I have a MFC dialog based application with a picture control and some buttons on the dialog. I register the button click using:
ON_BN_CLICKED(IDC_BUTTON_START, OnBnClickedButtonStart);
If I update the picture in OnPaint() using StretchBlt() at about 10 to 30 pictures per second triggered from calling Invalidate() inside a worker thread, the button click stops being responsive.
Is there way to get around this? Thank you.
Related
The question is for GTK+ programing in C++.
I have a main window with a button that activates a dialog window. The dialog window has OK and CANCEL buttons. I did it that way so when I hit the cancel button the dialog is closed. But once it is closed I cannot call it again with the button in the main window.
I have tried to call the dialog delete-event on the button click. I also tried to call the dialog destroy event when the button is clicked. But in both cases the dialog is destroyed and it does not show when I click the button that calls the dialog.
I suppose this is a follow up of your other question on the topic:
How to properly close a dialog made in Glade?
If it was created using GtkBuilder, if you destroy the window, it's really destroyed: GtkBuilder has created the widgets at parsing time, not when you call get_object, and won't create them again. So I think you should just hide the dialog with something like gtk_widget_hide_on_delete, and show it again when you click on the button in your main dialog.
My application can receive a message from another application. If the app is minimized, I want to restore it to the previous state without giving focus to it.
I'm doing it by calling
::ShowWindow(hWnd, SW_SHOWNOACTIVATE);
It works well if the app was minimized using the Minimize button in the title bar, but if the app was minimized by clicking its button in the Windows task bar, then the app will receive focus.
Can this be fixed or worked around?
You could do the following HWND hwndForegroundWindow = GetForegroundWindow() before your ShowWindow function call. Afterwards you can restore the foreground window with SetForegroundWindow(hwndForegroundWindow). It depends on what you mean with focus though, foreground window and focus are something different (For element focus use GetFocus and SetFocus).
I'm working on a themed ownerdraw button using Win32 native.
Following a tutorial and a sample project on another website, I got my button almost perfect(almost without bug), but there's one which left, and I have a issue in fixing it.
Basically, I'm subclassing using SetWindowLongPtr API the window of the button, and from there, when WM_LBUTTONUP is catched, I would need to call DrawThemeBackground for reset the state of the button, OR, just handle again WM_DRAWITEM. The problem is that WM_DRAWITEM is getting called only when my mouse is on the dialog window, which is not really a problem, if there would be a way for advice the main dialog to handle it when I want it. I tried with InvalidateRect, but it is not making WM_DRAWITEM, but WM_CTLCOLORBTN.
So, my question is:
Is there any way for let WM_DRAWITEM being handled even if the mouse is out of the dialog
OR
Is there any way for advice the main dialog that it should handle again WM_DRAWITEM, evne if the mouse is out of the dialog?
Thanks alot for taking your time in replyng me.
I have a QMainWindow with three QPushButtons (arranged in a QVBoxLayout in a QWidget). All have the same properties, except objectName, icon and iconSize. All are enabled and have two icons, one for normal and one for disabled.
When I start my application, always the top most icon shows the disabled icon (but is working, so it is enabled) the other two are fine. As soon as a focusable control in that window gets the focus, the icon changes to the active one and everything is fine.
Calling update or repaint in the showEvent of the window doesn't help either.
I'm using gcc 4.8.1 and qt 5.1.0.
Any ideas how to handle this glitch?
Update: It gets more strange: Starting the program, the icon shows disabled, getting another application the focus, the icon shows enabled, bringing the window on top again without giving it the focus (e.g. by using the task bar) changes the icon back to diabled. Clicking a control in the window, which can have focus will fix it again.
Well, well I finally got it. I just set the focus manually in the code and realized, that the icons were set in a wrong way. If a button was currently focussed it displayed the disabled icon. I had messed up the different button states and too many states got the disabled icon.
We have an MFC MDI app that during the process of operation can set the focus on a given control, e.g. it might change the active tab if the result of the operation is more appropriate for a different tab.
If the app has focus when the SetFocus occurs this is fine, tab changes and the correct control has focus. However, if the app does not have focus (ie the user has clicked on another app while waiting for the operation to finish) the SetFocus on the child window causes an OnActivate to occur in the parent MDI frame and the app becomes the foreground window.
How do we SetFocus to a child window without the whole app from becoming the foreground window if the user is working in another app.
Did you try to change focus using CDialog::GotoDlgCtrl ?