I want to display 2 strings (at different positions in the button) with different fonts and colors (I'm using the button's setTitle for one, and I need another one), and some attributes must be changed based on the current UIControlState (like the color).
So, I'm searching the best way to add a second label to a UIButton.
I need the label to be configurable per UIControlState (I want a different color for UIControlStateNormal and UIControleStateHighlighted for example).
I've tried the following approches:
Subclass a UIButton and use drawRect: while not recommended (and I now understand why), I don't think it's even possible, it looks like the button's drawRect method is called (and after the one of my subclass) even if I don't call super.
Create a new UILabel and add it as a subview to my button: this is working quite well, except I don't know how to change the color when the UIControlState of the button is changing
Create a new layer and use drawLayer: I don't know how to get the drawLayer method to be called every time the button state is changing (my drawLayer only gets called once, when I use setNeedsDisplay just after adding my layer to the button)
Is there another way to achieve what I'm trying to do, or maybe one of those solutions might work (with a few tweaks)?
Thanks!
The second of your approach works fine. Just add 2 targets: First update to "normal state" target using "all touch events". Second update to "highlighted" using "touch down" event.
If the states are not only changed by touches and want to handle this more generally, Id suggest multithreading. All you really need is calling performSelectorInBackground when initializing all this elements (the selector updates label according to button state) and then again call same performSelectorInBackground on the end of "update label" method, creating an infinite loop.
Ok, I think I found a working solution (for my problem at least).
I'm subclassing the UIButton class (it works for me, since I'm using a custom drawn button anyway), and I override the titleRectForContentRect method that gets called everytime the title has to be displayed (including after a state change, just before display).
I added an UILabel to the button's view to display the second string I want, and during the titleRectForContentRect, I compute the correct frame location for my label, I update my label's text font and color based on the button's state (self.state), and that's all I need.
Related
So if I have an NSView based tableview and inside the views are NSTextViews which are non-editable but selectable...
how can I get that nice functionality of command-A selects all the text? I don't mean row selection. I have row selection disabled for the tableview. I mean highlighting the text in blue so you can copy it to your clipboard. But not just 1 NSTextView's text from one row, all of them from all the rows.
And in addition to command-A click and drag should do this too. But out of the box it seems I can only select one row's text. Here is video showing problem:
https://dl.dropboxusercontent.com/u/2510380/table.mov
(i keep clicking and dragging but can't highlight text on the next row)
here are two mac apps (skype and gabble) that do this:
https://dl.dropboxusercontent.com/u/2510380/skype.mov
and
https://dl.dropboxusercontent.com/u/2510380/gabble.mov
Assuming they are NOT using WebViews with just HTML inside, how do you get this control over the clipboard? i.e. in Skype you select the text and only the conversation is highlighted, not the timestamp of each message. Also the text copied to the clipboard is formatted very nicely. Can you point me in the right direction to reverse engineer skype?
Unfortunately there's no way to do this easily. This is because only ONE control can be the first responder at a time. This means that, though you can have selection in multiple text views, there are several problems:
Only one text view's text will actually be highlighted with the "live" highlight color; the others will have the gray highlight of non-focused controls.
Copy commands will only apply to the first responder text view.
Drag session starts will be initiated from the control the mouse was actually pointing at (irrespective of first responder) and will only drag that control's text.
In a view-based table view, the controls may not even "exist" for a row not currently displayed, so it'll never get the message unless you forcibly create each row, which could be costly for a large table.
Knowing all this, you might be able to "fake it" by having your controller be complicit in a text view and table view subclass's special handling of a select-all message when it's first responder. On receiving this message, the text view subclass can call super then notify the controller (to get its default behavior AND to let you know it happened), at which point the controller can turn around and send the command to all (existing) text views. Highlighting can be spoofed by overriding the text view's drawing and a drag initiation could defer to a delegate (the controller), which would handle writing ALL the strings from your model to the pasteboard (not even touching the text views in possibly-nonexistent row views). The table view subclass would simply pass the same select-all message to the controller without calling super (and even forcibly making sure nothing is selected before returning for good measure).
I hope this helps. If I've forgotten any of your requirements, let me know.
Try like this:-
First create button programatically then write this code after you create button and also write this code in your load method or awakefromnib method.
NSButton *Buttn=// alloc initwithframe;
[Buttn setKeyEquivalentModifierMask:
NSCommandKeyMask];
[Buttn setKeyEquivalent:#"A"];
[Buttn
setAction:#selector(yourmeth:)];
[Buttn setTarget:self];
// now when you press cmd a write
below code in action method
- (void)selectRowIndexes:(NSIndexSet
*)indexes byExtendingSelection:
(BOOL)extend
I'm trying to set the text of the "Retake" and "Use" buttons on the PLUICameraViewController. I've programmatically navigated through the view hierarchy and found a few UIButtonLabel objects. Logging the text of these shows what I expect: "Retake", "Cancel" etc. However setting the text doesn't work. The buttons just keep their original text. Here's what I've tried:
if (q is a subclass of UIButtonLabel)
if ([q respondsToSelector:#selector(setText:)])
[q performSelector:#selector(setText:) withObject:#"zzz"];
The code runs w/o crashing. Also respondsToSelector is returning YES. How can I make the text on the buttons update?
By the way I'm aware of other approaches involving custom buttons, my own views etc. I'm really curious from an Objective-C/runtime/iOS perspective why the above code doesn't work.
Also note I'm doing this in
navigationController:willShowViewController:viewController:animated:
In this case, I don't think it's an issue of Private APIs, per se. This is just the way UIButton works.
Yes, the title of the button is a UILabel, and in practice, it is probably/currently an instance of the private class UIButtonLabel. But, the way Apple intends for you to change the title text is to use the methods in UIButton itself:
[self.button setTitle: #"newTitle" forState: UIControlStateNormal];
[self.button setTitle: #"newTitle" forState: UIControlStateSelected];
instead of trying to drill down into the button's subview heirarchy, find a button label, and call setText:.
Here's the relevant API documentation
As to why it doesn't work, I suppose that's because Apple wants it that way.
For one, changing a button's title is expected to be a normal use case. So, for convenience, they probably wanted to give you an easy method to call, directly in the UIButton interface. If they forced you do drill down into the view hierarchy, not only would you have to write more code, but it makes it a little harder for Apple to change the underlying implementation of a button. They may want to preserve the ability to change it later, and for that, it's better for them to keep some sort of wrapper APIs at the UIButton level.
Also, if you directly change the text on the button label, you are circumventing their design, where the label text depends on the button state (e.g. normal, highlighted, selected, etc.) Even though most people probably use the same button text for all states, the design allows for state-dependent text, and therefore, hiding the underlying UIButtonLabel helps enforce this design.
That's my guess as to their motivation.
So, to enforce this, it's entirely possible that in their implementation of UIButtonLabel setText:, they decline to update the text after the button has been initialized. After that, you have to use the setTitle:forState: method.
I'm still a noob to iPhone development so sorry for the dumb question. I'm creating an app that has a custom numeric keyboard. I have an IBAction 'buttonDigitPressed' that when a digit is pressed it will simply add the digit to a UILabel. Now I have another label that I wish to do the same yet I'm not sure how to gain 'focus' of that particular label. I placed an invisible button over the second label so when pressed hopefully I can call an action to switch the keyboard from the first label to the second label. Yet I have no clue how to accomplish this. Any help would be greatly appreciated!
First of all, having to put an invisible button over the UILabel is skanky. If you want the user to be able to tap a number to mean "next time I hit a digit, append its value to this number", you'll probably be happier if you just use a UIButton right from the start. You can make a UIButton that looks pretty much like a UILabel (i.e. it has no border or background color). To set a UIButton's title in code, call setTitle:forState: with the UIControlStateNormal state. So now you've got tappable numbers, i.e. these UIButtons.
Okay, so now let's pretend you've got, say, three UIButtons. You need to use an instance variable here. So, each button will have an action - let's say doButton:(id)sender. So doButton will store the value of sender (the button that was just pressed) in the instance variable. Now your buttonDigitPressed action just looks in that instance variable to learn which button to append to. That's part of the power of instance variables - they give a method in a class a place to store a value where another method in the same class can get at it.
I've got an Custom UIButton. It's got
a "static" background image
a variable text (the Title) which gets set in the code
Now I would like to add an icon (UIImage/UIImageView) inside the button on the left of the text. (I use the indent to move the text slightly to the right). Is there an easy way of adding that icon (and referencing it from code, so I can change it) or would you recommend creating a completely new button e.g. based on a UIView? (e.g. a view, that responds to touches)?
I'm just trying to get a feel for what the best approach would be for this. Any experience?
Two ways:
I prefer doing this by subclassing a UIView and (as you mention) implement the UITouch-responder methods. You're also able to override drawRect: what I really like because it makes your app soooooo much faster!
Since UIButton is a subclass of UIView, you can add a UIImageView to your button by using addSubview:. If you save it in your main-class (#property (...) UIButton *button) you can always access it by calling [self button]. You can also subclass your UIButton and add this #property. That's up to you.
It's totally up to you. However I prefer the first way!
I want to show a total inside a toolbar. I put in IB the UILabel on top of the toolbar .
However, when I run the app, the UILabel is totally invisible (but can set values on code fine).
The most bizarre thing is that in other form, all work fine. I don't see why in one form work but not in another...
Any idea in how fix this? Or why is this behaviour happening?
Don't use a UILabel.
Use a UIBarButtonItem. Then set it to style: plain. It looks like a label, but it actually borderless button. This is the general practice of displaying text on a bar.
You can also create UIBarButtonItem with a custom view in code. You are simple "wrapping" the UILabel in a UIBarButtonItem allowing you to add anything you want to a tool bar.
To add in response to comment:
Either way, you make the button "inactive" and it doesn't respond to touches. Even though it is a button, it doesn't appear to be one. This is how Apple expects to add views to a toolbar/navbar as apposed to "float things on top of it". It violates no HIG guidelines, much the opposite, it is a reccomended design technique.
To stop the glow:
Create the button programmatically, make sure it is disabled, add it to the bar, it should then be disabled, but not dim.
In IB, have you tried to select the label and use the "Bring to Font" menu item (under Layout)? It seems like you are trying to do something pretty standard.
When you try to set values, is the label coming up as nil or at address 0x0? It's possible that the label is there, but its text cannot be set because its instance is faulty (not properly connected in IB to the IBOutlet).... Just put a breakpoint on the line where you are trying to set the value(s) for the label, and verify that the label variable is not nil (or 0x0). If it's not, try setting the text and verify on the next line that its text was set properly.
drag a UIButton into your UIToolBar. Then uncheck User Interaction Enables for this button.
Customize your UIButton so that it will look like a UILabel. Hope this will help you.