Simplest Gradient

[qwert]

This was a bit of a puzzle for me, but with Yashied’s help, I figured it out.

I’d been investigating the use of _WinAPI_GradientFill, but found the first couple of rungs of the ladder missing.  By that, I mean that the explanations and examples I found were unclear about how to do the simplest gradient of all.  It didn’t help that terms like “vertex” and “logical units” were involved.  Anyone who had already worked with color fills obviously knew what they meant.  I didn’t.

So, here’s a modification of one of the very first examples from 2009.  It produces a simple 200x600 linear gradient (from one color to another color), as well as the original 400x400 blended gradient (of multiple colors).  Note the subtle differences in the DC processing, related to the use of _WinAPI_GetDC(), I believe.  (BTW, if anyone sees a way for further simplification, please submit a working replacement example.) 

Also, I went ahead and made the original gradient frameless and draggable, but only as a way of showing some variety.

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#Include <GUIConstantsEx.au3>
#include <GuiConstants.au3>
#Include <WinAPIEx.au3>

Global Const $STM_SETIMAGE = 0x0172
Global Const $STM_GETIMAGE = 0x0173

;========  ; basic 2-color gradient  ================
Dim $aVertex[2][3] = [[0, 0, 0x00FFAA], [200, 600, 0x00AA44]]       ; blue/green to different blue/green
$hDC = _WinAPI_CreateCompatibleDC(0)    ; create the bitmap
$hBitmap = _WinAPI_CreateBitmap(200, 600, 1, 32)
$hSv = _WinAPI_SelectObject($hDC, $hBitmap)
_WinAPI_GradientFill($hDC, $aVertex, 0, 1)          ; actual fill
_WinAPI_SelectObject($hDC, $hSv)
_WinAPI_DeleteDC($hDC)
$hForm = GUICreate('MyGUI', 200, 600, 300, 100)   ; create a GUI for the bitmap
GUICtrlCreatePic('', 0, 0, 200, 600)
GUICtrlSetState(-1, $GUI_DISABLE)
GUICtrlSendMsg(-1, $STM_SETIMAGE, 0, $hBitmap)
GUISetState()

;========   somewhat more complex gradient  + draggable ===========
Dim $aVertex[6][3] = [[0, 0, 0xFF0000],[400, 400, 0x00FF00],[0, 400, 0x0000FF],[0, 0, 0xFF0000],[400, 0, 0xFFFF00],[400, 400, 0x00FF00]]
$hColors = GUICreate('Color Wheel', 400, 400, 600, 200, $WS_POPUP)    ; Create square GUI
$idPic = GUICtrlCreatePic('', 0, 0, 400, 400,  -1, $GUI_WS_EX_PARENTDRAG)
$hPic = GUICtrlGetHandle($idPic)
$hDC = _WinAPI_GetDC($hPic)                         ; Create 6-point gradient
$hDestDC = _WinAPI_CreateCompatibleDC($hDC)
$hBitmap = _WinAPI_CreateCompatibleBitmap($hDC, 400, 400)
$hDestSv = _WinAPI_SelectObject($hDestDC, $hBitmap)
_WinAPI_GradientFill($hDestDC, $aVertex, 0, 2)
_WinAPI_GradientFill($hDestDC, $aVertex, 3, 5)
_WinAPI_ReleaseDC($hPic, $hDC)
_WinAPI_SelectObject($hDestDC, $hDestSv)
_WinAPI_DeleteDC($hDestDC)
_SendMessage($hPic, $STM_SETIMAGE, 0, $hBitmap)     ; Set gradient to control
Local $hObj = _SendMessage($hPic, $STM_GETIMAGE)
If $hObj <> $hBitmap Then _WinAPI_DeleteObject($hBitmap)
GUISetState()
GUIRegisterMsg($WM_NCHITTEST, "WM_NCHITTEST")

Do
Until GUIGetMsg() = $GUI_EVENT_CLOSE

Func WM_NCHITTEST($hWnd, $iMsg, $iwParam, $ilParam)
    If ($hWnd = $hColors) And ($iMsg = $WM_NCHITTEST) Then Return $HTCAPTION
EndFunc

[mLipok]

This is very useful.

But I want to ask How to make it as a background under Tabs

Here is my attempt:

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#include <GUIConstantsEx.au3>
#include <GuiStatusBar.au3>
#include <ComboConstants.au3>
#include <EditConstants.au3>
#include <WindowsConstants.au3>
#include <WinAPIGdi.au3>

Global $iMemo, $MainGUI, $hStatus

Example()

Func Example()
    Local $hGUI
    Local $aParts[3] = [75, 150, -1]

    ; Create GUI
    $hGUI = GUICreate("Example", 400, 300)

    ; Gradient made by qwert
    ; http://www.autoitscript.com/forum/topic/167016-simplest-gradient/
    Local Const $STM_SETIMAGE = 0x0172
    Local $aVertex[2][3] = [[0, 0, 0x00FFAA], [400, 300, 0x00AA44]]       ; blue/green to different blue/green
    Local $hDC = _WinAPI_CreateCompatibleDC(0)    ; create the bitmap
    Local $hBitmap = _WinAPI_CreateBitmap( 400 , 300, 1, 32)
    Local $hSv = _WinAPI_SelectObject($hDC, $hBitmap)
    _WinAPI_GradientFill($hDC, $aVertex, 0, 1)          ; actual fill
    _WinAPI_SelectObject($hDC, $hSv)
    _WinAPI_DeleteDC($hDC)
;~  GUICtrlCreatePic('', 0, 0, 400, 300,-1,$WS_EX_TRANSPARENT)
    GUICtrlCreatePic('', 0, 0, 400, 300)
    GUICtrlSetState(-1, $GUI_DISABLE)
    GUICtrlSendMsg(-1, $STM_SETIMAGE, 0, $hBitmap)

    GUICtrlCreateTab(5, 5, 390, 270)

    GUICtrlCreateTabItem("tab0")
    ; Create memo control
    $iMemo = GUICtrlCreateEdit("", 10, 30, 380, 270-30, $WS_VSCROLL)
    GUICtrlSetFont($iMemo, 9, 400, 0, "Courier New")
    GUICtrlSendMsg($iMemo, $EM_SETREADONLY, True, 0)
    GUICtrlSetBkColor($iMemo, 0xFFFFFF)
    GUICtrlCreateTabItem("tab1")

    GUICtrlCreateTabItem("") ; end tabitem definition


    ;===============================================================================
    ; defaults to 1 part, no text
    $hStatus = _GUICtrlStatusBar_Create($hGUI)
    ;===============================================================================
    _GUICtrlStatusBar_SetParts($hStatus, $aParts)

    GUISetState(@SW_SHOW)

    MemoWrite("StatusBar Created with:" & @CRLF & _
            @TAB & "Handle to GUI window" & @CRLF)

    GUIRegisterMsg($WM_NOTIFY, "WM_NOTIFY")

    ; Get border sizes
    MemoWrite("Horizontal border width .: " & _GUICtrlStatusBar_GetBordersHorz($hStatus))
    MemoWrite("Vertical border width ...: " & _GUICtrlStatusBar_GetBordersVert($hStatus))
    MemoWrite("Width between rectangles : " & _GUICtrlStatusBar_GetBordersRect($hStatus))

    ; Loop until the user exits.
    Do
    Until GUIGetMsg() = $GUI_EVENT_CLOSE
    GUISetState(@SW_ENABLE, $MainGUI)
    GUIDelete($hGUI)
EndFunc   ;==>Example

; Write message to memo
Func MemoWrite($sMessage = "")
    GUICtrlSetData($iMemo, $sMessage & @CRLF, 1)
EndFunc   ;==>MemoWrite

Func WM_NOTIFY($hWnd, $iMsg, $iwParam, $ilParam)
    #forceref $hWnd, $iMsg, $iwParam
    Local $hWndFrom, $iIDFrom, $iCode, $tNMHDR

    $tNMHDR = DllStructCreate($tagNMHDR, $ilParam)
    $hWndFrom = HWnd(DllStructGetData($tNMHDR, "hWndFrom"))
    $iIDFrom = DllStructGetData($tNMHDR, "IDFrom")
    $iCode = DllStructGetData($tNMHDR, "Code")
    Local $tinfo
    Switch $hWndFrom
        Case $hStatus
            Switch $iCode
                Case $NM_CLICK ; The user has clicked the left mouse button within the control
                    $tinfo = DllStructCreate($tagNMMOUSE, $ilParam)
                    $hWndFrom = HWnd(DllStructGetData($tinfo, "hWndFrom"))
                    $iIDFrom = DllStructGetData($tinfo, "IDFrom")
                    $iCode = DllStructGetData($tinfo, "Code")
                    _DebugPrint("$NM_CLICK" & @CRLF & "--> hWndFrom:" & @TAB & $hWndFrom & @CRLF & _
                            "-->IDFrom:" & @TAB & $iIDFrom & @CRLF & _
                            "-->Code:" & @TAB & $iCode & @CRLF & _
                            "-->ItemSpec:" & @TAB & DllStructGetData($tinfo, "ItemSpec") & @CRLF & _
                            "-->ItemData:" & @TAB & DllStructGetData($tinfo, "ItemData") & @CRLF & _
                            "-->X:" & @TAB & DllStructGetData($tinfo, "X") & @CRLF & _
                            "-->Y:" & @TAB & DllStructGetData($tinfo, "Y") & @CRLF & _
                            "-->HitInfo:" & @TAB & DllStructGetData($tinfo, "HitInfo"))
                    Return True ; indicate that the mouse click was handled and suppress default processing by the system
                    ; Return FALSE ;to allow default processing of the click.
                Case $NM_DBLCLK ; The user has double-clicked the left mouse button within the control
                    $tinfo = DllStructCreate($tagNMMOUSE, $ilParam)
                    $hWndFrom = HWnd(DllStructGetData($tinfo, "hWndFrom"))
                    $iIDFrom = DllStructGetData($tinfo, "IDFrom")
                    $iCode = DllStructGetData($tinfo, "Code")
                    _DebugPrint("$NM_DBLCLK" & @CRLF & "--> hWndFrom:" & @TAB & $hWndFrom & @CRLF & _
                            "-->IDFrom:" & @TAB & $iIDFrom & @CRLF & _
                            "-->Code:" & @TAB & $iCode & @CRLF & _
                            "-->ItemSpec:" & @TAB & DllStructGetData($tinfo, "ItemSpec") & @CRLF & _
                            "-->ItemData:" & @TAB & DllStructGetData($tinfo, "ItemData") & @CRLF & _
                            "-->X:" & @TAB & DllStructGetData($tinfo, "X") & @CRLF & _
                            "-->Y:" & @TAB & DllStructGetData($tinfo, "Y") & @CRLF & _
                            "-->HitInfo:" & @TAB & DllStructGetData($tinfo, "HitInfo"))
                    Return True ; indicate that the mouse click was handled and suppress default processing by the system
                    ; Return FALSE ;to allow default processing of the click.
                Case $NM_RCLICK ; The user has clicked the right mouse button within the control
                    $tinfo = DllStructCreate($tagNMMOUSE, $ilParam)
                    $hWndFrom = HWnd(DllStructGetData($tinfo, "hWndFrom"))
                    $iIDFrom = DllStructGetData($tinfo, "IDFrom")
                    $iCode = DllStructGetData($tinfo, "Code")
                    _DebugPrint("$NM_RCLICK" & @CRLF & "--> hWndFrom:" & @TAB & $hWndFrom & @CRLF & _
                            "-->IDFrom:" & @TAB & $iIDFrom & @CRLF & _
                            "-->Code:" & @TAB & $iCode & @CRLF & _
                            "-->ItemSpec:" & @TAB & DllStructGetData($tinfo, "ItemSpec") & @CRLF & _
                            "-->ItemData:" & @TAB & DllStructGetData($tinfo, "ItemData") & @CRLF & _
                            "-->X:" & @TAB & DllStructGetData($tinfo, "X") & @CRLF & _
                            "-->Y:" & @TAB & DllStructGetData($tinfo, "Y") & @CRLF & _
                            "-->HitInfo:" & @TAB & DllStructGetData($tinfo, "HitInfo"))
                    Return True ; indicate that the mouse click was handled and suppress default processing by the system
                    ; Return FALSE ;to allow default processing of the click.
                Case $NM_RDBLCLK ; The user has double-clicked the right mouse button within the control
                    $tinfo = DllStructCreate($tagNMMOUSE, $ilParam)
                    $hWndFrom = HWnd(DllStructGetData($tinfo, "hWndFrom"))
                    $iIDFrom = DllStructGetData($tinfo, "IDFrom")
                    $iCode = DllStructGetData($tinfo, "Code")
                    _DebugPrint("$NM_RDBLCLK" & @CRLF & "--> hWndFrom:" & @TAB & $hWndFrom & @CRLF & _
                            "-->IDFrom:" & @TAB & $iIDFrom & @CRLF & _
                            "-->Code:" & @TAB & $iCode & @CRLF & _
                            "-->ItemSpec:" & @TAB & DllStructGetData($tinfo, "ItemSpec") & @CRLF & _
                            "-->ItemData:" & @TAB & DllStructGetData($tinfo, "ItemData") & @CRLF & _
                            "-->X:" & @TAB & DllStructGetData($tinfo, "X") & @CRLF & _
                            "-->Y:" & @TAB & DllStructGetData($tinfo, "Y") & @CRLF & _
                            "-->HitInfo:" & @TAB & DllStructGetData($tinfo, "HitInfo"))
                    Return True ; indicate that the mouse click was handled and suppress default processing by the system
                    ; Return FALSE ;to allow default processing of the click.
                Case $SBN_SIMPLEMODECHANGE ; Simple mode changes
                    _DebugPrint("$SBN_SIMPLEMODECHANGE" & @CRLF & "--> hWndFrom:" & @TAB & $hWndFrom & @CRLF & _
                            "-->IDFrom:" & @TAB & $iIDFrom & @CRLF & _
                            "-->Code:" & @TAB & $iCode)
                    ; No return value
            EndSwitch
    EndSwitch
    Return $GUI_RUNDEFMSG
EndFunc   ;==>WM_NOTIFY

Func _DebugPrint($s_text, $line = @ScriptLineNumber)
    ConsoleWrite( _
            "!===========================================================" & @CRLF & _
            "+======================================================" & @CRLF & _
            "-->Line(" & StringFormat("%04d", $line) & "):" & @TAB & $s_text & @CRLF & _
            "+======================================================" & @CRLF)
EndFunc   ;==>_DebugPrint