I have an NSCollectionView that is showing some images. I have implemented an NSCollectionViewDelegate to tell it which items should be selected and/or highlighted. I'm using a stock NSCollectionViewItem to draw the images and their names. When the user selects an item, my delegate gets the messages about highlight state changes:
- (void)collectionView:(NSCollectionView *)collectionView
didChangeItemsAtIndexPaths:(NSSet<NSIndexPath *> *)indexPaths
toHighlightState:(NSCollectionViewItemHighlightState)highlightState
{
[collectionView reloadItemsAtIndexPaths:indexPaths];
}
I do a similar thing for didSelect/didDeselect:
- (void)collectionView:(NSCollectionView *)collectionView
didSelectItemsAtIndexPaths:(nonnull NSSet<NSIndexPath *> *)indexPaths
{
[collectionView reloadItemsAtIndexPaths:indexPaths];
}
In the NSCollectionViewItems view, I do the following:
- (void)drawRect:(NSRect)dirtyRect {
[super drawRect:dirtyRect];
NSColor* bgColor = [[self window] backgroundColor];
NSColor* highlightColor = [NSColor selectedControlColor];
NSRect frame = [self bounds];
NSCollectionViewItemHighlightState hlState = [collectionViewItem highlightState];
BOOL selected = [collectionViewItem isSelected];
if ((hlState == NSCollectionViewItemHighlightForSelection) || (selected))
{
[highlightColor setFill];
}
else
{
[bgColor setFill];
}
[NSBezierPath fillRect:frame];
}
The problem I'm seeing is that drawing the highlight or selection appears to be random. When it does draw the selection, it's almost always on the items the user has actually selected (though it often leaves off the last item for some reason). Occasionally, it will select a different item the user did not click on or drag over. Often, though, it just doesn't draw.
I've added printing to verify that it is calling -didChangeItemsAtIndexPaths:toHighlightState: and -didSelectItemsAtIndexPaths:. Is there anything I'm doing wrong here?
I've added some logging to the view's -drawRect: method, and it doesn't appear to be getting called on all transitions, even though I'm calling -reloadItemsAtIndexPaths: in the -didChange* methods. Why not?
I've also noticed that the delegate's -should/didDeselectItemsAtIndexPaths: does not seem to get called ever, even though the -should/didSelectItemsAtIndexPaths: does get called. Why is that?
The problem turned out to be calling [collectionView reloadItemsAtIndexPaths:]. When you do that, it removes the existing NSCollectionViewItem and creates a new one (by calling your data source's collectionView:itemForRepresentedObjectAt:). That immediately sets the new collection view item to not selected (or rather it doesn't set it to be selected). When that happens, it won't call your should/didDeselect methods because the existing item doesn't exist anymore, and the new one is not selected.
The real solution turned out to be to subclass NSCollectionViewItem and override -setSelected: to do the following:
- (void)setSelected:(BOOL)selected
{
[super setSelected:selected];
[self.view setNeedsDisplay:YES];
}
When the view's -drawRect: method gets called, it asks the item if it's selected and draws appropriately.
Therefore, I could completely remove all of the should/did/select/Deselect methods from the delegate without any problem, and it all just worked!
Related
I have implemented tableview in my viewcontroller. I have not given any cell selection style.
What problem I am facing is, when I click on any of the cell it becomes gray. Normally what should happen is only background should become gray and not the whole cell. But here whole cell becomes gray.
Can anyone provide solution for this?
Thanks in advance!
You will have to implement your custom selection style as following steps.
First, you will want to disable the default selection behaviour:
- (void)awakeFromNib {
[super awakeFromNib];
self.selectionStyle = UITableViewCellSelectionStyleNone;
}
Second, override setHighlighted method (when user tap the cell and not yet raise his finger):
- (void)setHighlighted:(BOOL)highlighted animated:(BOOL)animated {
[super setHighlighted:highlighted animated:animated];
// Configure the view for the selected state
self.YOURVIEW.background = [UIColor grayColor];
}
Third, override setSelected method (when user tapped and raise his finger):
- (void)setSelected:(BOOL)selected animated:(BOOL)animated {
[super setSelected:selected animated:animated];
// Configure the view for the selected state
self.YOURVIEW.background = [UIColor grayColor];
}
Finally, you will want to deselect the cell in your tableview at a proper time by calling:
[self.tableView deselectRowAtIndexPath:animated:];
In your cell's setSelected method don't call the super's one, and implement your own solution. (Like graying out only the background view.)
I got a really strange problem.
My tableView has all the delegate and datasource set up.
Everything is fine.
However, clicking the rows do not activate:
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
I used custom cells.
After I click and click and click and click and click, sometimes it goes through.
I wonder what can possibly cause that? It's as if the customCell is "absorbing" the touch event or something or what?
Could that be why? If so, if we want to implement customCell and we want the tableView to handle the touch up event, what should we do?
Additional symptom:
If I remove user interaction enabled from the custom cell then the problem is solved with a catch.
However, clicking the button will somehow erase all the label texts in the customCell.
The implementation of the custom Cell is the following:
- (BGUIBusinessCellForDisplay *) initWithBiz: (Business *) biz
{
if (self.biz == nil) //First time set up
{
self = [super init]; //If use dequeueReusableCellWithIdentifier then I shouldn't change the address self points to right
NSString * className = NSStringFromClass([self class]);
//PO (className);
[[NSBundle mainBundle] loadNibNamed:className owner:self options:nil];
self.frame =self.view.frame;
[self addSubview:self.view]; //What is this for? self.view is of type BGCRBusinessForDisplay2. That view should be self, not one of it's subview Things don't work without it though
}
if (biz==nil)
{
return self;
}
_biz = biz;
self.prominentLabel.text = [NSString stringWithFormat:#"Isi: %#", biz.isiString];
self.Title.text = biz.Title; //Let's set this one thing first
self.Address.text=biz.ShortenedAddress;
//if([self.distance isNotEmpty]){
self.DistanceLabel.text=[NSString stringWithFormat:#"%dm",[biz.Distance intValue]];
self.PinNumber.text =biz.StringPinLineAndNumber;
NSString * URLString=nil;
if(biz.Images.allObjects.count!=0){
//self.boolImage=[NSNumber numberWithBool:true];
Image * image=(biz.Images.allObjects)[0];
URLString = image.URL;
URLString = [NSString stringWithFormat:#"http://54.251.34.144/thumbnailer/Thumbnailer.ashx?imageURL=%#",URLString.UTF8Encode];
//url=[NSURL URLWithString:image.URL];
}else{
float latitude = biz.getCllLocation.coordinate.latitude;
float longitude = biz.getCllLocation.coordinate.longitude;
URLString = [NSString stringWithFormat:#"http://maps.googleapis.com/maps/api/staticmap?&zoom=16&size=160x160&maptype=roadmap&sensor=true¢er=%f,%f&markers=size:small|color:blue|%f,%f",latitude,longitude,latitude,longitude];
URLString = URLString.UTF8Encode;
}
//Should add code and add loading indicator here
[BGHPTools doBackground:^{
UIImage * imageBiz = [BGMDImageCacherAndDownloader getImageFromURL:URLString];
[BGHPTools doForeGround:^{
self.Image.image=imageBiz;
[self.Image makeRound];
}];
}];
//self.view=self.view;
/*if (self.tableViewCell == Nil)//Instantiate that tableviewCell
{
PO(self.tableViewCell);
}
self.tableViewCell.business = bis;
self.pinLbl.text = bis.StringPinLineAndNumber;
self.lblTitle.text=bis.Title;
//self.pinLbl.text=bis.pinNumber;*/
//}
/*self.name=[dict objectForKey:#"Title"];
self.address=[dict objectForKey:#"Street"];
CLLocation * cll=[[CLLocation alloc]initWithLatitude:[[dict objectForKey:#"Latitude"] doubleValue] longitude:[[dict objectForKey:#"Longitude"] doubleValue]];
self.distance=[NSNumber numberWithDouble:[cll distanceFromLocation:[cachedProperties currentLocation]]];*/
return self;
Update: I already figure out why the texts are gone. Turns out my background is white. When a row got selected, the text suddenly turn into white. So by setting selected style to blue I sort of get that "fixed".
However, I still do not see where in my code I specify that all label texts should be white if the underlying tableViewCell is selected.
After all, what's selected is the cell, not the label. How the hell the label knows that it has to turn white is beyond me.
If you are using a Storyboard to handle the interface, instead of using:
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
Try using
#pragma mark --- Push selectedObject to the detailView ---
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
RRAppDelegate *myAppDelegate = [[UIApplication sharedApplication]delegate];
if ([[segue identifier] isEqualToString:#"PushObjectSegue"]) {
NSIndexPath *selectedRowIndex = [self.tableView indexPathForSelectedRow];
RRObjectViewController *detailViewController = [segue destinationViewController];
detailViewController.selectedObject = [myAppDelegate.goals objectAtIndex:selectedRowIndex.row];
}
}
I was having the same problem with the method you used and instead used this, it started working perfectly. Of course you'd have to adapt the code to your app's viewControllers and data source because I used my AppDelegate as the datasource, and I wasn't using a custom cell.
The most likely thing is that a view in your custom cell is absorbing the touch. Sometimes this is what you want, e.g. a button that does something, rather than selecting the entire cell. Assuming you don't want this, then just set those views' userInteractionEnabled property to NO.
--Additional code for custom NIB loading.
All you have to do is register the NIB in your viewDidLoad routine:
[tableView registerNib: [UINib nibWithNibName:#"yourCellNibName" bundle:nil] forCellReuseIdentifier:#"yourCellTypeID"]
and then in your cellForRowAtIndexPath just call:
newCell = [tableView dequeueReusableCellWithIdentifier #"yourCellTypeID"];
...
return newCell;
And it will load a cell from your XIB (or give you one from the previously used queue).
I just want to update that I think I have figured out what the problem is but still can't solve that quite right yet. And well the update is comprehensive so I think it should be an answer though I hope it's not the answer because some puzzle is still missing.
All the problem is interrelated.
The problem is in this line:
[self addSubview:self.view];
I basically turn that into:
Basically the my custom view cell has a view whose type is also tableViewCell. That view cover the real tableViewCell.
That's why when user interaction is enabled, that view will absorb the user's interaction.
That's also why the label "disappear". What happen is the label doesn't disappear. The label got highlighted and become white. However, what's highlighted is the tableViewCell not the opague view. The white opague self.view is still white while the tableCell itself is tinted with blue. So the label becomes white in the middle of white background and is gone.
I think I should replace [self addSubview:self.view] into self= self.view
However, that would mean changing the value of self. Yes it's in init. But it's still awkward. If anyone has the WAY to implement custom subclass of UI with XIB it'll be great because I haven't found one till now.
Awkward.
I wonder if we can draw a pointer to an XIB and specify that the outlet is self itself.
If that fail, I'll set background of self to white and background of self.view to transparent.
After tons of error and trying I did this:
self.contentView.backgroundColor = [UIColor whiteColor];
//self.view.backgroundColor = [UIColor redColor];
self.frame =self.view.frame;
/*PO(self.view.subviews);
PO(self.subviews);
PO(self.Title.superview);
PO(self.Title);
PO(self.view);
PO(self.Title.superview);
PO(self.view.contentView);*/
//Suck all the subviews from my minions
for (UIView* aSubView in self.view.contentView.subviews) {
[self.contentView addSubview: aSubView];
//[self.contentView add]
}
Basically I "move" all the subViews of my view object to my self object. There is a catch though that when subclassing tableViewCell I should move the subviews of the contentView. Who knows why.
At the end I just set self.view to nil for it's no longer needed and my program works as expected.
Also to set background of your tableViewCell, you need also to set the background of self.contentView rather than self.view.
Another approach you can try is to use story board. Alternatively you can just move the contentView of the self.view to self.
Make sure you'r implementing that method and not
deselectRowAtIndexPath:animated
I'm currently facing a strange issue with UICollectionViewCell when adding subviews to it but only during certain situations.
Here is the scenario:
I have a "container" view which conforms to a very specific protocol (ADGControl) with a nested view, typically a UIKit control subclass I.e MyCustomTextField : UITextField for custom controls.
The "container" view exposes a property called "innerControlView" which holds a strong reference to the custom control which is what I'm trying to add as a sub view to the cell's content view.
Here is the code:
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
FormControlCollectionViewCell *cell = [self.formCollectionView dequeueReusableCellWithReuseIdentifier:#"formControlCell" forIndexPath:indexPath];
NSArray *sectionContents = [_controlList objectAtIndex:[indexPath section]];
// This works
//UITextField *textField = [[UITextField alloc] initWithFrame:CGRectMake(0.0f, 0.0f, 315.0f, 30.0f)];
//textField.borderStyle = UITextBorderStyleLine;
//[cell.controlView addSubview:textField];
// This doesn't (see the behaviour in video clip)
id <ADGControl> control = [sectionContents objectAtIndex:[indexPath row]]; // The container view I'm referring to
[cell.contentView addSubview:(UIView *)[control innerControlView]]; // [control innerControlView] is the typical UIKit control subclass for custom controls. In this example it will be a UITextField
return cell;
}
As you can see in the code comments above, whenever I try to add just a UIKit control (textField) directly, it works just fine. However, as soon as I try to add my custom control ([control innerControlView] I get the unexpected behaviour as seen in the video clip here: http://media.shinywhitebox.com/ryno-burger/ios-simulator-ios-simulator-ipad-ios-a
The above link is just a short 23 seconds video clip to better demonstrate the "unexpected behaviour" that I get.
If anybody can point out what I'm doing wrong of what the issue might be I will be grateful.
Thanks
As you can read in the documentation on UICollectionViewCells, you shouldn't add content subviews to the cell itself, but to it's contentView.
And, like said before in my comment, you shouldn't add subviews in the data source, but in the subclass. You already noted that initWithFrame: wasn't called, use initWithCoder: instead:
-(id)initWithCoder:(NSCoder *)aDecoder {
self = [super initWithCoder:aDecoder];
if (self) {
// Add your subviews here
// self.contentView for content
// self.backgroundView for the cell background
// self.selectedBackgroundView for the selected cell background
}
return self;
}
A view can only be in one superview at once. If its already a subview of your container view, you can't just add it as a subview of another view (your cell).
It's not really clear why you're using a view as part of your model object, but you'll either have to change that or remove the inner view from its current superview before adding it to the cell.
Grouped UITableViews don't appear to automatically animate the deselection of a row in the same way that plain UITableViews do, for example when a UITableViewController appears again after a detail view controller is pushed and subsequently popped. The iPhone Settings app does appear to implement this behaviour however.
I have tried to implement the behaviour in the viewWillAppear method of my grouped UITableViewController class but it simply has no effect:
- (void)viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];
//If returning from an edit then animate the deselection of the previously selected row
if ([self currentIndexPath] != nil)
{
[[self tableView] deselectRowAtIndexPath:[self currentIndexPath] animated:YES];
[self setCurrentIndexPath:nil];
}
...
The row and section properties of [self currentIndexPath] are always correct and valid according to my UITableView but the row deselection still does not animate. I've also tried deselecting the row using the following, again without success:
[[self tableView] deselectRowAtIndexPath:[[self tableView] indexPathForSelectedRow] animated:YES];
Please could someone help to shed some light on how this behaviour is implemented?
Is your indexpath correct?
I've absolutely no problems with this. Did you connect your TableView with self.tableview (if using an outlet connection)?
Best,
Christian
I am managing my own UINavigationBar. I need to do this due to extensive skinning. The documentation for UINavigationController warns that there are limitations to skinning the UINavigationBar when used with a UINavigationController.
I have put in extensive logging and from everything I can tell, pushing the "Back" button in the UINavigationController pops two items off of of the stack instead of one. I get a single delegate callback telling me that it is removing the logical item, but it actually removes that one and one more.
The item added to the UINavigationController in awakeFromNib should never be removed. It is being removed for some reason.
There are two similar questions, but neither have satisfactory answers. The two questions are:
UINavigationBar .items accessor doesn't return the current UINavigationItem
UINavigationBar seems to pop 2 items off stack on "back"
- (void)awakeFromNib {
[headerView setDelegate: self];
[headerView pushNavigationItem: tableDisplay animated: NO];
}
- (void) selectedStory: (NSNotification *)not {
[headerView pushNavigationItem: base animated: NO];
NSLog(#"Selected story: %#", base);
}
- (void) baseNav {
NSLog(#"Current items: %#", [headerView items]);
BaseInnerItem *current = (BaseInnerItem *)[headerView topItem];
[self addSubview: [current view]];
}
- (BOOL)navigationBar: (UINavigationBar *)navigationBar shouldPushItem: (UINavigationItem *)item {
return YES;
}
- (BOOL)navigationBar: (UINavigationBar *)navigationBar shouldPopItem: (UINavigationItem *)item {
return YES;
}
- (void)navigationBar:(UINavigationBar *)navigationBar didPushItem:(UINavigationItem *)item {
NSLog(#"didPushItem: %#", item);
[self baseNav];
}
- (void)navigationBar:(UINavigationBar *)navigationBar didPopItem:(UINavigationItem *)item {
NSLog(#"didPopItem: %#", item);
[self baseNav];
}
Edited to add relevant debugging from a single run:
2010-10-13 02:12:45.911 Remix2[17037:207] didPushItem: <TableDisplay: 0x5d41cc0>
2010-10-13 02:12:45.912 Remix2[17037:207] Current items: (
"<TableDisplay: 0x5d41cc0>"
)
2010-10-13 02:12:49.020 Remix2[17037:207] didPushItem: <WebDisplay: 0x591a590>
2010-10-13 02:12:49.021 Remix2[17037:207] Current items: (
"<TableDisplay: 0x5d41cc0>",
"<WebDisplay: 0x591a590>"
)
2010-10-13 02:12:49.023 Remix2[17037:207] Selected story: <WebDisplay: 0x591a590>
2010-10-13 02:12:59.498 Remix2[17037:207] didPopItem: <WebDisplay: 0x591a590>
2010-10-13 02:12:59.499 Remix2[17037:207] Current items: (
)
You always have to call [super awakeFromNib] when your subclass implements that method, per the documentation for -awakeFromNib:
You must call the super implementation of awakeFromNib to give parent classes the opportunity to perform any additional initialization they require
Importantly, however, ...
I don't understand why you have to actually manage your own navigation bar. If you subclass UINavigationBar and only override certain drawing or layout methods such as -drawRect:, -layoutSubviews, etc., then all of the logic behind managing the navigation bar in a navigation controller will just fall back on the original UINaviationBar class.
I've had to do extensive view customization for almost every major UIKit class, but I always left the complicated logic to the original classes, overriding only drawing methods to customize the look and feel.
Incidentally, it's actually much easier to skin an entire app without subclassing at all if all you're doing is using custom image assets. By setting a layer's contents property, you can either customize the look and feel of a UIView-based class on an as-needed basis or throughout your entire app:
#import <QuartzCore/QuartzCore.h>
...
- (void)viewDidLoad
{
[super viewDidLoad];
UIImage * navigationBarContents = [UIImage imageNamed:#"navigation-bar"];
self.navigationController.navigationBar.layer.contents =
(id)navigationBarContents.CGImage;
}
You can set the contents for any class that inherits from UIView: navigation bars, toolbars, buttons, etc. It's a lot easier to manage this way without having to subclass at all.
This appears to be a bug in the implementation of -[UINavigationBar items]
When called from inside the -navigationBar:didPopItem: delegate method, it will omit the last object. You can check this by calling [navigationBar valueForKey:#"_itemStack"] to retrieve the underlying array and see that the expected items are still there.
Adding a dispatch_async inside -navigationBar:didPopItem:method successfully works around the issue in my app.