For a simple example lets say I have a UITextView with a Button underneath it. These two controls are siblings both embedded in a parent UIView.
I now change the text within the UITextView and resize it accordingly. Is there a way to make the button automatically move to have the same relative distance to the bottom of the UITextView? This may seem trivial for this case, but I will have a longer hierarchy with multiple UITextViews that change and it would be nice not to have to calculate the height of every object manually.
One way to approach this would be with a table view: if you place each of your text views within its own table view cell, the table view will automatically calculate its total height from individual calls to its delegate’s -tableView:heightForRowAtIndexPath: method and lay itself out accordingly. Whenever the height of one of your text views needs to change, you can call -reloadData on the table view to make it lay itself out again. A disadvantage of this approach is that it’s really difficult to animate the height changes; if that’s essential to the effect you’re going for, I’m afraid you’re stuck with doing the entire layout manually.
Try the autoresizingMask property of UIView.
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I´m new trying to make some apps using objective c, so I´ve an idea using uitableview but I don't imagine how can I get this.
I´m trying to do something like you do in a spreadsheet where you have a fixed header and the first column too
So when scroll the uitableview vertically the header will stay visible at top of the table and rows will change
And finally when you scroll in horizontal direction the first cell of the row will stay visible and will change the header depending of how you scroll the uitableview
I hope you could give me an idea how to get this, because I don't imagine how to do this, also I don´t have a lot of experience with this programming language.
Thanks!
In a non-grouped table, section headers "stick" at the top of the table as the table scrolls. You can provide a custom UIView (or sub-class thereof) for a section header through the delegate method –tableView:viewForHeaderInSection:. This header view could be created on-the-fly programmatically or loaded from a NIB file. Either way, you can have it contain whatever you want, even update it as the app runs (provided you have given yourself access through ivars or class variables to the views contained in your header view.) If you go this route, you'll want to be clever about allocating resources that comprise this view, so that you are not constantly allocating new resources! This delegate method can be called frequently, and on all but the first call you could simply return the previously created (but updated as and if necessary) header view.
UITableView isn't designed to do this, although I am sure you could figure out some way eventually.
My approach would be to use a fixed UIView of some sort (possibly a UILabel, etc) in a UIViewController's nib as the header/locked cell, and add the UITableView under that. You couldn't then use a UITableViewController, but would have to implement the delegate and dataSource methods in your UIViewController, and use a UISwipeGestureRecognizer to pick up the gestures from the tableView and update the other views.
I've done this by adding a UIView that mimics the first cell in my table. In my case I am using a subclass of UITableViewCell, but that is perhaps not relevant. Normally this view is hidden with an alpha of 0.
If you view controller is the delegate of the UITableView then it will also be the delegate for the inherited UIScrollView. So in your view controller you can implement scrollViewDidScroll. When the scrollView's contentOffset is positive I set my custom view's alpha to 1 (I also do some small size tweaks to make sure there is a perfect match), and when the contentOffset returns to 0 or negative, I reset the alpha back to 0.
prepend the first row of data in your array to what ever in the first row is your headings, put the text in bold with attributed text, It wont be sticky but you will have headings...
I want to put a scroll view inside of the table view cell. I have a number of buttons in one cell of table view and I need to scroll that cell to show the appropriate button.
If you want to use a vertical scroll view then I wouldn't suggest you doing it because, as TechZen wrote, there will be a mess in this case.
If you want the inner scroll view to scroll horizontally then it might be achieved by 2 ways:
Implement a custom table view cell that will include a scroll view inside it.
Add a scroll view as a sub-view to your cell that you will return from tableView:cellForRowAtIndexPath: method.
I suggest you to use the second approach.
There are plenty of examples online. Usually the sub-views are labels or image views, but it is not complicated at all to add a scroll view instead...
I don't think you can do this. It would require nesting of scrollviews which isn't really supported.
Even if it was, it would be very difficult for a user to know which scrollview they were hitting with their pudgy finger. Remember, you don't have the one pixel precision of a mouse on the iPhone. You have an area of at least 15x15 pixels. You don't have a scroll bar but instead just drags anywhere on the screen.
Instead, you should use a master-detail pattern. Selecting the cell in the tableview pushes a detail view which has the scroll view with all the buttons.
Why do you want to do it like this?
I think the best idea is to draw your table view manually above your uiscrollview. I did it, and it works. It just takes more effort and drawing accuracy. But that takes a lot of time. :)
How do I arrange some UILabels and/or UIButtons of a variable length? I just want to add them to a UITableViewCell and they should arrange in a left-to-right flow, much like lines of text in a paragraph.
I only found possibilities to create lables with a fixed size and position using "initWithFrame:...". Same seems to be true for Interface Builder, as far as I can tell. Any solution is appreciated no matter if it's done in code or using a custom cell XIB-file.
UITableViewCell, UILabel, and UIButton are all subclasses of UIView and the documentation for UIView says:
Layout and subview management
A view may contain zero or more subviews.
Each view defines its own default resizing behavior in relation to its parent view.
A view can manually change the size and position of its subviews as needed.
So, it is certainly possible to do.
You can create your labels and buttons using initWithFrame: with the argument CGRectZero and then resize them (based on the text or whatever) using setBounds: or setFrame: (because right now you're just going to set the size of the view). Then, add these views as subviews of the cell's contentView.
Then, in a custom subclass of UITableViewCell you can implement your solution by overriding the default behavior (which does nothing) of layoutSubviews: to set the origin field of the subview's frames (i.e., CGRect) that will position the subviews in the cell's content view (the size has already been set). You may need to call setNeedsLayout: or layoutIfNeeded:.
This is really a rough outline of how it is possible to implement a solution because there are a lot of details left out. For example, if you resize a button based on the the text of the titleLabel you'll probably want to pad some to the width and height otherwise the button will be the size of the label and will look odd. In the layoutSubviews: method there could be a fair amount of logic to layout the labels and buttons the way you want (e.g., it would be simpler if all the subviews of a cell where of the same type such as all labels) esp. if the subviews could wrap to a new line.
For multiline UILabels to get the width and height you should use the NSString method sizeWithFont:constrainedToSize:lineBreakMode: you can then use the sizes you get to lay everything out where it needs to be.
I want to do the same thing to allow users to enter tags into a text field - a bit like how when you type in an email address, the address gets converted into a blue tag (the the users name in when that users email address is already in your contacts list). Haven't written it yet, but will be happy to share with you once I do. I can't commit to how long it I will take to write this unfortunately. However if no one else has code they can share and you need to get the job done quickly - Just as a tip, consider this:
Create tag view objects where each object knows the size of the parent text field/tag container view and where each tag object has a utility method which a further tag object can use to insert itself at the right position. This approach makes it easy to manage the view and relayout tags using a simple iteration flow.
Hi
If you still need an answer...
To get the size of text (and to then calculate the frame of the UILabel/UIButton etc) use the sizeWithFont: NSString function which will give you the width/height of a string of text using a specified font.
There is a little bit of maths that you'll need to do to work out the best fit, where to place the UILabels, and the spacing, but you will have the data that you need to do it.
Hope this helps!
I have a view which is similar to mail app. I have a scroll view and in that many other subviews. When the user clicks on any textview, it expands to show the text in it. e.g. "to" field in mail. I would want to resize the other subviews such that it starts below the expanded region. How can I do that.
I created the view through IB and I marked it for flexible top margin to facilitate this. But nothing happens automatically and hence I was wondering if I need to call sizethatFits/setneedsLayout.
When the subview resizes, call [[self superview] setNeedsLayout]. In your superview, implement -layoutSubviews to do the actual layout. You'll have to calculate everything yourself. Fixed/flexible margins are relevant to resizing the superview, not on peer views. The default -layoutSubviews does nothing at all; it just gets called at appropriate times.
If you need to force layout to happen at a particular point, then you can call -layoutIfNeeded on yourself or your superview. Read the docs on how this method works. Generally speaking you don't need to call this, though. It will usually get called at the appropriate time if you just use -setNeedsLayout.
I am building an application which allows the user to view and edit data on a daily basis. To accomplish this i have created a view in Interface builder which contains all of the daily data, and i "tile" this view within an appropriately sized UIScrollView to allow the user to swipe between the days. The view contains two UITextFields, a couple UILabels, and a UITextView. At any given time i have five instances of this view which i re-position around and update the data for the appropriate position.
Everything works great with the exception of the UITextView. The UITextView does not display its Text property until the user has interacted with it (I'm guessing this triggers a redraw).
Is there an easy way to get the UITextView to "paint" its content when its not on screen (but still added as a subview to another view)?
One thing you can try, which is what I just did to fix the same problem, is hook into the parent scrollview's scrollViewDidScroll delegate function. Then in that function, send a message to the UITextView that would force a redraw, my method was setting its frame to the same frame. It's pretty brute force but it's better than nothing.