImage.BorderThickness.Top)
 376
 377         imgCtrl.MouseLeftButtonDown.AddHandler(fun obj args ->
 378             setCurrentImage (state.SourceImages |> Seq.find (fun srcImg -> (srcImg :> Object) = imgCtrl.Tag))
 379             imgCtrl.UpdateLayout()
 380             zoomTo (args.GetPosition(imgCtrl))
 381             imgCtrl.CaptureMouse() |> ignore)
 382
 383         imgCtrl.MouseMove.AddHandler(fun obj args ->
 384             if imgCtrl.IsMouseCaptured
 385             then
 386                 zoomTo (args.GetPosition(imgCtrl)))
 387
 388         imgCtrl.MouseLeftButtonUp.AddHandler(fun obj args ->
 389             if imgCtrl.IsMouseCaptured
 390             then
 391                 imgCtrl.ReleaseMouseCapture())
 392
 393     let updatePreviews () =
 394         stackPreviews.Children.Clear ()
 395         for srcImg in state.SourceImages do
 396             addPreview srcImg
 397         updateCurrentImage ()
 398
 399     let updateGUI () =
 400         txtPatient.Text <- state.PatientID
 401         updatePreviews ()
 402         updateGlobalParasitemia ()
 403         updateDocumentStatus ()
 404
 405     let loadFile (filepath: string) =
 406         askSaveCurrent ()
 407         let previousFilePath = state.FilePath
 408         try
 409             state.FilePath <- filepath
 410             state.Load()
 411             updateGUI ()
 412         with
 413         | :? IOException as ex ->
 414             Log.Error(ex.ToString())
 415             state.FilePath <- previousFilePath
 416             MessageBox.Show(sprintf "The document cannot be loaded from '%s'" state.FilePath, "Error loading the document", MessageBoxButton.OK, MessageBoxImage.Error) |> ignore
 417
 418     let askLoadFile () =
 419         let dialog = OpenFileDialog(Filter = PiaZ.filter)
 420         let res = dialog.ShowDialog()
 421         if res.HasValue && res.Value
 422         then loadFile dialog.FileName
 423
 424     let newFile () =
 425         askSaveCurrent ()
 426         state.Reset()
 427         updateGUI()
 428
 429     txtPatient.TextChanged.AddHandler(fun obj args -> state.PatientID <- txtPatient.Text)
 430
 431     menuExit.Click.AddHandler(fun obj args -> mainWindow.Root.Close())
 432     menuSaveFile.Click.AddHandler(fun obj args -> saveCurrentDocument ())
 433     menuSaveAsFile.Click.AddHandler(fun obj args -> saveCurrentDocumentAsNewFile ())
 434     menuLoadFile.Click.AddHandler(fun obj args -> askLoadFile ())
 435     menuNewFile.Click.AddHandler(fun obj args -> newFile ())
 436
 437     menuAddSourceImage.Click.AddHandler(fun obj args ->
 438         let dialog = OpenFileDialog(Filter = "Image Files|*.png;*.jpg;*.tif;*.tiff", Multiselect = true)
 439         let res = dialog.ShowDialog()
 440         if res.HasValue && res.Value
 441         then
 442             let noSourceImage = state.SourceImages.Count() = 0
 443
 444             for filename in dialog.FileNames do
 445                 try
 446                     let srcImg = state.AddSourceImage filename defaultConfig
 447                     addPreview srcImg
 448                 with
 449                 | _ as ex ->
 450                     Log.Error(ex.ToString())
 451                     MessageBox.Show(sprintf "Unable to read the image from '%s'" filename, "Error adding an image", MessageBoxButton.OK, MessageBoxImage.Error) |> ignore
 452
 453             updateGlobalParasitemia ()
 454
 455             if noSourceImage
 456             then
 457                 updateCurrentImage ())
 458
 459     menuAnalysis.SubmenuOpened.AddHandler(fun obj args -> menuStartAnalysis.IsEnabled <- state.SourceImages.Count() > 0)
 460
 461     menuStartAnalysis.Click.AddHandler(fun obj args ->
 462         if Analysis.showWindow mainWindow.Root state
 463         then
 464             updateGlobalParasitemia ()
 465             updateCurrentImage ())
 466
 467     menuHightlightRBC.Click.AddHandler(fun obj args ->
 468         displayHealthy <- menuHightlightRBC.IsChecked
 469         updateRBCFramesPreview ()
 470         updateRBCFramesCurrent ())
 471
 472     menuAbout.Click.AddHandler(fun obj args -> About.showWindow mainWindow.Root)
 473
 474     mainWindow.Root.Closing.AddHandler(fun obj args -> askSaveCurrent ())
 475
 476     // Zoom on the current image.
 477     let adjustCurrentImageBorders (deltaX: float) (deltaY: float) =
 478         borderCurrentImage.BorderThickness <-
 479             Thickness(
 480                 (scrollViewCurrentImage.ViewportWidth + deltaX) / 2.,
 481                 (scrollViewCurrentImage.ViewportHeight + deltaY) / 2.,
 482                 (scrollViewCurrentImage.ViewportWidth + deltaX) / 2.,
 483                 (scrollViewCurrentImage.ViewportHeight + deltaY) / 2.)
 484
 485     canvasCurrentImage.SizeChanged.AddHandler(fun obj args ->
 486         let deltaX = args.NewSize.Width - args.PreviousSize.Width
 487         let deltaY = args.NewSize.Height - args.PreviousSize.Height
 488         if deltaX > 0.5 || deltaY > 0.5
 489         then
 490             adjustCurrentImageBorders 0.0 0.0
 491             // Center the view at the center of the image initialy.
 492             scrollViewCurrentImage.UpdateLayout()
 493             scrollViewCurrentImage.ScrollToHorizontalOffset(borderCurrentImage.ActualWidth / 2. - scrollViewCurrentImage.ViewportWidth / 2.)
 494             scrollViewCurrentImage.ScrollToVerticalOffset(borderCurrentImage.ActualHeight / 2. - scrollViewCurrentImage.ViewportHeight / 2.))
 495
 496     scrollViewCurrentImage.SizeChanged.AddHandler(fun obj args ->
 497         let deltaX = args.NewSize.Width - args.PreviousSize.Width
 498         let deltaY = args.NewSize.Height - args.PreviousSize.Height
 499         adjustCurrentImageBorders deltaX deltaY
 500         scrollViewCurrentImage.ScrollToHorizontalOffset(scrollViewCurrentImage.HorizontalOffset + deltaX / 8.)
 501         scrollViewCurrentImage.ScrollToVerticalOffset(scrollViewCurrentImage.VerticalOffset + deltaY / 8.))
 502
 503     let mutable maxScale = 4.
 504     let mutable minScale = 0.25
 505     let currentImageScaleTransform = ScaleTransform()
 506     canvasCurrentImage.LayoutTransform <- currentImageScaleTransform
 507     borderCurrentImage.PreviewMouseWheel.AddHandler(fun obj args ->
 508         let scaleFactor = if args.Delta > 0 then 2.0 else 0.5
 509         if scaleFactor > 1. && currentScale < maxScale || scaleFactor < 1. && currentScale > minScale
 510         then
 511             let previousScale = currentScale
 512             currentScale <-
 513                 let newScale = currentScale * scaleFactor
 514                 if newScale > maxScale then maxScale elif newScale < minScale then minScale else newScale
 515             let realScaleFactor = currentScale / previousScale
 516
 517             let centerX = scrollViewCurrentImage.HorizontalOffset + scrollViewCurrentImage.ViewportWidth / 2. - borderCurrentImage.BorderThickness.Left
 518             let centerY = scrollViewCurrentImage.VerticalOffset + scrollViewCurrentImage.ViewportHeight / 2. - borderCurrentImage.BorderThickness.Top
 519
 520             currentImageScaleTransform.ScaleX <- currentScale
 521             currentImageScaleTransform.ScaleY <- currentScale
 522
 523             scrollViewCurrentImage.ScrollToHorizontalOffset(centerX * realScaleFactor - scrollViewCurrentImage.ViewportWidth / 2. + borderCurrentImage.BorderThickness.Left)
 524             scrollViewCurrentImage.ScrollToVerticalOffset(centerY * realScaleFactor - scrollViewCurrentImage.ViewportHeight / 2. + borderCurrentImage.BorderThickness.Top)
 525
 526         args.Handled <- true)
 527
 528     // Pan on the current image.
 529     let mutable scrollStartPosition = Point(0., 0.)
 530     let mutable scrollStartOffsetX = 0.
 531     let mutable scrollStartOffsetY = 0.
 532     borderCurrentImage.PreviewMouseLeftButtonDown.AddHandler(fun obj args ->
 533         scrollStartPosition <- args.GetPosition(scrollViewCurrentImage)
 534         scrollStartOffsetX <- scrollViewCurrentImage.HorizontalOffset
 535         scrollStartOffsetY <- scrollViewCurrentImage.VerticalOffset
 536         borderCurrentImage.Cursor <- Input.Cursors.ScrollAll
 537         borderCurrentImage.CaptureMouse() |> ignore
 538         args.Handled <- true)
 539
 540     borderCurrentImage.PreviewMouseMove.AddHandler(fun obj args ->
 541         if borderCurrentImage.IsMouseCaptured
 542         then
 543             let position = args.GetPosition(scrollViewCurrentImage)
 544             let deltaX = scrollStartPosition.X - position.X
 545             let deltaY = scrollStartPosition.Y - position.Y
 546             scrollViewCurrentImage.ScrollToHorizontalOffset(deltaX + scrollStartOffsetX)
 547             scrollViewCurrentImage.ScrollToVerticalOffset(deltaY + scrollStartOffsetY)
 548
 549             args.Handled <- true)
 550
 551     borderCurrentImage.PreviewMouseLeftButtonUp.AddHandler(fun obj args ->
 552         if borderCurrentImage.IsMouseCaptured
 553         then
 554             borderCurrentImage.Cursor <- Input.Cursors.Arrow
 555             borderCurrentImage.ReleaseMouseCapture()
 556             args.Handled <- true)
 557
 558     // Shortcuts.
 559     // Save.
 560     mainWindow.Root.InputBindings.Add(
 561         Input.KeyBinding(
 562             FSharp.ViewModule.FunCommand((fun obj -> saveCurrentDocument ()), (fun obj -> true)),
 563             Input.KeyGesture(Input.Key.S, Input.ModifierKeys.Control))) |> ignore
 564
 565     // Save as.
 566     mainWindow.Root.InputBindings.Add(
 567         Input.KeyBinding(
 568             FSharp.ViewModule.FunCommand((fun obj -> saveCurrentDocumentAsNewFile ()), (fun obj -> true)),
 569             Input.KeyGesture(Input.Key.S, Input.ModifierKeys.Control ||| Input.ModifierKeys.Shift))) |> ignore
 570
 571     // Open.
 572     mainWindow.Root.InputBindings.Add(
 573         Input.KeyBinding(
 574             FSharp.ViewModule.FunCommand((fun obj -> askLoadFile ()), (fun obj -> true)),
 575             Input.KeyGesture(Input.Key.O, Input.ModifierKeys.Control))) |> ignore
 576
 577     // New file.
 578     mainWindow.Root.InputBindings.Add(
 579         Input.KeyBinding(
 580             FSharp.ViewModule.FunCommand((fun obj -> newFile ()), (fun obj -> true)),
 581             Input.KeyGesture(Input.Key.N, Input.ModifierKeys.Control))) |> ignore
 582
 583     // Viewport preview.
 584     scrollViewCurrentImage.ScrollChanged.AddHandler(fun obj args -> updateViewportPreview ())
 585
 586     updateDocumentStatus ()
 587
 588     mainWindow.Root.Show()
 589
 590     match fileToOpen with
 591     | Some filepath -> loadFile filepath
 592     | None -> ()
 593
 594     app.Run()