How to use the Document/View architecture in MFC - c++

I'm still working on a Data Acquisition program in MFC and am getting stuck working with the Document/View architecture. Basically, I want my application to have a couple windows. One is used to show a video that's recorded from a high speed camera, another has a plot displaying data from the DAQ system, and maybe another has controls for configuring the camera and DAQ, etc.
So, really I have a lot of modeless windows each showing a portion of the data, usually from a different source. Now, going through and using the App Wizard I get confused with the Doc/View stuff, and even though I can turn it off, it isn't technically off. Now that aside, I've tried opening modeless Dialogs and FormViews all to no success. Mostly I just can't figure out how to open the new View, the documentation isn't really helpful. I've been able to open a Modal plotting dialog from a Ribbon Button command and I mark that as a success, but not exactly what I need.
So, does anyone have helpful insight on fitting my application to the Doc/View architecture or opening a modeless dialog or FormView from within another application. I should say I'm using Microsoft Visual Studio 2010 and I'm using MFC and C++.
EDIT:
So, I've gone with MDI and will have one document that handles all the data to be shown. What I am stuck on now is how to create the multiple windows I want. I sublcassed CFormView to be the graph View of the document, and I am trying to create that window when I click a menu button. I was able to do it with a modal Dialog, like this:
void CDAQUniversalApp::OnScopebtn()
{
// TODO: Add your command handler code here
CScopeDlg dlg = new CScopeDlg(); //CScopeDlg is Subclass of CDialog
dlg.DoModal();
}
That worked, but not what I want, so I tried this, and it didn't work at all:
m_pScopeTemplate = new CMultiDocTemplate(
IDD_SCOPEFORMVIEW,
RUNTIME_CLASS(CDAQUniversalDoc),
RUNTIME_CLASS(CMDIChildWnd),
RUNTIME_CLASS(CScopeFormView)); //Subclass of CFormView
if (!m_pScopeTemplate)
return FALSE;
void CDAQUniversalApp::OnScopebtn()
{
// TODO: Add your command handler code here
CMDIChildWnd* pFrame = NULL;
pFrame = DYNAMIC_DOWNCAST(CMDIChildWnd, CWnd::GetActiveWindow());
CMDIChildWnd *pScopeFrame = (CMDIChildWnd*)m_pScopeTemplate->CreateNewFrame(pFrame->GetActiveDocument(), NULL);
if (pScopeFrame == NULL)
return;
m_pScopeTemplate->InitialUpdateFrame(pScopeFrame, pFrame->GetActiveDocument(), TRUE);
}
This just causes an unhandled exception. I really just bruteforced my way to that point finding various largely unhelpful sections of documentation code and modifying it to what I think I need.

Your different windows (for video display, data display and configuration) are actually all views (different view classes) for a single document, which manages the data (assuming the DAQ works on the video data?).
I suggest you pack your application into an MDI app, thus having a main window, with all those different views as subwindows. So you have multiple views for a single document (or even multiple documents in MDI).
MFC can be a pain, if your application does not fit the classical document/view architecture (like Word for example), but I think this would be the best way to fit your application into this framework.

Related

MFC dialog-based app with tab control - Visual Studio bugs/restrictions make recommended path impossible?

Create a dialog-based application in Visual Studio 2019. Insert a new dialog in the resources. Place a control (or two) on that dialog that you will later (try to) hook up to a variable (e.g. an edit box to enter your name).
Prepare to add that control variable by creating a class for this second dialog. If you inherit from CDialogEx (or perhaps other classes too - not tested), you can go on to add a variable for the control you added - easy, normal.
But if you had the "tab control" context from the title above in your mind, and chose to inherit from CMFCPropertyPage instead, can you add a variable subsequently? No you cannot - the class added makes no reference to the ID of the dialog resource, and so the Add Variable process has no basis to find a class to add the variable to.
I think this is a bug in Visual Studio... but I'm not 100% sure because I have always found the documentation around property sheets and property pages somewhat confusing. Specifically:
Do the classes implementing the tabs contents on a tab control "contain" the controls "on" the tab... or is the tab control really just a way to provide visual cues to show/hide sets of controls, and all of those controls and associated variables reside in one class?
I believe it's intended to be the former, but I can imagine that one uses a tab control because there are strong similarities between tab contents, and therefore potential benefits in implementing all the control variables in one place so as to avoid duplication. I just wish it was stated explicitly somewhere what the intention was.
Wider context: I'm trying to implement a dialog-based app with a tab control dominating that dialog. MS documentation says to implement a tab control using CPropertySheet and CPropertyPage to implement the tabbed dialog and tab contents. However, there is no (direct) way to create a dialog-based application whose main dialog inherits from CPropertySheet. When you look for examples of tab controls at the application level, you readily find things that deviate from the documented path considerably - using neither CPropertySheet nor CPropertyPage and using the WM_LBUTTONDOWN event instead of TCN_SELCHANGE, both without obvious reasons.
Any tips on (a) how to repair the apparent Visual Studio bug and/or (b) how to inherit from CPropertySheet for my application dialog and/or (c) where to find a clearer and more conventional example of tab control use at the top level would be greatly appreciated.
Given that there appears to be no clear and consistent way of approaching this, if (like me) you think "how hard can it be?", you might naively set out to see if you can create a new dialog-based application based on CDialog and manually convert it to CPropertyPage. You might fare better; I quickly hit a weird problem with the app compiling but not running - it could not load the window caption from the resource ID, despite the caption literally being there in black and white. Due to the weirdness, this was a red flag, and so to my mind problem (b) seems to be not worth the effort.
Without a CPropertySheet at the top level, there is no point having any kind of CPropertyPage or CMFCPropertyPage involved, making problem (a) pointless. That said, if you manually convert from (default) CDialogEx to CPropertyPage for your tab classes, it seems to have no problem compiling and running - the tabs just don't have any functionality that integrates with the main dialog.
Instead, I can now recommend working through the details of the video example even though it does strange things at first glance. You can achieve the desired result in more or less the same way as follows:
Use plain CDialogEx throughout, and so provide all the tab switching/showing/hiding/control work yourself (which the example demonstrates).
Create your main dialog and all tabs in the resource editor, adding the CDialog-based classes from there.
If you create your tab dialog resources via Insert Dialog (generic) instead of Add Resource (uses specific templates) then you will have to manually set certain dialog properties for each tab:
Border: Thin (or I preferred None)
Style: Child
System Menu: false
Title Bar: false
You can simplify the repositioning of the tabs (see below; it barely justifies the separate SetRectangle() function)
You should (probably) drive the tab changing from the TCN_SELCHANGE event instead of WM_LBUTTONDOWN
As noted, repositioning the tabs can be simplified to something like:
CRect tabRect;
m_tabControl.GetWindowRect( &tabRect );
for ( int i = 0; i < m_totalTabs; i++ )
{
m_pTabPage[ i ]->SetWindowPos( &wndTop, tabRect.left, tabRect.top, 0, 0,
i == m_currentTab? SWP_NOSIZE|SWP_SHOWWINDOW : SWP_NOSIZE|SWP_HIDEWINDOW );
}
Additional calls to ShowWindow() for each tab shown in the example are redundant.
One time, I had made on application as such. I don't remember if I used the Visual Studio new project wizard. Most probably, I did. But I will assist you on how to do it if you can not reach how to do it via the assistant.
The essential things:
Define the main dialog in the resources and the respective class in its H and CPP files.
In the YourAppClass::InitInstance you will need to have something like:
YourMainDlgClass dlg;
m_pMainWnd = &dlg;
INT_PTR nResponse = dlg.DoModal();
if (nResponse == IDOK)
{
// TODO: Place code here to handle when the dialog is
// dismissed with OK
}
else if (nResponse == IDCANCEL)
{
// TODO: Place code here to handle when the dialog is
// dismissed with Cancel
}
else if (nResponse == -1)
{
TRACE(traceAppMsg, 0, "Warning: dialog creation failed, so application is terminating unexpectedly.\n");
TRACE(traceAppMsg, 0, "Warning: if you are using MFC controls on the dialog, you cannot #define _AFX_NO_MFC_CONTROLS_IN_DIALOGS.\n");
}
Insert a CMFCTabCtrl element in your dialog for tabs, instead of using a CPropertySheet.

Displaying image using CDialog::CreateIndirect

I'm modifying MFC C++ code that previews dialogs from Win32 apps when they are being localised/internationalised. One of the limitations of our current approach is that we can't display images from an app being localised, we just insert a placeholder image.
What I would like is a way to enhance this functionality to display an image loaded externally from another app into a child dialog that I create myself.
We preview a dialog from a given Win32 program and recreate the dialogs plus any changes translators have made, using the CDialog::CreateIndirect function.
In effect, we are recreating the original dialog from the Win32 app as a child window of our software.
CDialog::CreateIndirect takes a DLGTEMPLATE structure as an argument which contains all of the data needed to reconstruct a dialog. It's here that we insert the resource id of our placeholder image.
I have searched to see is there are way to write the raw binary data of the image I want to display, or else dynamically add the image into my own app's list of resource IDs so I can use it that way, but ours seems to be an obscure use case.
Any help or advice would be appreciated, thanks.

CMFCMenuBar and TestStack.White win.MenuBar is null

I'm trying to use TestStack.White to Automated an MFC Application (for UI testing purposes)
When using TestStack.White with an MFC Application written with CMFCMenuBar (the later Docking framework MFC) I noticed that code like the following fails due to window.MenuBar being null
var menu = window.MenuBar.MenuItem("Window");
menu.Click();
I know I can overcome this issue with the following
TestStack.White.UIItems.MenuItems.Menu windowMenu = win.Get<TestStack.White.UIItems.MenuItems.Menu(SearchCriteria.ByText("Window"));
windowMenu.Click();
But what I really want to do is get the ChildMenus so that I can check the list of windows open in the window menu, but the windowMenu.ChildMenus is empty
I am pretty sure this is because the menu is really a toolbar/toolstrip (dockable)
Does anyone know how to get the menu items (Tile,Cascale,Window1....) from the Window Menu
Has anyone else seen this issue or found a work around?
Thanks in advance
Paul
Yes, the MFC feature pack menu is really a toolbar with buttons. And it is fulfilled using a different process compared to the old style menu.
In your CFrameWndEx derived class, for getting the menu bar you can do:
CMFCMenuBar *pMenuBar= m_Impl.GetMenuBar();
Then it depends on what to do with it. For example, if you want to get the CMenu object that constitutes the menu bar you can do:
CMenu* pMenu= pMenuBar->GetMenu();
If you want to remove some of the menus, you can do (Notice the reverse order):
pMenuBar->RemoveButton(4);
pMenuBar->RemoveButton(3);
You can not get the menu the typical way by YourCFrameWndExDerivedClass::GetMenu() because these new MFC Feature Pack classes intentionally do SetMenu(NULL) when initializing the main frame, as you can see in the call stack:
I am not absolutely sure, but I think you won't also be able to do the override YourCFrameWndExDerivedClass::OnInitMenu() as you could in the old style menus. But you can still use the YourCFrameWndExDerivedClass::OnInitMenuPopup() overrride.

Create a property sheet using a dialog template

I need to extend an existing MFC app with a UI that will end up very cluttered unless I use a tab control. However, the nature of the UI is that there are some controls that are global, and only some that can be localised to a particular tab.
The standard use of tab controls (CPropertySheet + CPropertyPage) more or less expects there only to be CPropertyPage instances (tabs) visible on the CPropertySheet object, and nothing else. There is a Microsoft Example Project that shows a single additional window painted outside the area occupied by the tab control... but it's not immediately clear how it is created/drawn/handled, and it is only one single additional window that generates few events (I guess it is painted, so there must be a WM_PAINT event handler lurking somewhere).
Is it possible to lay out a bunch of controls with the MS Dialog Editor, including a tab control, and create the CPropertySheet using that template, hook up event handlers in a nice way, etc... or some equivalent way of getting the MFC framework to do as much of the creating, drawing and event handling as possible when it comes to a situation like this?
Yes it is possible to create dialog templates and use them in a CPropertyPage.
Each CPropertyPage behaves nearly like a dialog and handles all events for the controls on it.
Also there are features like OnApply that help you to manage the data exchange between the controls and your internal storage.
The central CPropertySheet only creates the dialog that get active. So OnInintDialog for a page is called the first time when the page gets active.
In the MFC since 2010 are more possibilities than a CPropertySheet. You can create tabbed views, that again may be CFormViews. I don't like CDialog based applications so I would prefer a tabbed view in a standard frame with toolbar and menus if appropriate for the application. So another method to unclutter your UI is to choose the MDI interface with tabbed documents... but multiple documents maybe isn't what you want.
Here is a sample of an SDI application with multiple tabbed views.
Also Coeproject shows some more samples here and with splitters and tabs here.
There are at least three solutions paths:
Try to squeeze the situation into the CPropertySheet + CPropertyPage framework which does not naturally allow for additional dialog controls on the CPropertySheet object, and so you will get no framework support this
Place a tab control on an ordinary dialog, and then use the TCN_SELCHANGE messages to fire code that manually hides & shows individual dialog controls subject to the tab control (again no framework support, but this time "within" the tab control instead of outside it)
Follow Mark Ransom's observation that if you can embed one kind of CWnd-based control on a CPropertySheet then you can probably embed any such object, including a CDialog-based object that has been developed in the MFC Dialog Editor
All of these approaches are going to encounter challenges, and it will depend on the specifics of the situation as to which is better. But first you should really consider whether there is a cleaner UI design which would lend itself to a simpler solution.
In my specific case, I saw no cleaner design alternatives, and found it easiest to take the second approach. It left me with some reasonably simple calls to ShowWindow() to show/hide the controls inside the tab control.

Gtkmm 3.0 How to switch between frames or windows

I'm rather new to C++, I have a bit of experience with MCV programming in Java. im using GTKmm on C++
What I'm trying to do is writing an application for teaching assistants to submit and edit applications to various positions, and administrators to come in view, and accept these applications.
What I'm trying to do at the begging is create 3 'frames' (I'm working on the submitting application for students only at the moment)
This first will have 2 buttons 1 for selecting if you're a student/admin
Upon clicking you're a student I want to hide this frame and show my second frame
The second frame will have another 2 buttons one for creating an application, and the other for editing applications
My core problem is that I don't understand how to switch between the frames, I've written all the code for my Model, and understand everything I want it to do however I cant seem to find how to do this...
My only idea would be to create windows for each of these, make them look all nice w/e, then when a button is pressed have that window close and a string written to file I can access to see which button has been pressed, then open a new window accordingly. Should I do it like this or is there a better way?
I think I can suggest a better/more idiomatic option for any version >= GTK+ 3.10 - which, to be fair, arrived about half a year after the accepted answer.
If you want to switch between widgets one-at-a-time without any accessories like tabs, then a Gtk::Stack seems like a better option. Because it's specifically geared for one-at-a-time presentation, without any redundancy and (theoretical) overhead from a Notebook's manual tabbing features, which you'd just be disabling straight away! It's a container with multiple children, with one visible at any given moment, and of course methods to change the active child.
You can hook up your own widgets and/or events to manage which of the Stack's children is shown. Alternatively - albeit possibly just restoring the redundancy in this case - there's a StackSwitcher companion widget, which is pretty much a vertical tab-bar as seen in the GTK+ demo and GNOME Tweak Tool.
Easiest way is to use a Notebook widget. You can hide the tabs since you will be controlling which page is showing, using method set_show_tabs(false). Put the top level widget for each of your frames in a pane using method append_page(), and switch between them using set_current_page(). You might want to hide the notebook's bevel if it's distracting, using method set_show_bevel(false).
Use signals to make a widget (e.g. "I'm a student" button) on one page do something (e.g. go to the second page). If you don't know what this means or how to do it, go through the gtkmm tutorial, it will explain this and more.
A bit too late ! But here is my try :
Gtk::Notebook is great but it is not ideal in switching between app frames on menu item clicks. Gtk::Stack, since gtkmm 3.10, exists to mitigate this. Assuming you're using glade and Gtk::Builder :
class
class AppName : public Gtk::ApplicationWindow
{
public:
//...Your app methods and callbacks
void on_mb_itemname_selected(); // The call back for our menu item click/select
private:
//Builder which will help build the app from a .glade file
Glib::RefPtr<Gtk::Builder> _builder;
//...
//Your menu item to activate a particular frame
Gtk::MenuItem * _mb_itemname;
//Your handle to Gtk::Stack which is usually the stack for the whole app
Gtk::Stack * _app_stack;
//...
}
constructor
AppName::AppName(BaseObjectType *cobj,
Glib::RefPtr<Gtk::Builder>& ref_builder)
:Gtk::ApplicationWindow(cobj),_builder(ref_builder)
{
//.. Other setup
_builder->get_widget("your_glade_id_to_stack",_app_stack);
_builder->get_widget("your_glade_id_to_menu_item",_mb_itemname);
// Connect signal_select of our menu item to appropriate signal handler.
mb_itemname->signal_select().connect(
sigc::mem_fun(*this,&AppName::on_mb_itemname_selected));
}
our callback
void AppName::on_mb_itemname_selected()
{
// Change the visible child of the stack concerned.
Gtk::StackTransitionType ttype = STACK_TRANSITION_TYPE_NONE;
_app_stack->set_visible_child("your_widget_name",ttype);
// Note that widget name is not widget glade id.
// You can set your widget under name Packing -> Name
return;
}