I have an app with different pages, each with subviews like imageviews and button. My question is what's best to do when loading the new page. When a button is tapped on the first page a new UIView appears with different subviews. Should I remove the old page and its subviews or keep them? On the new view I have a button that should lead back to the first page, so if I would remove them when adding the new page I would have to initialize them agin.
What should I do to get it as smooth as possible?
I asked a similar question a few months ago.
Basically, the answer is :
In general, it's better to avoid doing optimizations like this until you've built your app and then profiled it to see how/where it needs improvement..
Code, get it working, and then, learn how to use Instruments, to detect where and when to optimize your app !
Good luck with iOS development.
Related
I'm developing a iPad app which has a popover which appears to show you a list of items. I need the ability to delete one of the items, so I'm considering adding the ability to press-and-hold (a.k.a. long tap) on one of the list items which would show another popover for that item, with an action list showing a delete button.
Two questions:
In terms of iPad UX, is this a good idea? Haven't seen it anywhere, and I guess it could be a little confusing...but how else can I do this?
Is this possible, code wise? I haven't tried it, but I am still pretty new to iOS development so I could see myself fumbling round for hours before finding out there's a technical reason why it's not possible.
Thanks!
It's not a good idea, and I don't think it's possible even though it's possible.
Apple's Human Interface Guidelines clearly state that you should not do it. This is as definitive an answer as there can be regarding UX.
For inspiration on how to delete items without requiring a popover, look at how UITableView does it, for instance.
Often, you'll have an Edit button in the top toolbar inside the popover to trigger edit mode.
If you want some kind of confirmation dialog, use UIActionSheet. They look good and work well enough, especially in popovers. In your case, I think these are the way to go.
I've got a tabbed iPad application with just about each tab running a UIWebView. I'm getting all sorts of callbacks, like when a user tries to leave the corporate site (which only displays the company site to users). In this case, I pop up a "toast" style window that tells them to click a button to open the page in Safari. I also pop it up with a spinner and no text to indicate that a page is loading. The approximate look that I'm going for is used in lots of applications, but you can see it best when changing the volume on the iPhone or iPad. It's just a translucent rounded square that fades in and out.
Right now I've got it implemented on one of my tabs, and I did it by creating the objects (a spinner, a label, and a UIImage with the square) and then programmatically hiding and showing them using [UIView beginAnimations] and changing the label's text. It works perfectly but I've got these nagging things hovering over my interface in Xcode, and it takes a lot of setup to accomplish if I wanted it to be in another tab, which I do. I can't help but think that there's a better way to accomplish this. I thought about making and adding a subview, but that would leave a white background to the toast. What I'm thinking is creating some sort of object that I can allocate in a tab's view controller whenever it's needed.
What are your guys ideas, or have you done this in the past? I see it in a lot of prominent applications, like Reeder, so I'm sure it's been done more eloquently than I have done it.
Matt Gallagher has a great class called LoadingView here Showing message over iPhone Keyboard. I use it.
MBProgressHUD is a popular library for this, as well.
On my iPhone, when I go into the Settings app, I see "Airplane Mode", "Wi-Fi", "Notifications", etc. and I'm able to scroll through pages and pages of settings.
I'm new to objective-c and I'm trying to duplicate the functionality in my own app, but I don't know enough about the objects and techniques to know what to ask or what to look for. :)
With that in mind, can someone please explain what's going on with the settings app? What is this using? Is it a UITableView that allows me to scroll down the page? What control is being used to store the text "Airplane" mode? What is happening when I click on the ">" and see a new page?
Any tips are appreciated.
While nobody outside Apple can be 100% sure how they implement their apps, some reasonable guesses would be:
The main screen is a grouped UITableView. Each entry is a single cell.
The text and images in the cells are built using properties of UITableViewCell (e.g. the textLabel UILabel for the text "General"). Some of the more advanced items use custom cell views.
Each category view is another UIViewController, pushed onto the viewControllers stack of a UINavigationController.
The on/off switches are UISliders.
It is a TableView
Table View programming Guide
samplecode
These docs cover all you need
I am trying to design a feature in my application for the iPhone that simulates the Springboard feature (Main menu of the iPhone that allows you to view more apps), or the way Weather application works that allows you to flip between views.
Does anyone have any samples of this how I would go about doing this. It's seems very trivial but I am wondering if I am missing something that is already available either as an Apple example or someone who did a tutorial on this.
The image below show how the user would use it.
alt text http://www.agilitesoftware.com/SpringboardExample.png
As they slide their finger to the right (or left) the other image would begin to show up. And it would animate smoothly. The faster you swiped your finger the faster it would move to the next view.
Update: The other feature is that it should mimic the same feel when you slide your hand across the display that is snaps to the current view into place. It should not keep sliding across if there is more than 1 view to the direction you swiping your finger.
I've seen other applications use this so that is why I am asking.
This is accomplished using the UIScrollView with the pagingEnabled property set to true. Just add each of your views, adjust the contentSize, and it will automatically "page" to the width of the screen across the content.
There is a sample app (with code) with exactly this functionality on the iPhone developer site on Apple.com (I believe it's called "PageControl".) - I'd suggest checking it out.
d.
I'm writing an app that uses a similar UI. As NilObject recommended, we're using a UIScrollView with pagingEnabled=YES.
You may also be interested in this example code involving just two child views. I'm trying it out now; it's an interesting technique but I've had to write some additional special-casing code for some odd situations that resulted.
There's also another question on this site that asks about creating a grid of icons like the home screen.
I would check out Joe Hewitt's code from the Three20 project for this. It provides a nice interface and further refinement of the UIScrollView implemented as TTScrollView and TTScrollViewDelegate, TTScrollViewDataSource.
I'm quite confused with the whole animation stuff in iPhone SDK. I tried to study throught the SDK documentation, this website or tried googling it out without success.
I'm unable to get my scenario work.
I have single XIB file, with tab bar and a 4 tabs.
In a special event i want to switch from one page to another "in code", so I call eg: [tabController selectedIndex: 0].
I need this transition to be animated. Is there a way?
If user switches tabs manually, no animated transitions are needed
Also I have one subquestion:
In one of the tabs I have a UITableView with set of items. When user clicks any of these items, another set of items are beign shown (sort of hierarchy browser)
I tried to animate this transition using -deleteRowsAtIndexPaths:withRowAnimation: and -insertRowsAtIndexPaths:withRowAnimation:, but without luck.
Desired transition is shifting the old items set to the left side and the new items from the right side.
This is first time of my iPhone development, when I got lost even with all the forums and documentation. :)
Thanks in advance to anyone trying to help me!
As for your first question: Yes you can.
Try this link for some answer:
transition on tab bar sample code.
In short words: you should add a delegate object to handle the tab bar switching by setting the tabBarController.delegate = self.
Yet, what this forum post won't tell you is that you need to "import" some framework to do it.
First - right-click on the framework folder on the left hand list in Xcode and add an existing framework named: "QuartzCore.framework".
Than - add these lines to your tab bar holder (on .h file):
#import <QuartzCore/CAAnimation.h>
#import <QuartzCore/CAMediaTimingFunction.h>
As for your second question, try to replace the datasource (array or what ever) or create login function on the cell to replace its content.
Enjoy!
First Question: No, you can't animate tab switching. Please read Apple's Human Interface Guidelines on this. Tabs are meant to switch instantly. An animated transition would break the "tab" paradigm.
Second Question: When you tap on a row, the user does not expect other rows to disappear and new ones to appear. Instead, this sounds like a case for a UINavigationController. Please refer to Apple's sample code, specifically the UICatalog for sample code on how to implement this.