View source for WinCreateWindow

==WinCreateWindow==
; WinCreateWindow( ''hwndParent'', ''pszClass'', ''pszText'', ''flStyle'', ''x'', ''y'', ''cx'', ''cy'', ''hwndOwner'', ''hwndBehind'', ''id'', ''pCtrlData'', ''pPresParams'' );  : Creates a new window of class pszClass.

===Usage Explanation===

This API creates most of the windows in you see in OS/2, including main windows, entry fields, scroll bars and so on. Many of these windows can be created by use of a dialog template, but many others can not. This is probably one of the most used APIs during the startup phase of any application. It takes some practice to get used to the way it works, as it has way too many options.

This API sends WM_CREATE and WM_ADJUSTWINDOWPOS messages during window creation. The size can be set during the WM_CREATE message. It is also common to follow the WinCreateWindow call (with the window not set to visible) with a WinSetWindowPos call, during which size and position are set.

If this API is used to create a menu (WC_MENU), then pCtrlData should point to the menu template.

WM_CREATE is the first message a newly created window will receive, but the window is not yet visible when this message is received, and may have no size yet.

===Parameters===

; HWND ''hwndParent'' (input)
: Handle to parent window. If HWND_DESKTOP is specified, a main window is created.
; PSZ ''pszClass'' (input)
: Class name. Must already either be registered via [WinRegisterClass.html WinRegisterClass], or be a pre-defined PM class. This could be one of the following: {| border="1"
! Class
! Control Data
! Explanation
|-
| WC_BUTTON
| BTNCDATA
| There are many different types of buttons, including some which have their own class name.
|-
| WC_CIRCULARSLIDER
| N/A
| This was adopted from MMOS2, and looks like a volume control.
|-
| WC_COMBOBOX
| COMBOCDATA
| Entryfield/list box combination.
|-
| WC_CONTAINER
| CNRINFO
| Container control, ie. folder-like control.
|-
| WC_ENTRYFIELD
| ENTRYFDATA
| Entryfield. This needs subclassing if you need to have a numerical control only.
|-
| WC_FRAME
| FRAMECDATA
| Window frame control.
|-
| WC_LISTBOX
| LBOXINFO
| List box control. This needs filling at some point.
|-
| WC_MENU
| N/A
| Menu control. Can be either an action bar, or a pop-up menu.
|-
| WC_MLE
| MLECTLDATA
| Multi-Line Edit control. Can be used for simple editors.
|-
| WC_NOTEBOOK
| BOOKPAGEINFO
| Notebook control. This is the control in which the pages are created, not the frame.
|-
| WC_SCROLLBAR
| SBCDATA
| Horizontal or vertical scroll bar. This needs sizing, and should not be used where a slider is more appropriate.
|-
| WC_SLIDER
| SLDCDATA
| Horizontal or vertical slider.
|-
| WC_SPINBUTTON
| SPBCDATA
| Spin button control. You will need to fill it.
|-
| WC_STATIC
| N/A
| A static display of either text or bitmap.
|-
| WC_TITLEBAR
| N/A
| Title bar.
|-
| WC_VALUESET
| VSCDATA
| Value set control. You will need to supply some bitmap for this.
|}
; PSZ ''pszText'' (input)
: Window text. What happens with this text is specific to the class.
; ULONG ''flStyle'' (input)
: Window style. Usually chosen from pre-defined PM constants, but you can also create your own styles for your own classes. Here are the pre-defined PM styles: {| border="1"
| WS_ANIMATE
| Enables WPS animation, unless user has disabled this feature.
|-
| WS_CLIPCHILDREN
| Window cannot draw on children.
|-
| WS_CLIPSIBLINGS
| Window cannot draw on siblings.
|-
| WS_DISABLED
| Creates window disabled. This might be desirable for filling list boxes, and so on. WinEnableWindow must be used later.
|-
| WS_GROUP
| Start a new group for dialog box purposes. This should not be used on every window in the group, only the first one.
|-
| WS_MAXIMIZED
| Create this window maximized. Used only with frame windows.
|-
| WS_MINIMIZED
| Create this window minimized. Used only with frame windows.
|-
| WS_PARENTCLIP
| Window created with this style cannot draw outside their parents, but they CAN draw on their parent, so care sould be used.
|-
| WS_SAVEBITS
| PM will save the pixels underneath this window for when this window closes and moves away. This is faster, but uses more memory. With todays fast systems, if you are not concerned about higher RAM usage, this should be on.
|-
| WS_SYNCPAINTS
| WM_PAINT messages will be sent, rather than posted.
|-
| WS_TABSTOP
| Specifies that pressing tab in a dialog box will move the focus to this window. Otherwise it will be skipped.
|-
| WS_VISIBLE
| Without this style, the window will be created invisible, and will have to be displayed later with WinSetWindowPos or WinShowWindow. The window also has to have size to be displayed, but may come up underneath other windows.
|}
; LONG ''x'' (input)
: X position of lower left corner. Measured from left edge of screen, if HWND_DESKTOP is specified for parent. Otherwise measured from left edge of parent.
; LONG ''y'' (input)
: Y position of lower left corner. Measured from lower edge of screen, if HWND_DESKTOP is specified for parent. Otherwise measured from lower edge of parent.
; LONG ''cx'' (input)
: Width of window in pixels.
; LONG ''cy'' (input)
: Height of window in pixels.
; HWND ''hwndOwner'' (input)
: Owner of window. The owner will receive all notification messages regarding this window. This is usually HWND_DESKTOP for main windows, and hwndParent for other windows.
; HWND ''hwndBehind'' (input)
: The handle of the sibling window behind which this window will appear in the z-order. Usually HWND_TOP or HWND_BOTTOM for main windows.
; ULONG ''id'' (input)
: A value given by programmer for identification of the window by owner. between 0x0000 and 0xFFFF.
; PVOID ''pCtrlData'' (input)
: You can pass the class-specific data in the WM_CREATE message through this parameter. This is a pointer to a Control Data structure (see below). Frequently NULL.
; PVOID ''pPresParams'' (input)
: Pointer to class-specific presentation data passed to the window procedure in WM_CREATE.

===Returns===

; HWND hwnd
: Handle to the newly created window. NULLHANDLE is returned if there was an error. In this case, WinGetLastError might return: {| border="1"
| PMERR_INVALID_HWND
| 0x1001
|-
| PMERR_INVALID_FLAG
| 0x1019
|}

===Include Info===

 #define INCL_WINWINDOWMGR
 #define INCL_WIN
or
 #define INCL_PM
 #include <os2.h>

===Relevant Structures===

Control Data structures include the following:

 typedef struct _BOOKPAGEINFO {
   ULONG       cb;                // length of control data in bytes
   ULONG       fl;                // page flags - BFA_
   BOOL        bLoadDlg;          // load dialog now?
   ULONG       ulPageData;        // data to associate with page
   HWND        hwndPage;          // hwnd to associate with page
   PFN         pfnPageDlgProc;    // auto load of dialogs for app
   ULONG       idPageDlg;         // id of page
   HMODULE     hmodPageDlg;       // resource info
   PVOID       pPageDlgParams;    // page creation presentation parameters
   PDLGTEMPLATE  pdlgtPage;
   ULONG       cbStatusLine;      // page flags - BFA_
   PSZ         pszStatusLine;     // status line text string
   HBITMAP     hbmMajorTab;       // major tab bitmap handle
   HBITMAP     hbmMinorTab;       // minor tab bitmap handle
   ULONG       cbMajorTab;        // page flags - BFA_
   PSZ         pszMajorTab;       // major tab text string
   ULONG       cbMinorTab;        // page flags - BFA_
   PSZ         pszMinorTab;       // minor tab text string
   PVOID       pBidiInfo;         // reserved
 } BOOKPAGEINFO, *PBOOKPAGEINFO;

 typedef structc _BTNCDATA {
   USHORT      cb;                // length of control data in bytes
   USHORT      fsCheckState;      // check state of button
   USHORT      fsHilightState;    // highlight state of button
   LHANDLE     hImage;            // resource handle for icon/bitmap
 } BTNCDATA, *PBTNCDATA;

 typedef struct _COMBOCDATA {
   ULONG       cb;                // length of control data in bytes
   ULONG       reserved;          // reserved
   PVOID       pHWXCtlData;       // reserved
 } COMBOCDATA, *PCOMBOCDATA;

 typedef struct _CNRINFO {
   ULONG       cb;                // length of control data in bytes
   PVOID       pSortRecord;       // pointer to sort function
   PFIELDINFO  pFieldInfoLast;    // pointer to last column
   PFIELDINFO  pFieldInfoObject;  // pointer to IN-USE column
   PSZ         pszCnrTitle;       // text for container title
   ULONG       flWindowAttr;      // container attributes: CV_* CA_*
   POINTL      ptlOrigin;         // lower-left origin (virtual)
   ULONG       cDelta;            // number of records from end
   ULONG       cRecords;          // number of records in container
   SIZEL       slBitmapOrIcon;    // size of bitmap in pixels
   SIZEL       slTreeBitmapOrIcon;// size of tree bitmaps in pixels
   HBITMAP     hbmExpanded;       // bitmap for tree node
   HBITMAP     hbmCollapsed;      // bitmap for tree node
   HPOINTER    hptrExpanded;      // icon for tree node
   HPOINTER    hptrCollapsed;     // icon for tree node
   LONG        cyLineSpacing;     // space between two rows
   LONG        cxTreeIndent;      // indent for children
   LONG        cxTreeLine;        // thickness of the Tree Line
   ULONG       cFields;           // number of fields in container
   LONG        xVertSplitbar;     // position relative to container
 } CNRINFO, *PCNRINFO;

 typedef struct _ENTRYFDATA {
   USHORT      cb;                // length of control data in bytes
   USHORT      cchEditLimit;      // edit limit
   USHORT      ichMinSel;         // minimum selection
   USHORT      ichMaxSel;         // maximum selection
 } ENTRYFDATA, *PENTRYFDATA;

 typedef struct _FRAMECDATA {
   USHORT      cb;                // length of control data in bytes
   ULONG       flCreateFlags;     // frame creation flags
   USHORT      hmodResource;      // id of required resource
   USHORT      idResource;        // resource identifier
 } FRAMECDATA, *PFRAMECDATA;

 typedef struct _LBOXINFO {
   LONG        lItemIndex;        // item index
   ULONG       ulItemCount;       // item count
   ULONG       reserved;          // reserved - must be zero
   ULONG       reserved2;         // reserved - must be zero
 } LBOXINFO, *PLBOXINFO

 typedef struct _MLECTLDATA {
   USHORT      cb;                // length of control data in bytes
   USHORT      afIEFormat;        // import/export format
   ULONG       cchText;           // text limit
   IPT         iptAnchor;         // selection anchor point (start)
   IPT         iptCursor;         // selection cursor point (end)
   LONG        cxFormat;          // formatting rectangle width (pixels)
   LONG        cyFormat;          // formatting rectangle height (pixels)
   ULONG       afFormatFlags;     // format flags
 } MLECTLDATA, *PMLECTLDATA;

 typedef struct _SBCDATA {
   USHORT      cb;                // length of control data in bytes
   USHORT      sHilight;          // highlight code
   SHORT       posFirst;          // first possible position of scroll bar
   SHORT       posLast;           // last possible position of scroll bar
   SHORT       posThumb;          // scroll thumb current position
   SHORT       cVisible;          // number of lines (items) visible
   SHORT       cTotal;            // total number of lines (items) in MLE
 } SBCDATA, *PSBCDATA;

 typedef struct _SLDCDATA {
   ULONG       cb;                // length of control data in bytes
   USHORT      usScale1Increments;// number of divisions on scale 1
   USHORT      usScale1Spacing;   // space in pixels between increments
   USHORT      usScale2Increments;// number of divisions on scale 2
   USHORT      usScale2Spacing;   // space in pixels between increments
 } SLDCDATA, *PSLDCDATA;

 typedef struct _SPBCDATA {
   ULONG       cb;                // length of control data in bytes
   ULONG       ulTextLimit;       // entryfield text limit
   LONG        lLowerLimit;       // spin lower limit (numeric only)
   LONG        lUpperLimit;       // spin upper limit (numeric only)
   ULONG       idMasterSpb;       // id of the servant's master spinbutton
   PVOID       pHWXCtlData;       // reserved
 } SPBCDATA, *PSPBCDATA;

 typedef struct _VSCDATA {
   ULONG       cbSize;            // length of control data in bytes
   USHORT      usRowCount;        // number of rows in value set
   USHORT      usColumnCount;     // number of columns in value set
 } VSCDATA, *PVSCDATA;

===Gotchas===

===Sample Code===

<nowiki>
#define INCL_WINMESSAGEMGR
#include <os2.h>

ULONG flStyle = WS_VISIBLE;

WinCreateWindow (hwndFrame,            // Parent Window Handle
                 "CLIENT",             // Class Name
                 NULL,                 // Window Text
                 flStyle,              // Window Styles
                 0, 0, 50, 50,         // Position and size
                 hwndFrame,            // Owner Window Handle
                 HWND_BOTTOM,          // Z-order position
                 ID_CLIENT,            // Resource Identifier
                 NULL,                 // Control Data
                 NULL);                // Presentation Parameters
</nowiki>

==Related Functions==

WinCreateStdWindow, WinDestroyWindow, WinEnableWindow, WinSetWindowPos, WinShowWindow

=== OS Version Introduced ===

[[Category:The OS/2 API Project]]