C / C++ / MFC

26-Oct-03 13:39

Is there an easy way to route all messages from a child to it's parent's parent?

Can I do something like:

((GetParent())->GetParent())->SendMessage(WM_COMMAND);

I guess I could just try it, but i'm not home right now, so I can't yet...

Also i'd lik,e to see if you have a better approach???

Like override parent::OnCommand, PreTranslateMessage, etc and just route from there to it's parent...incase each message may need special handling first before being sent to it's parent parent???

Thanks again!

I'm drinking triples, seeing double and acting single Cool | :cool:

Re: Design question

Ravi Bhavnani26-Oct-03 13:57

Ravi Bhavnani

26-Oct-03 13:57

You can use the message reflection macros - that might be a "cleaner" (and easier) solution. I used this technique in a CWnd derived class I built that hosted a few controls.

My object received click and double-click notifications and decided what to do with them (when an item in the embedded list control was selected by the user, items in an embedded tree control were automatically selected).

/ravi

Let's put "civil" back in "civilization"
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Re: Design question

alex.barylski27-Oct-03 6:55

27-Oct-03 6:55

Thanks

I'll look into it Smile | :)

Cheers

I'm drinking triples, seeing double and acting single Cool | :cool:

CListCtrl DeleteItem

Jarek G26-Oct-03 13:05

26-Oct-03 13:05

Hello!
Is there someone here who can tel my why this is not working for me.
I want to delete some selected items in a ListControl, But It only deletes
a few of them not all of them??

POSITION p = m_ListControll.GetFirstSelectedItemPosition();
while (p)
{
   m_ListControll.DeleteItem(m_ListControll.GetNextSelectedItem(p));
}

He believed the commercials that said drink beer, get laid
but at closin' time he was alone, he didn't get paid.
Last night his lover was a razorblade..
"Dan Reed song Mix it up"

What do you want to patch today?

Daniel132426-Oct-03 13:53

Daniel1324

26-Oct-03 13:53

Look up GetNextSelectedItem() in MSDN.

Ravi Bhavnani26-Oct-03 13:54

Ravi Bhavnani

26-Oct-03 13:54

I would have thought that DeleteItem() would have a very noticeable side-effect on the current selection. Consider assigning item data's to the list control entries and using that to identify candidates for deletion.

/ravi

Let's put "civil" back in "civilization"
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ravib@ravib.com

Jarek G26-Oct-03 14:16

26-Oct-03 14:16

I tryed that to i did not work! Confused | :confused:

Ravi Bhavnani26-Oct-03 14:39

Ravi Bhavnani

26-Oct-03 14:39

Try this:

// Assign the item data to each list control entry
for (long nItem=0; (nItem < m_listCtrl.GetItemCount()); nItem++)
    m_listCtrl.SetItemData (nItem, nItem);

// Get the indexes of selected items
CUIntArray selectedItems;
POSITION pos = m_listCtrl.GetFirstSelectedItemPosition();
while (pos != NULL) {
      long nIndex = m_listCtrl.GetNextSelectedItem (pos);
      selectedItems.Add (nIndex);
}

// For each selected item...
for (nItem=0; (nItem < selectedItems.GetSize(); nItem++) {

    // Find the item in the list control...
    for (long nIndex=0; (nIndex < m_listCtrl.GetItemCount(); nIndex++)
        if (m_listCtrl.GetItemData (nIndex) == selectedItems.GetAt (nItem)) {

            // And delete it
            m_listCtrl.DeleteItem (nIndex);
            break;
        }
}

/ravi

Let's put "civil" back in "civilization"
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ravib@ravib.com

Jarek G26-Oct-03 23:32

26-Oct-03 23:32

Thank you!
I tryed something similar but I never used the CUIntArray.
This works Thank you again!

/Jarek

He believed the commercials that said drink beer, get laid
but at closin' time he was alone, he didn't get paid.
Last night his lover was a razorblade..
"Dan Reed song Mix it up"

What do you want to patch today?

Roger Allen27-Oct-03 2:21

Roger Allen

27-Oct-03 2:21

You have to iterate the list first to get all the selected items positions. Once you have that list go through it backwards to delete all the indexes as deleting them in the order you receive them changes the indexes of the following items.

int count = m_UsingList.GetSelectedCount();

// Get the list of selected items and remove them
if (count > 0)
{
    int *pIndexes = new int[count];
    int index = 0;

    POSITION pos = m_UsingList.GetFirstSelectedItemPosition();
    while (pos)
    {
        pIndexes[index++] = m_UsingList.GetNextSelectedItem(pos);
    }
    // we have to remove the items from the list in reverse order
    // as removing one before a later index changes the order!
    for (index = count - 1 ; index >= 0 ; index--)
    {
        m_UsingList.DeleteItem(pIndexes[index]);
    }
    delete []pIndexes;
    pIndexes = NULL;
    // done!
}

Roger Allen
Sonork 100.10016

Death come early, death come late,
It takes us all, there is no reason.
For every purpose under heaven,
To each a turn, to each a season.
A time to weep and a time to sigh,
A time to laugh and a time to cry,
A time to be born and a time to die.
Dust to dust and ashes to ashes,
And so I end my song.

David Crow27-Oct-03 4:46

David Crow

27-Oct-03 4:46

Here are two ways:

for (int x = 0; x < m_list.GetItemCount(); x++)
{
    int nItem = m_list.GetNextItem(-1, LVNI_SELECTED);
    BOOL bStatus = m_list.DeleteItem(nItem);
}

and

int nItem = m_list.GetNextItem(-1, LVNI_SELECTED);

do
{
    BOOL bStatus = m_list.DeleteItem(nItem);
    nItem = m_list.GetNextItem(nItem - 1, LVNI_SELECTED);

} while (nItem != -1);

The latter is a tad faster as it does not have to continually search from the beginning of the list for a match.

Five birds are sitting on a fence.
Three of them decide to fly off.
How many are left?

Jarek G27-Oct-03 7:59

27-Oct-03 7:59

It works fine Thank you!
I am suprised that there is so many ways to delete multiple files in a listbox, and I could not pick any of them Smile | :)

Thats the cool way of programming sometimes you know so much and so litle!

He believed the commercials that said drink beer, get laid
but at closin' time he was alone, he didn't get paid.
Last night his lover was a razorblade..
"Dan Reed song Mix it up"

What do you want to patch today?

Abin27-Oct-03 14:09

Abin

27-Oct-03 14:09

"DeleteItem" makes indices of all subsequent items decrease by one, so suppose the "next selected item" had index of 5, it could become 4 after a call of "DeleteItem". So you should do this instead:

m_ListControll.LockWindowUpdate();
POSITION p = m_ListControll.GetFirstSelectedItemPosition();
while (p)
{
    m_ListControll.DeleteItem(m_ListControll.GetNextSelectedItem(p));
    p = m_ListControll.GetFirstSelectedItemPosition();
}
m_ListControll.UnlockWindowUpdate();

Simply keep deleting the first selected item until there's no more, you really don't need to make things complicated, such as establishing an additional array.

CPP question

alex.barylski26-Oct-03 12:22

26-Oct-03 12:22

I have 3 classes

CFirst : CButton
CSecond : CFirst
CThird : CSecond

CSecond::OnTimer() sends the parent window a message using:

WPARAM wParam = MAKEWPARAM(GetDlgCtrlID(), BN_CLICKED);
GetParent()->SendMessage(WM_COMMAND, wParam, this);

I'm trying to notify the parent that this particular button was clicked, but i have 2 problems/questions:

1) How can I send the

this</code pointer? When I cast it as long woun't it loose it's RTTI? I need this for later :)<br />
<br />
2) When the parent recieves <code>WM_COMMAND

messages is there anyway the parent window can determine using the this pointer which class derived from CButton was clicked? CSecond or CThird

Will the parent be able to determine that it was a CSecond clicked or a CThird clicked??? or will it always get the CSecond? Do I have to make CSecond::OnTimer virtual?

Thanks in advance Smile | :)

I'm drinking triples, seeing double and acting single Cool | :cool:

Steve S27-Oct-03 1:46

Steve S

27-Oct-03 1:46

1. The notification is done only by window handle. For SendMessage, you should use something like

GetParent()->SendMessage(WM_COMMAND, wParam, (LPARAM)GetSafeHwnd());

2. It could examine the control ID, assuming you know at runtime which IDs are associated with each kind of button. The virtuality of OnTimer won't help. The sink (target) for the message must be able to work it out itself.

Steve S

alex.barylski27-Oct-03 6:53

27-Oct-03 6:53

Steve S wrote:
GetParent()->SendMessage(WM_COMMAND, wParam, (LPARAM)GetSafeHwnd());

I Initially had that, but figured sending a generic window handle to my parent wouldn't allow me to use RTTI Smile | :)

Unless I has code in my parent class that would create the appropriate object (CSecond or CThird) and attach the windows handle. Not quite the solution I wanted. I think i'll just use command ID's Smile | :)

Thanks again

Cheers

I'm drinking triples, seeing double and acting single Cool | :cool:

Roger Allen27-Oct-03 2:32

Roger Allen

27-Oct-03 2:32

There is a posibility that you can get the runtime class infromation and access that.

CWnd *pWnd = GetDlgItem(pMsg->wParam);
if (pWnd->GetRuntimeClass() == CFirst::GetRuntimeClass())
{
}

This will mean using the IMPLEMENT_DYNAMIC and DECLARE_DYNAMIC macros in yout CFisrt, CSecond and CThird classes

Roger Allen
Sonork 100.10016

Death come early, death come late,
It takes us all, there is no reason.
For every purpose under heaven,
To each a turn, to each a season.
A time to weep and a time to sigh,
A time to laugh and a time to cry,
A time to be born and a time to die.
Dust to dust and ashes to ashes,
And so I end my song.