I'm writing a dynamic wizard application using cocoa/objective c on osx 10.6. The application sequences through a series of views gathering user input along the way. Each view that is displayed is provided by a loadable bundle. When the app starts up, a set of bundles are loaded and as the controller sequences through them, it asks each bundle for its view to display. I use the following to animate the transition between views
[[myContentView animator] replaceSubview:[oldView retain] with:newView];
This works fine most of the time. Every once in a while, a view is displayed and some of the subviews are not displayed. It may be a static text field, a checkbox, or even the entire set of subviews. If, for example, a checkbox is not displayed, I can still click where it should be and it then gets displayed.
I thought it might have something to do with the animation so I tried it like this
[myContentView replaceSubview:[oldView retain] with:newView];
with the same result. Any ideas on what's going on here? Thanks for any assistance.
I don't think is good to use this [oldView retain]. This retain do not make sense. The function replaceSubview will retain it if it is necessary.
Because it work "most of the time" I think it is a memory problem. You try to use a released thing. Test without it and see what happens.
I got the same problem, replaceSubview didn't work.
Finally i found something wrong with my code. so here are the rules :
Both subviews should be in MyContentview's subviews array.
OldView should be the topmost subview on MyContentView or replacesubview will not take place.
here is a simple function to perform replacesubview
- (void) replaceSubView:(NSView *)parentView:(NSView *)oldView:(NSView *)newView {
//Make sure every input pointer is not nill and oldView != newView
if (parentView && oldView && newView && oldView!=newView) {
//if newview is not present in parentview's subview array
//then add it to parentview's subview
if ([[parentView subviews] indexOfObject:newView] == NSNotFound) {
[parentView addSubview:newView];
}
//Note : Sometimes you should make sure that the oldview is the top
//subview in parentview. If not then the view won't change.
//you should change oldview with the top most view on parentview
//replace sub view here
[parentView replaceSubview:oldView with:newView];
}
}
Related
I'm using the iCarousel library to show a coverflow-like UI. Animating the iCarousel subviews directly tends to blow up, so I create a wrapper for my animation and stick a subview inside of it which looks like the tapped cover. Then I hide the actual iCarousel view, and animate the fake cover on top of it.
I'm using UIView's transitionWithView:duration:options:animations:completion: method, but I'm running into some trouble. When animating another view onscreen for the first time, the view appears without any animation. When animating out, the view correctly flips and hides.
My view hierarchy is as follows:
main view, loaded from a nib
wrapper view
view to transition from
view to transition to
The view I'm transitioning to is a UINavigationController's view which contains a UITableViewController subclass. Instead of the initial animation, the UINavigationController appears and then the view grows upward a little, as if it's taking over the space otherwise occupied by a status bar.
Any idea why the table view might be animating like this? (I suspect containment APIs and/or wantsFullscreen, although I'm not explicitly using them. I simply install the views into the wrapper via addSubview:.)
Here's my "flip in" code, that animates every time but the first:
- (void) flipInWithCompletion:(MBTransitionCompletion)completion {
BOOL displayingPrimary = [self isDisplayingPrimaryView];
UIView *frontView = [self frontView];
UIView *backView = [self backView];
UIView *wrapperView = [self wrapperView];
[wrapperView addSubview:frontView];
[UIView transitionWithView:wrapperView
duration:0.8
options:UIViewAnimationOptionTransitionFlipFromRight
animations:^{
[wrapperView addSubview:backView];
[frontView removeFromSuperview];
}
completion:^(BOOL finished) {
[self setIsDisplayingPrimaryView:!displayingPrimary];
if (completion) {
completion();
}
}
];
}
What might cause the table view to grow instead of allowing the wrapper to flip?
Edit:
I've made a video demoing the exact problem.
Sounds like the view isn't properly loaded before it starts to animate in. I think I remember having a similar problem before. Try adding it to your view first, then remove it, and try to animate it into place to see if that fixes it.
That's not really a solution though, but it should give you a clue as to what might be wrong.
I'm using iCarousel to display editable question cards. The cards contain a UITextView for entering the question (or already contain text as you swipe through filled cards). However, when the carousel is presented and scrolled, sometimes text views appear empty.
This is due to a UITextView optimization of not drawing text offscreen. But text views in a UITableView will not suffer from this.
As many know, using setNeedsDisplay will NOT work due to the optimization, so it doesn't redraw the text.
I currently change the text view's frame by adding and then removing 1px. This forces a redraw. However, I can only do this when the item changes. iCarousel does not have a willDisplayCell delegate method. (Nick, can you add one easily? The code baffles me)
Because iCarousel is preloading many views for smoothness (which is necessary, setting iCarouselOptionVisibleItems doesn't fix anything) there doesn't seem to be anything else I can do but know when the view is about to come on screen. Suggestions?
- (UIView *)carousel:(iCarousel *)carousel viewForItemAtIndex:(NSUInteger)index reusingView:(UIView *)view
{
MIQuestionView *questionView = (MIQuestionView *)view;
if (questionView == nil)
{
MIQuestionType type = [self.testSection.questionType integerValue];
questionView = [[MIQuestionView alloc] initWithFrame:CGRectNull questionType:type];
questionView.delegate = self;
}
questionView.question = [self.testSection.questions objectAtIndex:index];
return questionView;
}
The text view is embedded in the MIQuestionView. The text is set in the question setter. There's no way for me to know when it's coming onto the screen. To be clear, I don't want to resize. The text is not drawn offscreen and appear blank when coming on-screen.
Sorry, I didn't look for ambiguous code above:
- (id)initWithFrame:(CGRect)frame questionType:(MIQuestionType)type
{
if (CGRectEqualToRect(frame, CGRectNull))
frame = CGRectMake(0, 0, 650, 244);
self = [super initWithFrame:frame];
...
It's an odd bug. I'm not sure if it's an issue with iCarousel or just a quirk of iOS that you need to deal with when dynamically adding and removing UITextViews from the view hierarchy.
I have a solution that's maybe a bit cleaner than the ones you've found though; Just add this to your MICardView:
- (void)didMoveToSuperview
{
if (self.superview)
{
_textView.frame = self.bounds;
}
}
This basically forces the textView to re-layout every time the cardView is recycled, and it avoids you having to do anything special in your view controller to work around the issue.
I have no idea why this code isn't working, but hopefully the fix is simple, I hope someone can help.
I have 2 functions, enterFullScreen and exitFullScreen.
In the enterFullScreen method, I set an NSView's frame to the Window's frame, which has a full-screen effect, this is what I want. Within this method I store the old frames so that in the exitFullScreen method I can set them back, but this isn't working. It has no effect whatsoever. The code is as follows:
NSView oldView, oldViewContainer;
- (void) enterFullScreen:(NSView*)newView
{
// Store original views
oldView = newView;
oldViewContainer = _newViewContainer;
// Set new views to fit window
[_newViewContainer setFrame:[_window.contentView frame]];
[newView setFrame:[_window.contentView frame]];
}
- (void) exitFullScreen:(NSView*)newView
{
// Restore old views
[_newViewContainer setFrame:[oldViewContainer frame]];
[newView setFrame:[oldView frame]];
}
The enter fullscreen method works exactly as expected, but for some reason I can't set the 2 Views back to their original size/location.
I don't know if it's because I can't just store the whole view, or if the origin is causing problems?
I've tried every combination, if somebody could help I'd be really grateful.
Thanks in advance.
You don't want to set oldView to newView, that makes them the same view, so when you resize newView to full screen, oldView's frame also is set to full screen. You want to save the old frame, not the view, so:
oldFrame = newView.frame; (to store the original frame)
then when you resize smaller,
[newView setFrame:oldFrame];
I am trying to add a UIButton to the view of a MPMoviePlayerController along with the standard controls. The button appears over the video and works as expected receiving touch events, but I would like to have it fade in and out with the standard controls in response to user touches.
I know I could accomplish this by rolling my own custom player controls, but it seems silly since I am just trying to add one button.
EDIT
If you recursively traverse the view hierarchy of the MPMoviePlayerController's view eventually you will come to a view class called MPInlineVideoOverlay. You can add any additional controls easily to this view to achieve the auto fade in/out behavior.
There are a few gotchas though, it can sometimes take awhile (up to a second in my experience) after you have created the MPMoviePlayerController and added it to a view before it has initialized fully and created it's MPInlineVideoOverlay layer. Because of this I had to create an instance variable called controlView in the code below because sometimes it doesn't exist when this code runs. This is why I have the last bit of code where the function calls itself again in 0.1 seconds if it isn't found. I couldn't notice any delay in the button appearing on my interface despite this delay.
-(void)setupAdditionalControls {
//Call after you have initialized your MPMoviePlayerController (probably viewDidLoad)
controlView = nil;
[self recursiveViewTraversal:movie.view counter:0];
//check to see if we found it, if we didn't we need to do it again in 0.1 seconds
if(controlView) {
UIButton *backButton = [UIButton buttonWithType:UIButtonTypeCustom];
[controlView addSubview:backButton];
} else {
[self performSelector:#selector(setupAdditionalControls) withObject:nil afterDelay:0.1];
}
}
-(void)recursiveViewTraversal:(UIView*)view counter:(int)counter {
NSLog(#"Depth %d - %#", counter, view); //For debug
if([view isKindOfClass:NSClassFromString(#"MPInlineVideoOverlay")]) {
//Add any additional controls you want to have fade with the standard controls here
controlView = view;
} else {
for(UIView *child in [view subviews]) {
[self recursiveViewTraversal:child counter:counter+1];
}
}
}
It isn't the best solution, but I am posting it in case someone else is trying to do the same thing. If Apple was to change the view structure or class names internal to the control overlay it would break. I am also assuming you aren't playing the video full screen (although you can play it fullscreen with embeded controls). I also had to disable the fullscreen button using the technique described here because the MPInlineVideoOverlay view gets removed and released when it is pressed: iPad MPMoviePlayerController - Disable Fullscreen
Calling setupAdditionalControls when you receive the fullscreen notifications described above will re-add your additional controls to the UI.
Would love a more elegant solution if anyone can suggest something other than this hackery I have come up with.
My solution to the same problem was:
Add the button as a child of the MPMoviePlayerController's view;
fade the button in and out using animation of its alpha property, with the proper durations;
handle the player controller's touchesBegan, and use that to toggle the button's visibility (using its alpha);
use a timer to determine when to hide the button again.
By trial-and-error, I determined that the durations that matched the (current) iOS ones are:
fade in: 0.1s
fade out: 0.2s
duration on screen: 5.0s (extend that each time the view is touched)
Of course this is still fragile; if the built-in delays change, mine will look wrong, but the code will still run.
I have a CGContext, which I can turn into an NSGraphicsContext.
I have an NSWindow with a clipRect for the context.
I want to put a scrollview into the context and then some other view into the scrollview so I can put an image into it... However, I can't figure out how to attach the scrollview into the context.
Eventually the view will probably be coming from a nib, but I don't see how that would matter.
I've seen this thread, (http://lists.apple.com/archives/quartz-dev/2006/Nov/msg00010.html) But they seem to leave off the step of how to attach the view into the context, unless there's something obvious I'm missing.
EDIT:
The reason I'm in this situation is that I'm writing a Mozilla Plugin. The browser gives me a CGContext (Quartz) and a WindowRef (QuickDraw). I can turn the CGContext into an NSGraphicsContext, and I can turn the windowRef into an NSWindow. From another data structure I also have the clipping rectangle...
I'm trying to draw an image into that context, with scrollbars as needed, and buttons and other UI elements... so I need (want) an NSView...
You can't put a view into a graphics context. A view goes either into another view, or as the content view of a window.
You can draw a view into a context by setting that context as the current context and telling the view to draw. You might do this as a means of rendering the view to an image, but otherwise, I can't think of a reason to do it. (Edit: OK, being a Netscape plug-in is probably a good reason.)
Normally, a view gets its own graphics context in NSView's implementation of the lockFocus method, which is called for you by display, which is called for you by displayIfNeeded (only if the view needs display, obviously), which is called for you as part of the event loop.
You don't need to create a context for a view except in very rare circumstances, such as the export-to-an-image case I mentioned. Normally, you let the view take care of that itself.
A partial solution?
What I have done currently is create a nib with a button in an IKImageView inside an NSScrollView. I load this in my plugin.
Then, since I have the NSWindow, I can get the contentView of the window. Then, I add the scrollview as subview of contentView.
It appears, but there seems to be some coordinate confusion about where the origin is. (top vs bottom) and since I'm mucking with the contentview of the WHOLE WINDOW, I'm doing some stuff very globally that perhaps I should be doing more locally. Like, the view never disappears, even when you close the tab, or go to another tab. (it does close when you close the window of course)
So, does this sound like a reasonable way of doing this? it feels a bit ... kludgy...
For future generations (and me when I forget how I did this and Google leads me back to my own question) Here's how I'm doing this:
I have a NIB with all my views, I load this on start-up.
on SetWindow, I set the clip rect and actually do the attaching:
NP_CGContext* npContext = (NP_CGContext*) window->window;
NSWindow* browserWindow = [[[NSWindow alloc] initWithWindowRef:npContext->window] autorelease];
NSView* cView = [browserWindow contentView];
NSView* hitView = [cView hitTest:NSMakePoint(window->x + 1, clip.origin.y + 1)];
if (hitView == nil || ![[hitView className] isEqualToString:#"ChildView"])
{
return;
}
superView = [hitView retain];
[superView addSubview: topView];
[superView setNextResponder: topView];
[topView setNextResponder: nil];
[browserWindow makeFirstResponder: topView];
To make sure I only addSubView once, I have a flag...
And then in handleEvent, I actually draw, Because I'm using an IKImageView, I can use the undocumented method: [imageView setImage: image]; which takes an NSImage.
So far this seems to be working for me. Hopefully this helps someone else.