CGRectOffset Causes Swiping The Wrong Way - iphone

Trying to be able to swipe away a cell and another view will show up. This is my code so far, but I am unable to see the rightView. Instead it limits me to seeing the leftView(I want the opposite...leftView does not even exist). Very confused with CGRects and CGRectOffsets. If you could correct my code that would be great. Thanks.
- (void)layoutSubviews
{
[super layoutSubviews];
CGRect frame = self.bounds;
self.scrollView.frame = frame;
self.scrollView.contentSize = CGSizeMake(frame.size.width*2, frame.size.height);
self.centerView.frame = CGRectOffset(frame, frame.size.width, 0);
self.rightView.frame = CGRectOffset(frame, frame.size.width*2, 0);
[self.scrollView scrollRectToVisible:self.centerView.frame animated:NO];
[self.scrollView setUserInteractionEnabled:YES];
self.scrollView.scrollEnabled = YES;
}

You are setting the centerView and rightView's offset to be frame.size.width and frame.size.width*2 respectively. What you want is for the center to be 0 and the right view to be frame.size.width.
You are just moving your views over too much so the left frame.size.width number of pixels just dont have a view.

Related

Dynamic UITextView in a dynamic UIScrollView - iOS

I'm facing a problem which takes me too long to solve.
I built a view, which contains a ScrollView. in the ScrollView, there's a view, which contains an image, and a UITextView. the textview should be in a dynamic height, with scrolling disabled. the textview gets all the text, but cut it off, and shows only the text that fits the height. in addition, the ScrollView doesn't changes.
- (void)viewDidLoad
....
//sets the text to the textview
[self.contentArticle setText:[NSString stringWithString:xmlParser.articleContent]];
//configures the scrollView
[self configureScrollView];
....
- (void)configureScrollView {
[self.contentView addSubview:self.contentArticle];
[self.scrollView addSubview:self.contentView];
CGRect frame = self.contentView.frame;
frame.size.height = self.contentArticle.contentSize.height;
self.scrollView.frame = frame;
[self.contentView sizeToFit];
[self.scrollView sizeToFit];
self.scrollView.contentSize = self.contentView.frame.size;
self.contentArticle.editable=NO;
self.contentArticle.scrollEnabled=NO;
//enable zoomIn
self.scrollView.delegate=self;
self.scrollView.minimumZoomScale=1;
self.scrollView.maximumZoomScale=7;
I did so many changes, and im not sure what is going on in there anymore!...
help would be sooo nice :)
UPDATE-
- (void)configureScrollView {
[self.contentView addSubview:self.contentArticle];
[self.scrollView addSubview:self.contentView];
CGRect textViewFrame = self.contentArticle.frame;
textViewFrame.size = [self.contentArticle contentSize];
self.contentArticle.frame = textViewFrame;
[self.scrollView setContentSize:textViewFrame.size];
self.contentArticle.editable=NO;
self.contentArticle.scrollEnabled=NO;
}
Try
- (void)configureScrollView{
self.contentView.autoresizingMask = UIViewAutoresizingNone;
self.contentArticle.autoresizingMask = UIViewAutoresizingNone;
CGRect textViewFrame = self.contentArticle.frame;
textViewFrame.size = [self.contentArticle contentSize];
self.contentArticle.frame = textViewFrame;
CGRect contentViewFrame = self.contentView.frame;
contentViewFrame.size.height = textViewFrame.origin.y+textViewFrame.size.height;
self.contentView.frame = contentViewFrame;
[self.scrollView setContentSize:contentViewFrame.size];
self.contentArticle.editable=NO;
self.contentArticle.scrollEnabled=NO;
//enable zoomIn
self.scrollView.delegate=self;
self.scrollView.minimumZoomScale=1;
self.scrollView.maximumZoomScale=7;
}
Source code
had same issue , tried to find solution for many days and finally i got it working.
I have a textview inside a scrollview.
disabled autolayout from storyboards
ive added the textview to scrollview with addsubview
and finally set the content of the scrollview, to the textview frame height.
Below my code:
_textView.text = stripped; //(some string ,yours: contentArticle)
[_textView sizeToFit];
CGRect frame = _textView.frame;
frame.size.height = _textView.contentSize.height;
_textView.scrollEnabled = NO;
_textView.frame = frame;
[self.scrollView addSubview:_textView];
[self.scrollView setContentSize:CGSizeMake(320,frame.size.height)];
Hope it helps!
You need to set self.contentView height first Use this code:
- (void)configureScrollView {
[self.contentView addSubview:self.contentArticle];
CGRect frame = self.contentArticle.frame;
frame.size.height = self.contentArticle.contentSize.height;
self.contentArticle.frame = frame;
[self.scrollView addSubview:self.contentView];
frame = self.contentView.frame;
frame.size.height += self.contentArticle.frame.height;
self.contentView.frame = frame;
self.scrollView.contentSize = self.contentView.frame.size;
self.contentArticle.editable=NO;
self.contentArticle.scrollEnabled=NO;
//enable zoomIn
self.scrollView.delegate=self;
self.scrollView.minimumZoomScale=1;
self.scrollView.maximumZoomScale=7;
}

iOS - UIScrollView is not working (it doesn't scroll at all - the image stays fixed)

I would like to display an image (width: 320 pixels, height: 1250 pixels) in an image view.
When I compile the application I get no scrolling at all. The view stays fixed.
What I did:
Added an UIScrollView via Interface Builder to my view.
Added an UIImageView via Interface Builder to my view.
Verified that UIImageView is below UIScrollView in Interface Builder.
Set the size of the UIScrollView with ViewDidLoad.
How do I do this?
Code:
- (void)viewDidLoad
{
[super viewDidLoad];
scrollView.contentSize = CGSizeMake(320, 1250);
}
Screenshots:
ImageView:
ScrollView:
I just have done the same task..
Try this one.....
scrollView.delegate = self;
scrollView.scrollEnabled = YES;
int scrollWidth = 120;
scrollView.contentSize = CGSizeMake(scrollWidth,80);
int xOffset = 0;
imageView.image = [UIImage imageNamed:[imagesName objectAtIndex:0]];
for(int index=0; index < [imagesName count]; index++)
{
UIImageView *img = [[UIImageView alloc] init];
img.bounds = CGRectMake(10, 10, 50, 50);
img.frame = CGRectMake(5+xOffset, 0, 50, 50);
NSLog(#"image: %#",[imagesName objectAtIndex:index]);
img.image = [UIImage imageNamed:[imagesName objectAtIndex:index]];
[images insertObject:img atIndex:index];
scrollView.contentSize = CGSizeMake(scrollWidth+xOffset,110);
[scrollView addSubview:[images objectAtIndex:index]];
xOffset += 70;
}
Also set this one....
imagesName = [[NSArray alloc]initWithObjects:#"image1.jpg",#"image2.jpg",#"image3.jpg",#"image4.jpg",#"image5.jpg",#"image6.png",#"image7.png",#"image9.png",nil];
images = [[NSMutableArray alloc]init];
So for me the problem was that setting the content size didn't work in viewDidLoad(). I tried everything and I didn't understand why it wouldn't want to work, and then I tried the same stuff in viewDidAppear() and it magically worked...
From you last screenshot and from your comments it looks like your scrollView is way to big.
The scrollview must be visible on screen completely. For example a full screen UIScrollView on iPhone would have a size of 320 x 460.
If the scrollview is the same size as its content you can't scroll.
The greenish rectangle shows the size of your scrollview, the pinkish the size of your content (your image):
Xcode 11+, Swift 5
You can find the complete solution here.
I came across this same issue on iOS6 and the solution was to programmatically adjust the ContentSize.
So I will just quote from Raja (above) to show this:
CGSize scrollViewContentSize = CGSizeMake(320, 400);
[self.scrollView setContentSize:scrollViewContentSize];
NOTE: I was not having this issue on iOS5.. seems like iOS6 decided to do alot of prank just like the rotation/orientation saga
Since Xcode 5 it does not work like before. Also scrolling to the end of a scrollable text field makes problems. There are also differences between doing it on iPhone or iPad. On iPhone it worked without delayed timer.
This worked for me:
- (void)viewDidLoad
{
[super viewDidLoad];
NSTimer *timerforScrollView;
timerforScrollView =[NSTimer scheduledTimerWithTimeInterval:0.1
target:self selector:#selector(forScrollView)userInfo:nil repeats:NO];
}
- (void) forScrollView {
[scrollviewPad setScrollEnabled:YES];
[scrollviewPad setContentSize:CGSizeMake(768, 1015)]; // must be greater then the size in Storyboard
}
I found I had a similar problem but none of the above code worked. The issue was due to autolayout. I found that if I turned off autolayout by going to the storyboard clicking on Utilities -> File Inspector and unchecked Use Autolayout the scrolling did work (I also set scroll.contentSize = ...).
Sometimes autoLayout checkbox is ticked in the xib. That also creates this issue in xcode 5. Which makes the UIScrollView scrolling off.
Don't forget to add the category protocol to the interface, like this
#interface MyViewController : <UIScrollViewDelegate>
If you don't, you will not be able to set the scroll view delegate to self
(i.e. [MyScrollView setDelegate:self];)
If you do this, it should work.
My code is:
-(void)viewDidAppear:(BOOL)animated {
[super viewDidAppear:animated];
[contentScrollView setDelegate:self];
[contentScrollView setScrollEnabled:YES];
contentScrollView.contentSize = CGSizeMake(310, 500);
contentScrollView.frame = CGRectMake(5, 188, 310, 193);
}
Did you assign the scroll's view delegate? Always remember these:
[self.scrollView setDelegate:self];
[self.scrollView setScrollEnabled:YES];
The image view has to be a subview (so inside AND below) of the scrollview. From your description it seems they are paralell
You forgot one line. Add this to your view load function:
[scrollView setScrollEnabled:YES];
You could try disabling AutoLayout. In XCode 5 I tested all the above answers and I could only scroll it by disabling autolayout and activating all autosizing masks under the Size Inspector. The following code was used too:
self.scrollView.contentSize = CGSizeMake(320, 900);
self.scrollView.delegate = self;
self.scrollView.scrollEnabled = YES;
self.scrollView.frame = self.view.frame;
CGRect scrollViewFrame = CGRectMake(0, 0, 320, 400);
self.scrollView = [[UIScrollView alloc] initWithFrame:scrollViewFrame];
[self.view addSubview:self.scrollView];
CGSize scrollViewContentSize = CGSizeMake(320, 400);
[self.scrollView setContentSize:scrollViewContentSize];
scrollView.delegate = self;
[self.scrollView setBackgroundColor:[UIColor blackColor]];
[scrollView setCanCancelContentTouches:NO];
scrollView.indicatorStyle = UIScrollViewIndicatorStyleWhite;
scrollView.clipsToBounds = YES;
scrollView.scrollEnabled = YES;
scrollView.pagingEnabled = YES;
NSUInteger nimages = 0;
CGFloat cx = 0;
for (; ; nimages++) {
NSString *imageName = [NSString stringWithFormat:#"image%d.jpg", (nimages + 1)];
UIImage *image = [UIImage imageNamed:imageName];
if (image == nil) {
break;
}
UIImageView *imageView = [[UIImageView alloc] initWithImage:image];
CGRect rect = imageView.frame;
rect.size.height = image.size.height;
rect.size.width = image.size.width;
rect.origin.x = ((scrollView.frame.size.width - image.size.width) / 2) + cx;
rect.origin.y = ((scrollView.frame.size.height - image.size.height) / 2);
imageView.frame = rect;
[scrollView addSubview:imageView];
[imageView release];
cx += scrollView.frame.size.width;
}
[scrollView setContentSize:CGSizeMake(cx, [scrollView bounds].size.height)];
Assuming that scrollView is a subview of view and fills it entirely you can use the following in viewDidLoad:
[scrollView setContentSize: CGSizeMake(self.view.frame.size.width, self.view.frame.size.height)];
I had a UIScrollView that was not scrolling and this allowed it to scroll.
Just add code
scrollView.contentSize = CGSizeMake(WIDTH,HEIGHT);
to method -(void)viewDidLayoutSubviews.
For more information checkout Stanford CS193p Lecture No 8 to understand View Controller Life cycle.
I had the same issue and was looking for the answer in this thread. I tried all the stuff, but nothing works. Then I found this:
.
You just need to deselect "Use Auto Layout" in File Inspector of your ViewController. Ta-Da, it works immediately for me. Enjoy.

Is it possible to add fixed content to a UIScrollView?

I want to create a subclass of UITableView or UIScrollView that will have some shading at the top when the content offset is > 0 to indicate that the content is scrollable. (See image attached)
The way I'm implementing it right now is using the UIViewController that is the delegate of the tableView. I simply have a GradientView on top of the tableView, and I intercept scrollViewDidScroll: to animate the visibility of that top gradient.
My problem with this implementation is that it's not "clean". I want my UIViewControllers to take care of logic, and not to deal with applying gradients and stuff. I wish I could just drop a subclass of UITableView that will do that for me.
The challenge for me is that I can't figure out how the tableView could add to itself a fixed content on top of the scrollable content.
Another question is what method/s of UIScrollView should I override to intercept the scrolling event. Obviously I don't want the tableView to be the delegate of itself...
Any ideas?
Thanks!
Ok, so I found the solution on Apple's WWDC 2011 Session 104 video - Advanced Scroll View Techniques.
There is a whole section in this video about "Stationary Views" inside a scroll view.
According to Apple, the way to go here is to override layoutSubviews and put there all the code to position whatever you want - wherever you want.
I tried it and it's actually pretty easy and it's working as expected.
So for example if I would like a shadowed header on top of the table when the content is being scrolled, this is the code I should write:
-(void) layoutSubviews
{
[super layoutSubviews];
[self positionTopShadow];
}
-(void) positionTopShadow
{
CGFloat yOffset = self.contentOffset.y;
// I'm doing some limiting so that the maximum height of the shadow view will be 40 pixels
yOffset = MIN(yOffset, 40);
yOffset = MAX(0, yOffset);
CGRect frame = self.topShadowView.frame;
// The origin should be exactly like the content offset so it would look like
// the shadow is at the top of the table (when it's actually just part of the content)
frame.origin = CGPointMake(0, self.contentOffset.y);
frame.size.height = yOffset;
frame.size.width = self.frame.size.width;
self.topShadowView.frame = frame;
if (self.topShadowView.superview == nil)
{
[self addSubview:self.topShadowView];
}
[self bringSubviewToFront:self.topShadowView];
}
I've managed to figure out a much simpler way of doing this then what Avraham did.
I use the fact that the UIScrollView calls scrollViewDidScroll: ever pixel the scrolling changes to set the object at the location of the offset. Below is my full code to keep a gray bar at the top of the scrollview as you move around:
- (void)viewDidLoad {
UIScrollView* scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(5.0, 50.0, self.bounds.size.width - 15.0, self.bounds.size.height - 60.0)];
[scrollView setBackgroundColor:[UIColor colorWithRed:251.0/255.0 green:251.0/255.0 blue:251.0/255.0 alpha:1.0]];
[scrollView setContentSize:CGSizeMake(scrollView.frame.size.width + 500, 1000.0)];
[scrollView setDelegate:self];
[self addSubview:scrollView];
UIView* header = [[UIView alloc] initWithFrame:CGRectMake(0.0, 0.0, scrollView.contentSize.width, 40.0)];
[header setTag:100];
[header setBackgroundColor:[UIColor darkGrayColor]];
[scrollView addSubview:header];
}
-(void)scrollViewDidScroll:(UIScrollView *)scrollView {
UIView* header = [self viewWithTag:100];
[header setFrame:CGRectMake(0.0, scrollView.contentOffset.y, header.bounds.size.width, header.bounds.size.height)];
}
You could try using viewForHeaderInSection method of tableView for the shaded view(and also heightForHeaderInSection)... Make the shaded portion as a header.That way there is a fixed content on top of the scrollable content.
#define kImageOriginHight 300
- (void)scrollViewDidScroll:(UIScrollView *)scrollView1{
CGFloat yOffset = scrollView1.contentOffset.y;
// NSLog(#" y offset := %f", yOffset);
//zoom images and hide upper view while scrooling to down position
if (yOffset < 0) {//-kImageOriginHight
CGRect f = imgV.frame;
f.origin.y = yOffset;
f.size.height = -yOffset + kImageOriginHight;
imgV.frame = f;
//viewTableUpperView.alpha = 1.5 - (yOffset/-kImageOriginHight);
//viewTableUpperView.userInteractionEnabled = NO;
if(yOffset+0.5 == -kImageOriginHight){
[UIView animateWithDuration:0.1 animations:^{
//viewTableUpperView.alpha = 1.0;
}];
//viewTableUpperView.userInteractionEnabled = YES;
}
}
}

How to slide a UIView right above a UITabBar

I have a UIView that I want to slide from behind a UITabBar to be position right on top of it.
This doesn't work. My view does not appear.
- (void)showNotificationBar
{
CGRect frame = CGRectMake(0, 500, 320, 32);
frame.origin.y = CGRectGetMaxY(self.parentViewController.tabBarController.tabBar.frame) - frame.size.height;
notificationBar.frame = frame;
[self.parentViewController.tabBarController.tabBar.superview insertSubview:notificationBar
belowSubview:self.parentViewController.tabBarController.tabBar];
[UIView animateWithDuration:0.5 animations:^{
CGRect frame = notificationBar.frame;
frame.origin.y = CGRectGetMaxY(self.parentViewController.tabBarController.tabBar.frame);
notificationBar.frame = frame;
}];
}
Initialize frame.origin.y like this:
frame.origin.y = self.tabBarController.tabBar.frame.origin.y;
In the animations block, set it like this:
frame.origin.y -= frame.size.height;
If you want it to show in every view, you could do to things: either show it at the bottom of every view or show it in the application's window. I personally like this second approach better because it helps avoiding duplicate code:
CGFloat notificationBarHeight = 40.0f;
UIView *notificationBar = [[UILabel alloc]initWithFrame:CGRectMake(0, self.tabBarController.tabBar.frame.origin.y - notificationBarHeight, 320, notificationBarHeight)];
[self.window insertSubview:notificationBar atIndex:[[self.window subviews]count]];
[self.view insertSubview:notificationView atIndex:1]; worked for me...

UIScrollView contentSize Issue

Within my view I create a scrollview with a width of 320 and a height of 70.
Responding to the user touching a button, I expand the scrollview, so it is 380(h) x 320(w) in size.
The code for this is shown below:
CGRect scrollviewFrame = CGRectMake(0, 30, 320, 380);
[scrollView setFrame:scrollviewFrame];
[self layoutScrollImages:YES];
CGSize srect = CGSizeMake([scrollView bounds].size.width, (kNumImages * kScrollObjHeight));
[scrollView setContentSize:srect];
As I debug this project, I can see that srect is 320 (w) x 8000 (h) in size; however my issue is the scrollable area (where the user can actually touch to scroll the scrollview) remains the same as when it was it's original size.
I'm obviously missing something, does anyone know what it is?
Edit: I have created a sample project to illustrate the issue I am having, it is available here: http://dl.dropbox.com/u/9930498/ScrollViewTest.zip
I think , you have issue with your below line of code.
CGSize srect = CGSizeMake([scrollView bounds].size.width, (kNumImages * kScrollObjHeight));
[scrollView setContentSize:srect];
debug your program and see the content of srect , Also let us know the value of below two constant
kNumImages,kScrollObjHeight .
You need to change the contentSize of the scrollview as well as the frame.
Maybe this will help aswell: UIScrollView Class Reference
Do this when setting the new size
scrollView.scrollEnabled = YES;
scrollView.showsHorizontalScrollIndicator = YES;
scrollView.showsVerticalScrollIndicator = YES;
[scrollView setFrame:CGRectMake(0, 30, 320, 380)];
CGSize srect = CGSizeMake([scrollView bounds].size.width, (kNumImages * kScrollObjHeight));
[scrollView setContentSize:srect];
[self layoutScrollImages:YES];