I have made a view in the application that shows a UITableView. It will be full of results (obviously) almost all the time, however when it does not have any results I want to show another view that inform the user about how he/she could populate the table.
I want to design that view in the interfacebuilder. I will have to check in the code whether the datasource is empty or not to toggle between the two different nibs. How do I instantiate and configure a view made in Interfacebuilder?
The easies way to do this is by adding the view in xib normally and make it visible
Design your both views, the table view and the other view, give the tableView a tag of 111 for example and give the otherview another tag 222 for example
Now in viewDidLoad
Get both the views
UIView *noDataView = [self.view viewWithTag:222];
UITableView *tableView = [self.view viewWithTag:111];
//Hide both of them or only the noDataView until you know if you have data from the dataSource or not
Check for your data source
//hasElements do you have any element to show?
if(hasElements)
{
noDatView.hidden = YES;
tableView.hidden = NO;
}
else
{
noDatView.hidden = NO;
tableView.hidden = YES;
}
You can load nib file based on condition.You can write category as follows:
self.view = (UIView *)[self loadNib:#"SecondView" inPlaceholder:self.view];
- (UIView *)viewFromNib:(NSString *)nibName
{
NSArray *xib = [[NSBundle mainBundle] loadNibNamed:nibName owner:self options:nil];
for (id view in xib) { // have to iterate; index varies
if ([view isKindOfClass:[UIView class]]) return view;
}
return nil;
}
- (UIView *)loadNib:(NSString *)nibName inPlaceholder:(UIView *)placeholder
{
UIView *nibView = [self viewFromNib:nibName];
[nibView setFrame:placeholder.frame];
self.view = nibView;
//[self.view insertSubview:nibView aboveSubview:placeholder];
//[placeholder removeFromSuperview];
return nibView;
}
The other answers give you possible technical solutions but I would propose that if you are using the standard Apple design guidelines, you probably don't even need to worry about it. For instance, somewhere on your screen you should have a bar button item with the identifier "Add" (which shows the plus icon). Then rather than giving a long (often poorly localised) description of how to add items, just have a header for an empty section which says "No items" replacing items with whatever pluralised noun is appropriate for your table's items. For example, for an Archery related app I am working on:
Notice how the Edit button is currently disabled too, thus no explanation is needed as the only thing they can do at this point is tap the Add button (screenshots on the Appstore will have shown them what they can expect to see after this point).
Related
I want to make horizontal paging in my app.
I have big text, which placed in UITextView, but I want to make horizontal paging, like iBooks or bookmate.
Do you have any solution or idea?
Have a look at the new (iOS 5) class UIPageViewController. For the iBooks page curl effect, try using
[controller initWithTransitionStyle:UIPageViewControllerTransitionStylePageCurl
navigationOrientation:UIPageViewControllerNavigationOrientationHorizontal
options:nil];
You can then set the view controllers using setViewControllers:direction:animated:completion:. For more reference for this class, visit the UIPageViewController Class Reference.
Use this handy class called PagedView which manages a paging scroll view as well as view loading/unloading and reuse for you.
You have to implement two delegate methods to get it working:
- (NSUInteger)numberOfPagesInPagedView:(PagedView *)view;
- (UIView *)pagedView:(PagedView *)view viewForPageAtIndex:(NSUInteger)page;
They will look familiar if you've ever used UITableView. In numberOfPagesInPagedView: you just have to return the number of pages you want to display.
- (NSUInteger)numberOfPagesInPagedView:(PagedView *)view
{
// return the number of pages in the paging view
return 10;
}
In pagedView:viewForPageAtIndex: you have to return a view for a specific page index. You can reuse the views by sending the dequeueReusableViewWithIdentifier: message to the paged view.
- (UIView *)pagedView:(PagedView *)pagedView viewForPageAtIndex:(NSUInteger)page
{
static NSString *reuseIdentifier = #"PageIdentifier";
UIView *view = [pagedView dequeueReusableViewWithIdentifier:reuseIdentifier];
if(view == nil) {
view = [[[MyPageView alloc] initWithFrame:view.bounds] autorelease];
}
// add contents specific to this page index to the view
return view;
}
In order to get view reuse working, your UIView subclass (MyPageView) should conform to the ReusableObject protocol and implement reuseIdentifier (in this case you would return #"PageIdentifier").
I have used this class in a number of projects and it works pretty well.
UIScrollView with pageEnabled turned on?
You can use a UIWebView (subclass of UIScrollView) for your horizontal paging needs.
For it to work, you'd need to split the NSString that you use to store your text, depending on the size (and height) of your web view.
Store the split NSString into an NSArray, and then depending on user swipe, load up the correct 'page' (array index) and display with animation.
Hope that helps.
I have an app which I add a subview to (and remove the same subview based on user interactions). I am looking for a way to check whether the subview is present or not at any given time.
For example:
In the current view (UIView *viewA) I add a subview (UIView *viewB). I then want a way of checking whether viewB is being displayed at any given time.
Sorry if this isn't very clear, it's quite hard to describe.
an UIView stores its superview and is accessible with the superview-property just try
if([viewB superview]!=nil)
NSLog(#"visible");
else
NSLog(#"not visible");
But the better approach is to use the hidden-property of UIView
I went through the same issue and consulted Apple Documentation and came up with this elegant solution:
if([self.childView isDescendantOfView:self.parentView])
{
// The childView is contained in the parentView.
}
I updated to Swift4, Thanks a lot to #Shinnyx and #thomas.
if viewB.superview != nil{
print("visible")
}
else{
print("not visible")
}
if selfView.isDescendant(of: self.parentView) {
print("visible")
}
else{
print("not visible")
}
func isDescendant(of: UIView)
Returns a Boolean value indicating whether the receiver is a subview of a given view or identical to that view.
Here's a method I put in the appDelegate so that I can display the entire subview hierarchy from any point.
// useful debugging method - send it a view and it will log all subviews
// can be called from the debugger
- (void) viewAllSubviews:(UIView *) topView Indent:(NSString *) indent {
for (UIView * theView in [topView subviews]){
NSLog(#"%#%#", indent, theView);
if ([theView subviews] != nil)
[self viewAllSubviews:theView Indent: [NSString stringWithFormat:#"%# ",indent]];
}
}
call it with a string with one character and it will indent for you. (i.e. [appDelegate viewAllSubviews:self.view Indent:#" "];)
I find it useful to clear the debug pane first, then call this from the debugger, and copy it into a text editor like BBEdit that will show the indents.
You can call it using the mainWindow's view and see everything on your screen.
I have an iPad application that adds buttons at runtime based on where the user touches within the view.
Now - I need to remove all these buttons at once.
I have set the tag of each button to be very high and grouped by type of button that was dropped.
How do I loop through all the button on the view and remove them if they fall into the right classification??
This removes all UIButtons. Adopt it to your needs. If you want to use tags I would recommend to tag every button that should stay in the view.
for (id object in [self.view subviews]) {
if ([object isKindOfClass:[UIButton class]]) {
[object removeFromSuperview];
}
}
Or you could add each UIButton to an NSMutableSet when you create them, and delete every button of the set if you don't need them anymore.
The only tag-based method is UIView#viewForTag and it returns a single object. (I believe it's the last view you added with that tag). But, you can adapt the above code for your purposes:
for (UIView *iView in [self.view subviews]) {
if (iView.tag == TARGET_CLASSIFICATION_TYPE) {
[iView removeFromSuperview];
}
}
Is it possible to select a row in a previous UITableview.
I provided image samples to get a more clear picture of what is happening exactly.
http://img186.imageshack.us/img186/933/picture8a.png
http://img405.imageshack.us/img405/9327/picture9d.png
http://img200.imageshack.us/img200/5386/picture10thm.png
At the morning workout screen , one can select a row and behind it so it will play a Movie.
If the movie plays you can press the secondbutton and it will take you to the final table.
If you press the backbutton you will simply return to the previous screen.
Now here is where my problem lies.
If i'm in my final screen after pressing the secondbutton and I press on the backbutton it would be great if it could play the previous video( in other words the video connected to the previously selected cell)
So if it's possible for me to create a function or some sort of action that can actually select the previously selected row from the first field ( for instance Lunge Forward in this example ).
perhaps with some like
previousRow = [ self.tableView indexPathForSelectedRow];
[self tableView:[self tableView] didSelectRowAtIndexPath:previousRow];
just doing something there
Even if it's not possible I would appreciate it if someone would let me know.
edit:
Here is some code behind the cell when it's going to play a video
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
//Get the dictionary of the selected data source.
NSDictionary *dictionary = [self.tableDataSource objectAtIndex:indexPath.row];
//check to see if video must be played
NSString *playVids = [dictionary objectForKey:#"playVids"];
finalscreen = [dictionary objectForKey:#"finalScreen"];
if(playVids == nil )
{
if(CurrentLevel != 0 )
{
if( finalscreen == nil )
{
NSString *movies = [dictionary objectForKey:#"movieID"];
NSURL *movie = [NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:movies ofType:#"m4v"]];
theMovie = [[MPMoviePlayerController alloc] initWithContentURL:movie];
[theMovie setOrientation:UIDeviceOrientationPortrait animated:NO];
[theMovie setScalingMode:MPMovieScalingModeAspectFit];
theMovie.backgroundColor = [ UIColor whiteColor];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(myMovieFinishedCallback:)
name:MPMoviePlayerPlaybackDidFinishNotification
object:theMovie];
[theMovie play];
[self getToolBarStuff];
lblTitle.text = [dictionary objectForKey:#"Title"];
[[[UIApplication sharedApplication]keyWindow]addSubview:toolbar2];
[[[UIApplication sharedApplication]keyWindow]addSubview:imageView];
[[UIApplication sharedApplication]keyWindow]addSubview:lblTitle];
}
}
else
{
WebViewController *web = [[WebViewController alloc] initWithNibName:#"WebView" bundle:[NSBundle mainBundle]];
[self.navigationController pushViewController:web animated:YES];
[web release];
}
}
else {
//Prepare to tableview.
rvController = [[RootViewController alloc] initWithNibName:#"RootViewController" bundle:[NSBundle mainBundle]];
//Increment the Current View
rvController.CurrentLevel += 1;
//Set the title;
rvController.CurrentTitle = [dictionary objectForKey:#"Title"];
//Push the new table view on the stack
[self.navigationController pushViewController:rvController animated:YES];
rvController.tableDataSource = Children;
[rvController release];
}
}
I get my info/feeds from a dictionaryfile and also different tags in my dictionary tell my tableview when to play the video and when not( playVids ).
so to be exact I have a start screen which brings you to a second screen and that one brings you to the morning workout screen and from there if you click a cell it will play a (different with every cell) video. I can't use the standard design from apple(with the backbutton above) since this assignment specifically asks to use their own design.
That's the reason why i created my own tabbar and backbutton.
My backbutton looks like this
-(void)back_clicked:(id)sender
{
[self.navigationController popViewControllerAnimated:YES];
CurrentLevel--;
switch( CurrentLevel ) {
case 0;
[toolbar removeFromSuperView];
default:
break;
}
}
So if I'm in the last screen I just pop that screen to return to my previous one( the morning workout). And what actually has to be done is pop that screen and play the last video. I thought I could do that by popping the last screen and then selecting the previously clicked cell in morning workout.
Any thoughts on that.
I am not sure I understand your problem exactly here. Can you show a bit more code? You have 3 view controllers, right? Are you using a standard navigation controller pattern with push/pop to get from one to the other? It looks like maybe you aren't since the buttons are in an odd layout.
If you are then pressing the back button can just pop view 3 and go back to view 2 naturally (it will still be there, so the video should still be playable) so I don't see why you need to mess with the table in view 1 in order to find that and make it show again. You should just be able to hook into viewWillAppear and do the same thing you did when coming from view 1.
And if you aren't using a standard navigation controller pattern then maybe this is the problem. From a UI perspective you probably should do that anyway - people will expect a standard back button in the title bar.
I am pretty sure your problem is soluble anyhow - you can always pass object references from one view to the other when creating them for example - but I don't think you need to resort to the method you have in mind.
edit: reading the additional detail I see you are indeed using push/pop. So you have a stack of views, and when one is popped it uncovers the one beneath it, right? It should therefore be possible to do what you want by implementing the viewWillAppear or viewDidAppear methods in your controller. When your final screen is popped, if I understand correctly it will uncover the view which is able to play the movie. Your viewcontroller will get the viewWillAppear / viewDidAppear messages in that case - by maintaining state and receiving those messages you can then implement logic to decide whether or not you need to play the movie. Rather than call the didSelectRow. method again you could perhaps put the movie play stuff in its own method so you can call from either viewDidAppear or didSelectRow...
I also am not sure that I fully understand your question either but it sounds similar to a problem I was working on recently. Check out this post on using up down arrows to move through the parent table while in a detail view. My app was based on the same sample code so you should be able to get this to work without much trouble.
Up/down arrows in nav bar of detail view to page through objects in parent table
I'm using Apple's MailComposer example application to send email from within my application (OS 3.0 functionality). Is it possible to set the To, Subject, or Body fields as first responder with MFMailComposeViewController?
In other words, the behavior would be: the user presses a button which presents the mail view (presentModalViewController). When the mail view is presented, the cursor is placed in one of the fields and the keyboard opens.
I notice the MFMailComposeViewController documentation says:
"Important: The mail composition interface itself is not customizable and must not be modified by your application. In addition, after presenting the interface, your application is not allowed to make further changes to the email content. The user may still edit the content using the interface, but programmatic changes are ignored. Thus, you must set the values of content fields before presenting the interface."
However, I don't care about customizing the interface. I just want to set that firstResponder. Any ideas?
You are able to make these fields become the first responder.
if you add the following method to your class...
//Returns true if the ToAddress field was found any of the sub views and made first responder
//passing in #"MFComposeSubjectView" as the value for field makes the subject become first responder
//passing in #"MFComposeTextContentView" as the value for field makes the body become first responder
//passing in #"RecipientTextField" as the value for field makes the to address field become first responder
- (BOOL) setMFMailFieldAsFirstResponder:(UIView*)view mfMailField:(NSString*)field{
for (UIView *subview in view.subviews) {
NSString *className = [NSString stringWithFormat:#"%#", [subview class]];
if ([className isEqualToString:field])
{
//Found the sub view we need to set as first responder
[subview becomeFirstResponder];
return YES;
}
if ([subview.subviews count] > 0) {
if ([self setMFMailFieldAsFirstResponder:subview mfMailField:field]){
//Field was found and made first responder in a subview
return YES;
}
}
}
//field not found in this view.
return NO;
}
Then, after you present the MFMailComposeViewController, pass the MFMailComposeViewController's view into the function along with the field you want to become first responder.
MFMailComposeViewController *mailComposer = [[MFMailComposeViewController alloc] init];
mailComposer.mailComposeDelegate = self;
/*Set up the mail composer*/
[self presentModalViewController:mailComposer animated:YES];
[self setMFMailFieldAsFirstResponder:mailComposer.view mfMailField:#"RecipientTextField"];
[mailComposer release];
In iOS 6, it is no longer possible to set first responder on any of the text fields AFAICT. Navigating the view hierarchy eventually reveals a UIRemoteView and the subviews within here are obfuscated away.
You can try just calling becomeFirstResponder on the controller itself. If that doesn't work, you can try in the debugger getting the list of subviews of the mail compose view until you find a familiar textfield or textview which you can then code specifically to set the responder status in code, which might look something like this (i don't know if this will work but it's an example):
[[[[mailcomposer.view.subviews objectAtIndex:3] subviews] objectAtIndex:2] becomeFirstResponder]
I like to simplify the code and make it easy to understand.
Just put the follow code after:
[self presentModalViewController:mailComposer animated:YES];
for (UIView *subview in mailComposer.view.subviews) {
NSString *className = [NSString stringWithFormat:#"%#", [subview class]];
//NSLog(#"%#", className); // list the views - Use this to find another view
//The view I want to set as first responder: "_MFMailRecipientTextField"
if ([className isEqualToString:#"_MFMailRecipientTextField"]){
[subview becomeFirstResponder];
break; // Stop search.
}
}