UIScrollView with variable height - ios

I have a scrollView with a UIView as subview, which in turn has many subviews, one of which is a textView with variable height. This is the hierarchy of views:
-UIScrollView
- UIView
-UITextView with variable height
-UImages
As can dynamically vary the height of the UIView and finally the scrollView based on the length of the content?

When the user edits your UITextView field, get its bounds height and recalculate the overall size of you scrollable view, then set UIScrollView's contentSize property.
You can detect the end of editing on a UITextView object by means of its UITextViewDelegate textViewDidEndEditing: method.

Related

Unable to increase the height of UIView in relation to TextView

I used the vertical stack view to hold two UIView.Second UIView has a textArea.But I could not find a way to change the UIview height when the height of TextView change

UITableView dynamic content size height inside UIScrollView with AutoLayout

I have a UIScrollView, inside this UIScrollView I have a UIView and inside the UIView I have some UITextField's, some UILabel's and at the bottom there is a UITableView.
I want the UITableView to fit it's content height, the UIView to fit it's content height and the UIScrollView to fit it's content height.
The UITableView height might change as I add / remove cells from it during usage.
What is the best way to handle it using AutoLayout?
- UIViewController
-- UIView
--- UIScrollView
---- UIView
----- UILabel
----- UITextField
----- UITextView
----- UITableView (at the bottom of the superview)
or as in the xib:
The best way to implement this is to scrap the hierarchy that you have now and do the following...
- UIViewController (or UITableViewController)
--- UITableView
----- UIView (as the tableView.tableHeaderView)
------- UILabel
------- UITextField
------- UITextView
----- Rest of the cells for the table view.
The tableView.tableHeaderView is a single (not reusable, concrete) view that is placed at the top of the content of the table view and scrolls with the content of the table view. It doesn't stick to the top of the screen like a section header view does.
This will allow you to delete the scroll view and place everything inside the table view and still doesn't change the methods that you are using to populate the cells as that remains untouched.
#Jan Greve is correct. But if you still want to do it
Set Bottom Space to Container constraint between the Table View and its super view to 0
Increase/decrease the height constraint of the Table View with each insert/delete (You will have to do this programmatically)
Set the content offset of the scrollview to the new view height
The best part of AutoLayout is now you don't have to worry about UIScrollView content size.
If you set all constraints properly(without any warnings) AutoLayout manage content size for scrollView itself.
Set all subview's constraints but don't add height and width constraints.
And for contentSize add bottom constraint of inner view (subview of scrollview) to UIScrollView. This will increaser scrollView content size and height as per inner view expand or shrink.
For more details: I asked question for same, you can check it. You can find code in question itself.
You can set a fixed height to the tableView and link the constraint to an outlet. Then you'd need to override viewDidLayoutSubviews() in order to set the height dynamically based on the contentSize of the table:
#IBOutlet weak var dynamicTVHeight: NSLayoutConstraint!
internal override func viewDidLayoutSubviews() {
let height = min(self.view.bounds.size.height, self.tableView.contentSize.height)
self.dynamicTVHeight.constant = height
self.view.layoutIfNeeded()
}

Scrollview content size set to screen width max

In my view I have a scrollview.
In my scrollview I have a UILabel.
I use constraints to set my scrollview in my superview and also for my UILabel.
If I set a long text inside my UILabel the scrollview's content extends to the width of my UILabel.
Instead of that, I would like the content view set to maximum width of my screen and the UILabel goes to multilines.
How can I do this ?
Try setting your label's number of line to 0 and preferredMaxLayoutWidth the width you want, then call setNeedsLayout with your main view.

UIScrollView does not Scroll completely

I have a ViewController. In it I put ScrollView with the View(contentView). Later I drag from contentView to View and set Equal Height. Now it scrolls, but not fully.
As you see there are it has continue below the textView, but it
doesn't scrolls. How can I fix it?
UIScrollView is able to automatically calculate it's content height and width, but you need to help it with this.
To do so you need to:
Bound contentView (in your case) to all sides of superview (which is Scroll View).
Let contentView to calculate it's sizes. Here is a small mistake in your approach. You've set height of the contentView equal to View's height. So basically Scroll View's contentSize.height is the same as View's height. Which is not really what you want with dynamic content.
Usually you want to set width of the contentView equal to View's width and do not set contentView's height. Instead you want to bind subviews of contentView to their superview in such a way that their superview (contentView) will calculate it's height automatically.
In your case I would bind:
pizza.jpg to left-top-right of superview (height of pizza.jpg will be set from intrinsic image size);
SAMPLE TITLE label - left-right to superview; top to pizza.jpg image;
Text View - left-bottom-right to superview; top to SAMPLE TITLE label; set a fixed height.
In this case contentView will define needed height by itself. Scroll View will set it's contentSize accordingly.
And your screen will be able to scroll vertically (it should be) ;)
You need to set the contentsize of the scrollview. Use the below code to do that:
func viewDidLayoutSubviews()
{
super.viewDidLayoutSubviews()
self.scrollView.contentSize = CGSizeMake(self.view.frame.size.width, self.contentView.frame.size.height);
}
To use Autolayout with UIScrollView is tricky.
In your code you have to update height constraint for your contentView by calculating height of subviews of contentView and that will automatically update the contentSize for your ScrollView and you can scroll through all subviews.
For more info to use Autolayout+UIScrollView your can read this.
According to this link (thanks to this Matt's answer first), UIScrollView acts differently with AutoLayout than the other views.
Subviews of a scrollView set their constraints from the contentView of the scrollView and not the scrollview directly. This allows the content to scroll.
So :
Add a UIView to your scrollView, this will represent the contentView of your scrollView. Add constraints to top, bottom, trailing, leading from the view to its superView
Interface Builder complains. Here you see the different between a basic view and a scrollView. The reason is a contentView has to be fill to know its size. So add a equal width from the contentView to the scrollView
The contentView knows now its width but not its height. So add your labels and your UIImage as subviews of the contentView. Add constraints from bottom to the top. Don't miss to add a height constraint to the UIImageView.
It should look like this :
Hope this helps
Read this (from Matt once again) for further informations

UIView within UIScrollView keeps setting its width and height to 0

My directory structure is this:
UIView
UIScrollView
UIView
Label
Label
I want to be able to center the uiView (the second one) to adjust its width for iphone 6. I set the uiscrollview width and height to constraint with 0 on all sides. Then when i set UIView constraints to all 0, which makes the uiview disappear. I don't know why it's disappearing?
If you are using autolayout with scrollView, you have some options.
First, you can set width and height constraint to contentView, so scrollView gets it as a contentSize. Second (in addition to first), you can fill the scrollView of views with size constraints. Third, you can set contentSize manually. Forth, you can make outlets for contentView size constraint and set them in viewWillLayoutSubviews manually.
So, your view dissappear because contentSize of scrollView is zero.

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