How to hide a part of my UIView? - iphone

I have few other UI in my UIView and i have a UIButton on the top which i want to be hidden until unless the user scrolls to see the content on the very top and then display the UIButton.
Is there a way to implement this.
Thanks,

UIView (and thus everything sub-classing it) has a hidden property, this includes a UIButton. You can simply set this to YES/NO to hide/show something to the user.
After that the real question comes down to the show/hide criteria and how to measure it. If you are using a UIScrollView then you can add/implement UIScrollViewDelegate. This will give you methods like scrollViewDidScrollToTop: to check if the user scrolled to the top.

Keep track of the previous scroll offset so that with each scroll you can compute the delta, telling you whether the user scrolled up or down. With that, you can toggle the button's "hidden" property. Hope that helps.

Related

Is it possible to make uipicker react only on swipe not on click?

I made UIPicker and with background on it:
(left is normal size of Picker, on the right is mine)
The problem is: when the user clicks on TextField - the picker reacts and scrolls down. Is it possible to prevent clicking, and make it to react only on swipe?
Add an another UIView above all view then add your UITextField on this UIView.
This will prevent the user interaction conflict.
I think you should move your UITextField farther away from the UIPickerView. Maybe a few notches up as the users touch would cover both the views.

Updatable, custom view on a UIToolbar

I want to make a small area to present some information in the middle of a UIToolbar and was wondering what the best way to do this is.
I need to show some text and a graphic, both of which need to be updated (around every 3 seconds) as new information arrives. The graphic is similar to the iPhone signal strength indicator, so it can be either custom drawn or selected from one of 3 graphics (low, medium, high strength).
I'll probably use initWithCustomView: to create a UIBarButtonItem, although I would like the view to be clickable (to allow the user to change the information shown).
What's the best way to make that view? Can I use a NIB, or do I need to do custom drawing in the view? What's the best way to update the buttons? I'm assuming that I'll have to remake the toolbarItems array each time and set it when the information changes. Is there a cleaner way to do this? Thanks.
Using initWithCustomView: sounds like a good way to go. You can create your custom view any way you want: with a NIB, by drawing it, even using images. It can also have its own subviews. It can be any object that inherits from UIView. (So, if you wanted, you could even make it actionable by using a UIButton, a custom UIControl, or a custom UIView with a gesture recognizer attached.)
You shouldn't have to remake toolbarItems (or, for that matter, do anything with it after you've added all your button items) if you just keep a pointer to your custom view UIBarButtonItem. It could be an instance variable. Then, to update the custom view, you could access it as you would any other view. I've never actually tried this, but I can't see any problem with doing it.
You sound like you had it mostly figured out. Hope this is helpful.
I needed the same solution and was hoping for some code examples from you. So I ended up doing it all in IB and the steps are here as follows:
Create UItoolbar in IB with no Items. (A Bar Button Item will be added again once you add the UIView)
Add UIView as subview of UIToolbar
Add UILabels to subview of UIView that is already a subview of the UIToolbar.
Create IBOutlets from UIToolbar, UIView and each UILabel and then you can reference the labels in your app.
I did set the backgrounds to clearColor so the text appears on top of UIToolbar without any box or borders.
And the text updates dynamically which was the desired outcome.
Hope this helps someone as this has been eluding me for a while.

In a table view can we give zoom in and zoom out effect?

I want to zoom the table view to see the contents of the cell???i want to know whether it is possible???any kind of suggesstion is highly appreciated
Important: You should not embed UIWebView or UITableView objects in UIScrollView objects. If you do so, unexpected behavior can result because touch events for the two objects can be mixed up and wrongly handled.
From UIScrollView documentation
Edit,
May be you should implement something like and alertView when user taps on cell. Present an animated scroll view and there do the zooming.

iPhone UIActionSheet with UISwitch and UITextField

I'm just looking for advice with this as I have no idea where to start but I think a UIActionSheet is probably best.
What I'd like to have is a pop up window (in my head I picture it as being translucent and dark gray). It will not take up the whole screen and the view underneath will still be visible.
In the pop up section there will be a textfield (with several lines) and underneath this there will be a number of UISwitches.
The pop up will be scrollable and will end with OK/Cancel buttons at the bottom.
Like I said, I really have no idea where to start with this but any advice is more than welcome!
A UIActionSheet is probably not what you are after in this case (although you may want a similar look and feel). Think of an action sheet as a traditional modal OK/cancel/Yes/No type dialog box:
Use the UIActionSheet class to present the user with a set of alternatives for how to proceed with a given task.
From the sound it of it, you need to create a UIView in InterfaceBuilder with a semi-transparent background and various child controls (UISwitches and UITextFields). You create your view using the XIB you have configured and add it as a subview of your UIViewController's view. If you want to mimic the animation you get from an action sheet, you can do that with an AnimationBlock.

UISwitch within UIScrollview nearly impossible to use

I'm using a UISwitch-Component at the bottom of a view that sits within a UIScrollView.
Now the problem that appeared, is that the switch is nearly impossible to swipe because the UIScrollView seems to dominate the userinput.
Switching works very well by tapping the switch, but from my point of view, most users "switch" the UISwitch instead of tapping.
Did anyone of you face the same / or similar problems and managed to come up with a solution?
thx in advance
sam
You have a design decision to make: if your content is meant to scroll horizontally, then a user swipe over a switch is ambiguous -- does it mean they want to scroll, or toggle the switch?
The easiest solution is to modify your UI so that this ambiguity disappears. For example, if the scroll's contentSize is not wider than the bounds of the scroll view, then it can't scroll horizontally, and a horizontal swipe will always activate the switch.
If you do want to allow horizontal scrolling, then it makes sense to replace the UISwitch with a UIButton that toggles on touch, similar to a play/pause button.
On the other hand, if you don't want to modify your UI, you could always just do:
myScrollView.delaysContentTouches = NO;
This will cause your switch to "get" the touches immediately, rather than have them go to the UIScrollView first. More info here. (You can also set this boolean in Interface Builder, as pointed out by Squeegy.)