I am writing because I have a problem with the Auto Layout.
I'm trying to create a simple view in InterfaceBuilder with Auto Layout I want to load code and enter as a header of a table (not as header section). I explain briefly what are the characteristics.
The imageView must be square and must be as wide as the screen.
The space under the picture to the bottom of view that contains the button and label must be high 50 points.
Between image and button has to be a fixed distance of 12 points.
Between image and label must be a fixed distance of 13 points.
All these features are able to get them with Auto Layout. I added a constraint to the aspect ratio of the image (1: 1) and the various constraints for distances. all right.
The real problem is that by launching the app on iphone 6+ simulator (414 points of width), the image (with the label and button) goes above the cells.
Enabling various transparencies I noticed that the superView of Image View, only increase the width. It does not increase its height! How do I fix?
This is the code:
- (void)viewDidLoad{
//...
PhotoDetailsHeaderView *hView = (PhotoDetailsHeaderView *)[[[NSBundle mainBundle] loadNibNamed:#"PhotoDetailsHeaderView" owner:self options:nil] objectAtIndex:0];
hView.delegate = self;
self.tableView.tableHeaderView = hView;
//...
}
This is how I create the xib:
and this is how it is on the simulator, the green box is Uiimageview and the yellow box (under green box) is the mainview (or superview):
How can fix it?
Many thanks to all!
You'll need to add a property to store your PhotoDetailsHeaderView:
#property (nonatomic, strong) PhotoDetailsHeaderView *headerView;
Then calculate its expected frame in viewDidLayoutSubviews. If it needs updating, update its frame and re-set the tableHeaderView property. This last step will force the tableView to adapt to the header's updated frame.
- (void)viewDidLayoutSubviews{
[super viewDidLayoutSubviews];
CGRect expectedFrame = CGRectMake(0.0,0.0,self.tableview.size.width,self.tableView.size.width + 50.0);
if (!CGRectEqualToRect(self.headerView.frame, expectedFrame)) {
self.headerView.frame = expectedFrame;
self.tableView.tableHeaderView = self.headerView;
}
}
The problem is probably that in iOS you have to reset the header of the table view manually (if it has changed its size). Try something along these lines:
CGRect newFrame = imageView.frame;
imageView.size.height = imageView.size.width;
imageView.frame = newFrame;
[self.tableView setTableHeaderView:imageView];
This code should be in -(void)viewDidLayoutSubviews method of your view controller.
Related
I have a static table view with cells that have a rounded border. I have noticed when testing on different simulators that whilst my auto layout constraints work, the border isn't always the right width. This particular screen consists of a view controller with a UIView containing an embedded tableViewController
I have done some investigating and found that the width of the border actually depends on the width of the storyboard phone. This means if I have a storyboard for an iPhone 8, the 8+ will have cells too short and vice versa, an 8+ storyboard results in cells that are too long (and extend off screen) for the 8.
Currently I am setting the cell borders in the viewDidLoad, here is the code I am using to configure the cells border:
- (void)configureCellThree {
//Add Border
CALayer *borderLayer = [CALayer layer];
CGRect borderFrame = CGRectMake(0, 0, (_contentCellThree.frame.size.width), (_contentCellThree.frame.size.height));
[borderLayer setBackgroundColor:[[UIColor clearColor] CGColor]];
[borderLayer setFrame:borderFrame];
[borderLayer setCornerRadius:_contentCellThree.frame.size.height / 2];
[borderLayer setBorderWidth:1.0];
[borderLayer setBorderColor:[kTextColor2 CGColor]];
// [borderLayer setOpacity:0.5];
[_contentCellThree.layer addSublayer:borderLayer];
}
Now if I run this code within the viewDidAppear, everything will work across both devices. I added some logs to my main view controller to find out how things were being set.
- (void)viewDidLoad {
[super viewDidLoad];
NSLog(#"VDL - SELF.VIEW = %#", self.view);
NSLog(#"VDL - CONTAINER VIEW = %#", self.profileScrollingContainerView);
}
- (void)viewDidAppear:(BOOL)animated {
[super viewDidAppear:animated];
NSLog(#"VDA- SELF.VIEW = %#", self.view);
NSLog(#"VDA - CONTAINER VIEW = %#", self.profileScrollingContainerView);
}
I had suspected that viewDidLoad was using the sizing information from the storyboard instead of the view itself (which doesn't seem right). This logging confirms this. If I look at the UIView responsible for displaying my tableview, when the storyboard is set to 8+ it has the following frame attributes: X = 0, Y = 349, W = 414, H = 338. Now lets look at the results of the logging:
VDL - SELF.VIEW = <UIView: 0x7fa545401f10; frame = (0 0; 375 667);
VDL - CONTAINER VIEW = <UIView: 0x7fa545401b50; frame = (0 349; 414 338);
VDA- SELF.VIEW = <UIView: 0x7fa545401f10; frame = (0 64; 375 603);
VDA - CONTAINER VIEW = <UIView: 0x7fa545401b50; frame = (0 285; 375 269);
So when the view loads the tableview is getting the wrong information about the views size. When the viewDidAppear gets called it has the correct sizing of the view and will work properly. My issue here is that I don't want to be calling initialising code in my viewDidAppear.
I read here that I should be putting my UI Geometry code into the viewWillAppear however I have tried this and I get the same issues.
VWA - CONTAINER VIEW = <UIView: 0x7fec04d97700; frame = (0 349; 414 338);
So to consolidate my question, How can I get the properties of my view before the view has loaded/appeared so I can correctly setup my UI?
I have read that I will need to subclass UIView and potentially use setFrame however I don't really know how I'd actually go about doing this.
Subclass UITableViewCell and implement layoutSubviews, i.e. see the docs:
"Subclasses can override this method as needed to perform more precise layout of their subviews. You should override this method only if the autoresizing and constraint-based behaviors of the subviews do not offer the behavior you want. You can use your implementation to set the frame rectangles of your subviews directly."
So it turns out I was using the wrong method to do this. I found this question which solved my whole issue. Basically if you need to perform UI calculations (such as adding custom views) you should be performing them in -(void)viewDidLayoutSubviews. This method is called after the view has worked out all of its sizing and constraints so anything you do in here will be executed using the right properties of your view!
I work on dynamically, programmatically layout a view for 3.5" devices as well as for 4" devices.
As such that works fine.
But I want rounded corners so that my images appear like playing cards.
And I get rounded corners nicely displayed in 3,5 inch devices on the simulator for simulated iOS 6.1 and 7 alike.
But when I choose iPhone retina 4 inch on 6.1 or 7, then the UIImage in the UIImageView is fully displayed.
It works nicely on simulated iPad devices (in iPhone simulation mode - it is an iPhone only app).
As for today, I do not have any 4" device with me to test it. I can test on a device during the upcoming week.
Hiere is the relevant code:
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
self.imageV.image = self.image; // The image property was set by the caller.
// Layout imageV within self.view with a margin of MARGIN
self.imageV.frame = CGRectMake(self.view.frame.origin.x + MARGIN, self.view.frame.origin.y + MARGIN, self.view.frame.size.width - 2 * MARGIN, self.view.frame.size.height - 2 * MARGIN);
// set the raidus and the mask to follow the rounded corners.
self.imageV.layer.cornerRadius = CORNER_RADIUS;
self.imageV.layer.masksToBounds = YES;
}
BTW: CORNER_RADIUS is 18 and MARGIN is 15. Changing these values has no effect on the issue.
UPDATE: Thanks to Matt I figured out that the problem disappears when I create the UIImageView programmatically. That is some really nice workaround plus it points into the right diretion, I guess, but it is not a solution. Any ideas what setting in the storyboard editor might have caused the problem?
As far as I can see, auto layout is disabled for all view controllers in this storyboard.
The answer is simple. The code did work. It did add round corners to the UIImageView object and the maskToBounds worked well.
But the actual image displayed is smaller. I used AspectFit as mode to ensure that the actual image is not squeesed but displayed in its original aspect ration. Because of the longer layout of the iPhone5 dimensions the image only filled a part of its owning UIImageView. I changed the background color to gray for the screenshot and now it gets clear.
So the solution will be that I'll have to calculate the proper size of the image view so that it matches exactly the size of the scaled image. Then it should work.
(I'll update this answer when it is done).
Update: this is what I finally did: I removed the UIImageView from the Storyboard and deal with it programmatically.
Don't get confused by the complexity. I added another view just to throw a shadow, although this is not related to the original question. The shadow I wanted to add anyway. And it turned out that CALayer's shadow and masksToBounds=YES don't really agree on. That is why I added a regular UIView which lies in between the card view and the background view.
Finally this is so much of a hassle for displaying a simple rectangle image, that I think, just subclassing UIView and drawing everything with openGL or so directly into the CALayer would be probably much easier. :-)
Anyway, this is my code:
- (void)viewDidLoad {
[super viewDidLoad];
self.state = #0;
// Create an image view to carry the image with round rects
// and create a regular view to create the shadow.
// Add the shadow view first so that it appears behind
// the actual image view.
// Explanation: We need a separate view for the shadow with the same
// dimenstions as the imageView. This is because the imageView's image
// is rectangular and will only be clipped to round rects when the
// property masksToBounds is set to YES. But this setting will also
// clip away any shadow that the imageView's layer may have.
// Therfore we add a separate mainly empty UIView just behind the
// UIImageview to throw the shadow.
self.shadowV = [[UIView alloc] init];
self.imageV = [[UIImageView alloc] initWithImage:self.image];
[self.view addSubview:self.shadowV];
[self.shadowV addSubview:self.imageV];
// set the raidus and the mask to follow the rounded corners.
[self.imageV.layer setCornerRadius:CORNER_RADIUS];
[self.imageV.layer setMasksToBounds:YES];
[self.imageV setContentMode:UIViewContentModeScaleAspectFit];
// set the shadows properties
[self.shadowV.layer setShadowColor:[UIColor blackColor].CGColor];
[self.shadowV.layer setShadowOpacity:0.4];
[self.shadowV.layer setShadowRadius:3.0];
[self.shadowV.layer setShadowOffset:CGSizeMake(SHADOW_OFFSET, SHADOW_OFFSET)];
[self.shadowV.layer setCornerRadius:CORNER_RADIUS];
[self.shadowV setBackgroundColor:[UIColor whiteColor]]; // The view needs to have some content. Otherwise it is not displayed at all, not even its shadow.
}
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
// Just to be save
if (!self.image) {
return;
}
self.imageV.image = self.image; // The image property was set by the caller.
// Layout imageV within self.view with a margin of MARGIN
self.imageV.frame = CGRectMake(MARGIN, MARGIN, self.view.bounds.size.width - 2 * MARGIN, self.view.bounds.size.height - 2 * MARGIN);
// Calculate the size and position of the image and set the image view to
// the same dimensions
// This works under the assumption, that the image content mode is aspectFit.
// Well, as we are doing so much of the layout manually, it would work with a number of content modes. :-)
float imageWidth, imageHeight;
float heightWidthRatioImageView = self.view.frame.size.height / self.view.frame.size.width;
float heightWidthRatioImage = self.image.size.height / self.image.size.width;
if (heightWidthRatioImageView > heightWidthRatioImage) {
// The ImageView is "higher" than the image itself.
// --> The image width is set to the imageView width and its height is scaled accordingly.
imageWidth = self.imageV.frame.size.width;
imageHeight = imageWidth * heightWidthRatioImage;
} else {
// The ImageView is "wider" than the image itself.
// --> The image height is set to the imageView height and its width is scaled accordingly.
imageHeight = self.imageV.frame.size.height;
imageWidth = imageHeight / heightWidthRatioImage;
}
// Layout imageView and ShadowView accordingly.
CGRect imageRect =CGRectMake((self.view.bounds.size.width - imageWidth) / 2,
(self.view.bounds.size.height - imageHeight) / 2,
imageWidth, imageHeight);
[self.shadowV setFrame:imageRect];
[self.imageV setFrame:CGRectMake(0.0f, 0.0f, imageWidth, imageHeight)]; // Origin is (0,0) because it overlaps its superview which just throws the shadow.
}
And this is how it finally looks like:
The problem is due to some issue with code or configuration you have not told us about. Proof: I ran the following and it works fine. Note that I create the image view in code (to avoid the auto layout problem) and fixed your frame/bounds confusion, and that I've skipped your self.image, but none of that is really relevant to the issue you are seeing:
#define CORNER_RADIUS 18
#define MARGIN 15
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
self.imageV = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"im"]];
[self.view addSubview:self.imageV];
// Layout imageV within self.view with a margin of MARGIN
self.imageV.frame = CGRectMake(self.view.bounds.origin.x + MARGIN, self.view.bounds.origin.y + MARGIN, self.view.bounds.size.width - 2 * MARGIN, self.view.bounds.size.height - 2 * MARGIN);
// set the raidus and the mask to follow the rounded corners.
self.imageV.layer.cornerRadius = CORNER_RADIUS;
self.imageV.layer.masksToBounds = YES;
}
It works fine (and you can prove that to yourself). Here is a screen shot of the 4-inch simulator:
Therefore the problem is outside the code that you quote in your question, and cannot be analyzed without further information.
This is what I want to do:
As you can see i want to:
Decrease the width of the tableView (I want more margin on the sides than the grouped tableView provides)
Corner radius (bigger radius than the default for grouped tableView)
Drop shadow around the table and a special shadow beneath the last cell
You can do this by "drawing" the backgroundView of the cells yourself.
I'd recommend getting an image to use as the background (if the cells are all the same height).
You'll need three images.
A "top" image with the top corners rounded.
A "bottom" image with the bottom corners rounded and the drop shadow how you want it.
And a "middle" image with no rounded corners.
If the cells don't have any texture or gradient within them then you can use stretchable images to reduce the memory footprint of them.
Then I would subclass the UITableViewCell and override the backgroundView to add a UIImageView. I'd also provide an accessor method to change the type (top, middle, bottom) of the cell.
Each cell can then have three placeHolder properties of a UIImage (topImage, bottomImage and middleImage). When the type of the cell is changed these can be accessed (use lazy instantiation to make sure they are only loaded once and only when needed) and then set the backgroundVIew image to be the required image.
Something like this...
In the UITableViewCell subclass define a type enum...
typedef enum {
CellTypeTop,
CellTypeMiddle,
CellTypeBottom
} cellType;
Then a property for the type...
#property (nonatomic) cellType cellType
Then in the .m ...
Define some more internal properties...
#property UIImageView *bgImageView;
#property UIImage *topImage;
#property UIImage *middleImage;
#property UIImage *bottomImage;
Then add the imageView (only once)...
- (void)awakeFromNib //or in the init depends how you are initialising the cell
{
self.bgImageView = [[UIImageView alloc] initWithFrame:blah];
[self.backgroundView addSubView:self.bgImageView];
}
Now when the type is changed...
- (void)setCellType:(cellType)cellType
{
switch(cellType) {
case CellTypeTop:
self.bgImageView.image = self.topImage;
break;
case CellTypeMiddle:
self.bgImageView.image = self.middleImage;
break;
case CellTypeBottom:
self.bgImageView.image = self.bottomImage;
break;
}
}
Finally a lazy instantiation of the images...
- (UIImage *)topImage
{
if (_topImage == nil) {
_topImage = [UIImage imageNamed:#"topImage"];
//alternatively...
_topImage = [[UIImage imageNamed:#"topImage"] stretchableImageWith...
}
return _topImage;
}
Now repeat these for the other images.
This will be more performant (by a long way) than using a CALayer alternative and, especially if using the stretchable images, will have a very small memory footprint.
Several other users have said that this is not good for performance, memory, design, whatever, but it really is the best way to get the best performance for UserExperience than CALayers. Yes, it will use more memory than CALayers but only marginally and it will get to a limit as there are only a few dequeueable cells created.
A couple of links explaining performance issues when using CALayers in scrollViews...
http://www.quora.com/iOS-Development/What-is-the-best-way-to-optimize-the-performance-of-a-non-paging-but-view-recycling-UIScrollView-involving-loading-potentially-caching-and-displaying-bundled-images
Bad performance on scroll view loaded with 3 view controllers, drawn with CALayer
::EDIT:: Edit to answer Michael's question.
In the storyboard create a UITableViewController (rename the Class in the inspector so that it matches your subclass UITableViewController - I'll call it MyTableViewController).
Create a subclass of UITableViewCell (I'll call mine MyTableViewCell) in the code (i.e. the .h and .m).
Add the above code to do with properties and types and imageViews to your MyTableViewCell.h file.
In the storyboard select the cell in the TableViewController and rename the class to MyTableViewCell. Also set the reuse identifier on it.
In the MyTableViewController code you will need a function like this...
-(UITableViewCell*)tableView:(UITabelView*)tableView cellForRowAtIndexPath:(NSIndexPath*)indexPath
{
MyTableViewCell *cell = [tableView dequeueCellWithReuseIdentifier:#"Cell"];
cell.cellType = CellTypeTop; //or whichever it needs to be
cell.textLabel.text = #"Blah";
return cell;
}
Oh, another thing, in the storyboard you will be able to layout your cell how you want it to look and link up all the labels and imageviews etc... Make sure you add IBOutlet to the UIImageView so that you can link it up in the storyboard.
make sure you have #import <QuartzCore/QuartzCore.h> imported, then you can start accessing the layers of the UITableView like.
UITableView *yourTable = [[UITableView alloc] initWithStyle:UITableViewStyleGrouped];
[[yourTable layer] setCornerRadius:10.0f];
[[yourTable layer] setShadowColor:[[UIColor blackColor] CGColor]];
[[yourTable layer] setShadowOffset:CGSizeMake([CALayer ShadowOffSetWidthWithFloat:10.0f], [CALayer ShadowOffSetWidthWithFloat:10.0f])];
[[yourTable layer] setShadowOpacity:[CALayer ShadowOpacity:1]];
[[yourTable layer] setMasksToBounds:NO];
UIBezierPath *path = [UIBezierPAth bezierPathWithRect:yourTable.bounds];
[[yourTable layer] setShadowPath:[path CGPath]];
This will add shadow affect to your table view with the shadow not masked to the bounds of the UITableView, at setCornerRadius you can set the corners of the table to whatever you want. You can also set the frame of the UITableView by doing
[yourTable setFrame:CGRectMake(CGFloat x, CGFloat y, CGFloat width, CGFloat height)];
EDIT
As another user has tried to point out that CALayer is very slow, this is not the case
CALayer was introduced to help performance issues around animation. Please read documentation. Loading an image straight in may seem like a good idea but in the long run will take up more memory. Please this question about memory allocation for images. As you can see it may seem faster, but it takes up 2.25 MByte of memory per image which after loading each image so many times your app will start to become slow.
I have 2 tables in one view. Table A lists a bunch of users. Table B lists a users objects. When a row is selected in Table A, Table B is reloaded with the objects that belong to that user.
So when a user selects a row in Table A, the image in the background of the cell changes to the highlighted version of the image.
Here is the normal version of the background image:
Here is the highlighted version of the background image:
As you can see, the highlighted version has a small arrow on the right of it. This arrow is beyond the width of the table cell the table itself. When the row is selected, the image changes as it should, but the image is sized down to fit the whole image into the cell.
What I would like to happen is the image goes outside of the table, or on top of the table for that selected row.
One possible solution I thought was to center the table on the selected row and then overlay that image, but if the user was to try to scroll through the table, the image would need to move and that would be a big pain.
So what I would like to know is it is possible to extend the cell's size beyond the table one it is selected?
Thanks in advance!
EDIT:
The following does not work, just in case anyone was going to try:
[cell setFrame:CGRectMake(cell.frame.origin.x, cell.frame.origin.y, cell.frame.size.width+20, cell.frame.size.height)];
Setting a views clipsToBounds property to NO will allow the view to draw outside of its own frame.
In your UITableViewController subclass:
- (void)viewDidLoad
{
[super viewDidLoad];
// Do what you normally do here, if anything then add...
self.view.clipsToBounds = NO;
}
Doing this has a side effect where you will see full cells be created at the bottom or top of the tableview instead of them scrolling partially into view. Either put the table view into another view that has clipsToBounds set to YES, align the edges of the table view with the edges of the screen, or have views covering over the bottom and top (like a UIToolbar and UINavigationBar normally would).
To get the UITableViewCell's selectedBackgroundView to extend past the table view's frame create a subclass of UITableViewCell and override the layoutSubviews method.
- (id)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier
{
self = [super initWithStyle:style reuseIdentifier:reuseIdentifier];
if (self) {
// Initialization code
self.backgroundView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"YQGyZ"]];
self.selectedBackgroundView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"CQXYh"]];
self.textLabel.backgroundColor = [UIColor clearColor];
self.detailTextLabel.backgroundColor = [UIColor clearColor];
}
return self;
}
- (void)layoutSubviews {
[super layoutSubviews];
CGRect frame = self.selectedBackgroundView.frame;
frame.size.width += 13; // where 13 is the size of the arrow overhang from the same images
self.selectedBackgroundView.frame = frame;
// You can also change the location of the default labels (set their background colors to clear to see the background under them)
self.textLabel.frame = CGRectMake(70, 0, 148, 30);
self.detailTextLabel.frame = CGRectMake(70, 30, 148, 30);
}
Good luck.
I would recommend modifying the image resource of the unselected cell background such that it is the same width as the selected background, but just has a transparent rectangle on the side.
I have a UIPopoverController in my app which simply displays two UILabels beside each other with a list of words in each of them. However sometimes there are only a couple of words in each list meaning there is tons of blank space in the popover view.
How can I make it so that the popover view in at least height dynamically adapts to how many lines of words there are in my label?
Any help always appreciated, thanks.
If text in label is specified before popover shows, you can achieve this by using similar code in viewDidLoad method:
- (void)viewDidLoad {
[super viewDidLoad];
// ...
CGFloat height = [label.text sizeWithFont:label.font
forWidth:label.frame.size.width
lineBreakMode:label.lineBreakMode].height;
// This calculates only height of the label, you may want to add some margins, etc.
CGSize size = CGSizeMake(self.view.frame.size.width, height);
self.contentSizeForViewInPopover = size;
}