I would like the Subtitle-style cells in my iOS 8 table view to resize automatically in height to allow subtitle content of any number of lines. And, I would like to accomplish this without using custom cells, if possible. That is, I would like to use the "canned" prototype cells that are available when dragging a new TableViewController to the story board.
I have found that this is easy to do with Basic-style cells: that is, prototype cells with Style set to "Basic" so that there is just one label in the cell -- "Title", by default. This is the label that is accessible by cell.textLabel!.text in code. If I set that textLabel's number of lines to 0, and add the two lines below to viewDidLoad(), then the cell heights resize automatically:
tableView.estimatedRowHeight = 144.0
tableView.rowHeight = UITableViewAutomaticDimension
All without having to define a custom cell or muck around with auto-layout or constraints. (In fact, I find it's not possible to add constraints to a canned prototype cell.)
But if I change the cell Style to "Subtitle," so that there are two labels in the cell -- textLabel and detailTextLabel in code -- then the cells do not automatically resize in height, even after setting both (or either) line numbers to 0 and playing around with different estimatedRowHeight values.
Am I missing something, or is it not possible to automatically resize cell height without a custom cell?
Thank you!
or is it not possible to automatically resize cell height without a custom cell?
Yes, it is not possible. And the reason is the reason that you gave. The automatic-resizing-cell-height feature depends upon internal constraints. But, as you have rightly said:
it's not possible to add constraints to a canned prototype cell.
However, note that you can accomplish what you want without supplying a cell subclass (though personally I like supplying one). You can just design your cell, constraints and all, right there in the prototype cell — the Custom prototype cell.
Related
I have a UITableView. The height and content of each cell of the table view varies, depending on the data feeding to the cell. To give an example - some might have pictures, some might only have text; some might have 1 picture, some might have more than 1 picture. So, I am thinking about subclassing the UITableViewCell so I can use the subclass in other table views that I might have.
Is there some sample code that I can follow to achieve that goal - subclassing UITableViewCell, varied content, varied height?
This has been asked many times.
Also, you don't need to subclass to get variable row height, nor to put custom controls into the cell, but for the latter case subclassing may be convenient.
I am basically trying to find the correct way to design a UITableViewCell that has two UITextViews and three UILabels inside it. The two UITextViews have dynamic content and their size cannot be determined until runtime.
I have tried various methods of recalculating the height of my UITextViews based on the content that is loaded in them at runtime, and though very laborious and inane, I have gotten that to work, but they then bleed over the UILabels positioned in the xib below them.
Do I really have to recalculate the y coordinates of every UILabel after calculating the new size of the UITextViews? Is there a way to simply have the elements in the xib 'push' the elements below them down based on their new size?
What is the correct approach to configuring a UITableViewCell with multiple dynamic text views so that my entire application is not comprised of code to calculate heights and coordinates?
Or is the answer that I should not be putting more than one dynamic UITextView in the same UITableViewCell ?
I have used something like this for a cell to calculate its height in
tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
function
CGSize labelSize = [self.comments sizeWithFont:[UIFont fontWithName:#"Verdana" size:17.0]
constrainedToSize:CGSizeMake(280.0f, MAXFLOAT)
lineBreakMode:UILineBreakModeWordWrap];
return labelSize.height + 20;
+20 is for padding.
and also if you are having every cell like the one you mention above, than you can create a class of UITableViewCell with following UIView elements inside it.
iOS doesn't seem to have any sort of flow layout engine -- at least none that I can think of.
If, however, your labels are located at the bottom of your UITableViewCell, you might be able to get away with setting the UILabel's autoresizingMask mask property to UIViewAutoresizingFlexibleBottomMargin so that the UILabels will anchor itself at the bottom. This is assuming that you already adjusted the size of the UITableViewCell to fit the entire controls. Otherwise, I think the best way to handle this is to recalculate the y coordinates of the labels.
I found it useful to add this sort of behavior as a category on UIView so a view can resize one of its subviews to fit some arbitrary text, and optionally resize the parent view to fit the newly enlarged subview as needed.
http://blog.carbonfive.com/2009/07/10/resizing-uilabel-to-fit-text/
How can we set Separator style at cell level. i.e. each cell will be having different separator style?
I don't think you can set the cell separator style per cell. You might try setting the table view separator to UITableViewCellSeparatorStyleNone and then draw a custom "separator" yourself when you render out each cell.
Edit: How to do it depends a lot on your current code, what type of table, whether you are using a custom table cell, what exactly you mean by "different separator style", etc.
I have not tried this, but one option I can think of off the top of my head would be to use the UITableViewCell.backgroundView property. You could add a subview with a different color that is only a few pixels high along the bottom or you could create a UIImageView that fills the backgroundView and set the image to achieve the "different" separator.
I have a UITableViewCell with two subviews, a UILabel on the left, and a random input control on the right. The random input control on the right can vary in size, as can the length of the text, but since I can set the word wrap of the text on the left, I need to be able to adjust the size of the UILabel based on the width of the random input control. To complicate matters, the app needs to work in both portrait and landscape modes, which give the table cells different widths.
This wouldn't be difficult if I could read the width of the table cells and set the widths of its subviews appropriately, but at creation time the width of the cell is 0.
Any ideas?
Nothing easier than that: every UITableViewCell is also a UIView, which has a method designed for just that: layoutSubviews, which is called whenever the view (here: cell) needs a re-layout. This is where you lay out the content.
Question
How can you detect when the Table View is done drawing the cells?
Issue
I got two labels within the contentView of an UITableViewCell. The size of these labels are dynamic. I was able to do so by subclassing UITableViewCell, in the drawRect method I adjust the frames of the two labels depending on their content. Now I want to align all the second labels.
My Thoughts in Steps
Determine the content in the table view and let it load automatically.
Run through the table view cells and determine the x position of the second label within the UITableViewCell that is the furtherest away.
Store this x position and when any cell is drawn use this x position to place the second label.
The problem is that if I use the following code:
for (int row = 0; row < [self.tableView numberOfRowsInSection:section]; row++) {
UITableViewCustomCell *cell = (UITableViewCustomCell *)[self.tableView cellForRowAtIndexPath:[NSIndexPath indexPathForRow:row inSection:0]];
NSLog ([cell.labelTwo description]);
}
The second label has not yet been drawn, meaning I can't determine the size of the frame and thus can not find the proper x position to align all second labels.
I have tried subclassing the UITableViewController and looking at events such as viewDidLoad and viewDidAppear unfortunatly also in these events the cells aren't drawn yet.
What I Want ...
What I want is for the table view to draw the cells at least once so I can determine the sizes of the labels within the table view cell. I thought to accomplish this by looping through all the cells with cellForRow, but although it successfully returns the cell the content is not drawn yet meaning the frame remains with a width of zero.
Does anyone have a solution?
Thanks in advance,
Mark
Try calling sizeWithFont: on the contents of these labels to get the max width before you draw anything. You should be able to use it later in your cellForRowAtIndexPath: to adjust the width as you need.
I would recommend you reconsider using UITableViewCellStyleValue2 cells instead and attempt to configure the textLabel and detailTextLabel. I had a similar situation and this is how I did it.
First off, you really ought to just pick an explicit, fixed position at which the first label ends and the second one begins, based on what you know about the minimum and maximum lengths of the text that will be put in those labels. That would eliminate this problem entirely.
But if you want a solution: use the sizeWithFont: method or one of its cousins (see the Xcode docs). Specifically, loop through the values that will go in the first labels, apply sizeWithFont to each, and keep track of the largest width you see. (I'm assuming you have access to the values before they go in the cells; since they're dynamic, they must be passing through the table view controller, no?)
Now you have the value you seek, without having to perform the extremely wasteful operation of creating a bunch of cell objects and never using them for their intended purpose.
I think what you need to do is to add a viewController to the have the UITableViewController control the UITableViewCell itself so that you can capture the events of the labels loading. The viewController will have references to both labels so it can adjust them accordingly in response to -viewDidAppear.
I've never done this but a UITableViewCell is a view like any other so you should be able to set up a controller for it. You might need to manually activate the controller since you have no navigation controller to do it for you in this context.