I am learning to develop iphone apps and I have a simple question.
I am making a really simple app which allows the user to set the volume of the device on the settings screen using a slider instead of the volume buttons.
It may be quite obvious for experienced developers but I just can't find the answer I am looking for.
My question is:
How can I make this slider?
Basically I want to do this (image: https://www.dropbox.com/s/b81bzdwyrab0ha7/slider.png?dl=0):
I used to think that I could use a regular UISlider but some documentation says that I need to use something called a MPVolumeView. The problem is that I can´t find a good tutorial that tells how to use this explicity.
I found this link on the apple documentation but I dont understand how this works. – http://developer.apple.com/iphone/library/documentation/MediaPlayer/Reference/MPVolumeView_Class/Reference/Reference.html
And the description says: Use a volume view to present the user with a slider control for setting the system audio output volume, and a button for choosing the audio output route. When first displayed, the slider’s position reflects the current system audio output volume. As the user drags the slider, the changes update the volume. If the user presses the device volume buttons while sound is playing, the slider moves to reflect the new volume.
This is exactly what I want but I dont understand the example it gives. If you could please tell me how t make this slider work, even if it is on a new one-view project, I would really appreciate it.
Also I am aware that this method also creates an airPlay button next to the volume slider. Is there a way to delete this button? (My app is a simple productivity app so I only want the slider, not the airplay button).
I also understand that this will not work on the simulator. How am I supposed to know that this will work without having to test it on an actual device (I am not registered as a developer yet)?
Plus, I only know objective-c, not swift. If you could please restrain from using swift in your answers I would apreaciate.
Thank you so much for your help.
PD: English is not my first language. Sorry for any mistakes I made.
The MPVolumeView class is designed to let you do exactly this. It's in MediaPlayer.framework, so add that to your app to make things build correctly.
You create it and make it visible the way you instantiate any other subclass of UIView, which you probably know by now.
You disable the routing button by setting the "showsRoutingButton" property to false.
"How am I supposed to know that this will work without having to test it on an actual device?"
By seeing that it's been there since iOS 2.0, and is used in countless apps?
The process to writing such a slider is incredibly simple, look into UISlider(https://developer.apple.com/library/ios/documentation/UIKit/Reference/UISlider_Class/) and then use the float value from the slider to set the volume.
If you do not want to write your own slider, look on GitHub(github.com) for controls that do this for you. After doing a quick search, I found this UISlidersubclass that adjusts volume.
Related
Setting showsTouchWhenHighlighted, e.g. via the IB option "Shows Touch On Highlight," on a button without a title will alter the VoiceOver description. After reading the accessibility label, VoiceOver beeps and announces a description of the image. Is there a way to disable this behavior?
Setting the accessibilityContainerType value to UIAccessibilityContainerTypeSemanticGroup works and that's great 👏 but I'm not sure that
this is the goal of this element.
Even if a button my be seen as a container, I understood this instance property dealt with
data-based containers rather. 🤔
I looked into your problem that arouse my curiosity and couldn't find out an appropriate solution with the Apple API unfortunately.
First, I thought that this solution may help but it didn't work as you mentioned in your comment... thanks. 😉
Apparently, when the showsTouchWhenHighlighted property is used, there's an added view inside the button that renders the glow touch ⟹ this is a UIButtonBarPressedIndicator image you can detect thanks to the Debug Hierarchy in Xcode for instance. 👍
This new image seems to put the default value of the accessibility trait property of your button image even if you have already changed it programmatically. 🤯
So, in order to avoid VoiceOver from using the screen recognition and reading out some useless information, I made something very ugly but efficient to reach your goal in the viewDidAppear for instance (see the 'basic operations' sheet of this link):
myButton.subviews.forEach{$0.accessibilityTraits = .none}
Bad hack due to a native problem of implementation or a simple line of code that anyone can understand, this solution removes every possible VoiceOver screen recognition from the button 🥳... and I'm still interested if you can explain a little bit the reason why your solution works, please. 😉
Set accessibilityContainerType = UIAccessibilityContainerTypeSemanticGroup.
This is more of a theoretical question. I'm fairly new to iOS programming so haven't nailed fully the terms to use in scenarios like this. I've been asked to create an application where I need to fire an event to capture an image programmatically. The application will be in the foreground, and will have the requisite permissions to use the camera. I've been unlucky with my searches so far - likely because I haven't termed them correctly.
My question is this; Given an application with a camera view, set up to capture images - is it possible for me to fire an event within said app to capture the image, without a button necessarily being pressed? If so, how would I go about finding documentation to guide me through?
In an ideal world, I'm hoping for something as simple as cameraObject.capture() or something of that ilk - but an ideal world is a rarity!
Thanks in advance!
Is there any way to distinguish in the iOS app a situation that someone have changed volume by hardware buttons on iPhone/iPad from the situation that it has been done by some UI control in the app?
I have searched for that and so far I came up with many ways to be notified that the volume has been changed but there is no way to find out whether it was done by the UI control or hardware buttons. Notifications include info abut a reason of change but it is the same for both situations.
After a long search I came up with this:
There is no way to detect hardware button been pressed (so far iOS 7). You can only be informed with the result - volume changed. It means that the only solution will be to properly handle situation when the volume change is triggered by some UI component.
You might want to have a look at the private API. rpetrich did some research again.. :) click here
But you need to know that this is not really a good idea because apple probably will reject your app when accessing private apis.
I have implemented an alternative keyboard on my first iPhone app. I would like to play a sound when a button is pressed. The default click sound when the standard keyboard is pressed would be fine, but I don't know how to get that sound.
In this answer I found how to play a 'tock' sound:
Playing system sound without importing your own
I got this to work easily enough but it is a very loud sound. I've searched Stack Overflow and the Xcode help for available iOS system sounds other than 'tock' and I can't find them.
Are there other built-in sounds, maybe even the default keyboard sound, that I can use?
Prior to, and since posting this question almost 2 weeks ago I have searched high and low for a method to make the keyboard click sound work in my app. I have attempted to implement and understand Apple's documentation on custom input views. I butchered my app in many ways attempting to make it work and created several test projects. I tried to interpret how to do this from various other sources on the web. All to no avail. I have finished my app all but for this last function.
I finally hit on a simple answer towards the end of this IPhone Dev SDK form question/post. The ultimate answer is easy and can be done in a few seconds with these easy steps.
Link the 'AudioToolbox.framework' to your project (Click on your project's Target, select 'Build Phases' and under the 'Link Binary with Libraries' item click the + button and add the framework.
Add the following to the header file of the class where you want to implement the click:
#import <AudioToolbox/AudioToolbox.h>
Add the following line of code in the implementation file of your class wherever you want the keyboard click sound to appear:
AudioServicesPlaySystemSound(0x450);
THAT'S IT! AND IT WORKED!!! HALLELUJAH!
According to Paul in the other forum this has the following downside:
"keyboard keys won't be affected by the iOS user preference for keyboard sound on/off."
But when I turn the volume up or down on my iPhone or if I mute the iPhone, the keyboard click sounds do go up and down or are muted as would be expected. Given that I found it impossible to implement keyboard clicks "UIInputViewAudioFeedback" as documented, I'm happy to have anything work.
P.S. If anyone has a link to an actual project that I can download, build and run on my iPhone to see EXACTLY how to properly implement: "UIInputViewAudioFeedback" I'd be happy to give it a look. But so far I've found none, nor any step-by-step newbie style instructions on how to make it work.
[Sept 30, 2012 UPDATE:] I'm happy to say that my app was accepted into the app store using this method. Here it is: https://itunes.apple.com/app/fine-tip-tip-calculator/id563429225
...Dale
Try UIDevice's playInputClick:
[[UIDevice currentDevice] playInputClick];
From the documentation:
Use this method to play the standard system keyboard click in response to a user tapping in a custom input or keyboard accessory view. A click plays only if the user has enabled keyboard clicks in Settings > Sounds, and only if the input view is itself enabled and visible.
Make sure you adopt the UIInputViewAudioFeedback protocol in your input view class, and implement the enableInputClicksWhenVisible delegate method to return YES, as per the documentation.
EDIT - For implementation of delegate methods, check out Apple's documentation on custom input views.
I am working with a small camera app for a client and I have now finished all functionality of it. In the standard camera controls i need to modify one thing , the cancel button should say gallery instead.
But unless i am missing something i will need to remove the overlay by setting showsCameraControls to NO and then building my entire overlayView from scratch.
I have found this solution but I am afraid to go this route due to the warning in the beginning of the post.
So is there any valid way of doing simple small modifications to the existing camera overlay control UI or do you have to build it from scratch if you need to change one tiiiiiiny thing?
Unfortunately, having been in this situation I can safely say you need to build the controls from scratch. You really only have two options: create your own camera overlay, or use the default one.
Now, you could use the techniques described in the link you cite, and iterate through the various subviews and modify them 'blind'. The rather large danger with this is every time Apple change the internal structure of the image picker it could potentially break your solution. So I'd definitely stay clear of it.