Reset Spinning Progress Indicator - objective-c

A simple question here for many of you. I have an indeterminate NSProgressIndicator which I start and stop many times in my code. Does it reset when you call restart it, or do you have to manually do that? If you do have to do it manually, how would I go about doing it?
Many thanks,
jrtc27

There's no concept of resetting an indeterminate spinner... It's indeterminate. Which aspect of the spinner do you want to reset???

Related

LabVIEW disabled Slider is enabled

I have a large problem disabling a slider in LabVIEW. Here is my minimal example:
I have a simple Slider, which is disabled and grayed out if the value is higher than 5. Otherwise the Slider is enabled.
If I drag the slider higher than 5, the Slider gets grayed out. But I am still able to move the slider around and change the value. Only after I dropped the Slider, the Slider is disabled to use.
In my opinion, this is a large bug of LabVIEW. Is there any way to disable the Slider correct during drag?
Thank you for your answers!
Additional information:
Like I said, the snippet is only my minimal example to show the basic problem. In my application the following is happening:
I have s statemachine with a state that enables the Slider and a state that disables my Slider. The state can change every moment, so it´s possible, the user is using the slider at the moment of statechange --> moment of disabling. At this moment the slider should be disabled (it only gets grayed out) directly ... not after releasing it. So limiting the maximum is not real target. I want to prohibit all slider actions for a user.
"Link to question asked on NI Discussion Forums"
As suggested by Alexander_Sobolev on the NI forum (but I promise I thought of it independently!), you can end the slider drag by generating a mouse up event. On Windows you can do this with Simulate Mouse.vi from the NI site, which calls mouse_event from user32.dll:
Note that one of that VI's mouse position inputs is erroneously marked as 'Required'; I fixed that before creating the code above.
I do think this is a UI technique that should only be used if it's really justified by the requirements of the system, and if the users will understand why it works like that; otherwise it could make for a frustrating and annoying user experience. I don't think it's a bug, rather a design decision, because the opposite behaviour could be equally undesired in other circumstances.
I guess you could set the slider value to 5 inside the case structure, alongside the greying out, by adding another property node. This should keep the slider stuck at 5, if the user tries to pull it above.
This appears to be strange behavior as the Value Change event is triggered while the mouse button is held down even when the control is Disabled & Grayed Out.
One way I can think of to limit the value would be to update the Data Entry Limits Maximum property for this control and setting the Response to Value Outside Limits for Maximum to be Coerce.

Optimizing QListView update

I'm writing a logging application which is using a QListView with custom QStandardItems to display the log data. I have implemented filters in the app that will color the matching rows differently and when changing a filter I have to manipulate every item in the list, which after a while gets very slow. I'm not sure what's causing this yet, but I wonder if it could be that it repaints after every item change. If that is the case, could I somehow tell QT to not repaint until I'm done manipulating all the items?
Thanks for any help!
For helping others, I could add that I fixed this by implementing my own view that handles the paint event itself and only paints the rows currently visible on screen. This makes it extremely fast and no internal QT view seem to be able to do something similar.

Text Editing with NSCollectionView

I've been banging my head against the wall (Cocoa) for about a week with this problem and wanted to get some advice if possible.
I'm trying to provide a list of NSTextFields to the user representing a list of features – letting them add additional textfields using an 'Add' button. This is part of a bigger form and the user should just be able to tab through the whole form (including the list)
I implemented the above using an NSCollectionView which pretty much worked except tabbing seemed to intermittently stop working in the NSCollectionView for reasons I can not figure out. You'll be hitting tab, cycling through normally when all of a sudden the collection view is skipped altogether, or sometimes if you're in a specific text field in the collection view hitting tab will just highlight the text but will never jump to the next field without mouse clicking outside the collection view. I was wondering if anyone had experienced this before... or has any advice for debugging something like this? I've attempted logging what the nextResponder is every time a control becomes the responder and there doesn't seem to be any pattern explaining why tabbing just stops working suddenly and then begins again.
There are 3 TabViews with a collection view in each. I have been wondering if that may be causing an issue?
Thanks for any help anyone can provide.
OK, after all this time I may have solved this (Tentatively anyway... I haven't seen any problems on numerous run-throughs and it usually occurs at least once every time before)
Turning on Auto Recalculates View Loop on the Main Window seems to have resolved whatever was happening. I have to admit I don't completely understand why, except that maybe because of the tab views and collections views the key loop needs to be recalculated to keep everything in sync. I'm thinking I need to do more research into exactly how the key loops work...

how to make a UIScrollView track something?

i want my app to be able to track a person when he moves 2 dimensionally upwards. I already have a vertical scroll view, and it works, but when i press a button i want it to track a little stick figure as he walks vertically, how can i control this? i thought of setting the scrollview.contentoffset to a certain position, but it just changes it one time when i want it to change it fluidly. i suppose i could make a timer that updates the contentOffSet every like .001 seconds or something, but i thought there maybe a better way.
Also, while i was searching the UIScrollView's methods, one of them was an isTracking method, which is a boolean, and I'm assuming it returns yes if the scrollview is tracking something, so given that i assume there is a feature in scrollview so that you can track things. Also, if to track things you have to use some other framework thing that would be helpful to know too
THANKYOU FOR ANY HELP!
The property tracking tells if the scroll view is currently tracking the user's movement. So that definitely won't help you out. (See David H's post for a better explanation for what the property indicates.)
However, you could use setContentOffset:animated: and set animated to YES. That results in a smooth transition to the new content offset.
Instead of calculating a reasonable content offset you might find it easier to specify an area that contains the stick figure. If so use scrollRectToVisible:animated:. Obviously animated should be set to YES.
1) don't use contentOffset = x;, use "- (void)setContentOffset:(CGPoint)contentOffset animated:(BOOL)animated". Experiment how often you need to send this message, but I'm guessing you can do it no more than 10 times a second and get nice results.
2) isTracking means the user has their finger on the scrollView but has not started dragging it. By testing "isTracking" and "isDragging" you can determine if the user is fiddling with your scrollView or not.

Applescript and Cocoa window positions

I know that using Applescript I can change the size and position of any application's window, but is it possible to get a notification whenever a window has changed it size or position?
If thats not possible, then what I was thinking was making a thread in the background, and constantly check the positions of windows and see if they have changed, if they did then they moved.
But that would take a lot of cpu resources to constantly compare the positions/sizes of window. So is it possible? If not , is there a better way? Thanks!
I'm not sure but i think there isn't a notification for that.
I would listen for mouse events. When the mouse was dragged you can check the windoews for changes. Hope that helpa.