iphone code for auto uiLabel & uiTableViewCell resizing when font changed? - iphone

Can someone summarise the key pieces of objective-c code that would assist in solving this.
Objective - Autoresize a UITableView after a user changes the font size. Therefore if the user increases or descreases font both the (a) uiLabel heights should change to ensure they nicely include text, and (b) uiTableViewCell heights should also adjust.
Assumption is that:
UITableView has been extended via
creation of a custom cell view -
i.e. create a new view in a NIB that
forms for the content view of the
UITableView cells
each custom
cell has four UILabel's which form a
2 x 2 patter of UILabels - i.e. two
on top line and two on bottom line
so as the user increases the font
the horizontal spacing of the
UILabels would remain the same,
however the label heights would
change
So I assume the challenge / questions I have would include (and hopefully be answered by some sample code that someone can post)
Is it OK that the starting point here is an already laid out custom UITableViewCell in InterfaceBuilder? (or does the solution require it is constructed totally programmatically)?
How to calculate the heights the label's should be? Is this just with the NSString method "sizeWithFont:minFontSize:actualFontSize:forWidth:lineBreakMode:", and do I need to add addition for margins etc?
How programmatically to increase the height of the labels dynamically - in which method do you do this & how to change the height itself
How to ensure that when UILabel at the top is expanded & grows, that it automatically pushes down the UILabel on the 2nd row? Does this happen by default or is there a specific property/setting you have to you to ensure this hapens.
How to then automatically increase the height of the TableViewcell, after the above has occurred. Which method to do this in, and how programmatically to perform the increase & redraw.
Hope this makes sense.
thanks

You can base on the XIB file as a default layout, then adjust the position/size later during runtime.
Yes use that method to calculate the required height. You need to add margins between labels yourself.
Change the label's frame.
You need to calculate the x,y of the 2nd row's label base on the x,y,height from the 1st row's label + margin.
hook with the following method and return the new height:
(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath

To get the UILabel's height to match your target font, you use the sizeWithFont function of NSString.
NSString *myText = #"Go Hokies";
UIFont *myFont = [UIFont boldSystemFontOfSize:15];
CGFloat lineHeight = [myText sizeWithFont:myFont].height;
The problem you may run into is if the text doesn't fit horizontally in the bounds you've defined. If you want the font to downsize accordingly, turn on the adjustment flag and set a min like this.
myUILabel.minimumFontSize = 10;
myUILabel.adjustsFontSizeToFitWidth = YES;

Related

Dynamically set UIScrollView height and UITableView Height depending on content

Setup: I have a scrollview with a label, uiimage, and a tableview (grouped) nested within. The label, uiimage, and tableveiw are populated by a webservice. The last section in the grouped table view contains text that will never be the same and could be as long as 5 characters to 250+. Also, this view is pushed from a basic tableview (so it has a navigation bar. If that matters at all).
Expected: The tableview should extend in height depending on the length of the content received from the web service. Then set the scrollview height to accommodate the height of the tableview
Problem: I'm not quite sure how to approach the issue. I really only know how to change the height to fixed values, which will not work properly in many scenarios.
The width and height of the cell are ignored; the cell cell is re-sized according to the value you return from -tableView:heightForRowAtIndexPath: or (failing that) tableView.rowHeight. It might appear as if the cell is big enough if the label in the cell is sized to be big enough, because the label is allowed to be bigger than (and render outside) the cell.
One way is to override -tableView:heightForRowAtIndexPath: to return the correct height. This isn't really the intended use of UITableView (it's primarily designed for lots of rows of a single height, dynamically generated from a list of content).
Another way is to set tableView.tableFooterView = myCustomFooter instead. This is probably the easiest way. Size it correctly before performing the assignment (the height matters; the table view will set the width for you anyway). Also make sure that the autoresizing flags are not set, or the size will appear to randomly change when the table view changes size (e.g. on autorotation).
I'd just focus on the variable height element, figure out the height that fits the text there. To figure out the height that a string will take when rendered use a snippet like this:
CGFloat MY_TABLECELL_WIDTH = 320;
CGFloat MY_MAX_HEIGHT = 10000;
UIFont *MY_FONT = nil; // load the correct font here.
CGSize maxSize = CGSizeMake(MY_TABLECELL_WIDTH,MY_MAX_HEIGHT);
CGSize textSize = [serverString sizeWithFont:MY_FONT
constrainedToSize:maxSize
lineBreakMode:UILineBreakModeWordWrap];

How to configure iOs UITextViews and UILabels so that their height is determined by their content

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/

Adjusting the width of a UILabel in UITableViewCell based on the width of a second UIView in the Cell

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.

Multi-line UITableViewCell using UITableViewCellStyleValue2 style

I'm trying to figure out how to replicate the UITableViewCellStyleValue2 style so that the detail text can be multiple lines - as seen in the 'address' cells in the Contacts app. Like the Contacts app, some of the fields (like street name) are optional; so it would show say 3 lines instead of 4, if the street was not nil.
I'm I missing a trick, or do I have to create a custom cell in IB? How to ensure the text and detail text labels line-up with other UITableViewCellStyleValue2 cells?
Thanks for any tips.
Another round of searching found this:
http://the-lost-beauty.blogspot.com/2009/11/multi-line-uitableviewcell-using.html
Quickly tried it, and it works - just need to set the font size down a bit.
It sounds to me like you'll have to create a custom UITableCell. The only way to ensure the text lines up is to get the margin/text width values correct, which can be done via trial and error, or using a measuring tool such as xScope.
Create a custom cell for you table and place a UILabel and a UITextView inside it. Position the label & text view to match their x,y positions to the other cells you are using in that table. You insert "\n" in the textview's text wherever you want line breaks to occur. You resize the textview height depending on the number of lines in the textview using something like:
CGRect frame = yourTextView.frame;
frame.size.height = yourTextView.contentSize.height;
yourTextView.frame = frame;
return frame.size.height + 20.0; // Pad the cell's height as necessary for your applicaion
I also had the problem that the textLabel and the detailTextLabel had a different position. Solution: For the detailTextLabel use the same height like the textLabel (e.g. 13)

UITableViewCell - how to make right UILabel truncate instead of left one?

I have created a UITableViewCell using UITableViewCellStyleValue1, which the Apple docs define as:
A style for a cell with a label on the left side of the cell with left-aligned and black text; on the right side is a label that has smaller blue text and is right-aligned. The Settings application uses cells in this style.
I am trying to set the cell text to display some short text on the left, and some long text on the right, e.g.
URL http://www.mylongurl.com/subdirectory/etc
My problem is that the left UILabel gets truncated instead of the right one so it displays as:
U... http://www.mylongurl.com/subdirectory/etc
If I make the URL even longer then BOTH the labels get truncated, e.g.
U... http://www.mylongurl.com...subdirectory/etc
Is there any way to make the right UILabel truncate instead of the left one without using a custom UITableViewCell? I know how to create a custom UITableViewCell, but it seems like overkill?
I can set the UILineBreakMode to change where the text truncates within the UILabel, but I can't see a way to make the detailTextLabel adjust its width to let the textLabel display itself.
[[lCell textLabel] setText:#"URL"];
[[lCell detailTextLabel] setText:#"http://www.mylongurl.com/subdirectory/etc"];
[[lCell detailTextLabel] setLineBreakMode:UILineBreakModeMiddleTruncation];
You have a couple of options.
Probably the closest in spirit to what you seem to be asking for is to muck around with the label frames in your UITableViewDelegate's tableView:willDisplayCell:forRowAtIndexPath:. (Doing cell layout modifications in your UITableViewDataSource's tableView:cellForRowAtIndexPath: won't fly, since UITableViewCells do all their own internal layout work after tableView:cellForRowAtIndexPath:.) You can use NSString's -sizeWithFont: to help figure out the layout requirements for your textLabel.
You can also take different approaches, as you mentioned, such as subclassing UITableViewCell or setting cell.textLabel.adjustsFontSizeToFitWidth = YES.
The best solution would be to create a subclass of UITableView cell and set your customizations to the labels like you have here in init. You will probably want to override layoutSubviews and resize the labels if you want the left one to be wider.
- (void)layoutSubviews {
[super layoutSubviews];
self.textLabel.frame = CGRectMake(0.0, 0.0, 100.0, self.frame.size.height);
self.detailTextLabel.frame = CGRectMake(0.0, 0.0, 220.0, self.frame.size.height);
}
Obviously those are arbitrary values. You will want to play with different sizes to meet your needs.