ATL / WTL / STL

Re: How to creat an Object from with a pointer

30-Sep-02 7:51

I have this code wich creates a Grid, this works using a wrapper class.
CdxDBGrid m_grid;
m_grid.Create(_T("TestGrid"),WS_CHILD|WS_VISIBLE, CRect(1, 2, 3, 4), this,
1);

So the question How do I achive the same as above but with a pointer. Or how do I create a View with my pointer.

IdxDBGridPtr m_pGrid Cry | :((

Paul M Watt30-Sep-02 9:57

Paul M Watt

30-Sep-02 9:57

<br />
CdxDBGrid *m_pgrid;<br />
<br />
// Allocate space for you object.<br />
m_pgrid = new CdxDBGrid;<br />
if (!m_pgrid)<br />
{<br />
    return error;<br />
}<br />
<br />
// create the actual window that the object wraps.<br />
m_grid->Create(_T("TestGrid"),WS_CHILD|WS_VISIBLE, CRect(1, 2, 3, 4), this,1);<br />
<br />
// when you are done, delete the object.<br />
delete m_pgrid;<br />
<br />

Build a man a fire, and he will be warm for a day
Light a man on fire, and he will be warm for the rest of his life!

Re: How to creat an Object from with a pointer

Jose Cruz1-Oct-02 3:43

1-Oct-02 3:43

First I appreciate your answer. But What I really want to know is, if it is a good idea to use a Grid that resides in a DLL. And if so How do I create an Object of it. I did this but with MFC and the autogenerated wrapper classes and everything works OK but I don`t know how to use it in a ATL/WTL project. This is because if I try to use the generated class I get some error about undefined class. OMG | :OMG:

Combo heigth problem

Jose Cruz30-Sep-02 7:46

30-Sep-02 7:46

How do I set my combos height wich resides in a DialogBox Sleepy | :zzz:

Paul M Watt30-Sep-02 10:00

Paul M Watt

30-Sep-02 10:00

First make a call GetDlgItem with the handle of the parent dialog and the ID of your combo box. This will return a handle to the combo box to you.

You can then use that handle in a call to MoveWindow to resize and move the combo box.

Build a man a fire, and he will be warm for a day
Light a man on fire, and he will be warm for the rest of his life!

Jose Cruz1-Oct-02 3:51

1-Oct-02 3:51

The problem is when I click on the combos down arrow, it won`t display the list. The list does contains some items. But I can`t see them.

Ed Gadziemski1-Oct-02 4:06

Ed Gadziemski

1-Oct-02 4:06

Bring up your dialog in the resource editor. Click on the dropdown and pull the sizing box downward to the size you want.

Jose Cruz1-Oct-02 5:16

How to do this properly with STL?

1-Oct-02 5:16

Thakn you for your answer.

Seems like everything it`s dificult not knowing how to do it

STL reference?

User 988527-Sep-02 6:53

User 9885

27-Sep-02 6:53

Is there some article that demonstrates the use of one STL container inside another?

for example, how to use

std::map<std::string, std::vector<std::string> > x;

ie, how do i insert?
how do i get back the reference of the vector instead of copying it out?

etc.

Thomas

modified 29-Aug-18 21:01pm.

Re: STL reference?

RedZenBird27-Sep-02 8:18

RedZenBird

27-Sep-02 8:18

maybe multimap is a better fit for what you want here?

but, here is a code snippette that may be worth while though:

...

// define types
//
using namespace std;

typedef vector<string> STRING_LIST;
typedef map< string, STRING_LIST* > MAP_STRING_TO_LIST;
typedef MAP_STRING_TO_LIST::iterator MAP_STRING_TO_LIST_ITER;

// declare variable of type
//
MAP_STRING_TO_LIST oMyList;

bool InsertString( string oKey, string oValue )
{

MAP_STRING_TO_LIST_ITER oIter = oMyList.find( oKey );
if ( oMyList.end() == oIter )
{
// no entry yet for this key...
//
STRING_LIST* poList = new STRING_LIST;
poList->push_back( oValue );
oMyList.insert( MAP_STRING_TO_LIST::value_type( oKey, poList );
}
else
{
STRING_LIST* poList = (*oIter).second;
poList->push_back( oValue );
}
}

hope that helps

Just trying to keep the forces of entropy at bay

atl full control

Anonymous23-Sep-02 18:05

Anonymous

23-Sep-02 18:05

I can't recieve WM_CREATE message in my control . How could this happen? What are the possible reasons?

Re: atl full control

Todd Smith24-Sep-02 7:03

Todd Smith

24-Sep-02 7:03

You might need to set the following variable in your constuctor

CComControlBase::m_bWindowOnly = TRUE;

Todd Smith

Re: atl full control

Jörgen Sigvardsson3-Oct-02 14:28

Jörgen Sigvardsson

3-Oct-02 14:28

If it's dialogbased control, you should receieve WM_INITDIALOG instead.

--
Please state the nature of your medical emergency.

Mark Tutt23-Sep-02 3:49

23-Sep-02 3:49

I've come across an interesting problem, that I can't find a nice clean solution to.

The problem is how to manage adding and deleting objects from two vectors containing different objects.

Here's what I've got: A list of objects that contain an vector of ints as data points. The object holding the list has an vector of description objects containing information about each of the ints in the vector. They have a one to one relationship.

Now, I need to support adding or removing data points. What I can't figure out how to do is how to do this without a lot of overhead. My first thought was that I'd simply get the position of the data point description object that was added, then simply do a for_each over the list and call insert or erase for the appropriate position in the data points vector as required by the operation. Unfortunately both of those functions require an iterator to the item being erased, or the position the new item is being inserted at, not just it's index position.

Is there a way to do this without iterating over each data point vector? Since the position in the vector is going to be the same for all the objects, it seems like there should be a way to do this without all the manipulation.

Any ideas?

Joao Vaz23-Sep-02 4:02

Joao Vaz

23-Sep-02 4:02

Mark Tutt wrote:
Here's what I've got: A list of objects that contain an vector of ints as data points. The object holding the list has an vector of description objects containing information about each of the ints in the vector. They have a one to one relationship.

Why didn't you make a map in this case ? a map of <DataPoints,DescriptObj> ????? or if Description objects must be a vector of points ...
<DataPoints,vector<DescriptObj>> ?

So you want to remove a specific data point , it's enough to reference the data point .

Cheers,Joao Vaz
And if your dream is to care for your family, to put food on the table, to provide them with an education and a good home, then maybe suffering through an endless, pointless, boring job will seem to have purpose. And you will realize how even a rock can change the world, simply by remaining obstinately stationary.-Shog9

Mark Tutt23-Sep-02 4:14

23-Sep-02 4:14

If I'm understanding your question, it was to avoid the memory overhead of needing the have the description objects for each of the data point vectors.

A map would involve copies of the objects, greatly increasing memory requirements. There may be 10's or 100's of thousands of data point vectors, and I only need one set of description objects. Even having a pointer to the associated description object for each data point essentially doubles the memory requirements.

Mark

Joao Vaz23-Sep-02 6:17

Joao Vaz

23-Sep-02 6:17

And why not use instead vector of pointers to Data Points ?

Cheers,Joao Vaz
And if your dream is to care for your family, to put food on the table, to provide them with an education and a good home, then maybe suffering through an endless, pointless, boring job will seem to have purpose. And you will realize how even a rock can change the world, simply by remaining obstinately stationary.-Shog9

Mark Tutt23-Sep-02 15:52

23-Sep-02 15:52

I think you're missing the point of what I was trying to do...

Think of rows in a database table. All you need is the data, stored in rows, in a sequential list that you can move through. (leaving out indexing for now)

The column information, i.e. Name, data type, default value, nullable, etc. is going to be the same for every row in the table. You don't need to carry the weight of that data along with each row, so you just have one copy of this for the table.

Now assume you've got a doubly linked list containing vectors (rows) of 10 integers each. You've got another vector that contains the column information for the 10 columns.

If you want to delete the 8th column, you've got to delete the 8th int from each row in the list.

If you were to add pointers to the integers, you're not really changing the basic requirement of the operation, and you're adding additional memory overhead of a 32byte pointer to a 32byte int, i.e. doubling the memory requirement.

What someone else pointed out was that given that we know the position in our column information vector, we can use datapoint.begin()+pos to get the datapoint iterator to the datapoint position that we have to erase, so we can do something like this to perform a 'column delete' operation on our entire dataset.

for_each(datalist.begin(), datalist.end, erase(data.begin()+pos))

Joaquín M López Muñoz23-Sep-02 9:09

Joaquín M López Muñoz

23-Sep-02 9:09

You can have constant-time access to the n-th element of a vector v via the iterator v.begin()+n. I agree with you that proably std::vector is the best choice for holding huge arrays of ints. As for the description list, you'd probably be better off using a std::map<int,CDescription>. Access is log-time given the position, and insertions and deletions are way cheaper.

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

Mark Tutt23-Sep-02 10:41