Sorry if the questions is asked/answered already, or if my title is poorly worded.
I am currently writing an iPhone app, and have considered a useful tool for debugging. I would like to write a method that just prints variables and other info that I want. That part is simple and all, but I want this to be called by keystroke.
For now I have been just adding NSLog()'s to viewDidLoad or to other button methods to check if my variables are being set properly, but it's becoming tedious and the code is long so I tend to forget about some and spend a lot of time looking for them haha.
I just want one method that I can go to to write my NSLog()'s, and have that method call whenever I hit 'space' or something of that sort.
Can this be done?
Thanks!
-SF
It's pretty hard to do, you need to have a hidden text field that you keep in focus, hide the software keyboard for it, then listen on its delegate methods for changing text.
An alternative would trigger the code inside applicationWillResignActive: which gets called on application hiding, notification center showing, or double home press.
Related
I'm still pretty new to scripting in Unity3D, and I'm following along with a tutorial that uses GUI.Button() to draw a button on the screen.
I am intrigued by how this function works. Looking through the documentation, the proper use of GUI.Button is to invoke the function in an if statement and put the code to be called when the button is pushed within the if statement's block.
What I want to know is, how does Unity3D "magically" delay the code in the if statement until after the button is clicked? If it was being passed in as a callback function or something, then I could understand what was going on. Perhaps Unity is using continuations under the hood to delay the execution of the code, but then I feel like it would cause code after the if statement to be executed multiple times. I just like to understand how my code is working, and this particular function continues to remain "magical" to me.
I don't know if it's the right term, but I usually refer to such system as immediate mode GUI.
how does Unity3D "magically" delay the code in the if statement until
after the button is clicked?
GUI.Button simply returns true if a click event happened inside the button bounds during last frame. Basically calling that function you are polling: every frame for every button asking the engine if an event which regards that button (screen area) is happened.
If it was being passed in as a callback function or something, then I
could understand what was going on
You are probably used to an MVC like pattern, where you pass a controller delegate that's called when an UI event is raised from the view. This is something really different.
Perhaps Unity is using continuations under the hood to delay the
execution of the code, but then I feel like it would cause code after
the if statement to be executed multiple times.
No. The function simply returns immediately and return true only if an event happened. If returns false the code after the if won't be executed at all.
Side notes:
That kind of system is hard to maintain, especially for complex structured GUI.
It has really serious performance implications (memory allocation, 1 drawcall for UI element)
Unless you are writing an editor extension or custom inspector code, I'd stay away from it. If you want to build a menu implement your own system or use an external plugin (there are several good ones NGUI, EZGUI,..).
Unity has already announced a new integrated UI System, it should be released soon.
Good question. The unity3d gui goes through several event phases, or in the documentation
Events correspond to user input (key presses, mouse actions), or are UnityGUI layout or rendering events.
For each event OnGUI is called in the scripts; so OnGUI is potentially called multiple times per frame. Event.current corresponds to "current" event inside OnGUI call."
In OnGUI you can find out which event is currently happening with >Event.current
The following events are processed link:
Types of UnityGUI input and processing events.
-MouseDown
-MouseUp,mouse button was released
-MouseMove,Mouse was moved (editor views only)
-MouseDrag,Mouse was dragged
-KeyDown, A keyboard key was pressed
-KeyUp A keyboard key was released.
-ScrollWheel The scroll wheel was moved.
-Repaint A repaint event. One is sent every frame.
-Layout A layout event.
-DragUpdated Editor only: drag & drop operation updated.
-DragPerform Editor only: drag & drop operation performed.
-DragExited Editor only: drag & drop operation exited.
-Ignore Event should be ignored.
-Used Already processed event.
-ValidateCommand Validates a special command (e.g. copy & paste).
-ExecuteCommand Execute a special command (eg. copy & paste).
-ContextClick User has right-clicked (or control-clicked on the mac).
Unity GUI has much improved lately and is quite usefull if you want to handle things programmatically. If you want to handle things visually, i recommend looking at the plugins heisenbug refers to.
If you decide to use unity gui, i recommend using only one object with ongui, and let this object handle all your gui.
I am working on a large (>30k lines) event-driven app. I have a sequence of inputs that produces a bug. What I want to do is to break as soon as the final input enters my code.
Is there a general way to do that?
I understand that for any specific sequence of inputs, I can find out where that last input is going to enter my code, then set a breakpoint there. What I would like to do is take out the step of "find out where that last input enters my code." In other words, I am running the app in the simulator, and I want to set a flag somewhere that says "break the next time you are going to enter non-system Objective C code." Then I send the event that causes the problem.
I understand what you are asking, but have you tried using an Exception Breakpoint? This will basically act like an auto-inserted breakpoint on the piece of code that throws the exception. If that doesn't work for you, try a symbolic breakpoint
If you want to intercept UI events, you can try subclassing UIWindow and overriding its sendEvent: method, then setting this class as the class of the UIWindow object in your main XIB file. sendEvent: will be called each time the user generates a touch event. Unfortunately, at this point you cannot yet know which UI object will finally consume the event (read: which event handler code will be ultimately called) since that depends on the actual state of the responder chain. But anyway, you can use this method to inject events into the system.
My iPhone app has a tabBar at the bottom.
The 5th tab is rarely used... but pretty memory-intensive... so I want to make it UNLOAD each time it is exited (by the user clicking on a different tab).
But how?
I thought I just needed to call "[self viewDidUnload]" but that doesn't seem to do it.
Where is the "forceThisViewToUnload" and where should I put it?
i think you can call didReceiveMemoryWarning but its bit hacky way :)
just make sure it's not referenced anywhere.
so remomve it from the view-stack, and if you own it, send it a release message.
I have an app that uses UiWebViews, and I need to not show the keyboard for a text field within such a view. I provide my own buttons that insert the limited sorts of text the field allows, but I also need to allow pasting (I will filter what gets pasted) and adjusting the cursor position. Any way to do this?
It looks like this can't be done, I've researched it further and that's pretty clear. I don't want to accept a wrong answer, so I figured I'd just answer this myself and say: can't be done.
if you just want the textField do normal things except the showing keyboard action, you could subclass UITextField and overwrite the touchesBegan/Moved/Ended, just call super touchesBegan/Moved/Ended and add additional code which would hide the keyboard, if you have a reference to the keyboard ( you may figure it out urself how-to ), call the method : [keyboard resignFirstResponder], you may try to Category the UITextField class so you would have the reference to the keyboard ( if it's private ) - but not recommended because categorying may break our project design, but if you just need it for the only purpose, give it a try. Hope it helps.
The iPad virtual keyboard will disappear in one of (at least) these 3 circumstances:
If the control (say, a UITextField) programmatically resigns first responder.
If the user taps the "dismiss keyboard" button in the lower right.
If the user connects to the USB/keyboard dock peripheral.
In all cases, I get the UIKeyboardWillHideNotification.
The problem is that the first two cases are generally equivalent-- in other words, the user is done editing the text field. But in the third case, the text field is still being edited, just from another input source.
The problem is detecting the difference between cases 2 and 3. All I get in both cases is UIKeyboardWillHideNotification. In case 2, I generally want to also lock the edit control and commit the value. In case 3, I generally want to do nothing and allow editing to continue.
But how can I tell the difference?
Apple's Pages app seems to be able to distinguish this on document-title renaming.
I would look at the UIKeyboardBoundsUserInfoKey passed with the notification. The physical keyboard probably has empty bounds.
It sounds like you're just trying to figure out when a user is done editing. You could listen for the UITextFieldTextDidEndEditingNotification notification for cases 1 and 2.
A much simpler solution would be couldn't you just check against the editing property of UITextField to determine if it's still supposed to be editing or not? I don't have a physical keyboard, so I have no way to test this. I'm just guessing.
Here's a link to the documentation on that property: http://developer.apple.com/iphone/library/documentation/UIKit/Reference/UITextField_Class/Reference/UITextField.html#//apple_ref/occ/instp/UITextField/editing
I'm very curious to know if this works or not... :)