MFC: How can I initialise CTabbedPane tabs (dialogs) using information from the Document in a SDI? - c++

I'm fairly new to MFC and would like to create an SDI application that has a pane of tabs always embedded on the right of the window with a view left of it. In my app I have a calculation core, with variables that are changed in the tabs with edit boxes. I would like to initialise these variables in the calculation class and then during the initialisation of the dialogs used for tabs set the initial values in the edit boxes to those of the corresponding variable in the calculator.
Currently, I create an instance of the calculator in my document class.
I also create a CTabbedPane in the MainFrame OnCreate Method as follows:
m_TabbedPane.Create(_T(""), this, CRect(0, 0, 290, 200),
TRUE,
(UINT)-1,
WS_CHILD | WS_VISIBLE | WS_CLIPSIBLINGS |
WS_CLIPCHILDREN | CBRS_RIGHT |
CBRS_FLOAT_MULTI))
m_tab = new CParametersDlg();
m_tab->Create(IDD_TAB, this);
m_TabbedPane.AddTab(m_tab);
I would the like to be able in CParameterDlg's OnInitDialog do something like:
BOOL CParameterDlg::OnInitDialog() {
CDialog::OnInitDialog()
float value = pointerToDocument->GetCalculatorVariable();
And use value to initialise an edit box. However I can't access the document from in the main frames OnCreate as it returns null (using GetActiveDocument, AfxGetApp etc).
How can I initialise the tabs then? I have thought about trying to put the Calculator in the App class instead. Or possibly trying to initialise the dialogs somewhere else which is called later when the document is properly initialised and linked? Or should I be doing things entirely differently?

I think that CMainFrame::OnCreate() is too early in the sequence of events to access the document class, it would not normally be created yet.
It would be better to wait until the docuent is created / initialised, the document class could then call a new method in CMainFrame() passing this as a parameter to create the tabs.

Related

How to Make a Simple GUI with DropDown Menus with C++

I am really struggling how to make a window with three selections of options. I currently have a setup that uses a CFileDialog object and have successfully implemented two dropdown menus and multiple check items.
What I want is to implement a pop up window that has the two drop down menus and the check boxes. If a certain item is selected in one of the dropdown menus then the file dialog is opened.
Currently I am trying to make a CWnd object and try to write code for it there.
CWnd myWindow;
BOOL VALUE = myWindow.Create(_T("DesktopApp"), _T("test"), WS_VISIBLE | WS_BORDER | WS_CAPTION,
RECT{ 100,100,400,400 },
myWindow.GetDesktopWindow(), 12);
myWindow.ShowWindow(SW_SHOWNORMAL);
if (VALUE == FALSE) {
return 0;
}
Every time I run this, it prematurely returns (VALUE == FALSE). Did I do something wrong? Is there a simpler way to create a window?
The first argument to CWnd::Create is the window class name. A class with the requested name must have been registered before it can be created.
It is common to register an application local class for the application's main window. MFC provides a convenient wrapper function (AfxRegisterWndClass) to register a window class.

How to show CDockablePane after it has been closed

I understand CDockablePanes remember their state when the program is closed and then opened again, but I don't understand how I'm supposed to show a CDockablePane that has been closed in a previous use.
This is my initialisation code :
DWORD dwPaneStyle = WS_CHILD | WS_VISIBLE | WS_CLIPSIBLINGS | WS_CLIPCHILDREN | CBRS_FLOAT_MULTI;
MyPane.Create(_T("MyPane"), this, CRect(0, 0, 0, 120), TRUE, ID_VIEW_MYPANE, dwPaneStyle | CBRS_BOTTOM));
MyPane.ShowPane(TRUE, FALSE, TRUE);
So this would create my pane and then set it to be shown, but for some reason I can't see it in my main frame... What am I missing?
Also, I would like to be able to show the pane when a certain button is pushed. I already have my MessageMap and OnButtonFct() ready. I just need to know how to show the pane.
Thanks!
I found it... it seems MFC saves the entire state of how the program was left in. So when the app is launched, the panel is shown, but then the app loads the last state and hides the panel. I was able to make it visible again by using the same line :
MyPane.ShowPane(TRUE, FALSE, TRUE);
on a button push event instead of during the creation.
There seems to also be a way to disable the automatic "Load last state" behaviour by adding the following in the CWinAppEx constructor.
m_bSaveState = FALSE;

How to insertItem to 2nd colum in CListCtrl

I am new to MFC & BGCControlBar.
Now I plan to use CBCGPListCtrl which is defined as:
class BCGCBPRODLLEXPORT CBCGPListCtrl : public CListCtrl
&
CBCGPListCtrl m_wndWatch;
Now in the demo code I plan to change:
int CWatchBar::OnCreate(LPCREATESTRUCT lpCreateStruct)
{
if (CBCGPDockingControlBar::OnCreate(lpCreateStruct) == -1)
return -1;
m_Font.CreateStockObject (DEFAULT_GUI_FONT);
CRect rectDummy;
rectDummy.SetRectEmpty ();
// Create output pane:
const DWORD dwStyle = WS_CHILD | WS_VISIBLE | WS_CLIPSIBLINGS | WS_VSCROLL | LVS_REPORT | LVS_EDITLABELS ;
m_wndWatch.Create (dwStyle, rectDummy, this, ID_LIST_1);
m_wndWatch.SendMessage (LVM_SETEXTENDEDLISTVIEWSTYLE, 0,
LVS_EX_FULLROWSELECT | LVS_EX_GRIDLINES);
m_wndWatch.InsertColumn (0, _T("Variable"), LVCFMT_LEFT, 100);
m_wndWatch.InsertColumn (1, _T("Value"), LVCFMT_LEFT, 100);
m_wndWatch.InsertItem (0, _T("m_nCount"));
m_wndWatch.SetItemText (0, 1, _T("100"));
m_wndWatch.SetFont (&m_Font);
return 0;
}
What I get is a list(as in pic), I can only edit the 1st colum and the data can not be retained. How can I edit the second column text and make the data retainable?
You need a grid control rather than a CListCtrl (or derived class). Actually, it's possible to add support for edition in other columns but it's a looooooot of work and not the kind of thing I'd recommend to a newcomer.
According to this page of their web site, they have a grid control.
There are a few things you need to do in order to make a MFC CListCtrl editable. This is a very broad overview without going into too many details:
As mentioned above it is quite a bit of work and you need to derive a class from CListCtrl, since CListCtrl by itself does not allow you to explicitly edit all of the columns.
You need a routine that will calculate the row/column number of the particular cell you clicked on, given a cursor position CPoint.
In the derived CListCtrl class you also need a method to edit the selected cell, creating and making visible a CEdit control of the appropriate size.
Create a derived CEdit control, such that it sends the LVN_ENDLABELEDIT message and self-destructs upon completion.
An example Visual Studio 2010 project implementing an editable list control is downloadable from this site:
http://www.technical-recipes.com/2014/making-a-mfc-list-control-editable/
Upon running/debugging the example, you get an example dialog project implementing an editable list control as shown:

How to create controls at runtime?

How to create dynamic MFC controls and handle message maps of the controls at runtime?
It really depends on which controls do you want to create, especially if you want to know which flags should you set. In general it goes down to this:
Normally a CWnd-derived control is created using Create or CreateEx. For a CButton, for instance:
CButton button;
button.Create("Button text", WS_CHILD | WS_VISIBLE | WS_TABSTOP | BS_PUSHBUTTON | DT_CENTER, CRect(5, 5, 55, 19), this, nID);
where the CRect specifies the button position, this is a pointer to the parent window, and nID is the control ID.
If the control doesn't come out as expected, it's probably because some flags are missing. I suggest you draw a sample control in design mode, check out the code for that control in the RC file, and copy the flags to the Create caller.
As for the message maps, they are normally routed to the parent window. The nID value you used in Create is important here, because it will be the number that identifies the control in the message map. If you have a fixed number of controls, you can hard-code the nID numbers for your controls (starting at 10000, for instance); if not, you'll have to provide a way for the parent window to identify them. Then you just add the message map entries.
ON_BN_CLICKED(10000, OnBnClicked)
ON_CONTROL_RANGE(BN_CLICKED, 10010, 10020, OnBtnsClicked)
You can use the ON_CONTROL_RANGE message map to map a range of IDs to the same function.

create a control programmatically using MFC

I just wonder how to do it.
I write :
CEdit m_wndEdit;
and in the button event handler (dialog app),
I write :
m_wndEdit.Create(//with params);
but I still don't see the control appear in the UI.
I actually wrote this in the button handler :
CWnd* pWnd = GetDlgItem(IDC_LIST1);
CRect rect;
pWnd->GetClientRect(&rect);
//pWnd->CalcWindowRect(rect,CWnd::adjustBorder);
wnd_Edit.Create(ES_MULTILINE | ES_NOHIDESEL | ES_READONLY,rect,this,105);
wnd_Edit.ShowWindow(SW_SHOW);
this->Invalidate();
id 105 doesn't exist. (I used it in the Create member function of CEdit). I just put it in there. isn't it supposed to be the id you want to give to the new control ? Should it already exist ?
Check with the following set of flags as the example mentioned in MSDN:
pEdit->Create(ES_MULTILINE | WS_CHILD | WS_VISIBLE | WS_TABSTOP | WS_BORDER | ES_NOHIDESEL | ES_READONLY,
rect, this, 105);
The Invalidate() is not necessary
Add the WS_VISIBLE flag to your create flags, you don't need the ShowWindow
You are creating the button on the location where IDC_LIST1 is - you probably want to do pWdn->Destroy() after the GetClientRect()
The id you pass to Create() can be anything, of course if you want to handle messages from this button later you'll need to use the correct id. In that case it's easiest to manually add an entry to resource.h.
What do you mean with 'I put this code in the button event handler' - which button? A different one from the one you're trying to create, I may hope? Does your code get called at all, does it stop when you put a breakpoint in? What's the value of wnd_Edit->m_hWnd after the call to Create()?
wnd_Edit is a member of your dialog, right, and not a a function local variable?
What is wnd_Edit exactly? If it's a local variable in that function, that is likely the problem. The CWnd destructor destroys the window associated with the CWnd. So when wnd_Edit goes out of scope, the edit box is destroyed too.
If that's not it, check the return value of Create(). Is it NULL? If it is, check the value of GetLastError().