take a snapshop of a qgraphicsview - qt

I am using Qt 4.5 and a qgraphicsscene/view to show video to the user.
I would like to provide a "take a snapshop" button and I am sure that there is a pretty straightforward way much simpler of everything I am thinking about.
How can I do this elegantly?
BTW, the code is here :
http://gitorious.org/handy

You can use the method QWidget::grab(). This method renders the given widget to a pixmap and returns that pixmap. Then you can do whatever you like with that, like saving to a file using QPixmap::save().

See QScreen::grabWindow() and QWidget::grab().
With grabWindow you can even capture a window outside of your application, e.g. the screenshot example program:
http://doc.qt.io/qt-5/qtwidgets-desktop-screenshot-example.html

Related

Sometimes willHideViewController from UISplitViewControllerDelegate is not called

I have a problem.
My app is a tab bar controller and its first view controller is a split view controller.
This seems to be not ok for Apple because documents say a split voew controller must be the root, so perhaps that is the reason of my problems.
The problem is that sometimes, willHideViewController from UISplitViewControllerDelegate is not called, so, for this reason, the upper/left button sometimes is not created, which is anoying.
I realised, to reproduce this error, try several times this:
-Landscape mode.
-Select a tab different to split view controller tap.
-Move the iPad to portrait in that tab.
-Go to the split view controller tab, and sometimes, willHideViewController is not called so you will not see the upper button. However if I rotate my iPad to landscape and after that to portrait, it's fixed.
I tried to force manually several rotations to work around this problem, but no luck.
I still have to try any split view controller clone class from github or similar.
Do you have idea what's going on or any work around?
Here I show you two examples working properly.
Thanks a lot for your help.
Where do you set the splitViewControllers delegate? Perhaps you can set the delegate when you load the tab. It sounds like you set it only when you have rotated once?
Otherwise, see this example
Here they have the TableViewController be the delegate of the splitviewcontroller. Perhaps you could do the same with the TabBarController?
I've concluded that this can't be done in any way that I consider 'sufficiently' legitimate. It's possible to get frustratingly close, but the issue of having the willShow..., willHide disseminated to the split view controllers under each tab remains.
The solution that seems most likely to work is,
https://github.com/grgcombs/IntelligentSplitViewController/blob/master/IntelligentSplitViewController.m
Though this code is undoubtedly clever, it's a bit too 'side door' for me. I suspect (but don't know) that just invoking the delegate methods is not sufficient. Surely the UISplitViewController itself needs to change it's internal state as well as calling the delegate methods? This method 'just' invokes the delegate methods when there's an orientation change.
So... I've decided on a more legitimate solution, which is to use the new method introduced in iOS 5.
- (BOOL) splitViewController:(UISplitViewController *)svc
shouldHideViewController:(UIViewController *)vc
inOrientation:(UIInterfaceOrientation)orientation
{
return NO;
}
So, the master menu is never hidden, and therefore the problem of managing the popover doesn't arise.
Of course, this is still not totally 'legit' as it still includes UISplitViewControllers that are not at the top level (the UITabViewController is at the top level, and the split views are on each tab)
Good luck with whichever solution you choose.
I'll update this reply when I've confirmed Apple will approve an app using this solution.

Does an mx:Window component have it's own applicationComplete?

I'm working on an app that, from the Main.mxml, opens one or many Window.mxml instances. When it's done I want all windows to be chromeless so the custom controls need to work.
In Main I've added applicationComplete="init();" so the init function gets ran, which contains clickhandlers, which makes the buttons work.
However, this way of running an init function doesn't seem to be valid for an mx:Window.
I can cheat by not using a clickhandler for the minimize and close buttons with a click="this.minimize();", but I don't know of a way like this to make the move work because it's a MOUSE_DOWN event.
Question 1:
Is there a way to have such an init function in an mx:Window?
Question 2:
What's a good way to make the buttons on the Window instances all work?
ps. If you think question 2 needs a separate post please let me know, they're so closely related and seemingly simple I couldn't decide.
Example code:
Main.mxml - http://pastebin.com/0HHVpkb8
Window.mxml - http://pastebin.com/g5TWuLYk
Window doesn't have an applicationComplete event, but it does have windowComplete event. Perhaps that would work for you. There is a list if Window events here.

iPad Split View App - DetailViewController Methods Never Called

I'm using a fresh iPad split-view template application in Xcode. I've added a sample data array and the data shows up just fine in the Popover view. However, when it's tapped, it doesn't call any methods from DetailViewController.m (setDetailItem in particular) like I'd expect it to.
Am I missing something here?
(I'm not sure what code I should post for this particular question, so I'll wait on you guys to ask for it.)
Thanks SO much in advance!
To troubleshoot this issue, you should check the method called didSelectRowAtIndexPath in the delegate for the table view. I remember that was called RootViewController by default and exists in the RootViewController.m file.
It should call the setDetailItem method. Check if it does so.
Posting the didSelectRowAtIndexPath method body here will help better.

windows.sendkeys equivalent in flex/adobe air

Is it possible to capture user typed inputs from keyboard and overwrite user entered text with pre-defined words in Flex/Adobe Air? I'm looking for a functionality in Adobe Air something like "typinator" does.
Yes, you can do this.
You can set up a KeyListener event on the stage, and it should catch any and all keystrokes. After that, you can send whatever command you like to whatever component you like. If you are looking to access programs outside of AIR, like windows.sendkeys can do, please look at this post for how that might work.
Specific components can stopPropagation(), but I don't think text input objects do this by default. See this doc for more on capture/bubble.

How to turn on line number tooltip while scrolling infragistics ultrawebgrid

I once saw this feature in action but I don't know how to turn it on. The grid can show a tooltip with the current row number (or row ID) while dragging the scrollbar. This helps you to stop the scroll in the right place. I'm assuming some property will turn this on, but I can't find it.
Maybe it is also dependent on the scroll mode?
UPDATE:
In the image below you can see an example of the tooltip I'm looking for. This is displayed while the scrollbar is being dragged (up or down). The number in the tooltip is the row number (you can't see it in this image, way to the left in the grid). This is the same grid that I am using now. Just from a very old build of our product. Somehow this tooltip was turned off. And no one knows how to turn it back on :(
I'm pretty sure this is a built in feature of the ultrawebgrid. Not something that required extra coding.
alt text http://img138.imageshack.us/img138/6337/croppercapture.jpg
Right! Now that we've established that you have version 6.3, I've hopefully got a solution for you. I don't have 6.3 myself, but I've got a slightly later one that I think didn't have Virtual Scrolling added as a feature yet.
So try this code:
webgrid.DisplayLayout.XmlLoadOnDemandType = XmlLoadOnDemandType.Virtual;
This should automatically put a tooltip on the grid as you scroll down. Have a look here for a running sample... (and remember to choose the virtual option)
Here's hoping!
Rob G
I don't know if there's a UltraWebGrid property to simply turn on the behavior you're looking for. I almost suspect you experienced this feature in another application, perhaps not even a web based one (sorry!). I do however, know exactly what you're talking about.
As a work-around, I would suggest allowing the user to input the destination row number, and to simply "jump" to it, using this technique.
If that doesn't satisfy you, it may be possible to achieve this behavior with JavaScript. You would need to use something like this technique to get the information you need, estimate (or actually detect, if possible) the row number, and the rest is up to the GUI. I would go with the work-around described above though :)
I'm typing this from memory here as I don't have it installed on this machine and I haven't seen that setting before, but how about adding something like this to the InitializeRow event:
foreach (UltraGridCell cell in e.Row.Cells)
{
if(cell.Column.Key == "Topic") //from your grid above
cell.Title = cell.Row.Index;
}
The row object itself does not have a "Title" property from memory, but the cell does.
See if that works...
Regards,
Rob G
OK - I think I've found your illusive setting:
You can set the TipStyleScroll on the Override to Show on the Grid (this may be version dependant).
You can determine which field is displayed as the tooltip by using the ScrollTipField property of the band.
I did it like so:
myGrid.DisplayLayout.Override.TipStyleScroll = TipStyle.Show;
myTopBand.ScrollTipField = "Id";
...and it works like a charm!
If it's a really long list, sometimes setting the ScrollStyle to Deferred helps:
myGrid.DisplayLayout.ScrollStyle = ScrollStyle.Deferred;
Hope that helps...
Rob G
Once again - not sure which version you have, so to be safe here's somthing you can try from 2009 version:
myGrid.Behaviors.VirtualScrolling.Enabled = true;
myGrid.Behaviors.VirtualScrolling.TooltipVisibility = DefaultableBoolean.True;
If your scrolling mode is Deferred instead of Virtual, then the tooltip is normally enabled by default.
You can find full details about this feature here
Hope that helps,
Rob G

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