How to identify if data in QClipboard is result of cut or copy of windows action ?
For e.g select the folder in windows explorer, press Ctrl+X (cut action), now activate Qt GUI application and paste it. now Qt application needs some mean to identify previous windows action if it needs to delete selected folder(in case of cut action in windows explorer) or not(in case of copy action in windows explorer)
There is no way to do this. The clipboard simply holds data. In fact, I don't think any operating system distinguishes between copy and cut. Cutting is essentially copying and then deleting the data at the source.
*edit:
The only way I could think to do this would be to have your application monitor key presses. So if the user ever types Ctrl+X you know they've cut. However that won't help if they right click to cut. Either way, it's not a great solution.
Related
We have built a WebDav Service with your Engine and have a one problem when we create a new Folder or File:
The new folder / file is created successfully, but not showing in the Windows Explorer. Only if you press F5, the new folder / file is showing (and the name is already selected to be edited).
This behavior is reproducible even with a blank WebDav Solution.
We can reproduce this on Windows 7 and Windows 8 (8.1) using WebDav .NET Server 3.8 and the latest 3.9.
Is there a way to get around this “refresh-problem”?
I solved this issue but clicking in the folder explorer at view > options > then i restored to default and everything is back to normal.
I assume this issue is in Windows Explorer on a single computer. Most likely the WebDAV server-side code is failing with with some exception. Here are some ideas how to detect what is wrong:
Unmount network connections executing 'net use * /DELETE' in a command prompt, this will unmount WebDAV connections too and simulate 'clean' environment.
Retry reproducing the issue and examine your WebDAV logfile. By default it is located in /App_Data/WebDAV/Logs/ folder. Are there any exceptions in it?
Use Fiddler tool or any other debugging proxy to capture and examine HTTP requests. Are there any failed requests?
In case you are creating a folder/file on one computer using Windows Explorer (Microsoft Mini-redirector driver) or IT Hit Ajax File Browser and expect the files list to refresh automatically on another computer this would not work. Mini-redirector does not support any notifications from server and WebDAV does not submit any notifications, you need to refresh the files list manually to see the new items created.
I found this video on Youtube that explains in very much detail how to fix this problem: https://www.youtube.com/watch?v=UUiCPsQquqc
It is a bit lengthy, so I'll just quickly sum it up here:
The reason for these problems are one or more (broken) Shell Extensions that prevent the refresh of the Windows Explorer
To fix it, open up regedit.exe (requires admin privileges), do a search for the Registry Key "DontRefresh". If it is "1", set it to "0". There might be multiple matches for that Key, so repeat until all Keys have the value "0".
This might not work immediately, you may have to kill and restart your explorer.exe process (easiest to do with the Task Manager). Or you can simply reboot your computer. In my case, it worked immediately.
According to the video, the Keys should only be located under HKEY_CLASSES_ROOT/CLSID, but in my case I could only find such Keys in HKEY_LOCAL_MACHINE/Classes/Wow6432Node/CLSID.
I figured it makes most sense to simply search the complete Registry, it does not take very long.
I tred a lot of hacks, from scanning the system, to recreating the profile to hacking Registry keys and hives.
Finally what worked for me -
Right click on desktop
Select Personalize
Click Themes
Click Change desktop icons
Click Restore default & OK
And instantly it began to auto refresh with a new folder, rename, delete, copy, etc.
Well, i have a QProcess that works as my program updater, but on Windows you CAN'T modify exe files when they're running, but if you close the program that created the Updater process i suppose that the Updater closes too. It's possible to make the Updater process independent?
Then, on Windows Vista (and later) it's impossible to run my updater because it returns that i need to elevate my level to administrator, It is possible to elevate the permissions for the process?
First of all, in opposite to Linux, Windows processes are independent from their parents by default and would not be closed after parent process closes.
Right way to solve your problem would be making your updater a Windows service. Then, it wouldn't be launched by application and it will have privileges to write to system folders etc. (see here)
Here is library for services support in Qt (and it actually works).
If you want simpler solution, you can use ShellExecute to escalate privileges to launch your updater.
I'm using Ubuntu and Qt Creator 4
I have a .cpp program in the executable form (say abc.out) that I wish to run when I press a button. It contains a number of cin and cout, so I want it to run on a "terminal" (on Ubuntu) so that I am able to input and output values to it. How can I do that?
I've tried system() and
also,
QProcess p1;
p1.start(./abc.out);
Using QProcess, my executable runs but stops at the first cout. It runs on the application output screen in Qt Creator and not on terminal.
For example:
I see on application output:
enter name:
When I type the value and press enter here, it doesn't accept the value, but moves to the next line and allows me to type further.
I want to run this abc.out file on the terminal. Any ideas would be really helpful.
Do you mean Qt Creator 2.4? In any case, on the Projects tab, you should find the Run settings section and from there you can find a "Run in terminal" checkbox. You could also use a Custom Executable option and type there: gnome-terminal --command ./abc.out The exact details can vary a bit as I'm using Qt Creator 2.5.
This should work when launching from Qt Creator, but when you use your app outside the IDE, you need to launch it from terminal and not by double clicking the executable. To fix this, I can think of two ways:
Launch a terminal window from QtGui (something like QProcess::execute("gnome-terminal --command ./abc.out"); ), though the problem is different systems have different terminal names.
Provide a Qt input/text box yourself as part of your GUI which then forwards the user input to the executable (something like myqprocess.write(input_asked_from_user_by_QtGui); ). Here you probably need to know what information to ask the user beforehand. If you want to display the cout output of the started process, you can use the read method and friends of the QProcess.
From your question I assume that you are writing an application that launches other applications using QProcess. Thats fine, but if your subprocess is waiting for data from the standard input it will wait forever since you did not provide any data. The stdin of your parent application cannot be automatically guided to the subprocess. Imagine you are starting two processes from your main app. To which child process should the input go?
If you want to communicate with child processes, you must use the QIODevice methods of QProcess and send/read data from/to that application.
The only sensible solution is to launch the target application in a terminal. Whether your own code provides the terminal window or you reuse an existing terminal application is up to you.
I have Qt GUI application which I want that the user will open one only. I want that if the user will click first time on th exe - it will open the application and when he will click it again it will open the first one.
i don't want to do it with QtSingleApplication.
I want to know exacly how to open the GUI on the second time.
Help me please!
Even if you don't want to, QtSingleApplication is what works. If you want to learn how it is implemented, you can always read the source code.
I'm new to web development so please, could you help me to understand if I'm working in the right direction?
There will be a webpage intended for our customers (not intranet) from where they can print labels. Some of the larger customers will have special label printers where configuration and printing using COM-port is the only acceptable option. Basically we have very limited knowledge and control over their environment.
The web-page itself will be a pretty simple html-page or more complex AJAX.
After the customer inputs all the data and happens to chose this type of printing we have following tasks:
1) get data about the printers on the customer's system installed to a comport and if possible get printer settings (like paper size and orientation). Ideally would like to be able to adjust the settings, but if it is a pain can just put into requirements that your printer must be installed to COM1 and configured correctly.
2) send commands and read answers and send PCL code to the selected com port
As I understand I'll need to install something on the customer's machine to be able to talk to com port and get any settings. Just HTML+Javascript are not capable of doing that. Right?
I found RXTX library which seems to communicate to com port on most platforms. Can it be called from JavaScript or I still need to do a Java plugin? Are there technologies other than Java plugin that would solve the task?
The web-page will be used in different environment - platforms and web-browsers. We would like to minimize the number of customized solutions. Will Java allow us to do the same plugin for all environments with minimal customization?
If we require the user to install a plugin will the user be prompted with our credentials to confirm the installation? Will our web-site require higher trust settings?
Thanks for you help!
Well, I've had to do this in the past. Here is what I did and the circumstances
1) I knew that our customers were in a windows environment so I wrote win32 software to handle the printing.
2) I created a file format to be read by the win32 software that allowed me to specify print parameters and the label data. XML works ok for things like this.
3) My web app created a file in the format used by the win32 software and returned it to the user when they clicked on the "Print Labels" button. The file extension on the file returned was registered by the installer of the win32 software. That means when their browser looked for a default app handler for that file, it found my win32 software.
Bottom line is that the browser is handing off the printer communications to a native application instead of talking directly to the printer.
Obviously you need to be able to dictate your end user's are using a windows machine (or mac or whatever you can write native code). Associating a file extension with my program and returning that file to the user was the key to making the process work for me.
Whether your native code sends pcl directly to the printer or translates into a print api (like the win32 api as mine does) is another consideration.
Another approach you could consider is instead of sending PCL codes, you could create a PDF of the document. Format the document to the size and orientation of the label printer. The user will still have to hit the print button, but that might work. I have done this for printing to bar code printers and it works fine. Sometimes getting the margin and orientation correct is a little tricky, but that can be figured out.