iPhone application : is-it possible to use a "double" slider to select a price range - iphone

I'm working on an iphone application (not web app) and I'd like to build a form asking a user to indicate a price range. Instead of using two text fields, I would prefer to use a double slider to set the minimum and the maximum price. I know that it is possible de use a simple slider (sound control for exemple) but i've never seen a double one. Can anyone help ?

This is not possible without creating a custom control. You'll need to inherit from UIControl or UIView and provide a custom drawRect method. You'll also need to respond to touch and drag events to update the state of the control. I have not done this myself, but I would be prepared for a fairly significant amount of work to get everything to respond and display as expected.
I'm curious as to why you need to have both values specified on a single slider? Why not use two sliders either side-by-side or stacked? It would not require any more input steps than a double slider, and would conform more to standard UI guidelines.

I think you can specify multiple thumbs for a single slider if you subclass UISlider, at least I vaguely remember that being possible in MacOSX. But Code Addict is right, you'll probably be better off using the standard controls - a double-thumbed slider seems like it'd be pretty difficult to deal with in the touchscreen environment.

I built such a control and added it to GitHub so feel free to have a look and if you like the control extend it and contribute.
GitHub page: http://github.com/doukasd/DoubleSlider
Blog post (showing a video of how it works): http://dev.doukasd.com/2010/08/double-slider/

Related

iphone How to make custom UISwitch with three states (options)

I want to make Switch, which have three states.Basically I need to store value 0 or 1 or 2.
By checking the state of Switch.
Please Help to make this switch.If it can be made Using IB that will be very nice because it will be easy to place in the right place.
(I have image but not able to show bec am new, dont have 10 reputation yet)
Thanks in advance for your creative thinking
You should use a UISegmentedControl for this. It's part of the standard set of controls, Apple has taken care of accessibility support, and users will know what to do with it.
Making a custom control that looks like UISwitch but behaves differently is a bad idea.

How to make iPhone app "skinnable"?

I was asked by a client to make a "skinnable" app and I don't really know what that means.
I googled like crazy and I didn't found a clear answer or an example.
If anyone has a clue about this, any tip would be appreciated.
Thanks.
Generally this means the app will allow the user to choose different looks for the UI, each of which will have a different color scheme, feel, etc.
What I actually did with my project. I decided to use multiple storyboards to give me greater control over the entire UI and UX of each theme. I programmatically link them all together via a master storyboard that links them all together. That's what I did, and it works very very well. Performance is great, while still maintaining high level of fine grain control over each theme. You can even keep your Header and Implementation files the same for individual view controllers, just so as you keep the names the same on the storyboard.
So for instance, one of my apps that I'm working on called Jam-mout (A music player) has multiple high quality themes. (Image attached). Each theme has it's own storyboard.
For iPhone apps, where the majority of the GUI design is provided by the operating system, you could do it by setting custom Navigation bar background images, custom button graphics, and different fonts/sizes/weights and whitespace. Make sure you're working with a designer who's familiar with the iPhone GUI (if you're not working closely with a designer this is going to be a nightmare).
I recently put together an app for a client who wanted a heavily customised GUI: http://itunes.apple.com/us/app/gogoparis/id428497937?mt=8. A 'skinnable' app would have several sets like this, so the user could choose between several different overall styles. (I hope your client has an enormous design budget!)
my post here should help you get started:
What is the recommended method of styling an iOS app?
if you need live theme changes, each theme in this example could post notifications when the user selects another theme (or skin) - then you can update either the theme instance itself.
alternatively, you can create identifiers for themes which are mapped (NSCFDictionary) to a central theme factory. an example identifier for a specific view for use with the theme factory could be a string MONImageSelectorTableCellThemeIdentifier.
an example manager/factory which handles all theme loading and vends references to themes:
#interface MONThemeManager : NSObject
//...
- (MONTheme *)themeForCurrentlySelectedSkinForViewWithIdentifier:(NSString *)identifier;
//...
#end
beyond that, it's hard to answer your question in more detail without knowing your requirements. the implementation of skinning an app can range from very simple to very very complex. good luck.
Already some good answer here, but I'd add that if you use a ui toolkit such as Three20
you can skin everything using CSS as you might for web pages.
I do realise this is an old post, but I thought I'd share my penny on the matter:)
To make any Cocoa app skinnable you need you think of 3 aspects of the app:
1) Uniformity: By this I mean that on all windows, views (including buttons, text inputs etc...) you want to have a 'standard' that will apply throughout the app. This is the first thing you need to look at. Although iOS and OS X alike already have 'themes' as to put it i.e. Apples default way of shading and laying things out, you can override these (refer to the individual view / window etc... documentation.
2) Performance: With skinning etc... performance is always an issue when it comes to writing your own drawRect etc... methods. The code apple have in place for the 'default' is already optimised, so you need to keep a close eye on the performance of the app whilst you are doing this. Good examples are: Do I use an image with a gradient, or do I use NSGradient? Both of which have performance issues when it comes to rendering them, but it's a question of which is the better of the two
3) userDefaults: This is generally the area where you'd be getting your 'skin settings' pulled from. userDefaults is basically where you store all of the information which you generally set in a preference pane.
If I were you I'd look into the class reference of it:
http://developer.apple.com/library/mac/#documentation/Cocoa/Reference/Foundation/Classes/NSUserDefaults_Class/
Furthermore, here's a nifty example of using userDefaults:
http://mobile.tutsplus.com/tutorials/iphone/nsuserdefaults_iphone-sdk/
Hope this helps!

Is UITextInput missing selection handling mechanics?

If you implement UITextInput on your custom view and - say - use CoreText to render the text you get to a point where you can draw your own cursor and selection/marking and have that fully working with the hardware keyboard. If you switch to Japanese input then you see the marking, but there's something curious: if you long press into the marking you get the rectangular system loupe and selection handling without having to deal with the touches yourself.
What I don't get why we would have to implement our own touch handling for the selection, draw our own loupes etc. It's working for marking! So what do I have to do to get the standard gesture recognizers added to my custom view as well?
the one sample on the dev site only has a comment about that user selection would be outside the scope of the sample. Which would indicate that indeed you have to do it yourself.
I don't think that it is in Apple's interest that all developers doing their own Rich Text editor class keep doing their own selection handling code, let alone custom drawing of the round and rectangular loupes?! Granted you can try to reverse engineer it such that it comes really close, but that might give users a strange feeling if the selection mechanics differ ever so slightly.
I found that developers are split in two groups:
1) rapes UIWebView with extensive JavaScript code to make it into an editor
2) painstakingly implements the selection mechanics and loupe drawing themselves
So what is the solution here? Keep submitting Radars until Apple adds this missing piece? Or is this actually already existing (as claimed by the aforementioned engineer I met) and we are just too stupid to find how to make use of it, instead resorting to doing everything (but marked text) manually?
Even the smart guys at Omnifocus seem to think that the manual approach is the only one working. This makes me sad, you get such a great protocol, but if you implement it you find it severely crippled. Maybe even intentionally?
Unfortunately the answer to my question is: YES. If you want to get selection mechanics on a cusrom view you have to program it yourself.
As of iOS 6 you can subclass UITextView and draw the text yourself. According to an Apple engineer this should provide the system selection for you.

iPhone - Proper UI controls for calculations

I am pretty new to iPhone development and currently working on an application which includes a view that performs a simple numerical calculation. In particular, the user enters 3 or 4 values into text fields and the view displays the result. Something along the lines of http://www.moneychimp.com/calculator/compound_interest_calculator.htm
What is the nicest way to achieve this? I am currently using simple UITextFields and a UILabel for the result but it doesn't look nice or "native-like". What UI object would be best to use?
Thank you!
It's entirely up to you. You're using the right classes for actual input- it comes down to how you choose to style those classes. I'd suggest looking at the documentation for UIView and CALayer (youView.layer, and include QuartzCore framework in your project).
A good start might be to choose a color scheme, a background for your app, and the look and feel you're shooting for- this will inform your styling. Try looking for apps that you think are elegant and attractive, and boil down what they do and what you like about them.
I'd say;
use a grouped table style (with the white tables with round corners on a blueish striped background)
embed settings values directly in the cell (aligned to the right) as much as possible
you can show a relevant keyboard (text, numbers) or picker view to let the user pick values, directly when they tap the cell. Use sliders and switches where relevant.
You may want to take a look at http://www.inappsettingskit.com/, we are currently investigating it for the same purpose and it seems to do the job
You can use either a UISlider or a UIPickerView if some of your values have limits.
You can use UISwitch for toggles.
You can also switch the default keyboard for your textfields to be numeric.
Other than that you seem to be on the right track.
Also, sometimes putting a view inside a scrollview makes things seem cooler even if its only one page. The auto bounce on scrollviews is kind of cool.

should one customize default iphone controls?

my app asks the user yes-no questions, user replies using a uiswitch on screen. i've been thinking about creating a custom version of the switch that would display yes/no instead of on/off and would use a green/red background as an indicator of the value. after creating a mock up i'm not so sure this is the way to go. using the default switch doesn't feel right but so does changing it too much. what do you think?
It really depends; some custom applications have extremely custom UIs (such as ConvertBot, for example) and it works great for them. The risk is sometimes worth the effort. In other scenarios, custom widgets result in breaking usability. I don't think that changing 'ON/OFF' to 'YES/NO' is groundbreaking, if you do it right you can pull it off no problem.
I think if your mockup was better done (the slider should be divided into two to have YES AND NO of equal length with equal padding on both sides) it would look a little better.
From a user interface perspective, this is a bad idea. People have already learned the default switch, so why change it now?
Additionally, you run the risk of adding another source of bugs to your application that was not present before.
Depending on the app, this can be very valid. Sure people are used to the default controls, but changing the text or colors is not going to break the user's understanding of these controls. Its still the same switch underneath.
In your example you color both the Yes/No. That is the only concern I would have that you did change how the core switch works. Typically, it works with a highlighted color and a grey color. So, having it stay colored on both options could potentially be confusing.
Regardless, if you want to build your app this way, you should. Just because the iPhone offers great default controls doesn't mean developers shouldn't innovate and add their own or take the default controls to the next level.
Take a look at the custom UISwitch control that I built to allow me to change the background color of the control. You could use the same method to change the text, the font, or the text color very easily.
http://www.homick.com/posts/custom-uiswitch-control
The code is available on Github and includes a PSD that is used to build three different png files that the control uses. You can modify the contents of the psd to recreate the png files in whatever format you like. Swap those into the control and away you go.