Choosing between a Dialog Based Vs SDI Projects - c++

I am new to MFC well not entirely new but wanted to ask experts on this forum as why one would choose one project over the other. I hope this is not a stupid question as I am relatively new to MFC.
Thanks so much

Chose based on what template your application fits best into:
Single Document Interface (SDI) - if your application needs to work with only 1 document or data object or data set at a time
Example: notepad.exe
Multiple Document Interface (MDI) - if your applicaiton needs to work with multiple documents or data objects or data set at a time
Example: Visual Studio
Dialog Based - for anything else.
Example: Calculator
No matter what you chose, you still have the same functionality available to you in the end and you can cusotmize it in any way. So you aren't limiting yourself to anything you start with.
All variants come with CWinApp which is the base class for which you derive your MFC applications.
With a dialog based application you start with a CDialog as well. With an SDI application you start with CMainFrame, CDocument, and CView as well.

If you select an SDI project you get a whole Model-View-Controller framework included.
You get a document class (inheriting from CDocument) which ideally should hold all of the data, and a view class (inheriting from CView) to do with the display.
You get given a hosting frame with a menu already attached, and there are functions you can override to save and load to file.
If you have a dialog based application, then you get one dialog. That's it. Of course, this dialog can spawn off others, but the application essentially consists of a dialog.
If you're developing a small application that just does one task, a dialog application is appropriate, because you don't need the overhead.
If you are developing an application where the user will be loading, editing and saving data, then the SDI path would be more appropriate.
Having answered your question, I'd politely ask if there was a compelling reason why you were choosing MFC over Windows Forms. I believe that MFC was an excellent technology for its day, but the Visual Studio suite offers more advanced tools (if you're prepared to go down the .NET path).

If a "document" is the right metaphor for your application, use SDI or MDI. (Single of only one document can be open at a time, Multiple if more than one.) When you think about it, the document metaphor really isn't appropriate for most applications.

Related

What is a good MFC C++ GUI architecture for multiple similar window arrangements

I am considering a rewrite of an MFC Dialog application I wrote over a decade ago. I originally chose a Dialog application type because in general the user clicks control inputs and the application provides real-time data from hardware via USB and displays the data in edit boxes. The app also writes information to a file. Since the user never does any file editing I didn't see a need for SDI or MDI application type.
I've now learned that the SDI application type along with CFormView provides some interesting advantages such as scrolling, window resizing:
http://forums.codeguru.com/showthread.php?267664-MFC-Dialog-How-to-enhance-a-dialog-based-application-with-Menu-Toolbar
The reason for my rewrite is that my application is un-maintainable and doesn't scale well. Originally I created a CDialog for each type of "screen" that I show but lots of code is common among the various screens. In fact over time I started reusing CDialog classes and with the use of state variables simply hid, renamed, or repositioned many of the controls to make the screen look appropriate in the context of the application.
I tried deriving the CDialog classes from a common base class but I didn't achieve great code reuse this way. I also found that I had common resources that I was constantly passing around to the various windows which just added unnecessary overhead.
As the application evolved it also became difficult to keep track of the state of the application (for processing USB hardware data input, user input, button enabling etc). Using a hierarchical statechart as the basis for my application might clean this up.
Should I consider putting a superset of ALL the necessary controls on ONE CFormView and simply hiding, renaming, and repositioning controls from the very beginning and using a statechart to manage this?
All the examples I see put the code directly in the input control handlers but maybe I should use the handlers to change state and then let the state machine do the decision-making to reduce this spaghetti code.
So my primary questions are:
1. Would SDI would buy me anything for writing and reading files (such as reporting and logging) if the user does not perform editing?
2. Does CFormView make sense?
3. Does it make sense to put all controls on one CFormView instead of multiple classes and Dialog resources?
4. Have you tried using a state machine in MFC such as Boost Statechart or Miro Samek's Quantum Leaps?
http://www.boost.org/doc/libs/1_58_0/libs/statechart/doc/index.html
http://www.state-machine.com/products/index.html

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.

Document-view architecture in MFC

I have a question about the necessity of using MFC's built-in document-view architecture. I was given an old dialog-based project in which I have to replace the main dialog with a frame and add a ribon. It has sort of a doc-view architecture, created without the built-in classes and I preffer to reuse it in the new version. However, if I try to bypass the CDoc and CView derivatives, normally generated by the project wizzard, all I can see is an empty window without a ribon. So... do I REALLY have to implement these built-in doc-view architecture, or am I just missing something? Isn't it possible to use the already existing code from the project?
If you will be using multiple views & documents in your frame then it is advisable to use the existing framework's design (CDocument, CView etc).
If you are doing it only for ribbon and will be just moving your controls from dialog to frame then you can skip the standard Document/View architecture and directly instantiate ribbon control.
If you don't have to re-write a lot of code, then I would suggest that you use standard Document/View architecture as in a long run it will save a lot of time, make your app scalable to a bigger multi-doc design etc.

Creating a window that can only be dragged within the parent window

I have a WIN32/C++ app and I want to create child windows in it that cannot be dragged out of the parent window. I want these windows to be owner-drawn, if it matters anyway. Should be simple enough; I'm looking for some basic guidance and tips regarding the subject.
It seems that you want to make an MDI app. This is much easier using a higher level framework such as MFC, WinForms, VCL etc., but can, of course, be done with plain Win32.
The MSDN documentation can be found here: Multiple Document Interface.
What you are looking for is called Multiple Document Interface (MDI).

Skin a dialog box

I am writing a C++ application and I have a Login Box that's shown in a regular Dialog Box Frame. I see that some people can SKIN the entire dialog box and makes it look really nice. I was wondering if anyone can give me some pointers as to how to do that.
I'd need more details to give you a good answer.
The answer very much depends on which OS you're using and how you're programming your GUI (for example on Windows - plain Win32, MFC, ATL, Qt, Windows Forms, WPF etc etc).
If you're just using the Windows API here's a link to get you started.
http://www.codeproject.com/KB/dialog/skinstyle.aspx
Beware: custom skinning dialog boxes can be a very large task if you want to customise the look of every control as you end up writing very complicated custom controls.
Alternatively do you just want to make sure that your dialogs appear with Windows XP visual style rather than pre-XP style? This will require changes to your application to use the new common controls and visual style. Note that this changes the behaviour of some Windows APIs and can potentially have side effects (see ISOLATION_AWARE_ENABLED).