Implemented High-DPI support for Windows.

Applications should use ``scaleToDpi()`` to convert pixel numbers from 96 DPI to system DPI.

4 files changed, 52 insertions, 27 deletions

diff --git a/src/nigui.nim b/src/nigui.nim
index a318ea4..6a4551c 100755
--- a/src/nigui.nim
+++ b/src/nigui.nim
@@ -383,6 +383,9 @@ proc isDown*(key: Key): bool
 
 proc downKeys*(): seq[Key]
 
+proc scaleToDpi*(val: int): int
+proc scaleToDpi*(val: float): float
+
 
 # ----------------------------------------------------------------------------------------
 #                                       Dialogs
@@ -924,17 +927,22 @@ import unicode
 #                                   Global Variables
 # ----------------------------------------------------------------------------------------
 
+const 
+  defaultDpi = 96
+  defaultFontSizeForDefaultDpi = 12.0
+
 var
   fErrorHandler: ErrorHandlerProc = nil
   windowList: seq[Window] = @[]
   fScrollbarSize = -1
   fDownKeys: seq[Key] = @[]
-
+  fSystemDpi = defaultDpi
+  
   # Default style:
   fDefaultBackgroundColor: Color # initialized by platform-specific init()
   fDefaultTextColor: Color # initialized by platform-specific init()
   fDefaultFontFamily = ""
-  fDefaultFontSize = 15.float
+  fDefaultFontSize = defaultFontSizeForDefaultDpi
 
 
 # ----------------------------------------------------------------------------------------
@@ -1056,6 +1064,9 @@ proc isDown(key: Key): bool = fDownKeys.contains(key)
 
 proc downKeys(): seq[Key] = fDownKeys
 
+proc scaleToDpi(val: int): int = (val * fSystemDpi) div defaultDpi
+proc scaleToDpi(val: float): float = val * fSystemDpi.float / defaultDpi.float
+
 proc internalKeyDown(key: Key) =
   if not fDownKeys.contains(key):
     fDownKeys.add(key)
@@ -1365,8 +1376,8 @@ proc init(control: Control) =
   control.tag = ""
   control.fWidthMode = WidthMode_Static
   control.fHeightMode = HeightMode_Static
-  control.fWidth = 50
-  control.fheight = 50
+  control.fWidth = 50.scaleToDpi
+  control.fheight = 50.scaleToDpi
   control.fScrollableWidth = -1
   control.fScrollableHeight = -1
   control.resetFontFamily()
@@ -1648,7 +1659,7 @@ method setFontSize(control: Control, fontSize: float) =
   # should be extended by ControlImpl
 
 method resetFontSize(control: Control) =
-  control.setFontSize(fDefaultFontSize)
+  control.setFontSize(app.defaultFontSize)
   control.fUseDefaultFontSize = true
   control.triggerRelayoutIfModeIsAuto()
 
@@ -1922,8 +1933,8 @@ proc newLayoutContainer(layout: Layout): LayoutContainer =
   result.layout = layout
   result.xAlign = XAlign_Left
   result.yAlign = YAlign_Top
-  result.spacing = 4
-  result.padding = 2
+  result.spacing = 4.scaleToDpi
+  result.padding = 2.scaleToDpi
 
 method naturalWidth(container: LayoutContainer): int =
   # echo container.tag & ".naturalWidth"
@@ -2232,10 +2243,10 @@ method `text=`(frame: Frame, text: string) =
   # should be extended by NativeFrame
 
 method getPadding(frame: Frame): Spacing =
-  result.left = 4
-  result.right = 4
-  result.top = 4
-  result.bottom = 4
+  result.left = 4.scaleToDpi
+  result.right = 4.scaleToDpi
+  result.top = 4.scaleToDpi
+  result.bottom = 4.scaleToDpi
   # should be extended by NativeFrame
 
 method `onDraw=`(container: NativeFrame, callback: DrawProc) = raiseError("NativeFrame does not allow onDraw.")
@@ -2256,8 +2267,8 @@ proc init(button: Button) =
   button.fOnClick = nil
   button.fWidthMode = WidthMode_Auto
   button.fHeightMode = HeightMode_Auto
-  button.minWidth = 15
-  button.minHeight = 15
+  button.minWidth = 15.scaleToDpi
+  button.minHeight = 15.scaleToDpi
   button.enabled = true
 
 method text(button: Button): string = button.fText
@@ -2302,8 +2313,8 @@ proc init(label: Label) =
   label.fText = ""
   label.fWidthMode = WidthMode_Auto
   label.fHeightMode = HeightMode_Auto
-  label.minWidth = 10
-  label.minHeight = 10
+  label.minWidth = 10.scaleToDpi
+  label.minHeight = 10.scaleToDpi
 
 method text(label: Label): string = label.fText
 
@@ -2333,8 +2344,8 @@ proc init(textBox: TextBox) =
   textBox.ControlImpl.init()
   textBox.fWidthMode = WidthMode_Expand
   textBox.fHeightMode = HeightMode_Auto
-  textBox.minWidth = 20
-  textBox.minHeight = 20
+  textBox.minWidth = 20.scaleToDpi
+  textBox.minHeight = 20.scaleToDpi
   textBox.editable = true
 
 method naturalHeight(textBox: TextBox): int = textBox.getTextLineHeight()
@@ -2393,8 +2404,8 @@ proc init(textArea: TextArea) =
   textArea.ControlImpl.init()
   textArea.fWidthMode = WidthMode_Expand
   textArea.fHeightMode = HeightMode_Expand
-  textArea.minWidth = 20
-  textArea.minHeight = 20
+  textArea.minWidth = 20.scaleToDpi
+  textArea.minHeight = 20.scaleToDpi
   textArea.wrap = true
   textArea.editable = true
 
diff --git a/src/nigui/msgbox.nim b/src/nigui/msgbox.nim
index eefb57a..596fb12 100755
--- a/src/nigui/msgbox.nim
+++ b/src/nigui/msgbox.nim
@@ -22,7 +22,7 @@ proc buttonClick(event: ClickEvent) =
   event.control.parentWindow.dispose()

 

 proc msgBox*(parent: Window, message: string, title = "Message", button1 = "OK", button2, button3: string = ""): int {.discardable.}  =

-  const buttonMinWidth = 100

+  const buttonMinWidth = 100.scaleToDpi

   var window = new MessageBoxWindow

   window.init()

   window.title = title

@@ -32,7 +32,7 @@ proc msgBox*(parent: Window, message: string, title = "Message", button1 = "OK",
       window.dispose()

 

   var container = newLayoutContainer(Layout_Vertical)

-  container.padding = 10

+  container.padding = 10.scaleToDpi

   window.control = container

 

   var labelContainer = newLayoutContainer(Layout_Horizontal)

@@ -46,7 +46,7 @@ proc msgBox*(parent: Window, message: string, title = "Message", button1 = "OK",
   var buttonContainer = newLayoutContainer(Layout_Horizontal)

   buttonContainer.widthMode = WidthMode_Expand

   buttonContainer.xAlign = XAlign_Center

-  buttonContainer.spacing = 12

+  buttonContainer.spacing = 12.scaleToDpi

   container.add(buttonContainer)

   var b1, b2, b3: Button

 

@@ -68,8 +68,8 @@ proc msgBox*(parent: Window, message: string, title = "Message", button1 = "OK",
     b3.onClick = buttonClick

     buttonContainer.add(b3)

 

-  window.width = min(max(label.width + 40, buttonMinWidth * 3 + 65), 600)

-  window.height = min(label.height, 300) + buttonContainer.height + 70

+  window.width = min(max(label.width + 40.scaleToDpi, buttonMinWidth * 3 + 65.scaleToDpi), 600.scaleToDpi)

+  window.height = min(label.height, 300.scaleToDpi) + buttonContainer.height + 70.scaleToDpi

 

   # Center message box on window:

   window.x = parent.x + ((parent.width - window.width) div 2)

diff --git a/src/nigui/private/windows/platform_impl.nim b/src/nigui/private/windows/platform_impl.nim
index a84ffbd..6a04c46 100755
--- a/src/nigui/private/windows/platform_impl.nim
+++ b/src/nigui/private/windows/platform_impl.nim
@@ -17,7 +17,6 @@ import tables
 const pTopLevelWindowClass = "1"
 const pContainerWindowClass = "2"
 const pCustomControlWindowClass = "3"
-
 var pDefaultParentWindow: pointer
 var pKeyState: KeyState
 var pKeyDownKey: Key
@@ -37,7 +36,7 @@ proc pCheckGdiplusStatus(status: int32, showAlert = true) =
       pRaiseLastOSError(showAlert)
     else:
       raiseError("A GDI+ error occured. (Status: " & $status & ")", showAlert)
-
+  
 proc pColorToRGB32(color: Color): RGB32 =
   result.red = color.red
   result.green = color.green
@@ -379,6 +378,10 @@ proc init(app: App) =
   app.defaultBackgroundColor = GetSysColor(COLOR_BTNFACE).pRgb32ToColor()
   app.defaultFontFamily = "Arial"
   fScrollbarSize = GetSystemMetrics(SM_CXVSCROLL)
+  # High DPI support:
+  discard SetProcessDpiAwareness(PROCESS_SYSTEM_DPI_AWARE)
+  fSystemDpi = GetDpiForWindow(pDefaultParentWindow)
+  fDefaultFontSize = defaultFontSizeForDefaultDpi.scaleToDpi
 
 proc runMainLoop() =
   var msg: Msg
diff --git a/src/nigui/private/windows/windows.nim b/src/nigui/private/windows/windows.nim
index f35e603..e43bc56 100755
--- a/src/nigui/private/windows/windows.nim
+++ b/src/nigui/private/windows/windows.nim
@@ -24,6 +24,7 @@
 {.pragma: libShell32, stdcall, dynlib: "Shell32.dll".}
 {.pragma: libGdiplus, stdcall, dynlib: "Gdiplus.dll".}
 {.pragma: libComdlg32, stdcall, dynlib: "Comdlg32.dll".}
+{.pragma: libShcore, stdcall, dynlib: "Shcore.dll".}
 
 
 # ----------------------------------------------------------------------------------------
@@ -190,7 +191,9 @@ const
   PixelFormat32bppARGB* = 2498570
   ImageLockModeWrite* = 2
   MAPVK_VSC_TO_VK_EX* = 3
-
+  PROCESS_DPI_UNAWARE* = 0
+  PROCESS_SYSTEM_DPI_AWARE* = 1
+  PROCESS_PER_MONITOR_DPI_AWARE* = 2
 
 
 # ----------------------------------------------------------------------------------------
@@ -428,6 +431,7 @@ proc GetClipboardData*(uFormat: int32): pointer {.importc: "GetClipboardData", l
 proc SetClipboardData*(uFormat: int32, hMem: pointer): pointer {.importc: "SetClipboardData", libUser32.}
 proc EmptyClipboard*(): bool {.importc: "EmptyClipboard", libUser32.}
 proc MapVirtualKeyW*(uCode, uMapType: int32): int32 {.importc: "MapVirtualKeyW", libUser32.}
+proc GetDpiForWindow*(hWnd: pointer): int32 {.importc: "GetDpiForWindow", libUser32.}
 
 when defined(cpu64):
   # Only available on 64-bit Windows:
@@ -523,3 +527,10 @@ proc CommDlgExtendedError*(): int32 {.importc: "CommDlgExtendedError", libComdlg
 proc GetOpenFileNameW*(lpofn: var OpenFileName): bool {.importc: "GetOpenFileNameW", libComdlg32.}
 proc GetSaveFileNameW*(lpofn: var OpenFileName): bool {.importc: "GetSaveFileNameW", libComdlg32.}
 
+
+# ----------------------------------------------------------------------------------------
+#                                       Comdlg32 Procs
+# ----------------------------------------------------------------------------------------
+
+proc SetProcessDpiAwareness*(value: int32): int32 {.importc: "SetProcessDpiAwareness", libShcore.}
+