How to center align text in CDateTimeCtrl? - c++

I'm using CDateTimeCtrl in my dialog application. Now we have already agreed with the client about the size of the CDateTimeCtrl. The 1st problem is, it is by default left-aligned, and is really close to the left border. The 2nd problem is it leaves a really wide space on the right side of the control. Hence, the solution to solve both problems would be to center align text.
Unfortunately, in the Properties window, there is no alignment property (except for "Right align" in which there were no changes when I tried to toggle it).
Now, I've tried calling CWnd::ModifyStyle in the OnInitDialog() event. Also, no luck with this.
For the actual code,
auto timePicker = (CDateTimeCtrl*)GetDlgItem(IDC_TIME_PICKER);
timePicker->ModifyStyle(0, SS_CENTER);
return TRUE; // this function is the OnInitDialog()
What could I be missing that calling this function does not center the text of CDateTimeCtrl?

You can't use a style that is suited for a static control and use the style in a date time control.
All available styles are listed here.
The control itself also doesn't have child controls. It draw the values itself.
Maybe there is a chance to subclass the control and overwrite the WM_PAINT message and doing a kind of ownerdrawing by yourself.
I don't use the date time picker and I confess: I don't like it at all. I wrote a complete own control that is much more flexible.

Related

Is there a safe way to paint a little extra onto a subclassed control?

Let's say you want to add a little extra graphical info to a Windows control. For example, you want to add drag/drop functionality to a listview (using the procedure discussed here), but with horizontal lines signaling the drop/insertion points as the user drags an item. (The control belongs to your own application.)
Is there a safe way to subclass the control and draw onto it directly? In my limited experimentation in trying to do this, I encountered some problems. First, it wasn't clear whether I should call BeginPaint and EndPaint during the WM_PAINT message, since the control itself would be calling those functions once the message was passed along to the default procedure. I also inevitably encountered flickering, since some areas were being painted twice.
I thought a safer way would be just to create a transparent overlay window and draw on that, since that would avoid conflicts with the default paint procedure, but I thought I'd ask before going down that road. Thanks for any advice.

MFC CEdit character delete not working

I stumbled upon a strange problem today on one of my client's Windows XP SP 3: deleting with BACKSPACE or DELETE buttons a text from a CEdit won't work. To be more accurate, i place the cursor at the end of the text, and hitting the BACKSPACE button will result in moving the text cursor to the left, but deleted characters won't dissapear. The actual delete takes place, because if i force a refresh of the window, the deleted characters are missing.
I guess is a paint issue, but i can't find what's wrong and how to work around it, and i couldn't reproduce the bug elsewhere.
I checked the code, and the CEdits that behave like that have no events overriden, and no special properties set.
My answer is a guess: You overwrote WM_CTLCOLOREDIT and you are returning a NULL Brush to draw transparent.
The result is what you see. Without the capability to overwrite the background the edit control shows artifacts...
This "trick" of drawing transparent in Standard controls isn't a real good one but it is spread all over the Internet so that everybody uses it without knowing the drawbacks. Usually this works only for static controls that don't change.

How do I handle WM_NCCALCSIZE and make chrome-like interface?

I'm currently using Google Chrome as my main browser. I wondered how the developers put the custom titlebar, because I wanted to incorporate into one of my own applications.
If you guys don't know what I'm talking about, here's a picture:
I found an article about the interface, which is here:http://social.msdn.microsoft.com/Forums/en/vcgeneral/thread/33870516-9868-48d3-ab53-6269d9979598
However, I don't know how to do this. I'm currently using VC++ Express. Can anyone give me step by step instructions and how to get an interface like that? Except I don't want tabs on top.
I'm writing this in Win32.
If memory serves, the main things you need to handle aren't WM_NCCALCSIZE, but WM_NCHITTEST and WM_NCPAINT.
WM_NCHITTEST is what tells the system when the cursor is over the title bar, so you need to take a cursor position and decide whether it's over the area you consider "title bar". In particular, if the user clicks and drags with the cursor in this area, the whole window gets dragged.
WM_NCPAINT is just like WM_PAINT except for the non-client area -- i.e., this is when you need to actually draw whatever you're going to for the title bar (and window borders, if memory serves).
I should add that I haven't played with this in quite a while. There's almost certainly more I'm not remembering right now.
OK, the answer is simple:
Chomre simply does not use the Windows built in functionality for drawing a frame border, titlebar, titlebar buttons, etc..
When you call GetWindowRect(hChromeWindow) and GetClientRect(hChromeWindow) you will notice that the rectangles are identical. This means that Chrome turns off all Windows functionality for drawing a border (simply return 0 in WM_NCCALSIZE without doing anything else) and then they draw EVERYTHING into the client area.
So in WM_PAINT they draw the titlebar and the upper part of the window (URL bar, tabs, etc..) together. In WM_NCPAINT they do nothing.
This is not the common way to do it, but the easiest, and it is bullet-proof.
By the way: Java applications do the same.

Custom draw button using uxtheme.dll

I have implemented my custom button inheriting from CButton and drawing it by using uxtheme.dll (DrawThemeBackground with BP_PUSHBUTTON).
Everything works fine but I have two statuses (Normal and Pressed) which Hot status is the same. It means when the user places the cursor over the button it is drawn alike regardless the button status (Pressed or not).
This is a bit confusing to the user and I would like to change the way the button is drawn in Pressed & Hot status. Does anybody know a way?
I have also thought about custumizing the whole drawing but the buttons use gradients, borders, shadows, etc. So it is not easy to achive the same look&feel drawing everything by myself. Is there a way to find the source code of the dll or know how to do it?
Thanks in advance.
Javier
Note: I think I could be able to achive what I want to do by using CMFCButton and overriding the OnDraw method. Let the control draw the button on OnDrawBorder and then drawing the inside button myself. But I need to know how the control draws the inside button when pressed. It is a gradient and I can't guess how it's done. Does anybody have a clue?
In answer to your second question, if you derive from CMFCButton instead of CButton you can override OnDraw() or OnDrawText() instead of the usual DrawItem(). That way the default button background will be drawn, and then your drawing code is executed.
The only way I know of to really tackle this is to use 'custom draw', rather than 'owner draw'. Custom draw came in with Windows 2000, but is only used by button controls with comctrl32 6.0 (so Windows XP onwards), isn't very clearly documented, and isn't something MFC goes out of its way to support.
Anyway, the good thing about custom draw is that it lets you hook in at various points in the drawing process, unlike owner draw, which makes you deal with the whole thing. Have a look in MSDN at the NM_CUSTOMDRAW notification message.
For the other part of your problem, detecting the 'hot' state, the easiest way to do this is to use WM_MOUSEMOVE messages and the TrackMouseEvent() function to track whether the mouse is over your button.
Unfortunately this is a bit of a vague answer: the amount of code you need to demonstrate a button that uses custom draw is a bit too much to type into these answer boxes! I do have a project that demonstrates such techniques, using a custom draw button (falling back to owner draw on older Windows versions) that adds a little arrow to the button. You can have a look at the source code by getting
Windows_UI_source.zip
Open it and have a look at the "DropArrowButton" class. The important bit is the OnCustomDraw() handler and its helper function DrawControl(): these get called at the various button drawing phases, and use UxTheme to draw the control appropriately.
I finally figured out how to achive what I want to do. It's pretty easy indeed.
I use two calls to DrawThemeBackground. The first one with PBS_PRESSED and the second one with state PBS_HOT. Then I make a ExcludeClipRect to avoid from drawing over the center of the button.
Something like this:
DrawThemeBackground( hTheme,
pCustomDraw->hdc,
BP_PUSHBUTTON,
PBS_PRESSED,
&pCustomDraw->rc,
NULL);
CDC *pDC = CDC::FromHandle(pCustomDraw->hdc);
CRect rectClient;
GetClientRect(rectClient);
CRect rectInternal = rectClient;
rectInternal.DeflateRect(4,4);
pDC->SelectClipRgn(NULL);
pDC->ExcludeClipRect(&rectInternal);
DrawThemeBackground( hTheme,
pCustomDraw->hdc,
BP_PUSHBUTTON,
PBS_HOT,
&pCustomDraw->rc,
NULL);
pDC->SelectClipRgn(NULL);
Of course this is not the whole code but I think is enough to make my point.
Thanks.

How to fix an MFC Painting Glitch?

I'm trying to implement some drag and drop functionality for a material system being developed at my work. Part of this system includes a 'Material Library' which acts as a repository, divided into groups, of saved materials on the user's hard drive.
As part of some UI polish, I was hoping to implement a 'highlight' type feature. When dragging and dropping, windows that you can legally drop a material onto will very subtly change color to improve feedback to the user that this is a valid action.
I am changing the bar with 'Basic Materials' (Just a CWnd with a CStatic) from having a medium gray background when unhighlighed to a blue background when hovered over. It all works well, the OnDragEnter and OnDragExit messages seem robust and set a flag indicating the highlight status. Then in OnCtrlColor I do this:
if (!m_bHighlighted) {
pDC->FillSolidRect(0, 0, m_SizeX, kGroupHeaderHeight, kBackgroundColour);
}
else {
pDC->FillSolidRect(0, 0, m_SizeX, kGroupHeaderHeight, kHighlightedBackgroundColour);
}
However, as you can see in the screenshot, the painting 'glitches' below the dragged object, leaving the original gray in place. It looks really ugly and basically spoils the whole effect.
Is there any way I can get around this?
Remote debugging is a godsend for debugging visual issues. It's a pain to set up, but having a VM ready for remote debugging will pay off for sure.
What I like to do is set a ton of breakpoints in my paint handling, as well as in the framework paint code itself. This allows you to effectively "freeze frame" the painting without borking it up by flipping into devenv. This way you can get the true picture of who's painting in what order, and where you've got the chance to break in a fill that rect the way you need to.
It almost looks like the CStatic doesn't know that it needs to repaint itself, so the background color of the draggable object is left behind. Maybe try to invalidate the CStatic, and see if that helps at all?
Thanks for the answers guys, ajryan, you seem to always come up with help for my questions so extra thanks.
Thankfully this time the answer was fairly straightforward....
ImageList_DragShowNolock(FALSE);
m_pDragDropTargetWnd->SendMessage(WM_USER_DRAG_DROP_OBJECT_DRAG_ENTER, (WPARAM)pDragDropObject, (LPARAM)(&dragDropPoint));
ImageList_DragShowNolock(TRUE);
This turns off the drawing of the dragged image, then sends a message to the window being entered to repaint in a highlighted state, then finally redraws the drag image over the top. Seems to have done the trick.