I have a UICollectionViewCell subclass that I have defined in a nib...
It uses AutoLayout to layout all of the (two, lol) components. The date picker is laid out with left, right and bottom constraints to the superview and a height constraint to make sure it always shows full content.
Then, when configuring the layout of the collection view I use this...
_layout = [[UICollectionViewFlowLayout alloc] init];
_layout.itemSize = CGSizeMake(CGRectGetWidth(self.collectionView.frame), CGRectGetHeight(self.collectionView.frame));
_layout.minimumInteritemSpacing = 0;
_layout.minimumLineSpacing = 0;
This works as when I'm debugging the view I can see that the frame of the UICollectionViewCell is correct, but the content of the cell is not resizing as you can see from these two screenshots.
Collection View Cell selected and is correct.
Content of collection view selected and is not correct.
In fact, you can see that the content is the same size and shape as defined in the nib. But
this should resize to match the cell size. If I make the nib content really small it stays really small in the app.
This is, potentially, happening in UITableViewCells too as the cell separators are not showing all the way across the screen for bigger devices.
Related
I am having abit of trouble here trying to make this post description label to grow and shrink based on content size on IOS9. I have a view (I will refer it topView) that I am using as a header for the tableview (So when I scroll up the header disappears). Inside the topView, there are a bunch of stack views. I wish to grow and shrink the post description label in height based on content size. I do know how to do it in simple case where everything is inside the prototype cell (i.e. set estimated row height and set uitableviewautomaticDimensions, set sizetoFit on label and change number of lines to 0). However, this is a different case because the post description label is not really inside the cell, it is in its view before the table view cells.
Note that all items in the view has static height except the postdescription label. Post description label is inside a stack view that is pinned only left and right (So that top and bottom would grow?). Also, the main stack view that contains all elements is pinned towards the four sides with the topview that contains the main stack view also pinned towards the four sides. With this setup, I would expect the topview to grow and shrink based on the content size. However, I do not see that in the output. I dont know if it is the stackview that is holding the label refusing to grow or the top view refusing to grow to allow more space for the stackview for the label. Thanks
UPDATE
Thanks Riadluke, I tried doing something as suggested which is resizing the headerview after calculating the required height. I have placed the following code in viewDidLayoutSubview and it works with an issue
postDescriptionLbl.sizeToFit()
let headerView = commentTableView.tableHeaderView!
headerView.setNeedsLayout()
headerView.layoutIfNeeded()
let height = TopStackView.frame.size.height + ImageStackView.frame.size.height + postDescriptionLbl.frame.size.height + SpacerStackView.frame.size.height + BottomStackView.frame.size.height
headerView.frame.size.height = height
commentTableView.tableHeaderView = headerView
The issue I now have with this method is that when the view controller appears, I can physically see the postDescription label height grow from the default height in storyboard to the required height. For example, when the VC first appears, I see a line of label with some string being cut off, however after 0.5 second, the headerview and the label grow to the size that I wanted. I know this would be expected because I was calling the manipulation after the viewDidLayout Subview. I was wondering if there is a better way such that I dont see that transition and the view appears to be the right height straight away. Ie. let the view know exactly how high the label is to determine how high the headerview needs to be before appearing on screen?
I'm afraid the view set as tableHeaderView of a UITableView does not get resized automatically. Its height will be fixed to the height it had in IB.
What you have to do is set its size manually and then reassign it as the tableHeaderView so it is displayed in the height you want.
It could take only few lines since you're using autolayout.
You can try this code right after you've set the header view's contents:
//for the target size you have set the width as your tableView's width when it is already displayed on screen.
//note that when it is accesed inside viewDidLoad the tableView's bounds
//may be different to the actual bounds it will be displayed with,
//here I am just using the screen bounds
let targetSize = CGSize(width: UIScreen.mainScreen().bounds.width, height: 10000)
//set the tableHeader's size to its size after its layout constraints are resolved
tableHeader.bounds.size = tableHeader.systemLayoutSizeFittingSize(targetSize)
//reassign it as the tableHeaderView to update the height it will be displayed in
tableView.tableHeaderView = tableHeader
After many many attempts, I could not get anything to work with the original setup. The best I achieved was to resize it after view did appear which is not idea as you see the previous layout.
It is now working with a complete different approach. I have created two prototype cell and have one as "HeaderViewCell" and implemented the following functions
commentTableView.estimatedSectionHeaderHeight = 400
commentTableView.sectionHeaderHeight = UITableViewAutomaticDimension
func tableView(tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
Everything works like a charm after that.
Context
I am trying to create something similar to a Table view using UICollectionView.
I am using Xcode7 and storyboarding.
The way I do it is that I drag the collection view across the entire controller view.
And then I drag the entire cell across the row and align it with the right and left boundaries.
Problem
But, when I place a label inside the cell, then it gets displayed correctly only when the device is in a horizontal position.
When the device is vertical, it gets cut off at the left boundary.
Question
How do I ensure that the width of the collection view cell matches that of the container width?
1) Implement the function of cell size and return the collection width:
-(CGSize) collectionView: (UICollectionView*) collectionView layout:(UICollectionViewLayout*) collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath*) indexPath {
CGFloat height = 50; //set the wanted height
return CGSizeMake(collectionView.frame.size.width,height);
}
2) Reload the collection when the screen size change (i.e. orientation change).
It is because you are not using autolayout. You can achieve this entirely in storyboard or through code.
Using Storyboard
Add UICollectionView in your UIViewController in storyboard.
Drag UICollectionView to fill up in your UIViewController.
Add Constraints as shown in image.
Drag UICollectionView to fill up in UICollectionView.
Add UILabel (Or whatever you want to have in cell). Also add constraints in that element.
Build and run.
I have a UIView that is a footerview of a uitableview. At run time, the user enters text into a uitextview within the footerview that should adjust to the size of the text content with a height constraint in autolayout.
All other objects in the view (labels, imageviews) have appropriate constraints to accommodate the expansion of the textview.
HOWEVER the height of the overall footerview will not change size, and it is impossible to use autolayout on the tableview footerview height.
Does anyone have a solution? Thanks
Haven't found an actual, elegant, solution yet, but I've postponed fixing this by using a workaround:
Setting the frame of the view used as a footer to be as large as you might possible need. In my case this meant giving it about 60px of spare vertical room. Since it's the footer and there's nothing below it to reposition the user won't be affected by the workaround.
The contents of the footer view are pinned to the top and have enough space to expand when needed.
For the record: my view is loaded from a nib file.
Although in theory the size one gives to the top level view in interface builder is just for design-time and the runtime size should be calculated based on constraints and the resulting intrinsic size, for this specific case I found the height stays the same as it was in IB.
We can change the height of the footer view run time by the following code:
func methodToChangeTableViewFooterHeight()
{
var footerView:UIView = self._tableView.tableFooterView! as UIView
var frame:CGRect = footerView.frame
frame.size.height = self.heightCollectionCS.constant + 10
footerView.frame = frame
self._tableView.tableFooterView! = footerView
}
Here , self.heightCollectionCS.constant is the height constraint for our Collection View.
We can use text content height on that place.
You may try to set again the footer view each time you footer height changes, to inform the table it should change the footer height. Or use inset. From within the footer view:
SetNeedsLayout()
LayoutIfNeeded()
ownertable.TableFooterView = this
Sorry about that, misread that question long ago. You can access the footer directly through the tableview's property tableFooterView.
What you could do is create your default footer in a xib or in your viewDidLoad:. Once you need to increase the size of the footer, you can pull out the UIView from that property and edit its frame if necessary to make it larger.
So make sure the tableFooterView gets assigned a UIView because it is nil by default. To just make the height taller, you can use self.tableView.tableFooterView.frame = CGRectMake(whatever rect you need);
I am using a UICollectionView with fixed size CollectionViewCells. I display this CollectionView in a popOver with an UIPopoverController.
My goal is that the popOver automatically resize to the CollectionView's content. So if I only have 4 cells, than it should be small. And if I have more cells, it should be bigger. I want to avoid the empty space left in the popOver.
So I don't want a fixed popOver size, but a variable one depending on the number of cells in the CollectionView.
Any suggestions?
I had a hard time figuring this out myself but just got it finally. You have to access your Collection View's collectionViewLayout property and then use the collectionViewContentSize method to get the size of your content. You can then use those to resize your Collection View by setting it's frame.
CGRect rectangle;
rectangle = _collectionView.frame;
rectangle.size = [_collectionView.collectionViewLayout collectionViewContentSize];
_collectionView.frame = rectangle;
Now that your collection view is sized to it's content, you can set the popOver's size based on the collection view size. It may look something like this.
popOver.frame = _collectionView.frame;
or
[popOver sizeToFit];
I have a grouped tableView in my iPad-app, and I've been trying to set cell.imageView.center = cell.center to center the image instead of putting it to the leftmost position. This is apparently not possible without a subclass of the UITableviewCell(If someone could explain why, that'd also be appreciated.. For now I just assume they are 'private' variables as a Java-developer would call them).
So, I created a custom tableViewCell, but I only want to use this cell in ONE of the rows in this tableView. So in cellForRowAtIndexPath I basically write
cell = [[UITableViewCell alloc]initWith//blahblah
if(indexPath.row == 0)
cell = [[CustomCell alloc]initWith//blahblah
This is of course not exactly what I'm writing, but that's the idea of it.
Now, when I do this, it works, but the first cell in this GROUPED tableView turns out wider than the rest of them without me doing anything in the custom cell. The customCell class hasn't been altered yet. It still has rounded corners though, so it seems it knows it's a grouped tableView.
Also, I've been struggling with programmatically getting the size of a cell, in cellForRowAtIndexPath, I've tried logging out cell.frame.size.width and cell.contentView.frame.size.width, both of them returning 320, when I know they are a lot wider.. Like, all the rows are about 400 wide, and the first cell is 420 or something. It still writes out 320 for all the cells..
This code will not work for a couple of reasons:
cell.imageView.center = cell.center;
Firstly, the center is relative to its superview. I believe the cells superview is the tableView. The imageView's superview will be the content view of the cell. Therefore the coordinate systems are different so the centens will be offset. E.g. the 3rd cell down will have a center of 0.5 widths + 3.5 heights. You should be able to ge around this issue by doing:
cell.imageView.center = CGPointMake( width / 2 , height / 2 );
The second issue is related to how the table view works. The table view manages its cells view's. The width of a cell is defined by the table view's width and the height is defined by the table view's row height property. This means the cell itself has no control over its size.
You can however size its subviews, but you must do this after the cells size has been set (otherwise you can get strange results). You can do this in layout subviews (of the custom UITableViewCell class). See this answer.
- (void)layoutSubviews {
[super layoutSubviews];
self.imageView.frame = ....
}
When layoutSubviews is called the cells frame has been set, so do your view logging here instead of cellForRowAtIndexpath.
As for the GROUPED style. Im not sure if this is designed to work with custom views. I suspect it sets the size of its cells to its own width minus a 20 pixel margin on each size, then applies a mask to the top and bottom cells in a section to get the rounded effect. If you are using custom view try to stick with a standard table view style.