You know, you don't have to handle the keys yourself with the standard treeview control; the left, right, up and down arrows all do expand/collapse navigate.
As far as "select (or simply 'highlight') the first child of the selected item (via click or keyboard)", that you *do* have to do yourself, as the default behavior is to select the node clicked or to which you have navigated.
I learned all this when I had to replace a standard treeview control with "something else"; I spent a lot of time playing with the standard treeview so I could emulate its behavior. Yes, I *was* surprised by all the stuff it does with the arrow keys.
MCM
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Working example
So far this is the best I can come up with starting with Tonny's code. I've changed a place or two where Michael rightly questioned the use of CBCTL in WM_NOTIFY.
The program is supposed to react to a click on the parent node by expanding the child nodes and highlighting the first one. Using the down arrow and coming up on another parent node will auto expand that node. Please do that will several nodes. Once several are open, use the up and down arrows and it should jump over the Parent nodes.
The mouse works to collapse or expand any parent node that doesn't have a highlighted item in it.
The left arrow will collapse every node it's on when pressed and the same is true of the right arrow.
The action I'm looking for is similar to a panel control where the sub items sit directly beneath the section headers which look like buttons that float up and down based on expanding or collapsing. This method however allows many nodes to be open at the same time with a scroll bar.
Please see notes in comment section and especially the code in TVN_SELCHANGED area.
Bob Mechler
Code:'MESSAGE http://www.powerbasic.com/support/forums/Forum7/HTML/003114.html 'FORUM: Source Code 'TOPIC: Basic TreeView LPStr_TextCallBack Demo 'NAME: Tonny Bjorn, Member 'DATE: March 05, 2007 09:51 AM '============================================================================== ' Basic demo on using large amounts of data into TreeView using %LPSTR_TEXTCALLBACK ' and %TVN_GETDISPINFO for better performance. NB: %LVN_GETDISPINFO for ListView '------------------------------------------------------------------------------ ' Used Compiler: PB/WIN 8.03 ' WIN32API Date: 01*Feb*2005 (Updated 27 January 2005) ' COMMCTRL Date: 01*Feb*2005 (Updated 27 October 2003) ' Prg tested on: Windows 2000 SP3, Windows XP Pro SP2 ' 03/11/09 by Bob Mechler 'changed slightly to test skipping level one nodes and opening up access to ' the child nodes as in a Menu where section headers divide up the menu into ' logical divisions and serve as a place to expand or collapse a long menu ' in other words the Parent node level should only expand or collapse the next ' level ' Looking for any comments '============================================================================== #COMPILE EXE #DIM ALL %USEMACROS = 1 #INCLUDE "WIN32API.INC" #INCLUDE "COMMCTRL.INC" '============================================================================== %ID_TREEVIEW = 100 '============================================================================== GLOBAL hTreeView AS LONG ' TreeView Handle GLOBAL TVTextArray() AS STRING ' TreeView Text Label Storage '============================================================================== ' Get the text from the selected item in the TreeView '------------------------------------------------------------------------------ ' hTree - TreeView Handle ' hTVItem - Selected TreeView item '============================================================================== FUNCTION TVGetText(BYVAL hTree AS LONG, BYVAL hTVItem AS LONG) AS STRING LOCAL zText AS ASCIIZ * 255 LOCAL lTVItem AS TV_ITEM lTVItem.hItem = hTVItem lTVItem.Mask = %TVIF_TEXT lTVItem.pszText = VARPTR(zText) lTVItem.cchTextMax = 255 TreeView_GetItem(hTree, lTVItem) FUNCTION = zText END FUNCTION '============================================================================== ' Insert an item in the TreeView using LPSTR_TEXTCALLBACK for improved speed '------------------------------------------------------------------------------ ' hTree - TreeView handle ' hParent - Handle for position type (root, parent child) in the tree ' lItemNum - Indicator coresponding to the text in the TVTextArray for the TreeView ' lTextMax - Length of the string being added '============================================================================== FUNCTION TVInsertLPSTRItem(BYVAL hTree AS LONG, BYVAL hParent AS LONG, BYVAL lItemNum AS LONG, BYVAL lTextMax AS LONG) AS LONG LOCAL tTVInsert AS TV_INSERTSTRUCT LOCAL tTVItem AS TV_ITEM IF hParent THEN tTVItem.mask = %TVIF_CHILDREN OR %TVIF_HANDLE tTVItem.hItem = hParent tTVItem.cchildren = 1 TreeView_SetItem(hTree, tTVItem) END IF tTVInsert.hParent = hParent tTVInsert.Item.Item.mask = %TVIF_TEXT OR %TVIF_PARAM tTVInsert.Item.Item.pszText = %LPSTR_TEXTCALLBACK tTVInsert.Item.Item.cchTextMax = lTextMax tTVInsert.Item.Item.lParam = lItemNum FUNCTION = TreeView_InsertItem(hTree, tTVInsert) END FUNCTION '============================================================================== FUNCTION FillTreeViewTest(BYVAL lCount AS LONG) AS LONG LOCAL hTopRoot AS DWORD LOCAL hRoot AS DWORD LOCAL hParent AS DWORD LOCAL hChild AS DWORD LOCAL g AS LONG LOCAL h AS LONG LOCAL i AS LONG LOCAL j AS LONG LOCAL k AS LONG LOCAL sBuffer AS STRING k = 0 ' ======================================================================= ' Test if array is big enough to hold string, else REDIM and add a ' little extra to minimize slow redim process time. The extra array ' overhead is balanced out by improved speed. IF UBOUND(TVTextArray) < k THEN REDIM PRESERVE TVTextArray(k + 100) ' Add string to array for %LPSTR_TEXTCALLBACK 'TVTextArray(k) = "Root" ' Insert the item in the TreeView 'hTopRoot = TVInsertLPSTRItem(hTreeView, 0, k, LEN(TVTextArray(k))) hTopRoot = 0 ' ======================================================================= FOR i = 1 TO lCount ' Add Parent sBuffer = "Parent Pos #" & FORMAT$(i) INCR k IF UBOUND(TVTextArray) < k THEN REDIM PRESERVE TVTextArray(k + 100) TVTextArray(k) = sBuffer hRoot = TVInsertLPSTRItem(hTreeView, hTopRoot, k, LEN(TVTextArray(k))) ' Add Childs FOR j = 1 TO 5 INCR k IF UBOUND(TVTextArray) < k THEN REDIM PRESERVE TVTextArray(k + 100) TVTextArray(k) = "Child1 Pos #" & FORMAT$(j) hParent = TVInsertLPSTRItem(hTreeView, hRoot, k, LEN(TVTextArray(k))) ' Add Childs FOR h = 1 TO 5 INCR k IF UBOUND(TVTextArray) < k THEN REDIM PRESERVE TVTextArray(k + 100) TVTextArray(k) = "Child2 Pos #" & FORMAT$(h) hChild = TVInsertLPSTRItem(hTreeView, hParent, k, LEN(TVTextArray(k))) ' Add Subs FOR g = 1 TO 3 INCR k IF UBOUND(TVTextArray) < k THEN REDIM PRESERVE TVTextArray(k + 100) TVTextArray(k) = "Sub Pos #" & FORMAT$(g) TVInsertLPSTRItem(hTreeView, hChild, k, LEN(TVTextArray(k))) NEXT NEXT NEXT NEXT FUNCTION = k DIALOG DOEVENTS END FUNCTION '============================================================================== CALLBACK FUNCTION DialogProc() LOCAL lpTV AS NM_TREEVIEW PTR LOCAL pTVDI AS TV_DISPINFO PTR LOCAL lpNmh AS NMHDR PTR STATIC hTreeItem AS LONG LOCAL lTime1 AS LONG LOCAL lTime2 AS LONG LOCAL lCount AS LONG LOCAL TVtxt AS STRING STATIC hChild AS LONG STATIC hSectionFlag AS LONG LOCAL kKey AS TV_KEYDOWN PTR STATIC kKeylastkey AS LONG SELECT CASE AS LONG CBMSG CASE %WM_INITDIALOG ' Pre DIM the array for encreased speed. 'DIM TVTextArray(100000) ' Kick it in motion POSTMESSAGE CBHNDL, %WM_USER + 1000, 0, 0 CASE %WM_USER + 1000 ' Fill the TreeView with Test Data doing x loops lTime1 = TIMER lCount = FillTreeViewTest( 1000 ) lTime2 = TIMER MSGBOX FORMAT$(lCount) & " items added to the TreeView in ~" & FORMAT$(lTime2 - lTime1) & " sec.",,"Info" CASE %WM_NOTIFY lpNmh = CBLPARAM lpTV = CBLPARAM SELECT CASE @lpNmh.idFrom CASE %ID_TREEVIEW SELECT CASE @lpNmh.Code ' Get the text in TVTextArray to be displayed. CASE %TVN_GETDISPINFO pTVDI = CBLPARAM IF (@pTVDI.item.mask AND %TVIF_TEXT) THEN POKE$ @pTVDI.item.pszText, LEFT$( TVTextArray( @pTVDI.item.lParam ), @pTVDI.item.cchTextMax) END IF FUNCTION = 0 EXIT FUNCTION CASE %TVN_KEYDOWN kKey = CBLPARAM kKeylastkey = @kKey.wVKey CASE %TVN_SELCHANGING ' Get and select item when [+] is clicked CASE %TVN_SELCHANGED lpTV = CBLPARAM hTreeItem = @lpTV.ItemNew.hItem TVtxt$ = TVGetText(hTreeView, hTreeItem) IF INSTR(TVtxt$,"Parent") > 0 AND kKeylastkey <> 39 AND kKeylastkey <> 38 AND kKeylastkey <> 37 THEN hChild = SendMessage(hTreeView, %TVM_GETNEXTITEM, %TVGN_CHILD, hTreeItem) TreeView_SelectItem(hTreeView, hChild) ELSEIF INSTR(TVtxt$,"Parent") > 0 AND kKeylastkey = 38 THEN hChild = SendMessage(hTreeView, %TVM_GETNEXTITEM, %TVGN_PREVIOUSVISIBLE, hTreeItem) TreeView_SelectItem(hTreeView, hChild) ELSEIF INSTR(TVtxt$,"Parent") > 0 AND kKeylastkey = 37 THEN TreeView_Expand(hTreeView,hTreeItem,%TVE_COLLAPSE) ELSEIF INSTR(TVtxt$,"Parent") > 0 AND kKeylastkey = 39 THEN TreeView_Expand(hTreeView,hTreeItem,%TVE_EXPAND) END IF kKeylastkey = 0 CASE %TVN_ITEMEXPANDED ' Get selected item hTreeItem = @lpTV.ItemNew.hItem ' Select the item where [+] was clicked 'TreeView_Select(hTreeView, hTreeItem, %TVGN_CARET) FUNCTION = 0 EXIT FUNCTION END SELECT END SELECT CASE %WM_COMMAND SELECT CASE AS LONG CBCTL CASE %IDCANCEL ' End DIALOG END CBHNDL, 0 END SELECT CASE %WM_DESTROY ' Nuke the array just to make sure ERASE TVTextArray() END SELECT END FUNCTION '============================================================================== FUNCTION PBMAIN() AS LONG LOCAL hDlg AS DWORD DIALOG NEW 0, "Skip Section Headers", , , 300, 260, _ %WS_CHILD OR %WS_SYSMENU OR %WS_MAXIMIZEBOX OR %WS_MINIMIZEBOX OR %WS_CAPTION TO hDlg CONTROL ADD "SysTreeView32", hDlg, %ID_TREEVIEW, "", 10, 10, 280, 245, _ %WS_CHILD OR %WS_VISIBLE OR %WS_CLIPCHILDREN _ OR %TVS_HASBUTTONS _ '+/- buttons for parent nodes with children OR %TVS_HASLINES _ 'shows connector lines & buttons for tree structure (below the root) OR %TVS_LINESATROOT _ 'shows connector lines & buttons at root level of tree structure OR %TVS_DISABLEDRAGDROP _ 'does not send dragdrop notifications OR %TVS_SHOWSELALWAYS _ 'Show selected item even when treeview does NOT have focus OR %TVS_TRACKSELECT _ 'Underlines item where mouse cursor points , %WS_EX_CLIENTEDGE CONTROL HANDLE hDlg, %ID_TREEVIEW TO hTreeView DIALOG SHOW MODAL hDlg CALL DialogProc END FUNCTIONLeave a comment:
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>CONTROL ADD "SysTreeView32", hDlg, %ID_TREEVIEW, "", 10, 10, 280, 245,
As a general rule, CBCTL is meaningless when the control is added with CONTROL ADD "classname" because DDT has no way knowing how "classname" sends its notification messages to the dialog's CALLBACK FUNCTION. Does it use WM_COMMAND? WM_NOTIFY? Something else?
Essentially all you can count on being valid in this case is CBHNDL, CBMSG, CBLPARAM and CBWPARAM.
Lots of things might "work" but I must refer you, too, to the current thread on "forgiving" at http://www.powerbasic.com/support/pb...ad.php?t=40098
MCMLeave a comment:
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That part was from the sample code I borrowed, but you're right it needs to be idFrom. It wasn't causing a problem though in this sample.
Bob MechlerLeave a comment:
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CBCTL is not the correct way to identify control ID under WM_NOTIFY.Code:lpNmh = CBLPARAM lpTV = CBLPARAM SELECT CASE [B][COLOR="Red"]CBCTL[/COLOR][/B]
You want ot use @lpnmh.idFrom or the new CB.NMIDLeave a comment:
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I found this code and modified a portion under TVN_SELCHANGED to illustrate what I want to do. I'm about halfway there. I can tell when I'm on a 'Parent or Section Header node based on the text and don't want the user to be able to highlight it since it won't be doing anything in the production code. It is however supposed to allow for expanding and collapsing the child items level.
Initially when you click on any of the parent nodes it will currently detect that and get the first child, expanding the node as needed. I've also trapped the up and down arrow keys to allow the up and down arrow to 'skip' over the parent node. The only thing I lack is the ability to close up the node. I've locked that action from happening somehow. I'm thinking I'll need to do that in the TVN_SELCHANGING EVENT but I'm not sure how to do that.
Any help please
Bob Mechler
Code:'MESSAGE http://www.powerbasic.com/support/forums/Forum7/HTML/003114.html 'FORUM: Source Code 'TOPIC: Basic TreeView LPStr_TextCallBack Demo 'NAME: Tonny Bjorn, Member 'DATE: March 05, 2007 09:51 AM '============================================================================== ' Basic demo on using large amounts of data into TreeView using %LPSTR_TEXTCALLBACK ' and %TVN_GETDISPINFO for better performance. NB: %LVN_GETDISPINFO for ListView '------------------------------------------------------------------------------ ' Used Compiler: PB/WIN 8.03 ' WIN32API Date: 01*Feb*2005 (Updated 27 January 2005) ' COMMCTRL Date: 01*Feb*2005 (Updated 27 October 2003) ' Prg tested on: Windows 2000 SP3, Windows XP Pro SP2 '============================================================================== #COMPILE EXE #DIM ALL %USEMACROS = 1 #INCLUDE "WIN32API.INC" #INCLUDE "COMMCTRL.INC" '============================================================================== %ID_TREEVIEW = 100 '============================================================================== GLOBAL hTreeView AS LONG ' TreeView Handle GLOBAL TVTextArray() AS STRING ' TreeView Text Label Storage '============================================================================== ' Get the text from the selected item in the TreeView '------------------------------------------------------------------------------ ' hTree - TreeView Handle ' hTVItem - Selected TreeView item '============================================================================== FUNCTION TVGetText(BYVAL hTree AS LONG, BYVAL hTVItem AS LONG) AS STRING LOCAL zText AS ASCIIZ * 255 LOCAL lTVItem AS TV_ITEM lTVItem.hItem = hTVItem lTVItem.Mask = %TVIF_TEXT lTVItem.pszText = VARPTR(zText) lTVItem.cchTextMax = 255 TreeView_GetItem(hTree, lTVItem) FUNCTION = zText END FUNCTION '============================================================================== ' Insert an item in the TreeView using LPSTR_TEXTCALLBACK for improved speed '------------------------------------------------------------------------------ ' hTree - TreeView handle ' hParent - Handle for position type (root, parent child) in the tree ' lItemNum - Indicator coresponding to the text in the TVTextArray for the TreeView ' lTextMax - Length of the string being added '============================================================================== FUNCTION TVInsertLPSTRItem(BYVAL hTree AS LONG, BYVAL hParent AS LONG, BYVAL lItemNum AS LONG, BYVAL lTextMax AS LONG) AS LONG LOCAL tTVInsert AS TV_INSERTSTRUCT LOCAL tTVItem AS TV_ITEM IF hParent THEN tTVItem.mask = %TVIF_CHILDREN OR %TVIF_HANDLE tTVItem.hItem = hParent tTVItem.cchildren = 1 TreeView_SetItem(hTree, tTVItem) END IF tTVInsert.hParent = hParent tTVInsert.Item.Item.mask = %TVIF_TEXT OR %TVIF_PARAM tTVInsert.Item.Item.pszText = %LPSTR_TEXTCALLBACK tTVInsert.Item.Item.cchTextMax = lTextMax tTVInsert.Item.Item.lParam = lItemNum FUNCTION = TreeView_InsertItem(hTree, tTVInsert) END FUNCTION '============================================================================== FUNCTION FillTreeViewTest(BYVAL lCount AS LONG) AS LONG LOCAL hTopRoot AS DWORD LOCAL hRoot AS DWORD LOCAL hParent AS DWORD LOCAL hChild AS DWORD LOCAL g AS LONG LOCAL h AS LONG LOCAL i AS LONG LOCAL j AS LONG LOCAL k AS LONG LOCAL sBuffer AS STRING k = 0 ' ======================================================================= ' Test if array is big enough to hold string, else REDIM and add a ' little extra to minimize slow redim process time. The extra array ' overhead is balanced out by improved speed. IF UBOUND(TVTextArray) < k THEN REDIM PRESERVE TVTextArray(k + 100) ' Add string to array for %LPSTR_TEXTCALLBACK TVTextArray(k) = "Root" ' Insert the item in the TreeView hTopRoot = TVInsertLPSTRItem(hTreeView, 0, k, LEN(TVTextArray(k))) ' ======================================================================= FOR i = 1 TO lCount ' Add Parent sBuffer = "Parent Pos #" & FORMAT$(i) INCR k IF UBOUND(TVTextArray) < k THEN REDIM PRESERVE TVTextArray(k + 100) TVTextArray(k) = sBuffer hRoot = TVInsertLPSTRItem(hTreeView, hTopRoot, k, LEN(TVTextArray(k))) ' Add Childs FOR j = 1 TO 5 INCR k IF UBOUND(TVTextArray) < k THEN REDIM PRESERVE TVTextArray(k + 100) TVTextArray(k) = "Child1 Pos #" & FORMAT$(j) hParent = TVInsertLPSTRItem(hTreeView, hRoot, k, LEN(TVTextArray(k))) ' Add Childs FOR h = 1 TO 5 INCR k IF UBOUND(TVTextArray) < k THEN REDIM PRESERVE TVTextArray(k + 100) TVTextArray(k) = "Child2 Pos #" & FORMAT$(h) hChild = TVInsertLPSTRItem(hTreeView, hParent, k, LEN(TVTextArray(k))) ' Add Subs FOR g = 1 TO 3 INCR k IF UBOUND(TVTextArray) < k THEN REDIM PRESERVE TVTextArray(k + 100) TVTextArray(k) = "Sub Pos #" & FORMAT$(g) TVInsertLPSTRItem(hTreeView, hChild, k, LEN(TVTextArray(k))) NEXT NEXT NEXT NEXT FUNCTION = k DIALOG DOEVENTS END FUNCTION '============================================================================== CALLBACK FUNCTION DialogProc() LOCAL lpTV AS NM_TREEVIEW PTR LOCAL pTVDI AS TV_DISPINFO PTR LOCAL lpNmh AS NMHDR PTR STATIC hTreeItem AS LONG LOCAL lTime1 AS LONG LOCAL lTime2 AS LONG LOCAL lCount AS LONG LOCAL TVtxt AS STRING STATIC hChild AS LONG STATIC hSectionFlag AS LONG LOCAL kKey AS TV_KEYDOWN PTR [COLOR="Red"] STATIC kKeylastkey AS LONG[/COLOR] SELECT CASE AS LONG CBMSG CASE %WM_INITDIALOG ' Pre DIM the array for encreased speed. 'DIM TVTextArray(100000) ' Kick it in motion POSTMESSAGE CBHNDL, %WM_USER + 1000, 0, 0 CASE %WM_USER + 1000 ' Fill the TreeView with Test Data doing x loops lTime1 = TIMER lCount = FillTreeViewTest( 1000 ) lTime2 = TIMER MSGBOX FORMAT$(lCount) & " items added to the TreeView in ~" & FORMAT$(lTime2 - lTime1) & " sec.",,"Info" CASE %WM_NOTIFY lpNmh = CBLPARAM lpTV = CBLPARAM SELECT CASE CBCTL CASE %ID_TREEVIEW SELECT CASE @lpNmh.Code ' Get the text in TVTextArray to be displayed. CASE %TVN_GETDISPINFO pTVDI = CBLPARAM IF (@pTVDI.item.mask AND %TVIF_TEXT) THEN POKE$ @pTVDI.item.pszText, LEFT$( TVTextArray( @pTVDI.item.lParam ), @pTVDI.item.cchTextMax) END IF FUNCTION = 0 EXIT FUNCTION ' The TreeView is changing [COLOR="Red"] CASE %TVN_KEYDOWN kKey = CBLPARAM kKeylastkey = @kKey.wVKey[/COLOR] CASE %TVN_SELCHANGING FUNCTION = 0 EXIT FUNCTION ' Get and select item when [+] is clicked CASE %TVN_SELCHANGED [COLOR="red"] lpTV = CBLPARAM hTreeItem = @lpTV.ItemNew.hItem TVtxt$ = TVGetText(hTreeView, hTreeItem) IF INSTR(TVtxt$,"Parent") > 0 AND kKeylastkey <> 38 THEN hChild = SendMessage(hTreeView, %TVM_GETNEXTITEM, %TVGN_CHILD, hTreeItem) TreeView_SelectItem(hTreeView, hChild) ELSEIF INSTR(TVtxt$,"Parent") > 0 AND kKeylastkey = 38 THEN hChild = SendMessage(hTreeView, %TVM_GETNEXTITEM, %TVGN_PREVIOUSVISIBLE, hTreeItem) TreeView_SelectItem(hTreeView, hChild) END IF kKeylastkey = 0[/COLOR] CASE %TVN_ITEMEXPANDED ' Get selected item hTreeItem = @lpTV.ItemNew.hItem ' Select the item where [+] was clicked TreeView_Select(hTreeView, hTreeItem, %TVGN_CARET) FUNCTION = 0 EXIT FUNCTION END SELECT END SELECT CASE %WM_COMMAND SELECT CASE AS LONG CBCTL CASE %IDCANCEL ' End DIALOG END CBHNDL, 0 END SELECT CASE %WM_DESTROY ' Nuke the array just to make sure ERASE TVTextArray() END SELECT END FUNCTION '============================================================================== FUNCTION PBMAIN() AS LONG LOCAL hDlg AS DWORD DIALOG NEW 0, "LPSTR_TEXTCALLBACK TreeView Demo", , , 300, 260, _ %WS_CHILD OR %WS_SYSMENU OR %WS_MAXIMIZEBOX OR %WS_MINIMIZEBOX OR %WS_CAPTION TO hDlg CONTROL ADD "SysTreeView32", hDlg, %ID_TREEVIEW, "", 10, 10, 280, 245, _ %WS_CHILD OR %WS_VISIBLE OR %WS_CLIPCHILDREN _ OR %TVS_HASBUTTONS _ '+/- buttons for parent nodes with children OR %TVS_HASLINES _ 'shows connector lines & buttons for tree structure (below the root) OR %TVS_LINESATROOT _ 'shows connector lines & buttons at root level of tree structure OR %TVS_DISABLEDRAGDROP _ 'does not send dragdrop notifications OR %TVS_SHOWSELALWAYS _ 'Show selected item even when treeview does NOT have focus , %WS_EX_CLIENTEDGE 'OR %TVS_TRACKSELECT _ 'Underlines item where mouse cursor points CONTROL HANDLE hDlg, %ID_TREEVIEW TO hTreeView DIALOG SHOW MODAL hDlg CALL DialogProc END FUNCTIONLeave a comment:
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Return value/Exit function?
As far as selecting, I don't think you want the drop highlight flag....[from TVN_SELCHANGED]
...
Return Value
The return value is ignored.
And expanding?flag
Action flag. This parameter can be one of the following values:
TVGN_CARET
Sets the selection to the given item. The control's parent window receives the TVN_SELCHANGING and TVN_SELCHANGED notification messages.
I think changing that flag ought to do wonders for you.Remarks
If the specified item is the child of a collapsed parent item, the parent's list of child items is expanded to reveal the specified item. In this case, the parent window receives the TVN_ITEMEXPANDING and TVN_ITEMEXPANDED notification messages.
MCMLeave a comment:
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Helpful info.
htree&(2) is what I used not knowing how to get it using @lpnmh.hWndfrom.
I put in the expand part because it didn't auto expand for me.
After some testing, this code works about half the time. It sometimes fires twice and I get the second child down and the first child is gone so I'll just leave it a while and test in a test area.
I was also unsure about the EXIT FUNCTION. I was trying to get it to go to the first child then assumed the %TVN_SELCHANGED would fire again. Not real clear on how I can programmatically walk the tree without getting into trouble.
Thanks,
Bob MechlerLeave a comment:
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The treeview_Expand should not be needed, as TreeView_select should automatically expand the item if necessary to make it visible.
>IF TreeView_GetParent(htree&(2),@lpTV.ItemNew.hItem)
What is hTree&(2)?
When processing WM_NOTIFY, @lpnmh.hWndfrom is a handle to the control sending the message; that is, there is n need to maintain that in a STATIC or GLOBAL array.
If you need a handle to another treeview control on the screen while processing the message from this treeview, you can always use GetDlgItem(hWnd,%ID_OTHER_TREEVIEW).
In window procedures, you virtually never have to maintain window handles in STATIC or GLOBAL variables.. beacuse given the Hwnd passed as parm one to callback, you can get just about anywhere you need. (the plethora of "GLOBAL hDlg" in the help file notwithstanding)
MCMLeave a comment:
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This does what I want. The double-clicking of the root node toggles between expanded and/or collapsed but the single click of the + or the - doesn't respond. Might be ok this way, just checking.
Bob MechlerCode:IF (@lpNmh.Code = %TVN_SELCHANGED) AND (@lpNmh.idFrom = %ID_TREE2) THEN lpTV = CBLPARAM IF TreeView_GetParent(htree&(2),@lpTV.ItemNew.hItem) = 0 THEN 'on a header item SetWindowText hdlg,"On a header item" TreeView_Expand(hTree&(2),@lpTV.ItemNew.hItem,%TVE_EXPAND) TreeView_Select(htree&(2),TreeView_GetNextItem(htree&(2),@lpTV.ItemNew.hItem,%TVGN_CHILD),%TVGN_DROPHILITE) EXIT FUNCTION ELSE SetWindowText hdlg,"On a child item" END IF END IFLeave a comment:
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Is it possible to cause the item navigated to or single clickedMCMCode:WM_NOTIFY/TVN_SELCHANGED If new_selection = "Root item" THEN Treeview_Select (First child of same) ....
Leave a comment:
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Treeview question
I'm using a treeview as a menu where the root level are really section headers and the nodes that call programs are in the first child level.
Is it possible to cause the item navigated to or single clicked in the root level to auto move to the first child node and highlight it? A root node will always have child nodes.
I would still like the normal behaviour of double-clicking the root node to open or close the first level of child nodes.
Bob Mechler
Leave a comment: