C / C++ / MFC

Dynamic Generation of Child Dialog Windows

2-Nov-06 14:24

Have you called AfxInitRichEdit() or AfxInitRichEdit2() somewhere in your code?

Re: Rich Text Edit

Hamid_RT3-Nov-06 5:43

Hamid_RT

3-Nov-06 5:43

When you run your program you dont see anything if yes you need to call AfxInitRichEdit

WhiteSky

acerunner3162-Nov-06 13:10

2-Nov-06 13:10

How do you generate content of a child dialog during runtime? I want something like this http://www.codeproject.com/dialog/scrollablechilddialog.asp but all the controls inside the child window need to be dynamically created. For example, the user can specify a number X on the parent window, and then I would generate X number of edit boxes with corresponding buttons in the child window.

Mark Salsbery2-Nov-06 13:38

2-Nov-06 13:38

Controls are child windows so create the controls and position them on the dialog window.

Using MFC or not?

Mark

acerunner3162-Nov-06 13:55

2-Nov-06 13:55

Yes, MFC.
Can you be more specific? Maybe a sample code how to generate controls and how to position them. Also I will need those controls to be able to display data from the parent window. How can I do that?
Thanks

Mark Salsbery2-Nov-06 14:21

2-Nov-06 14:21

Here's the basic idea...dialog should be modeless...

void CMyDialogClass::AddButtonAndEditControls()
{
	CButton *pButton = new CButton();
	pButton->Create(_T("Text"), WS_CHILD|WS_VISIBLE|BS_PUSHBUTTON|WS_TABSTOP, CRect(10,10,100,24), this, IDC_BUTTON1);
	CEdit* pEdit = new CEdit;
	pEdit->Create(WS_CHILD|WS_VISIBLE|WS_TABSTOP|WS_BORDER, CRect(120,10,100,24), this, IDC_EDIT1);
}

You'll probably want to keep the created control pointers in a container of some kind
(array, list, whatever) and assign each control unique IDs as they're created. Also adjust the
CRect params to position them properly or use MoveWindow() (example pButton->MoveWindow(...)) to
reposition them after they're created.
Don't forget to delete them when the dialog closes or when you're going to re-populate the window
with a different set of controls.

acerunner316 wrote:
Also I will need those controls to be able to display data from the parent window. How can I do that?

Maybe pass a pointer to the parent window to the dialog when it's created so it can call parent
window methods to get the data.

acerunner3162-Nov-06 15:06

2-Nov-06 15:06

I understand than all controls must have a unique ID, but if I were to generate the controls dynamically, I want a code that will generate the ID dynamically as well. I don't want to repeat this code for IDC_BUTTON1 through IDC_BUTTON200. Is there a way generate the ID in a for loop or something?

Can you also elaborate on passing pointers from parent window to child window? I am currently trying to call a function of the child class from the parent class to have it update the edit boxes.
for example: CChildDlg::UpdateEditBoxes();
but i'm getting the error "illegal call of non-static member function".
I want to be able to control when the edit boxes are updated from the parent window. So would I have to pass a pointer everytime I update?

Thanks again.

Mark Salsbery2-Nov-06 15:33

2-Nov-06 15:33

acerunner316 wrote:
Is there a way generate the ID

Generate the IDs any way you'd like to. To extend the last example, add a couple variables (to
track the IDs) to your dialog class, initializing them in the constructor or (OnInitDialog()):

class CChildDlg : public CDialog
{
...
protected:
	UINT NextButtonId;
	UINT NextEditId;
...
};

CChildDlg::CChildDlg()
{
...
	NextButtonId = 100;  // choose any base ID that fits your needs
	NextEditId = 500;
...
}

void CChildDlg::AddButtonAndEditControls()
{
	CButton *pButton = new CButton();
	pButton->Create(_T("Text"), WS_CHILD|WS_VISIBLE|BS_PUSHBUTTON|WS_TABSTOP, CRect(10,10,100,24), this, NextButtonId++);
	CEdit* pEdit = new CEdit;
	pEdit->Create(WS_CHILD|WS_VISIBLE|WS_TABSTOP|WS_BORDER, CRect(120,10,100,24), this, NextEditId++);
}

acerunner316 wrote:
for example: CChildDlg::UpdateEditBoxes();
but i'm getting the error "illegal call of non-static member function".

You need to call the UpdateEditBoxes() on an object. Use the pointer obtained when you created
the child dialog:

pChildDlg = new CChildDlg(...);
pChildDlg->Create(...);
...
pChildDlg->UpdateEditBoxes();

acerunner3163-Nov-06 10:12

3-Nov-06 10:12

Thanks that worked. So now I can access child functions from the parent?
How about vice versa? How can I access parent functions from the child?
Same for variables. For example, if I press a button in the child (ie CChildDlg::OnButtonPress() ), I want the parent to react to it.

Also, after having dynamically generated the buttons and edit boxes along wiht the ID, how do I now assign a member variable to it? Do I need some sort of dynamic code in the DoDataExchange function?

Mark Salsbery3-Nov-06 10:44

3-Nov-06 10:44

acerunner316 wrote:
So now I can access child functions from the parent?

Yes, as long as you have a child object to use (pointer allocated with new in the example code).
As long as you keep that around as a member variable in the parent you can call any methods or use
any public variables in the child class.

acerunner316 wrote:
How about vice versa? How can I access parent functions from the child?

Sure. You need to get a parent window pointer in the child somehow. You could use GetParent()
in the child class and cast the returned pointer to your parent class. You could also provide
a method in the child class that accepts a pointer to the parent window. Your CDialog and CWnd
derived classes are just classes. CDialog/CWnd wrap the windows API but beyond that you can
extend derived classes any way that suits your needs.

acerunner316 wrote:
Same for variables. For example, if I press a button in the child (ie CChildDlg::OnButtonPress() ), I want the parent to react to it.

You could use the ON_COMMAND_RANGE macro in your message map for the range of possible button IDs.
Then in the command (range) message handler use the parent window (obtained like above) to
call a method on the parent to do something. Another way is to post a user msg (using
PostMessage() or SendMessage()) to the parent. If your dialog class always knows its parent
window class (in other words, it won't be used as a child of another class) then using a pointer
to that class type is easiest.

acerunner316 wrote:
Also, after having dynamically generated the buttons and edit boxes along wiht the ID, how do I now assign a member variable to it? Do I need some sort of dynamic code in the DoDataExchange function?

If you want to use DDE then yes you'll need to loop through your controls and call DDX_Control()
on each of them. You can always manipulate the controls directly as well. See the CButton and
CEdit class docs for all the member functions you can use.

acerunner3163-Nov-06 13:16

3-Nov-06 13:16

This is getting a lot more complicated than I thought. Confused | :confused:

In case you haven't noticed, I'm pretty new to Windows programming. heh.

My next question, how can I change the size of the child window after dynamically adding more controls? The scrolling size will have to change as I add more. If you see the code from the original scrolling child windows example, the scrolling ratio is fixed to the size of the child window as it appears in the resource editor.

acerunner3163-Nov-06 14:42

3-Nov-06 14:42

I am having trouble using GetParent().

Here is my code that I put in the child dialog. I am trying to access functions and variables of the parent class.

CWnd* pParentWindow;
pParentWindow = GetParent();

pParentWindow->SomeFunction();
x = pParentWindow->TempInt;

The error is "SomeFunction() is not a member of CWnd" and "TempInt is not a member of CWnd".

Mark Salsbery3-Nov-06 15:03

3-Nov-06 15:03

You need to cast the CWnd pointer down to the parent window class.
The safest is using dynamic_cast. Enable RTTI (run time type info) in your project and do
something like this...

CMyParentWndClass* pParentWindow = dynamic_cast<CMyParentWndClass*>(GetParent());
if (pParentWindow)
{
	pParentWindow->SomeFunction();
	x = pParentWindow->TempInt;
}

If you're absolutely positive of the parent window's class type you can use static_cast:

CMyParentWndClass* pParentWindow = static_cast<CMyParentWndClass*>(GetParent());
if (pParentWindow)
{
	pParentWindow->SomeFunction();
	x = pParentWindow->TempInt;
}

or a regular C++ cast

CMyParentWndClass* pParentWindow = (CMyParentWndClass*)GetParent();
if (pParentWindow)
{
	pParentWindow->SomeFunction();
	x = pParentWindow->TempInt;
}

acerunner3166-Nov-06 9:42

6-Nov-06 9:42

I get the error that CMyParentWndClass (well for me it's CMainDlg) is an undeclared identifier. Is there any other method?
Thanks

Mark Salsbery6-Nov-06 10:52

6-Nov-06 10:52

Add a #include directive to include the header file containg your CMainDlg class declaration:

#include "MainDlg.h"

acerunner3166-Nov-06 13:10

6-Nov-06 13:10

Oh, I'm an idiot, I didn't think you have to include that if it's a child window.

So how about changing the size and the scrolling ratio when I have dynamically generated controls? How is that done?

Thanks.

Mark Salsbery2-Nov-06 15:36