AutoLayout multiline UILabel cutting off some text

Question

I\'m trying to learn auto layout, finally thought I was getting the hang on it when this happened. I\'m playing about with prototype cells and labels. I\'m trying to have a

Answer 1

Found an even better answer after reading this: http://johnszumski.com/blog/auto-layout-for-table-view-cells-with-dynamic-heights

creating a UILabel subclass to override layoutSubviews like so:

- (void)layoutSubviews
{
    [super layoutSubviews];

    self.preferredMaxLayoutWidth = CGRectGetWidth(self.bounds);

    [super layoutSubviews];
}

This ensures the preferredMaxLayoutWidth is always correct.

Update:

After several more release's of iOS and testing more usecase's i've found the above to not be sufficient for every case. As of iOS 8 (I believe), under some circumstances only didSet bounds was called in time before the screen load.

In iOS 9 very recently I came across another issue when using a modal UIVIewController with a UITableView, that both layoutSubviews and set bounds were being called after heightForRowAtIndexPath. After much debugging the only solution was to override set frame.

The below code now seems to be necessary to ensure it works across all iOS's, controllers, screen sizes etc.

override public func layoutSubviews()
{
    super.layoutSubviews()
    self.preferredMaxLayoutWidth = self.bounds.width
    super.layoutSubviews()
}

override public var bounds: CGRect
{
    didSet
    {
        self.preferredMaxLayoutWidth = self.bounds.width
    }
}

override public var frame: CGRect
{
    didSet
    {
        self.preferredMaxLayoutWidth = self.frame.width
    }
}

Answer 2

I'm not sure I understand you right and my solution is really far from the best one, but here it is:

I've added a height constraint on label that was cut, connected that constraint to cell's outlet. I've overrided layoutSubview method:

- (void) layoutSubviews {
    [super layoutSubviews];

    [self.badLabel setNeedsLayout];
    [self.badLabel layoutIfNeeded];

    self.badLabelHeightConstraint.constant = self.badLabel.intrinsicContentSize.height;
}

and viola! Please try that method and tell me results, thank you.

Answer 3

I did spend some time with wrapping up the cell, looking like this:

+--------------------------------------------------+
| This is my cell.contentView                      |
| +------+ +-----------------+ +--------+ +------+ |
| |      | |    multiline    | | title2 | |      | |
| | img  | +-----------------+ +--------+ | img  | |
| |      | +-----------------+ +--------+ |      | |
| |      | |     title3      | | title4 | |      | |
| +------+ +-----------------+ +--------+ +------+ |
|                                                  |
+--------------------------------------------------+

After many attempts I did came with a solution how to use prototype cell that is actually working.

Main trouble was that my labels could be or could be not there. Every element should be optional.

First of all, our 'prototype' cell should only layout stuff when we are not in "real" environment.

Therefore, I did create flag 'heightCalculationInProgress'.

When somebody(tableView's dataSource) is asking to calculate height we are providing data to prototype cell using block: And then we're asking our prototype cell to layout the content and grabbing height out of it. Simple.

In order to avoid iOS7 bug with layoutSubview recursion there is a "layoutingLock" variable

- (CGFloat)heightWithSetupBlock:(nonnull void (^)(__kindof UITableViewCell *_Nonnull cell))block {
    block(self);

    self.heightCalculationInProgress = YES;

    [self setNeedsLayout];
    [self layoutIfNeeded];

    self.layoutingLock = NO;
    self.heightCalculationInProgress = NO;

    CGFloat calculatedHeight = [self.contentView systemLayoutSizeFittingSize:UILayoutFittingCompressedSize].height;
    CGFloat height = roundf(MAX(calculatedHeight, [[self class] defaultHeight]));

    return height;
}

This 'block' from the outside could looks like this:

[prototypeCell heightWithSetupBlock:^(__kindof UITableViewCell * _Nonnull cell) {
    @strongify(self);
    cell.frame = CGRectMake(0, 0, CGRectGetWidth(self.view.frame), 0);
    cell.dataObject = dataObject;
    cell.multilineLabel.text = @"Long text";
    // Include any data here
}];

And now starts the most interesting part. Layouting:

- (void)layoutSubviews {
    if(self.layoutingLock){
        return;
    }

    // We don't want to do this layouting things in 'real' cells
    if (self.heightCalculationInProgress) {

    // Because of:
    // Support for constraint-based layout (auto layout)
    // If nonzero, this is used when determining -intrinsicContentSize for multiline labels

    // We're actually resetting internal constraints here. And then we could reuse this cell with new data to layout it correctly
        _multilineLabel.preferredMaxLayoutWidth = 0.f;
        _title2Label.preferredMaxLayoutWidth = 0.f;
        _title3Label.preferredMaxLayoutWidth = 0.f;
        _title4Label.preferredMaxLayoutWidth = 0.f;
    }

    [super layoutSubviews];

    // We don't want to do this layouting things in 'real' cells
    if (self.heightCalculationInProgress) {

        // Make sure the contentView does a layout pass here so that its subviews have their frames set, which we
        // need to use to set the preferredMaxLayoutWidth below.
        [self.contentView setNeedsLayout];
        [self.contentView layoutIfNeeded];

        // Set the preferredMaxLayoutWidth of the mutli-line bodyLabel based on the evaluated width of the label's frame,
        // as this will allow the text to wrap correctly, and as a result allow the label to take on the correct height.
        _multilineLabel.preferredMaxLayoutWidth = CGRectGetWidth(_multilineLabel.frame);
        _title2Label.preferredMaxLayoutWidth = CGRectGetWidth(_title2Label.frame);
        _title3Label.preferredMaxLayoutWidth = CGRectGetWidth(title3Label.frame);
        _title4Label.preferredMaxLayoutWidth = CGRectGetWidth(_title4Label.frame);
    }

    if (self.heightCalculationInProgress) {
        self.layoutingLock = YES;
    }
}

Answer 4

Omg, just have had the same issue. The @Simon McLoughlin's answer did not help me. But

titleLabel.adjustsFontSizeToFitWidth = true

did a magic! It works, I don't know why but it does. And yes, your label must have an explicit preferredMaxLayoutWidth value either.