Treeview icon change

[MasterDucky]

Hi,

I have a doubt about icon changes in a treeview.

Should it be handled in WM_NOTIFY by me or is it done by Windows as long as I fill in

        tvi.iImage = 0;
        tvi.iSelectedImage = 1;

[VictorN]

Could you explain more clear what your problem is?
If you just want to change an item icon (or icons) then send TVM_SETITEM message or call TreeView_SetItem macro.

[MasterDucky]

Well, they are not changing when I expand the tree. (opened folder, closed folder)

I send TreeView_SetItem from WM_NOTIFY but there must be something wrong.
Im checking for the TVN_ITEMEXPANDED message which value is 4294966890.
But when I click on a node I get the value of 4294967294.

So Im confused about for what message should I check?

 case WM_NOTIFY:    {
        case ID_TREEVIEW:
        {
            // mouse click
            if(((LPNMHDR)lParam)->code == NM_CLICK)
            {
                LPNMTREEVIEW nmtv = (LPNMTREEVIEW) lParam;
                cout << "4294966890 " << nmtv->hdr.code << endl;
                if (nmtv->hdr.code == TVN_ITEMEXPANDED)
                {
                    TVITEM item = nmtv->itemNew;
                    item.stateMask = TVIS_STATEIMAGEMASK;
                
                    if (nmtv->action == TVE_COLLAPSE)
                    {
                        item.state = 2;
                    }
                    else if (nmtv->action == TVE_EXPAND)
                    {
                        item.state = 0;
                    }


                    TreeView_SetItem(hwndTV, &item);
                }


            }
        }
    }
    return 0;

[2kaud]

Message 4294967294 is NM_CLICK.

As you are first checking for the code NM_CLICK, hdr.code will be NM_CLICK! Try this (not tested)

// mouse click
            if(((LPNMHDR)lParam)->code == TVN_ITEMEXPANDED)
            {
                LPNMTREEVIEW nmtv = (LPNMTREEVIEW) lParam;
                    TVITEM item = nmtv->itemNew;
                    item.stateMask = TVIS_STATEIMAGEMASK;
                
                    if (nmtv->action == TVE_COLLAPSE)
                    {
                        item.state = 2;
                    }
                    else if (nmtv->action == TVE_EXPAND)
                    {
                        item.state = 0;
                    }


                    TreeView_SetItem(hwndTV, &item);
                }

[MasterDucky]

Thank you very much 2kaud but still not working.

But maybe the problem comes from my set up of the treeview cause I only get one image of the two I assign.

HTREEITEM AddItemToTree(HWND hwndTV,                        LPTSTR lpszItem,
                        int nLevel,
                        LPARAM lParam)
{
    TVITEM tvi = {0};
    TVINSERTSTRUCT tvins = {0};
    HTREEITEM hti;


    tvi.mask = TVIF_TEXT | TVIF_IMAGE |
               TVIF_SELECTEDIMAGE | TVIF_PARAM;


    // Set the text of the item.
    tvi.pszText = lpszItem;
    tvi.cchTextMax = sizeof(tvi.pszText)/sizeof(tvi.pszText[0]);


    // Save the heading level in the item's application-defined
    // data area.
    tvi.lParam = lParam;
    tvins.item = tvi;
    tvins.hInsertAfter = hPrev;


    // Set the parent item based on the specified level.
    if(nLevel == 1)
    {
        tvins.hParent = 0;
        tvi.iImage = 0;
        tvi.iSelectedImage = 1;
    }
    else if(nLevel == 2)
    {
        tvins.hParent = hPrevRootItem;
        tvi.iImage = 2;
        tvi.iSelectedImage = 2;
    }


    // Add the item to the tree-view control.
    hPrev =(HTREEITEM)SendMessage(hwndTV,
                                  TVM_INSERTITEM,
                                  0,
                                  (LPARAM)(LPTVINSERTSTRUCT)&tvins);
    if(!hPrev)
    {
        ReportError("TVM_INSERTITEM");
        return FALSE;
    }


    hPrevRootItem = hPrev;




    return hPrev;
}

[VictorN]

What exactly "not working"?

[MasterDucky]

I have three icons loaded and verified: 1 closed folder, 1 opened folder and a file icon.

Only the closed folder icon getting displayed even in the place of the other two.

[VictorN]

I have three icons loaded and verified: 1 closed folder, 1 opened folder and a file icon.

Only the closed folder icon getting displayed even in the place of the other two.

Then your code is somewhere wrong!

[OReubens]

Well, they are not changing when I expand the tree. (opened folder, closed folder)

Treeview does NOT have this behaviour built in.

You can give an image for the regular case and an image for when the node is selected.

This is entirely unrelated at all to the state of a node being expanded, collapsed or 'not having children'.
If you want different images when the item collapses/expands, then you'll need to handle the Expand/collapse notifications and change the icon explicitely with SetItem().

Your code in #3 doesn't work because you aren't changing the image. you're only changing the state (or trying at least, the state value and state mask don't match up so the SetItem() in effect does nothing) which has nothing to do (at all) with the item image and item selected image.

[MasterDucky]

Thanks for the explanation that clears it up.

OK, then I will go one step at the time. Right now I just want it to change image when it's selected.

This must be built in because I have another code where it's working without the WM_NOTIFY message. Though the treeview there is in a dialogbox but I don't think that matters.

[OReubens]

just provide different images for nImage and nSelectedImage
the tree will automatically change the image of the selected node without any work needed by you.
if both nImage and nSelectedImage are identical, then nothing will appear to happen (though internally it'll still draw the select image which just happens to look the same).

As said, if you want collapsed/expanded images (should be Obvious already that an item is collapsed/expanded because of the [-] and [+] boxes and the fact you see (or don't see) children. But if you really want this.
Handle the collapse/expand notifications, and use SetItem() to set a new nImage and/or niSelectedImage. Don't forget to set the nMask properly. If you use MFC there's also the convenient SetItemImage() member.

[MasterDucky]

Thanks Reubens!

I verified the three images are loading and I assigned different images to iImage and iSelectedImage.
Actually it doesn't even matter what number I assign (4,5 non existing images) it will always display the first image from the list.

I post the relevant code to see if it could shed some light on the issue:

HTREEITEM AddItemToTree(HWND hwndTV,
                        LPTSTR lpszItem,
                        int nLevel,
                        LPARAM lParam)
{
    TVITEM tvi = {0};
    TVINSERTSTRUCT tvins = {0};
    HTREEITEM hti;


    tvi.mask = TVIF_TEXT | TVIF_IMAGE |
               TVIF_SELECTEDIMAGE | TVIF_PARAM;


    // Set the text of the item.
    tvi.pszText = lpszItem;
    tvi.cchTextMax = sizeof(tvi.pszText)/sizeof(tvi.pszText[0]);
    tvi.lParam = lParam;
    // Save the heading level in the item's application-defined
    // data area.
    tvins.item = tvi;


    // Set the parent item based on the specified level.
    if(nLevel == 1)
    {
        tvins.hParent = 0;
        tvi.iImage = 0;
        tvi.iSelectedImage = 1;
    }
    else if(nLevel == 2)
    {
        hti = TreeView_GetParent(hwndTV, hPrev);
        tvi.mask = TVIF_IMAGE | TVIF_SELECTEDIMAGE;
        tvi.hItem = hti;
        tvins.hParent = hPrevRootItem;
        tvi.iImage = 2;
        tvi.iSelectedImage = 2;
    }


    // Add the item to the tree-view control.
    hPrev =(HTREEITEM)SendMessage(hwndTV,
                                  TVM_INSERTITEM,
                                  0,
                                  (LPARAM)(LPTVINSERTSTRUCT)&tvins);




    // Save the handle to the item.
    hPrevRootItem = hPrev;
    return hPrev;
}

BOOL InitTreeViewItems(HWND hwndTV)
{
    HTREEITEM hti;


    int i=0,j=1,k=1;
  
    {
        // Add the item to the tree-view control.
        hti = AddItemToTree(hwndTV,"Parent",j,k++);
        hti = AddItemToTree(hwndTV,"Child",2,k++);
    }
    return TRUE;
}