Initially I was under the impression that it uses the table row slideup/down animations while inserting/deleting new rows but I doubt if it's doing that as it does it so fluidly even with thousands of items in the list (otherwise it would take a lot of time for the deletions/insertions to work).
Am I right in my assumption that it's simply attaching a new instance of the News list at the bottom of the screen, shrinking the above one while the one at the bottom expands to fill up space?
UPDATE:
Please see this video of what I mean: http://dl.dropbox.com/u/4960327/ReederAnim.mov
I can not tell you exactly how Silvio Rizzi made this, but as you see in the playback, a list view is added behind the shown list view, and the front list view fades out (.alpha = 0.0;) while the list view behind it expands its height per row.
When you desicate it frame by frame it becomes quite clear what he does, and it is really not that advanced. But I have to admit, with the white "milky" polished interface, it looks quite neat.
In addition, you can see that while animating, the background list view only renders the top 7 entries (hopefully calculated by dividing the view height with the average height of the cells shown) making the list view quick to load. Then afterwards, he can load an extended array of cells once you start scrolling, or in a background thread starting once the animation is complete.
Related
below i attached an app help guide screen. I am understanding how to build this screen.
If any body have idea please share here
View with semi transparent background color (backgroundColor:"rgba(0,0,0,0.5)";) and some images on top of it.
So, using images is bad. You'll need images for translations and if you do this as one image you'll need to ensure all devices are covered so your arrows point to the right element.
Minimise images == smaller app.
First thing you'll need to do is a create a blocker view -- so that's a view that will fill the screen and have a black background with opacity.
You can't apply that to the window as everything in it will be semi-transparent so:
Create a transparent Window that fills the screen.
Add to that window a view that fills the window and has opacity say 0.5 and black background
Add to the Window (not the view you just created) the other elements and button -- ideally, these should be individual graphics of the arrows, sized in such a way that you can position them based on the host element (the item they are pointing to / referring to). Use real text so you can handle translations / reduce file size.
So you'll need a way to associate each tip with a control they are anchored too, and that will ensure that regardless of the screen size, the tip will appear in the correct place.
First of all, always give a try before putting questions anywhere because it makes you learn things on your own for long time.
The easiest step for you to do this is to ask your designer to create a complete image just like that & you just have to show it on top.
If you have to show that image in different translations, then you can ask your designer to provide you required translations images.
I want to create a custom UIView that would be equivalent to a horizontal UIPickerView. The data elements, such as "Mountain View, Sunnyvale, Cupertino, Santa Clara, San Jose" would move left to right. The view would be long and thin. 50px in height, 350x in width sort of thing.
I will need to use protocols to obtain my datasource elements likely, but what I'm more interested in figuring out is the visual aspect of this.
How would I animate things left and right? Should I just make one incredibly long view (off screen), and change the frame left and right. This seems like a bad idea, as likely only 3-5 options need to be visible in the control at one time. If the datasource is 100 elements, there is no point in loading the other 95 off screen in a long view.
So perhaps I should load ~9 or something. The 3-5 on screen, plus an additional ~3 left and right. Each time the control is triggered to move left and right, it will load up another element on the view(?).
Is this a good way to achieve this? A long thin view with ~9 UILabel's. As the control moves to the right, I would shift the further left UILabel to move hidden to the far right, and change the UILabel to be the next in the data source.
I also likely want to change the text size based on its position. If it's currently selected, I either want to bold it and possibly increase the font size. How can I gradually achieve this as the view is moved? It would be weird if the text only changed once it was moved perfectly center inside the view. It should likely gradually grow as it gets closer to the middle.
How can I achieve this?
A collection view would do the trick, obviously there's some coding involved.
I'd suggest you to take a look at the code of, or use, the following library.
I've used it once,does almost exactly what you need and works very well:
AKPickerView
I am working on one Mac app. In which I want to play few tricks with insertion point of an NSTextView.
![NSTextView with overlay on it][2]
What am I doing is, I have an NSTextView (The whole image screen is of NSTextView) and above that I have placed one overlay (as you can see at the bottom of the image). There are two Labels at the extreme Left and Right end and has a white gradient view too. All these three I have placed above NSTextView.
Now when User types in, textview gets scrolled and at one point, typed letters goes below the overlay.
I have to manage this stuff only. I want to keep track that user has reached to the overlay border and if yes, I want to move the insertion point to little upside so that user can see the content which he/she is writing.
Will anyone suggest me, how to make this possible ?
I have tried many things, but its not working. Kindly help.
I have a window whose size I need to change when the user clicks on it. I am using [self setFrame:windowFrame display:YES animate:YES] to accomplish this.
Even though the window successfully changes size (I increase its height), it moves the contents of the window up with it. How do I prevent this from happening? I want the contents to remain in place.
I am on OSX Mountain Lion developing an app for OSX using Objective-C and Cocoa.
EDIT: Constraints and/or Springs and Struts will not work as I need to move the contents around after the window is resized.
Constraints and/or Springs and Struts will not work as I need to move the contents around after the window is resized.
In that case, you should use NSViewAnimation.
A single view animation can actually perform multiple animations to multiple views, and you can even do one to a window, despite the class's name and the fact that windows aren't views in Cocoa.
You create a view animation with initWithViewAnimations:, which takes an array of dictionaries. Each dictionary identifies the target (NSViewAnimationTargetKey) and what to do to it: Either change the target's frame (NSViewAnimationStartFrameKey and NSViewAnimationEndFrameKey) or fade the target in or out (NSViewAnimationEffectKey). For your case, you'll be changing the targets' frames.
When the user does the thing that causes the resize of the window, you'll need to compute the desired overall size of the window (taking care to adjust its frame's position so it doesn't grow off the screen), as well as the new frames—both positions and sizes—of your views. Everything that will move and/or change size, create a dictionary for it and throw it into the array. Then create the view animation.
An NSViewAnimation is a kind of NSAnimation, which provides all the methods for starting and stopping the animation, monitoring its progress, hooking into it, and chaining multiple NSAnimations together. If nothing else, you'll need to start the animation.
If you are using the Interface Builder to build these views, then I believe one approach is to set the "struts and springs." These are available under the "size inspector" and are the red arrows and bars above the "autosizing" label. Play around with these to get the effect that you want, but the general idea is that the arrows control how the size of the view adjusts to changes in the size of the parent view, and the bars control the relationship of the edges of the view to the edges of the parent view as the size changes.
In constraint-based layout, set the views around the edge of your window to be a fixed distance from their superview's edge.
Xcode will infer a lot of resizability from that; if anything still isn't resizing properly, adjust its constraints so that its width and/or height is no longer constant.
The easiest way is to move your views until blue lines show up in the editor. Each blue line corresponds to a rule in the HIG about how things should be lain out, and if you drop the view there, Xcode will create constraints matching those guidelines. For example, if you set a view 20 points from the right edge of its superview, you'll get a blue line for that, and if you drop the view there, you'll create a constraint that the view must remain that distance from that edge.
The superview isn't the only view with which you can create HIG-based constraints. You can also create guideline constraints between sibling views. For example, if you put a button next to another button at the appropriate distance, you'll get a blue line across that distance, and if you drop it, you'll create a constraint that those two buttons must remain that distance from each other.
If you want to do something really custom, the three buttons in the lower-right corner of the nib editor will let you create any constraint you want. What you have selected determines what constraints you can create; the nib editor's outline view will help you make sure you have the selection you want.
You are going to have to iterate through all of your subviews and change their frame positions based on the delta of your window frame.
so if you expand your window frame by 20 in all directions, all your subviews are going to have to increase their frame positions by (20,20) to offset the windows movement.
I think this is a new spin on an old question, but I'm completely stuck here.
In my app, I have a UITableView with 650 cells, each with a custom 16x16 RGB icon. On most recent iOS devices, loading all of those icons into memory before displaying the table works totally fine, but on older hardware, I'd like to implement a lazy load system that only loads icons it needs.
I've implemented the Apple LazyTableImages example, (which uses a UIScrollView delegate to determine when the table stops moving to load the visible icons), but I've run into another snag.
My UITableView also has a section index display (ie the list of labels on the right hand side you can swipe up and down to scroll quickly), and the LazyTableImages example hasn't taken this into account.
If I scroll using the index, the images won't lazy-load. :(
As far as I can see, the scroll index doesn't actually have any delegate events it triggers.
So I'm wondering, has anyone else tried to implement lazy-loading on a table with a scroll index? Is there any way to track the index and find out if the user has interacted with it?
Thanks!
After buzzing around a few of my iOS developer buddies, I came up with a solution that worked well enough.
I set it up so that in addition to the icons being loaded from the UIScrollView delegates, an NSTimer object will periodically call a method that checks the currently visible table cells ([UITableView indexPathsForVisibleRows]) every .5 seconds, and loads any icons on the screen that haven't been loaded yet in a single separate thread.
I tried to make the solution as efficient as possible, so I made sure the timer was only active when the tableView was visible and stationary, and I liked it since it meant that every visible icon regardless was addressed.
One thing I discovered was that if the tableView was reloaded while the thread was looping through the visible cells (rare, but was possible), it would crash. The solution to this was to make sure each cell data source entry was retained while the icon was being loaded.