I have some (fairly large) UIButtons. Instead of text, I would like to draw some simple colored graphics inside them (lines, boxes).
How can it be done without resorting to using prerendered images?
As you cannot subclass UIButton, you should subclass UIView and implement the drawRect: method. Then, add this to your UIButton as a subview.
Related
I have a UITableView and a UITableCell subclass. I'd like each table cell to have a UIScrollView with a custom UIView. The custom UIView will include a series of NSStrings from an array. I'd like the UIScrollView to horizontally page-scroll through the NSStrings in the UIView.
I can't figure out how to implement the custom UIView and draw the text to the view.
It was a suggestion from someone on my previous post, that I should draw the strings onto a custom UIView, rather than use UILabels. UITableView scrolling slow, memory leak issue
I have referred to both Apple's TableViewSuite and AdvancedTableCell projects, but I cannot grasp how to implement for my case.
Just use UITextView instead of UIView and UILabel if you don`t need editing you can turn it off using .editing property.
This tutorial shows how to draw on a graphics context for the view using Quartz 2D:
http://www.techotopia.com/index.php/An_iPhone_Graphics_Drawing_Tutorial_using_Quartz_2D
But I want to draw on a UIButton, not on a view. How can I do that?
Thanks
Draw on UIView . Add the view as subview to your UIButton.
A button IS a UIView. It inherits from UIControl, which inherits from UIView.
So buttons have a drawRect method.
So you can do everything described in the article you linked on a button.
However, buttons are set up to do a lot of things for you, and overriding the drawRect method could make those things not work correctly.
Buttons normally draw a title and a rounded rectangle frame. You can turn that off by setting the button's type to custom.
Custom buttons will draw an image if you install one.
Buttons normally also either draw a highlight over their image, or have a second image to use for the highlighted state. If you want to implement drawRect, you'll need to handle drawing the highlighted state yourself.
In general, you want to avoid using drawRect and use some other technique to get the content you want into your views.
What, exactly, are you trying to do?
I'd like to have a UIView where the user can select each of the four corners and stretch the view by independently moving them.
How would I implement such a view?
To do this, you will need to subclass UIView and handle touch events manually. When you get a touch event, you will have to do some math and then set the frame of the view to the new size. I'd recommend making the background image a stretchable image using stretchableImageWithLeftCap:topCap. It shouldn't actually be that hard.
I have subclassed UIView so I can draw some lines in it. In this UIView are a whole bunch of buttons which I decided to create as a method that drawRect calls after the lines are drawn. It works but sometimes only part of the button renders. If i remove the button creation and instead add the UIButton in the subclassed UIViews parent it works fine.
Is doing things like adding subviews in drawRect method a big no no or should I not do it all together in UIView?
yea that's a pretty big no no. drawRect is for adding stuff with CG, not views. It gets called repeatedly and unpredictably. Adding them in initWithFrame should be pretty safe though.
I have a UIView subclass. This subclass has multiple subviews. Is it possible to draw a line using core graphics inside a subview that is part of the uiview subclass?
For example, I have a SampleView class, which is a subclass of UIView. Inside this class's header file is the property for UIView *sampleSubView, which is a subview of SampleView. Is it possible to draw a line inside of sampleSubView from the SampleView class implementation?
Thanks for your help!
Josh
If you are asking how a UIView subclass can draw a line on itself, then see the Quartz demo sample code. Basically, you'll override the view's drawRect: method, get the current graphics context, then draw whatever you like onto it.
If you are asking how one view can draw a line on another view, perhaps you need to rethink your architecture.