Add combobox to Windows

src/nigui.nim

@@ -359,6 +359,11 @@ type
   TextBox* = ref object of ControlImpl
     fEditable: bool
 
+  ComboBox* = ref object of ControlImpl
+    fOptions: seq[string]
+    fStyle: string
+    fEnabled: bool
+
 # Platform-specific extension:
 when useWindows(): include "nigui/private/windows/platform_types2"
 when useGtk():     include "nigui/private/gtk3/platform_types2"
@@ -937,6 +942,40 @@ method wrap*(textArea: TextArea): bool
 method `wrap=`*(textArea: TextArea, wrap: bool)
 
 
+
+# ----------------------------------------------------------------------------------------
+#                                       ComboBox
+# ----------------------------------------------------------------------------------------
+
+proc newComboBox*(options = @[""], style = "simple"): ComboBox
+
+proc init*(comboBox: ComboBox)
+proc init*(comboBox: NativeComboBox)
+
+method options*(comboBox: ComboBox): seq[string]
+method `options=`*(comboBox: ComboBox, options: seq[string])
+
+method style*(comboBox: ComboBox): string
+method `style=`*(comboBox: ComboBox, style: string)
+
+method enabled*(comboBox: ComboBox): bool
+method `enabled=`*(comboBox: ComboBox, enabled: bool)
+
+method getOptionCount*(comboBox: ComboBox): int
+
+method addOption*(comboBox: ComboBox, option: string)
+
+method deleteOption*(comboBox: ComboBox, index: uint)
+
+method selectOption*(comboBox: ComboBox, index: uint)
+
+method findOptionIndex*(comboBox: ComboBox, search: string): int
+
+method getSelectedIndex*(comboBox: ComboBox): int
+
+method getSelectedValue*(comboBox: ComboBox): string
+
+
 # ----------------------------------------------------------------------------------------
 #                            Private Procedures Predeclaration
 # ----------------------------------------------------------------------------------------
@@ -2485,9 +2524,62 @@ method `wrap=`(textArea: TextArea, wrap: bool) =
   # should be extended by NativeTextArea
 
 
+# ----------------------------------------------------------------------------------------
+#                                       ComboBox
+# ----------------------------------------------------------------------------------------
+
+proc newComboBox(options = @[""], style = "simple"): ComboBox =
+  result = new NativeComboBox
+  # need to pass desired style (type) of combobox to NativeComboBox... is there a better way?
+  result.style = style  
+  result.NativeComboBox.init()
+  result.options = options
+
+proc init(comboBox: ComboBox) =
+  comboBox.ControlImpl.init()
+  comboBox.fOnClick = nil
+  comboBox.fWidthMode = WidthMode_Expand
+  comboBox.fHeightMode = HeightMode_Auto
+  comboBox.minWidth = 20.scaleToDpi
+  comboBox.minHeight = 20.scaleToDpi
+  comboBox.enabled = true
+
+method options(comboBox: ComboBox): seq[string] = comboBox.fOptions
+method `options=`(comboBox: ComboBox, options: seq[string]) = comboBox.fOptions = options
+
+method style(comboBox: ComboBox): string = comboBox.fStyle
+method `style=`(comboBox: ComboBox, style: string) = comboBox.fStyle = style
+
+method getOptionCount*(comboBox: ComboBox): int = discard
+# has to be implemented by NativeComboBox
+
+method addOption(comboBox: ComboBox, option: string) = discard
+# has to be implemented by NativeComboBox
+
+method deleteOption(comboBox: ComboBox, index: uint) = discard
+# has to be implemented by NativeComboBox
+
+method selectOption*(comboBox: ComboBox, index: uint) = discard
+# has to be implemented by NativeComboBox
+
+method findOptionIndex(comboBox: ComboBox, search: string): int = discard
+# has to be implemented by NativeComboBox
+
+method getSelectedIndex(comboBox: ComboBox): int = discard
+# has to be implemented by NativeComboBox
+
+method getSelectedValue(comboBox: ComboBox): string = discard
+# has to be implemented by NativeComboBox
+
+method enabled(comboBox: ComboBox): bool = comboBox.fEnabled
+
+method `enabled=`(comboBox: ComboBox, enabled: bool) = discard
+# has to be implemented by NativeComboBox
+
+
 # ----------------------------------------------------------------------------------------
 #                             Platform-specific implementation
 # ----------------------------------------------------------------------------------------
 
 when useWindows(): include "nigui/private/windows/platform_impl"
-when useGtk():     include "nigui/private/gtk3/platform_impl"
+when useGtk():     include "nigui/private/gtk3/platform_impl"

src/nigui/private/windows/platform_impl.nim

@@ -193,9 +193,11 @@ proc pCommonWndProc(hWnd: pointer, uMsg: int32, wParam, lParam: pointer): pointe
       control.handleTextChangeEvent(evt)
   of WM_CTLCOLORSTATIC, WM_CTLCOLOREDIT:
     let control = cast[Control](pGetWindowLongPtr(lParam, GWLP_USERDATA))
-    discard SetTextColor(wParam, control.textColor.pColorToRGB32())
-    discard SetBkColor(wParam, control.backgroundColor.pColorToRGB32())
-    return CreateSolidBrush(control.backgroundColor.pColorToRGB32)
+    # Without nil check, this cannot compile due to combobox addition? Why?
+    if control != nil: 
+      discard SetTextColor(wParam, control.textColor.pColorToRGB32())
+      discard SetBkColor(wParam, control.backgroundColor.pColorToRGB32())
+      return CreateSolidBrush(control.backgroundColor.pColorToRGB32)
   else:
     discard
   result = DefWindowProcA(hWnd, uMsg, wParam, lParam)
@@ -1529,3 +1531,64 @@ method `wrap=`(textArea: NativeTextArea, wrap: bool) =
   # It seems that this is not possible.
   # Word wrap depends on whether dwStyle contains WS_HSCROLL at window creation.
   # Changing the style later has not the wanted effect.
+
+
+# ----------------------------------------------------------------------------------------
+#                                       ComboBox
+# ----------------------------------------------------------------------------------------
+
+proc init(comboBox: NativeComboBox) =
+  var dwStyle: int32
+  # determine which "style" of combobox to display.. is there a better way to do this?
+  case comboBox.style:
+    of "dropdown":
+      dwStyle = WS_CHILD or CBS_DROPDOWN or WS_VSCROLL
+    of "dropdownlist":
+      dwStyle = WS_CHILD or CBS_DROPDOWNLIST or WS_VSCROLL
+    else:
+      dwStyle = WS_CHILD or CBS_SIMPLE or WS_VSCROLL
+  comboBox.fHandle = pCreateWindowExWithUserdata("COMBOBOX", dwStyle, 0, pDefaultParentWindow, cast[pointer](comboBox))
+  comboBox.ComboBox.init()
+
+# TODO: Find correct(?) way to calculate optimum height on combobox
+method naturalHeight(comboBox: ComboBox): int = 
+  case comboBox.style:
+    of "dropdown", "dropdownlist":
+      # just size of dropdown window
+      # (line height + 8 padding/margin)
+      return comboBox.getTextLineHeight() + 8
+    else:
+      # size of combolist and dropdown section - not sure if this is calculated correctly.
+      # (line height + 8 padding/margin) + (number of options * (line height + 2 margin)) ??
+      return (comboBox.getTextLineHeight() + 8) + (comboBox.getOptionCount() * (comboBox.getTextLineHeight() + 2))
+
+method `options=`(comboBox: NativeComboBox, options: seq[string]) =
+  for option in options:
+    discard SendMessageW(comboBox.fHandle, CB_ADDSTRING, nil, cast[pointer](newWideCString(option)))
+
+method getOptionCount(comboBox: NativeComboBox): int =
+    result = cast[int](SendMessageW(comboBox.fHandle, CB_GETCOUNT, nil, nil))
+
+method addOption(comboBox: NativeComboBox, option: string) =
+  discard SendMessageW(comboBox.fHandle, CB_ADDSTRING, nil, cast[pointer](newWideCString(option)))
+
+method deleteOption(comboBox: NativeComboBox, index: uint) =
+  discard SendMessageA(comboBox.fHandle, CB_DELETESTRING, cast[pointer](index), nil)
+
+method selectOption(comboBox: NativeComboBox, index: uint) =
+  discard SendMessageA(comboBox.fHandle, CB_SETCURSEL, cast[pointer](index), nil)
+
+method findOptionIndex(comboBox: NativeComboBox, search: string): int =
+  # wParam value -1 searches entire contents of ComboBox, result of -1 means option doesn't exist (not found)
+  var searchString: cstring = search
+  result = cast[int](SendMessageA(comboBox.fHandle, CB_FINDSTRINGEXACT, cast[pointer](-1), cast[pointer](searchString)))
+
+method getSelectedIndex(comboBox: NativeComboBox): int =
+  result = cast[int]((SendMessageA(comboBox.fHandle, CB_GETCURSEL, cast[pointer](0), cast[pointer](0))))
+
+method getSelectedValue(comboBox: NativeComboBox): string =
+  result = pGetWindowText(comboBox.fHandle)
+
+method `enabled=`(comboBox: NativeComboBox, enabled: bool) =
+  comboBox.fEnabled = enabled
+  discard EnableWindow(comboBox.fHandle, enabled)

src/nigui/private/windows/platform_types2.nim

@@ -14,3 +14,5 @@ type
   NativeLabel* = ref object of Label
 
   NativeTextBox* = ref object of TextBox
+
+  NativeComboBox* = ref object of ComboBox

src/nigui/private/windows/windows.nim

@@ -37,8 +37,20 @@ const
   BN_CLICKED* = 0
   BM_SETSTYLE* = 244
   BM_SETIMAGE* = 247
+  BM_GETCHECK* = 0x00F0
   BS_DEFPUSHBUTTON* = 0x00000001
   BS_GROUPBOX* = 0x00000007
+  CB_ERR* = -1
+  CB_ADDSTRING* = 0x0143
+  CB_DELETESTRING* = 0x0144
+  CB_FINDSTRINGEXACT* = 0x0158
+  CB_GETCOUNT* = 0x0146
+  CB_GETCURSEL* = 0x0147
+  CB_SETCURSEL* = 0x014E
+  CB_SETITEMHEIGHT* = 0x0153
+  CBS_SIMPLE* = 0x0001
+  CBS_DROPDOWN* = 0x0002
+  CBS_DROPDOWNLIST* = 0x0003
   CF_TEXT* = 1
   COLOR_BTNFACE* = 15
   COLOR_WINDOW* = 5
@@ -166,6 +178,7 @@ const
   WS_THICKFRAME* = 0x00040000
   WS_VSCROLL* = 0x00200000
   WS_EX_CONTROLPARENT* = 0x00010000
+  WS_VISIBLE* = 0x10000000
   # DT_CALCRECT* = 1024
   # OBJ_FONT* = 6
   # SM_XVIRTUALSCREEN* = 76
@@ -406,7 +419,7 @@ proc GetClientRect*(wnd: pointer, lpRect: var Rect): bool {.importc: "GetClientR
 proc BeginPaint*(hWnd: pointer, lpPaint: var PaintStruct): pointer {.importc: "BeginPaint", libUser32.}
 proc EndPaint*(hWnd: pointer, lpPaint: var PaintStruct): bool {.importc: "EndPaint", libUser32.}
 proc SendMessageA*(hWnd: pointer, msg: int32, wParam, lParam: pointer): pointer {.importc: "SendMessageA", libUser32.}
-# proc SendMessageW*(hWnd: pointer, msg: int32, wParam, lParam: pointer): pointer {.importc: "SendMessageW", libUser32.}
+proc SendMessageW*(hWnd: pointer, msg: int32, wParam, lParam: pointer): pointer {.importc: "SendMessageW", libUser32.}
 proc PostMessageA*(hWnd: pointer, msg: int32, wParam, lParam: pointer): pointer {.importc: "PostMessageA", libUser32.}
 proc GetSysColor*(nIndex: int32): RGB32 {.importc: "GetSysColor", libUser32.}
 proc InvalidateRect*(hWnd: pointer, lpRect: ref Rect, bErase: bool): bool {.importc: "InvalidateRect", libUser32.}
@@ -543,4 +556,4 @@ proc GetSaveFileNameW*(lpofn: var OpenFileName): bool {.importc: "GetSaveFileNam
 #                                       Shcore Procs
 # ----------------------------------------------------------------------------------------
 
-type SetProcessDpiAwarenessType* = proc(value: int32): int32 {.gcsafe, stdcall.} # not available on Windows 7
+type SetProcessDpiAwarenessType* = proc(value: int32): int32 {.gcsafe, stdcall.} # not available on Windows 7