I am currently working on an application that prompts the user when some task has completed, by popping up a dialog (think something along the lines of Growl).
If I start an operation on one space, then move to a different space, when the operation completes I am forced back to the first (initial) space. I believe this is caused by the QDialog getting focus, although this is just a hypothesis.
Is there any way to make a QDialog show() on the currently active space?
EDIT It seems that if I set the window flag Qt::Popup, the dialog behaves almost exactly like I want. That is, it shows up on the currently active space. However, it also grabs input and prevents the user from interacting with the other parts of the application. Furthermore, should it lose focus, it disappears entirely.
Can I set the popups to not grab input?
Can I make them stay on the screen, even if they lose focus?
Related
I have a bug that I am having a hard time solving. I have two windows.
Window A is the main window that contains a text box (in this simplified version). The user is able to edit the contents of this text box by clicking on it where Window B appears as a keypad. Besides the buttons for the numbers, there are 2 additional buttons, Enter and Done. If the user changes the value and presses Enter, then the value in the text box is immediately updated. Pressing Done will then exit the window.
However, if the user presses done without having first pressing enter, then a modal dialog will appear asking the user if they would like to save the value. Once a selection has been made, the model dialog and Window B will exit.
The bug occurs when the user enters a value and presses the Done button. When the modal dialog appears, Window B moves behind Window A. What should happen is that Window B stays ontop of Window A. Interestingly enough, when I step through the code, this bug never happens which is making it tricky to pinpoint.
Has anyone every ran into this issue before?
I am currently running Qt 5.9 on the latest version of Linux Mint (as of this writing)
Also, I have prepared a sample project that demonstrates this bug. Due to the larger complexity of it, I was unable to fit it into 1 file. If needed, I might be able to find some time this week to move everything in one file. However, I can post the Dropbox link if permitted.
Maybe the problem stems from a wrong setting of the parent child relationship of the [QDialog][1] classes.
The following passage might be crucial for your application, but it is hard to say, if you don't show a minimal-reproducible-example.
Note: The parent relationship of the dialog does not imply that the
dialog will always be stacked on top of the parent window. To ensure
that the dialog is always on top, make the dialog modal. This also
applies for child windows of the dialog itself. To ensure that child
windows of the dialog stay on top of the dialog, make the child
windows modal as well.
Hi I have a question concerning error-messages.
I have a window with several buttons including a OK and Cancel-button. My OK-button executes a program that moves some chart series and for doing so it needs to read in lots of data from a file and shift these values. The Cancel button cancels this operation. The calculations cannot be separated into smaller portions of code.
This works well for smaller amount of data but when I use it with large sets of data the program acts as if it crashed. Nevertheless, after some time everything is back to normal, the calculation is done.
There are 2 things I don`t like:
1) When I leave the program alone the program changes the headerline of my window to ....(keine Rückmeldung) which means no response.
After the end of the calculation the text ...(keine Rückmeldung) disappears in the header and everything is back to normal.
2) When I try to press the "cancel" button in my window while running the calculation, an additional window appears:
There again, when I leave the program alone and the calculation is finished this window disappears ( as well as the (keine Rückmeldung) in the header of my window) and and everything is back to normal.
To solve problem 2 I tried to disable my "Cancel" button but this does not help. The slot which is behnid the cancel-button gets executed anyway.
My question now is: Since I don´t want the user to see these error-messages, is there a way to prevent the program of showing them?
Thank you
Consider using a QThread for expensive computation tasks. Or better, you can use other built-in multi-threading utilities such as QConcurrentRun and QFuture.
You can then easily get the state of your background function and show a loading Window, or allow the user to perform other operations in the meantime.
I'm currently trying to develop an application to use two mice to perform completely different actions in Windows. However, after having spent couple days on it, I'm starting to wonder if what I want to do is even possible using Windows APIs. As I'm far from being an expert in Windows APIs, I would like to get your opinions to know whether I'm going in the right direction or whether I should try to do it completely differently (maybe developing a driver ?).
Here's what I want to do : Imagine two mice are plugged in my computer. I would like to use the first one as a regular mouse, while the second one would be used to perform completely different actions. For instance, by clicking the second left mouse button, it would open a new tab in Firefox (sending a CTRL+T command to FireFox app) and when clicking the right button, it would send a CTRL+C. Then, by moving the second mouse upwards, it would zoom in, and when moving it downwards, the firefox page would zoom out (so the mouse cursor on screen would remain fix while doing that !). The idea is to recognize as well which application is currently used (which one has mouse/keyboard focus) and perform different actions depending on it. So for instance, the second mouse left click would generate a CTRL+T in FireFox, a CTRL+B in WORD and a CTRL+S in Notepad (in fact, the idea is to parameterize those actions at will). All of that while the first mouse must continue to act just as a regular mouse.
So, it's important to understand that my application will run in the background and will never, per se, interact directly with the user (no GUI as it doesn't require the user to input anything). Its purpose is just to modify the mouse inputs coming from the second mouse and send other inputs(messages) to the application currently being used.
So far, I'm using raw input. I'm able to differentiate which mouse is being used and I'm able to send messages (application specific) to other applications when an action is performed on the second mouse. I'm even able to lock the cursor on screen when the second mouse is moved (so as only the corresponding message is sent to the application of interest !). However, I'm unable to block the button messages sent by the second mouse to the app with the mouse focus. Hence, when clicking on the second mouse right button in Notepad for instance, my specific command ("aaa" for the moment as I'm just trying with letters for sake of simplicity) is sent (and displayed in the notepad window) BUT the contextual Notepad menu opens as well… (hence it's received as well a WM_RBUTTONDOWN message).
My question is then : How can I block the mouse button messages ((WM_RBUTTONDOWN, and so on…) to be received by other applications when the second mouse is used? Is it even possible ? The problem is that (in my understanding) those messages have higher priority over the WM_input messages… So when I read the WM_input message in my application and detects that the button was pressed from the second mouse, it's already too late and the WM_xBUTTONDOWN was already sent !)
I know that using the mouse hooks, I could block those but then, there is no way to differentiate the origin of the message (and of course, detecting which mouse is used is the main point of my application).
I've tried as well using DirectInput8 but it doesn't support anymore the usage of several mice (Windows specifically says to use raw input to this effect).
So, I guess that by know you've gotten that I'm quite lost and have no idea whether what I want to do it even achievable. Any help would be more than welcome.
Looking forward to reading your replies.
I was about to suggest hooks, but then I read that you looked into that already. I guess, the last resort for your problem would be to write your own driver.
After Windows installed the second mouse in it's usual way, you can go to the Device Manager and change the driver of the mouse you want to "repurpose" to your own driver.
Although, developing a driver is probably nothing one will do as a side task in a project.
Problem
Windows has a system setting that will cause the mouse pointer to jump (move) to a new focus element automatically, e.g. the default button of a dialog that pops up. While the advantage is an increase in speed and a reduction of mouse movements, it has a disadvantage:
If this happens just when before the user clicks on another element, the user is unable to abort his/her action in time and will immediately accept the dialogs default button because the focus is moved by the system. Usually this may entail cumbersome work to retrace the steps up to this point (think a file chooser dialog that forgot the very long path you input previously) but it could also mean triggering an irreversible process (e.g. file deletion).
Aim
Essentially I would like to disable the dialog's inputs for a small amount of time, just enough to prevent an inadvertant mouse click or keyboard button press.
Question
It comes down to a C++ question, namely how to access the base classes' objects (GUI widgets) from the inheriting class, i.e.
disable the button widgets of a QMessageBox
start a single shot QTimer and connect it to a slot that
enables the previously disabled widgets
(As alternative, I probably could reimplement input event handlers that suppress all input for a specific amount of time, but although I intend to keep that time very short (e.g. 100 ms), the user is not informed of the disabled input using that method.)
A simple class derived from QDialogBox can be found at http://www.qtforum.org/article/24342/messagebox-auto-close-mouse-event-close.html.
Do you need to use one of the "native"-ish message boxes provided by the QMessageBox static functions?
Otherwise, that's pretty simple to achieve, by building a QMessageBox and adding standard buttons to it:
QMessageBox *messageBox = new QMessageBox;
QPushButton *okButton = messageBox->addButton(QMessageBox::Ok);
okButton->setEnabled(false);
// use a QTimer to add logic to reenable the button
// use QCursor to move the mouse cursor on the button
// add a nice countdown in the button's label, like Firefox does
// add other nice UX touches as wanted
Last points are left as an exercise to the reader :)
To en/disable the buttons in QMessagebox one would need access to them.
qmessagebox.cpp uses buttonBox = new QDialogButtonBox; and the addButton() method
d->buttonBox->addButton(button, (QDialogButtonBox::ButtonRole)role);
d->customButtonList.append(button);
But I don't understand Qt internals and am unable to find these in qmessagebox.h and thus fail to find out if there is a chance to access the buttons..
I have a stack of images on which I want to perform some operations. After processing each image, my program should pop up a dialog to prompt the user if they want to proceed with the next image or to abort. Before that, they should have an opportunity to do some manual changes either on the images or on the parameters. Anyway, they must have access to the windows of the applications, while the execution of the method that called the dialog should be blocked until the dialog is closed.
I tried to solve this with a QMessageBox, but if I open it via exec(), it blocks the entire application, and if I use show(), the execution of the program goes on without waiting for user's reaction.
Is there a convenient way to block the calling method or function with a dialog but permit the user to interact with other windows?
Thanks in advance for any hint.
You should split your method that you want to block into two parts. In the end of first part you need to show your dialog without blocking and connect "Next" button (for example) of the dialog to the slot that must contains second part of your old method. This slot will be executed only when user presses the button.
It's the right way to do it in Qt. You need posibly to change your code logic to implement this.
Also, do you really need the second dialog? You can place "Next" button to your main widget. You can also create another modal dialog that will contain some settings and "Next" button.