scrollRectToVisible UITextField doesn't scroll with Autolayout - uiscrollview

[self.scrollView scrollRectToVisible:textField.bounds animated:YES];
I can't seem to get my UIScrollView to scroll at all so that it doesn't obscure my UITextField. I thought that scrollRectToVisible would be my savior but it looks like a no go. Maybe I'm missing something like translating the coordinates of my textField to my scrollView. Either way check out my sample project.
https://github.com/stevemoser/Programming-iOS-Book-Examples/tree/master/ch20p573scrollViewAutoLayout2
Oh, and this project might be missing the delegate connection but I checked that and it still doesn't scroll.
I've seen other questions similar to this but none that mention Autolayout.

I was having issues with scrollRectToVisible:: as well after converting to Auto Layout. I just changed it to a direct call to setContentOffset:: and it started working again.

I had the same problem, I wanted to scroll an autolayouted UITextEdit into view without making it the first responder.
For me the issue was that the bounds of the UITextField were set later on during the auto layout pass, so if you do it immediately after setting up the layout the bounds are not valid yet.
To workaround I did create a descendant of UITextField, did overwrite setBounds: and added a 0 timer to scroll into view "later on" (You can't scroll in that moment because the auto layout pass of the system might no be finished at that point)
#interface MyTextField: UITextField
{
bool _scrollIntoView;
}
..
#end
#implementation MyTextField
-(void)setBounds:(CGRect)bounds
{
bool empty=CGRectIsEmpty(self.bounds);
bool isFirstResponder=self.isFirstResponder;
[super setBounds:bounds];
if (empty && !isFirstResponder && _scrollIntoView)
[self performSelector:#selector(scrollIntoViewLater) withObject:nil afterDelay:0];
else if (empty && isFirstResponder)
[self performSelector:#selector(becomeFirstResponder) withObject:nil afterDelay:0];
}
-(void)scrollIntoViewLater
{
CGRect r=[scrollView convertRect:self.bounds fromView:self];
[scrollView scrollRectToVisible:r animated:TRUE];
}
#end
If the field should be additionally editable with the on screen keyboard, simply call becomeFirstResponder later on: it scrolls automagically into view above the keyboard using the private scrollTextFieldToVisible API which in turn calls scrollRectToVisible:animated: of the scrollview.
Your sample link is broken btw...

Related

The blue focus ring outside NSTextField missing?

In normal case, a blue retangle would appear outside a NSTextField object which becomes the first responder, like this image:
link for Normal Case
However, I got a NSTextField that have no the blue border outside. Why is that?
Here is how it happerns:
1> I create a typical MAC OS app.
2> I switch app's subview by calling the corresponding view's addSubview: and removeFromSuperview methods.
3> In one subview (which is actually the image referenced above) I click the "Next" button. Its action is something like this (defined in the subview's controller .m file):
- (IBAction)actionNextClicked:(id)sender{
//_hdlThreadNext is a NSThread object
[[_hdlThreadNext alloc] initWithTarget:self selector#selector(threadNext:) object:nil];
[_hdlThreadNext start];
}
And the thread is like:
- (void)threadNext:(id)sender{
#autoreleasepool{
BOOL success;
[CATransation begin];
/* send username and password and decrypt responce */
... // balabala... and set "success"
if (success){
[[self view] removeFromSuperview];
[self sendMessageToSuperview:#"Add Next View"]; // Superview's method, telling superview to call addSubview: to add another subview
}
else{
/* Nothing special to do */
}
[CATransation commit];
}
}
4> The subview switch to another one. Its combo view seemed to be OK: image for combo view
But the other NSTextView's blue border would NOT appear anymore!
Does Any guy know what wrong I had done? Thank you very much!
Perhaps I did totally wrong programming, so that few people met this problem.
I found a way to solve this problem. I mentioned that all (or most of?) the graphic changes should be done in main thread in a blog. Therefore I change the "if(success)" as:
if(success){
dispatch_async(dispatch_get_main_queue()' ^{
[[self view] removeFromSuperview];
[self sendMessageToSuperview:#"Add Next View"];
});
}
Solved, the focus rings come back.

UITableView becomes unresponsive

UITableViewCell becomes unresponsive this was a very different problem with a very different solution.
My tableView which is a subView in a UIViewController initially works fine and I can select individual rows in the table. However, I have created my own popup when a row is selected (the popup is a UIView) that appears towards the bottom of the screen. As this pops-up I also create a another UIView which covers the screen behind the popup and it makes the background go dim. The third thing that happens is that i create a UITapGestureRecogniser to keep track of the user's taps, and if they tap outside the UIView then the two UIViews and the TapGestureRecogniser are removed and call the deselectRowAtIndex... method.
However, it is at this point that I cannot use the tableView, as i want to be able to select a different string within the tableView and the popup to appear again (the popup will eventually contain links that will enable the user to move to different viewControllers).
I have tried to reload the data, remove the tableview and replace it, edit the didSelectRowAtIndex, remove the deselectRowAtIndex method, however nothing I tried seems to work and i can't find anything on stackoverflow as my question seems to be quite specific (although I apologise if there is something out there).
I'll add a few parts of my code in, however, I'm not sure where the problem is and I may not have copied the right part in.
The remove overhead is the selector method from the tapGesture
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
if(_popOverView == nil)
{
_popOverView = [[UIView alloc]initWithFrame:CGRectMake(20, 200, 280, 150)];
_popOverView.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:#"wood.jpeg"]];
}
if(_mask == nil)
{
_mask = [[UIView alloc] initWithFrame:self.view.frame];
[_mask setBackgroundColor:[UIColor colorWithWhite:0.0 alpha:0.78]];
}
if (_tapDetector == nil)
{
_tapDetector= [[UITapGestureRecognizer alloc]initWithTarget:self action:#selector(removeOverHead:)];
}
[self.view addSubview:_mask];
[self.view addSubview:_popOverView];
[self.view addGestureRecognizer:_tapDetector];
}
-(void) removeOverHead:(UITapGestureRecognizer*) sender
{
CGPoint locationOfTap = [_tapDetector locationInView:self.view];
if (locationOfTap.y < (200 + 150) && locationOfTap.y > 200 && locationOfTap.x > 20 && locationOfTap.x < (20 + 280) ) {
NSLog(#"%f,%f",[_tapDetector locationInView:self.view].x,[_tapDetector locationInView:self.view].y);
}
else
{
[_mask removeFromSuperview];
[_popOverView removeFromSuperview];
[_tapDetector removeTarget:self action:#selector(removeOverHead:)];
/*this idea doesn't work :(
[self.tableView removeFromSuperview];
[self.view addSubview:_tableView];*/
}
}
I really hope the answer is in here and is very simple, and thank you in advance for taking the time to read this.
Solved it! Sorry for wasting your time. It was the wrong remove method for the gestureRecogniser. I replaced
[_tapDetector removeTarget:self action:#selector(removeOverHead:)]
with
[self.view removeGestureRecognizer:_tapDetector]
as the UIGestureRecogniser was lingering and obstructing the tableView!!
If you stick a breakpoint or NSLog() inside the else block of that remove method, do you get inside it?
It sounds like your if statement might be off. You should use CGRectContainsPoint(). However if I understand correctly, you're attempting to dismiss everything when the user taps the dimming background view. You could make this view a button or you could compare the touch's view pointer to the pointer to the background view.

Xcode 4.2.1 UIScrollViews not scrolling in storyboard

So basically I have this project, where I have 4 different tab bar pages. 2 of them uses navigation controller & tab bar, and 2 are just view controllers. Now there is this one viewcontroller, which I need to add a scroll view to. So basically, I click on the item in the tab bar, it takes me to a view controller, where I can scroll down and up. I have been following Youtube Video Link, but I do not get it to work. The problem is that I use the exact code, and I change the ViewController class to the .h and .m name (ScrollViewViewController), and I put in a scroll view that has 320 x 1000, and a button at the top, but it doesn't scroll! How can I solve this problem?
Note: That if you don't know my problem, but could very detailed walk me through on how to add a scroll view to storyboards in xcode 4.2, then that would be amazing :)!
scrollerViewController.m:
- (void)viewDidLoad {
[scroller setScrollEnabled:YES];
[scroller setContentSize:CGSizeMake(320, 1000)];
[super viewDidLoad];
}
scrollerViewController.h
#interface scrollerViewController : UIViewController {
IBOutlet UIScrollView *scroller;
}
#end
And here comes a picture of the storyboard.
I need some of the code in order to really know your problem, but let me throw in my guess. You may be setting the size 320x1000 to the frame size of the scrollview by any chance? The frame size of the scrollview has to stay 320x480, and the contentSize should be 320x1000. Sorry if it was a wrong guess, but shouldn't do any harm :)
Something like this in your ViewController of the scrollView...
- (void) viewDidLoad {
[super viewDidLoad];
UIScrollView * scrollView = self.view;
scrollView.frame = (CGRect){scrollView.frame.origin, CGSizeMake(320, 480)};
scrollView.contentSize = CGSizeMake(320, 1000);
scrollView.backgroundColor = [UIColor whiteColor]; // I am setting the white background, so that the scroll indicator is visible
}
I am assuming you are setting ScrollView as the top view of the ViewController in your Storyboard as in the attached image.
I followed the exact same movie and it did not work for me either. But this movie did: http://www.youtube.com/watch?v=YBlwepYK7Zs
I followed that one and now i got it to work.
A bit late but might be more people looking for a solution to this.

Show NSPopover from NSToolbarItem Button

I want to show an NSPopover from an NSToolbarItem button in my toolbar.
(i.e. positioned below the button).
Ideally, I want to pass the NSView of the button to the popover to position it.
My question is, how do I get the NSView of the NSToolbarItem?
[toolbarbutton view] always returns nil.
The answer appears to be in the video for the 2011 WWDC Session 113, "Full Screen and Aqua Changes." Basically, put an NSButton inside the NSToolbaritem and use the view of that.
A blog post is here: http://www.yellowfield.co.uk/blog/?p=33, and a sample project is on github at http://github.com/tevendale/ToolbarPopover
All in the sprit of http://xkcd.com/979!
You can send the action directly from the NSButton enclosed in the NSToolbarItem (which is what you should generally do anyways, consider segmented controls, where each segment has its own target/action), and that will do the trick.
Instead of getting the view from the IBAction sender, connect an IBOutlet directly to the toolbar item and use that to get the relative view:
In your header file:
#property (weak) IBOutlet NSToolbarItem *theToolbarItem;
#property (weak) IBOutlet NSPopover *thePopover;
In your implementation file, to show the popover:
[self.thePopover showRelativeToRect:[[self.theToolbarItem view] bounds] ofView:[self.theToolbarItem view] preferredEdge:NSMinYEdge];
This will also work for showing popups from menu item selections inside a toolbar item.
While I did achieve that the Popover was shown using the approach mentioned by Stuart Tevendale, I did run into problems when I tried to validate (enable / disable) the NSToolbarItems using the NSToolbarDelegate:
-(BOOL)validateToolbarItem:(NSToolbarItem *)toolbarItem {
BOOL enable = YES;
NSString *identifier = [toolbarItem itemIdentifier];
// This does never get called because I am using a button inside a custom `NSToolbarItem`
if ([identifier isEqualToString:#"Popover"]) {
return [self someValidationMechanism];
}
// For this the validation works when I am using a standard `NSToolbarItem`
else if ([identifier isEqualToString:#"StandardToolbarItem"]){
return [self someOtherValidationMechanism];
}
return enable;
}
So I would advise not to display a Popover from NSToolbarItem. An alternative might be to show a Page Sheet: How to show a NSPanel as a sheet

How to stop the animation on a determinate NSProgressIndicator?

NSProgressIndicator allows stopAnimation: when isIndeterminate == YES, but how does one stop the animation for determinate progress bars?
For context, the progress bar I am trying to do this with is a child of an NSView, which itself is the view property of an NSMenuItem. Sending ridiculously high numbers to setAnimationDelay: does what I want, but only temporarily -- when the parent menu is closed and re-opened, the progress bar is animated again.
(Possibly unnecessary disclaimer: I swear this is a legit use case; I have to be able to visually (i.e.: without using text) display the progress of very-long-running tasks which may pause and re-start as needed by the backend. Answers which boil down to "UI design: ur doin it rong" will be not be accepted unless accompanied by a brilliant alternative suggestion. ;) )
Subclass NSProgressIndicator like this, it also works with Lion:
#interface UnanimatedProgressIndicator : NSProgressIndicator {
#private
BOOL isAnimating;
}
#end
#interface NSProgressIndicator (HeartBeat)
- (void) heartBeat:(id)sender; // Apple internal method for the animation
#end
#implementation UnanimatedProgressIndicator
- (void) startAnimation:(id)sender
{
isAnimating = YES;
[super startAnimation:sender];
}
- (void) stopAnimation:(id)sender
{
isAnimating = NO;
[super stopAnimation:sender];
}
- (void) heartBeat:(id)sender
{
if (isAnimating)
[super heartBeat:sender];
}
#end
Solved the problem using the same approach as described previously, with one small change.
When the menu's delegate receives menuNeedsUpdate:, I send setAnimationDelay: (with the sufficiently huge number as the arg) to each progress bar. This is working reliably now, so I'm happy enough with it.

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