For some reason, my QTableView seems to never emit a single signal. At first I tried connecting to any slot programmatically, but then I realized even through the Signal/Slot Editor from the GUI I could not make something happen, no matter which signal or slot I chose.
One detail that I noticed after a lot of research was that the Qt Documentation specifies that "The signal is only emitted when the index is valid.", so I understand this may be a problem with my models.
However, I still have no idea what might be the issue, or how I can fix it. Displaying the cells work perfectly fine on all models I have, but none of them seem to provide the correct signaling behavior, so I can't really detect the problematic code to post it.
It might be relevant to note, I tried disabling editing, and I'm testing this on Mac OS X Lion 10.7.5.
I appreciate any help. This is my first question here, although I've long benefited from those asked by others. So, yes, I've thoroughly searched for solutions.
Okay, I finally figured it out. After I realized Qt Creator was never updating the executable, no matter which code I changed, it was simply a matter of manually cleaning the build directory. Using the GUI options to do so (either rebuild or clean+build) hadn't had any effect. I guess it's because I had renamed the project, but didn't update the build directory or something. I had changed (improved) so much code since then that I would never have guessed there was an issue as everything was working fine, until I decided to add some more functionality.
As I had expected, this is kind of underwhelming for my first published issue, but I don't think it deserves negative points. The reason I didn't post some self-contained code is because I had no idea which code was causing the issue; I suppose I was just expecting someone with more experience to point me in the right direction. In the end, it wasn't even an issue with my code, it was with Qt Creator, so I really couldn't have been clearer.
I'll keep this as it might be useful for other people, so
tl;dr Qt Creator was silently failing to recompile the code, and the solution was to manually remove the old binaries.
Related
I have a Qwidget inside of which, I have multiple children in the form of QmlApplicationViewer objects, each pointing to a different qml file.
Problem is, when I use mouse, all the qml files take events, but when I try to use the touch screen, only some of them does.
Can someone give a direction as to where the problem might be ? Will appreciate and sort of possible causes which might cause this issue.
Platform : Ubuntu 12.04 - Qt 4.8 - 32 bit
There really is not enough information here to even begin to answer this question. The most obvious answer that comes to mind is some of your qml files are not correctly defining the TouchArea within the qml. If you want more help you need to post code.
I tried using the EG-Touch touch drivers for my platform, which are supposed to have some issues on 12.04(as per some forums). I reverted back to Ubuntu 11.04 and used the e-Galax touch drivers instead, and things are working fine now.
P.S. : If someone finds a working driver for 12.04 or any other work around, please update. I will accept a better answer. Closing this for now.
I work on a QML-based UI where some elements are implemented in C++ plugin.
Everything worked fine so far in WinXP 32bit and Win7 32bit. Last week I got new laptop with Win7 64bit on board, and my code does not work properly there. Several seconds after start-up application behaves nicely, but then suddenly view stops redrawing. Neither QML-initiated events, nor plug-in calls to QDeclarativeItem::update() work. In plugin I am 100% sure that update() is called, but then I know, that calls to overriden QGraphicsItem::paint() do not happen as expected. The view only gets redrawn when window gets/looses focus.
I have quickly verified my application on a desktop running Win7 and had no problems there. This leads my to suspect that there is something different about how Windows 7 requests window update on my laptop and on other computers, however I am unable to figure out the difference right now.
Can someone help me out to understand what is going on there?
Thanks in advance!
p.s. Unfortunately my primitive mock-ups did not exhibit same problem, and I cannot share production code. If I will find a way to reproduce this problem in a prototype before actual solution will be found, I will post it.
Add a qapp->processEvents() after your update() call, it will probably work.
(I've come across a similar problem, but it happens on all platforms, hopefully this solution will work for you)
The answer to my question lays in something I overlooked initially in my problem description. The QDeclarativeItem::update() function was called from a non-Qt thread (certainly not GUI thread). I re-routed the call through Qt event loop and the problem was gone.
I was on Qt 4.7/4.8 at that time and cannot say how it'd behave in Qt 5.x.
My breakpoints have stopped working properly in the latest XCode 4 release. With no change to the project settings, the breakpoints no longer break at the line they are set.
For instance, in one function I can set a breakpoint anywhere within it's body, but the code will always break at the last line of the function.
In another instance, I can set a breakpoint anywhere in one function and the code will break at a line in the middle of a different function in the same file! Tracing through after the break shows that it did break in the wrong place and it's not just a file / debugger sync issue.
I have no idea why this has started. It did however seem to start on new breakpoints while old ones worked. Any new breakpoints I add break in the wrong place. And recently, some files now don't even break at all! I can only assume the breakpoint is so wrong it's moved into code that's not called. I have done numerous internet searches and forum searches for this problem, and although I have found people with similar issues, there was either no solution or the solution listed (rebooting device, swapping debug output, turning off optimization etc.) haven't worked for me.
It is worth mentioninig I'm mostly coding in C++ using .mm files. For the past year of development in XCode 3, and for the last few months in XCode 4 things have been fine! I have debug set up correctly. No optimization on a debug run, no dead code stripping and I'm using the LLVM compiler 2.0 with DWARD with dSYM debug file. However, changing these values makes no difference.
Please help, it's driving me mad!!
An update to this. It's started happening again on a brand new machine with a fresh Lion and xcode install. The whole editor is out of whack. Example below of the errors appearing on the wrong lines.
From what I've read all around, Xcode tend to get confused with breakpoints and the way to get rid of the out-of-sync problem is to clean the "Derived Data"; two ways of cleaning it so far I've found (instructions are valid for Xcode 4.x) :
a) go in the organiser, under the Projects, choose your project and hit that delete on the Derived Data
or
b) go in the Product menu, hold the ALT button on the keyboard and observe that the menu are changing... so the clean transform to "Clean Build Folder..."
With-in "Build Settings" under the project target change the "Optimization Level" for "Debug" to "None".
I found that this fixed the issue for me.
I have fixed this, although I haven't found the root cause.
I removed the references from the project for the files that were not working with breakpoints. I then did a full clean and went into the folders and deleted any build and temporary data. I then opened the project bundle and deleted all data except for the project file itself. I then compiled so it threw up errors due to the missing files. I then put the files back in the project.
Now, the exact same files work fine with breakpoints!
No idea why but happy it's fixed.
Have you cleaned your targets? Shift-Cmd-K.
This started happening to me after I upgraded to XCode 4. I just deleted all breakpoints, did a clean, then re-added my breakpoints. Seems to work OK now.
I have figured out why this happens now. As mentioned in one of the replies you can fix it by deleting the derived data. This will always fix the problem. The editor for some reason loses it's relationship between the source code and the markup of the code it uses to cross reference breakpoints and errors etc. Deleting the derived data forces it to recreate this.
I believe that this only happens with files using C or C++ code. Apple seem to ignore C++ developers on iOS. I know a lot of professional game developers and every single one uses C++ to write games. Apple's lack of support is annoying.
I've got this very odd bug that appears to be a quirk in Visual Studio 2010: Sometimes, when moving the cursor into double quotes of a CSS style="" attribute the cursor refuses to move. I can't type anything, and the keys that respond are the UP/DOWN cursor keys and the DEL key (but not BACKSPACE).
Typing does nothing, but pushing LEFT/RIGHT on the cursor keys produces the following error:
The operation could not be completed
I've got no idea what's causing this, but I would hazard a guess that Intellisense is getting very confused and bugging out.
At the moment, whenever this happens, I have to write any CSS outsite of the double quotes of the style attribute and then place the cursor where I want the CSS to appear (using the mouse) and press CTRL-V to paste it in. Very annoying :(
There must be a way of fixing this problem...?
Hopefully someone has an answer!
Just encountered the issue in VS 2012, in editing C#.
I noticed that the problem had occurred soon after the trial period of Resharper has ended and i inserted a valid license number. It also happened in only some of the source files.
The solution: Tools->Options->Resharper: Suspend.
Try typing - should work now.
Then: Tools->Options->Resharper: Resume.
Problem gone.
I have encountered this using Visual Studio 2013 and Resharper 8.2.1. None of the solutions provided in this thread worked (even suspending and resuming Resharper)
After contacting JetBrains support, it turned out to be a caching issue.
Deleting all the files from the following directory solved the issue, as Resharper re-creates new caches:
C:\Users\[Username]\AppData\Local\JetBrains\ReSharper\v8.2\SolutionCaches\[Project_reference]
I have some odd issues with the editor occasionally, a workaround for me is:
Ctrl-Tab (x2) to another code file and back to the same code (or alt tab to another app and back, one of these two... can't replicate issue to be sure)
An ultimate solution might be a re-install.
Microsoft have had variations on this problem reported quite a few times via their support portal. Here is one post and if you scroll down you will see a comment with a bunch of other reports all detailing similar(ish) problems.
Microsoft doesn't seem to be able to reproduce the problem but are "duping all the similar keyboard locking problems to a central bug, so that we can think a way to log the events if necessary". Which seems to be a generic response to a lot of these posts. Some people reported that it was simply becuase another window/pane/tab was in focus but I can see the OP obviously did not have this specific problem. Looks to me like one of those random unresolvable bugs. Hope I never get it! There's also numerous forum posts around the Internet, where users stated that removing certain 3rd party plugins has solved this issue.
I just spotted this particular post which has a possibly useful comment on it for you (which also link to this SO post. As I do not have the bug I cannot test its validity for you. The main point of it seems to be something about the keyboard layout switching.
I'm sorry for putting all this into an answer when technically it is not an answer and just a mass of research, but there was no way this was gonna fit into a comment. And also sorry for pretty much link spamming, but again there was no way I could extract everything that they said into this post. I hope there is something useful in there for you :)
EDIT: You should probably check the top rated answer below as this seems to solve a number of peoples issues, although I never had the Resharper plugin and still occasionally experienced this, but now I'm on VS2013 and have not had this problem re-occur, so maybe they fixed it...
Empty the solution cache folder
C:\Users\{UserName}\AppData\Local\JetBrains\ReSharper\v8.2\SolutionCaches\
This was suggested by JetBrains support when I contacted them.
Permanently fixing... Not too sure however I found that pressing pressing Ctrl+Shift+Caps Lock+Tab all at once seems to get rid of this and enables the mouse and keyboard again. I know this isn't the best of solutions but it works.
I have the same problem several times a day. I didn't notice it until I installed the web essentials extension. I just uninstalled it and will see what happens. I have tried reinstalling visual studio with no joy (but again, I didn't notice the problem until after I had already installed the various extensions).
Sometimes, closing and re-opening the specific code window I'm working in fixes it. If that fails, sometimes I close all windows and reopen just the one I was actively editing. If all of that fails it usually requires a complete restart of visual studio.
I find it funny that MSFT says that they can't duplicate the problem. Scott Guthrie experienced it first hand during his MVC4 beta demo here at about 28 minutes in.
UPDATE: So far, as of 4-5-2012 9:33am Central Time, the problem hasn't recurred since uninstalling Web Essentials. This is the longest I've gone without this bug occurring. If I make it through the next 24 hours, I'll be confident in blaming Web Essentials.
UPDATE: 4-6-2012 10:05am Central Time: Well, apparently it wasn't Web Essentials. It happened to me again this morning editing the contents of a block in my _Layout.vbhtml file. Closing the tab and reopening it fixed it.
I frequently encounter this editor freeze, not just on CSS quotes but any file arbitrarily. I have a dual monitor setp and I have the doucment windows one one monitor and all tool windows on the next one. Sometimes, certain tool windows would freeze too (i.e. not respond to click).
Previously, I used to shutdown/restart IDE; but serendipitously, I discovered that switching to/from Full Screen mode, restores sanity. So now everytme I see a freeze, mode switching comes to rescue.
Not sure if this will solve your issue, but worth a shot.
Rant: In general, I find this new WPF based product very falky and unstable than its predeccessors.
I have the same problem on IDE, some times the Return key is not working at all...
My solution is: CLEAN the project/solution.
BTW: CLEANing resolve also other unexpected behaviours after amendements on CSS or HTML.
I tried every other workaround here but nothing seemed to work, and the issue was only present in one solution but not another.
Disabling Resharper fixed it temporarily but it came back after re-enabling it which wasn't a viable long-term solution.
What worked for me was disabling all Resharper Extensions (Under Resharper -> Extension Manager). I was able to type again even after re-enabling all of them, so I'm unsure which extension specifically caused the issue, but that's another route to try for people who still have this issue.
I never had the problem until I installed plugins/extensions. Curious to know if anyone has had this problem without having any plugins/extensions installed. I don't know if they are the actual cause but since benefits of the plugins outweigh the occasional lockup, I have left them installed. BTW, I use the "closing/reopening of the window with the lockup" technique.
Using a source control (GIT, AKSVN)? If so, disable it, restart VS then enable it and open the solution again.
I started looking at Silverlight.FX by Nikhil Kothari to replace Prism/Unity with our Silverlight 3 project.
So far I like the code layout and structure. It looks well thought out.
But I can't get a lot of the samples working due to a System.Reflection.AmbiguousMatchException. Anyone else seeing this? Should I not be using this framework with Silverlight 3?
I'm using the framework with Silverlight 3 without issue. Referencing the pre-built dlls works for my project but I haven't tried compiling the source myself. Have you tried using the dlls?
After some heavy debugging this error is coming because some of the class names that Nikhil used I believe are now in Silverlight 3 beta 1. In the TaskList example the ListView's DataTemplate has a HoverEffect
<fxeffects:ColorFill FillColor="#406795D1" Duration="0:0:0.25"/>
This is the one causing all the problems I saw. Removing this took away the AmbiguousMatchException.
Well, that is avoiding the problem, not solving it. It looks like the problem is much deeper, and anything that uses classes that derive from the Effect base class is broken. That makes the use of Silverlight FX pretty boring.
I have tried to use the lib in the past, and had issues with it. While Nikhil Kothari is amazing in the things he has worked on, and his technical abilities, I find that he is not so responsive to solving issues (BTW, someone already posted this problem on his blog, without his response). I do not want this to sound like a knock on Nikhil, it is just something you need to consider when using open source for real-world projects.
I sure hope someone can figure out what the deal is with those classes, I have spent many hours debugging, without solving the issue.
I tried the Amazon Store sample and the TaskList sample using the latest version of the library (3.1 built against SL3), and samples seem to work fine, including the ColorFill effect.
I did rename the Effect class to AnimationEffect which you'd need to avoid the ambiguous API compile error you'd see if you tried to recompile the sources... but precompiled binaries would have been fine. Not sure I see why you'd get a runtime reflection issue however.
Sorry, I know it can be frustrating to not see a response/fix immediately, but theres just too many things going on esp. before a release. My hope is having the source around at least enables you to debug into/break into so at least one is not completely blocked. Yes, I realize its suboptimal, but at the same time it is the reality, as Noam pointed out... :-(