I am creating a student index app, in which you can save names, pictures and roles of students. Everything works just fine, but when I created a certain amount of students (with pictures) while app-testing, the app runs extremely slow. Please find the corresponding methods enclosed. Is there any way to compress the size of the Image Data?
- (IBAction)cameraButtonPressed:(id)sender
{
if (! [UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera] ) {
UIAlertView *alert = [[UIAlertView alloc]initWithTitle:#"Error" message:#"no access to camera" delegate:self cancelButtonTitle:#"Ok" otherButtonTitles: nil];
[alert show];
return;
}
UIImagePickerController *controller = [[UIImagePickerController alloc] init];
controller.delegate = self;
controller.sourceType = UIImagePickerControllerSourceTypeCamera;
[self presentViewController:controller animated:YES completion:nil];
}
- (void) imagePickerController:(UIImagePickerController *)picker didFinishPickingImage:(UIImage *)image editingInfo:(NSDictionary *)editingInfo
{
[picker dismissViewControllerAnimated:YES completion:nil];
_imageView.image = image;
_imageView.contentMode = UIViewContentModeScaleAspectFit;
}
- (IBAction)save:(id)sender
{
Student *student = [NSEntityDescription insertNewObjectForEntityForName:#"Student"
inManagedObjectContext:self.managedObjectContext];
self.student.picdata = UIImagePNGRepresentation(_imageView.image);
[self.managedObjectContext save:nil];
[self.delegate DetailStudentSavePressed:self];
}
You're already compressing the image. When you call UIImagePNGRepresentation, you get a PNG-style compressed image file.
You didn't post the details of your data model, but at a minimum, make sure that the picdata attribute is configured to use external storage in the model editor. Do that first.
If that doesn't help, there are other approaches to reducing the impact of binary blobs on Core Data. But those are not the next step. You specifically mention slowness rather than memory problems, and problems with Core Data and images are far more likely to cause memory issues. Rather than worry about image handling when you have a speed problem, use Instruments to profile your app. You'll find out exactly where it's slowing down.
Related
I'm no longer able to render collectionview cells after using data from Cloudkit via CKAssets. I was previously using images loaded in a folder on my desktop just for initial testing. I'm now using Cloudkit and I've created some test records via the CK dashboard using those same images. I was successfully able to query the CK database and retrieve the expected records. I then changed my code to populate the model data for the cells to use the CK data. That data previously came from the images retrieved locally. I can see from logging that I am getting the data from CK successfully, including the images. I can also see from logging that my custom CV cells are no longer getting initialed. From what I can tell, my code looks good based on examples I've seen online.
Can anyone help me with this? Thank you!
Designated initializer in the model...
- (instancetype)initImagesForSelection:(NSString *)selectionType {
self = [super init];
if (self) {
CKDatabase *publicDatabase = [[CKContainer defaultContainer] publicCloudDatabase];
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"ImageDescription = 'description'"];
CKQuery *query = [[CKQuery alloc] initWithRecordType:#"ImageData" predicate:predicate];
[publicDatabase performQuery:query inZoneWithID:nil completionHandler:^(NSArray *results, NSError *error) {
// handle the error
if (error) {
NSLog(#"Error: there was an error querying the cloud... %#", error);
} else {
// any results?
if ([results count] > 0) {
NSLog(#"Success querying the cloud for %lu results!!!", (unsigned long)[results count]);
for (CKRecord *record in results) {
ImageData *imageData = [[ImageData alloc] init];
CKAsset *imageAsset = record[#"Image"];
imageData.imageURL = imageAsset.fileURL;
NSLog(#"asset URL: %#", imageData.imageURL);
imageData.imageName = record[#"ImageName"];
//imageData.image = [UIImage imageWithData:[NSData dataWithContentsOfURL:imageAsset.fileURL]];
imageData.image = [UIImage imageWithContentsOfFile:imageAsset.fileURL.path];
NSLog(#"image size height:%f, width:%f", imageData.image.size.height, imageData.image.size.width);
[self.imageDataArray addObject:imageData];
}
NSLog(#"imageDataArray size %lu", (unsigned long)[self.imageDataArray count]);
}
}
}];
}
return self;
}
Collectionview viewcontroller which worked perfectly before pulling the data from Cloudkit...
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"Cell"; // string value identifier for cell reuse
ImageViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:CellIdentifier forIndexPath:indexPath];
NSLog(#"cellForItemAtIndexPath: section:%ld row:%ld", (long)indexPath.section, (long)indexPath.row);
cell.layer.borderWidth = 1.0;
cell.layer.borderColor = [UIColor grayColor].CGColor;
ImageData *imageData = [self.imageLoadManager imageDataForCell:indexPath.row];
cell.imageView.image = imageData.image;
cell.imageView.contentMode = UIViewContentModeScaleAspectFit;
return cell;
}
Ok, I figured this out. My code was actually working. The collectionview was not displaying due to a multithreading/asynchronous download issue with the data from cloudkit. I hit the camera button to take a pic, which refreshed the CV and everything in the CV appeared. I just need to use multithreading so things start rendering while the images are downloading.
I am currently working on a UICollectionView with a lot of images. However, it sometimes crashes in this view with memory warning. I am using AFNetworking and UIImageView+AFNetworking category to set image through setImageWithURL: method. One issue can be caching. I am not sure if AFNetworking deals with image caching. Anyway, is there a way to optimize this code in terms of memory management? Or if I am to implement didReceiveMemoryWarning method in this view controller, what can be put in this method? I attach the code for cellForItemAtIndexPath for this collection view.
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:#"RecipeCell" forIndexPath:indexPath];
// setting the image view for the cell using AFNetworking. Does this do caching automatically?
UIImageView *recipeImageView = (UIImageView *)[cell viewWithTag:6];
if (PRODUCTION) {
[recipeImageView setImageWithURL:[[self.recipes objectAtIndex:indexPath.row] objectForKey:#"recipe_image"] placeholderImage:[UIImage imageNamed:#"default_recipe_picture.png"]];
} else {
[recipeImageView setImageWithURL:[NSString stringWithFormat:#"http://localhost:5000/%#", [[self.recipes objectAtIndex:indexPath.row] objectForKey:#"recipe_image"]] placeholderImage:[UIImage imageNamed:#"default_recipe_picture.png"]];
}
// configure the back of the cell. fill all the info.
UITextView *recipeNameView = (UITextView *)[cell viewWithTag:8];
recipeNameView.text = [NSString stringWithFormat:#"%#", [[self.recipes objectAtIndex:indexPath.row] objectForKey:#"recipe_name"]];
UILabel *recipeNameLabel = (UILabel *)[cell viewWithTag:2];
recipeNameLabel.text = [NSString stringWithFormat:#"%#", [[self.recipes objectAtIndex:indexPath.row] objectForKey:#"recipe_name"]];
NSDictionary *user = [[self.recipes objectAtIndex:indexPath.row] objectForKey:#"user"];
UIButton *chefNameButton = (UIButton *)[cell viewWithTag:3];
[chefNameButton setTitle:[NSString stringWithFormat:#"%# %#", [user objectForKey:#"first_name"], [user objectForKey:#"last_name"]] forState:UIControlStateNormal];
NSMutableArray *missingIngredientsStringArray = [[NSMutableArray alloc] init];
NSArray *missingIngredients = [[self.recipes objectAtIndex:indexPath.row] objectForKey:#"missing_ingredients"];
for (NSDictionary *missingIngredient in missingIngredients) {
[missingIngredientsStringArray addObject:[missingIngredient objectForKey:#"name"]];
}
NSString *missingIngredientsString = [missingIngredientsStringArray componentsJoinedByString:#","];
UITextView *missingIngredientsView = (UITextView *)[cell viewWithTag:4];
missingIngredientsView.text = [NSString stringWithFormat:#"%u Missing Ingredients: %#", missingIngredients.count, missingIngredientsString];
// configure the front of the cell. chef name button and missing ingredients and likes on front view
UIButton *frontNameButton = (UIButton *)[cell viewWithTag:11];
[frontNameButton setTitle:[NSString stringWithFormat:#"%# %#", [user objectForKey:#"first_name"], [user objectForKey:#"last_name"]] forState:UIControlStateNormal];
[frontNameButton sizeToFit];
frontNameButton.frame = CGRectMake(160 - [frontNameButton.titleLabel.text sizeWithFont:[UIFont boldSystemFontOfSize:13]].width - 7, frontNameButton.frame.origin.y, frontNameButton.frame.size.width, frontNameButton.frame.size.height);
UILabel *likesLabel = (UILabel *)[cell viewWithTag:9];
likesLabel.text = [NSString stringWithFormat:#"%# likes", [[self.recipes objectAtIndex:indexPath.row] objectForKey:#"likes"]];
UIButton *missingIngredientsButton = (UIButton *)[cell viewWithTag:12];
[missingIngredientsButton setBackgroundImage:[UIImage imageNamed:#"badge_green.png"] forState:UIControlStateSelected];
if (missingIngredients.count == 0) {
missingIngredientsButton.selected = YES;
[missingIngredientsButton setTitle:#"" forState:UIControlStateNormal];
} else {
missingIngredientsButton.selected = NO;
[missingIngredientsButton setTitle:[NSString stringWithFormat:#"%u", missingIngredients.count] forState:UIControlStateNormal];
}
// make back view invisible.
UIView *backView = [cell viewWithTag:1];
UIView *frontView = [cell viewWithTag:5];
frontView.alpha = 1.0;
backView.alpha = 0;
// adding flip gesture recognizers
UIView *flipView1 = [cell viewWithTag:12];
UIView *flipView2 = [cell viewWithTag:1];
UITapGestureRecognizer *flipGestureRecognizer1 = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(flipCell:)];
UITapGestureRecognizer *flipGestureRecognizer2 = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(flipCell:)];
[flipView1 addGestureRecognizer:flipGestureRecognizer1];
[flipView2 addGestureRecognizer:flipGestureRecognizer2];
return cell;
}
[Edit] I attach a screenshot of my Instruments run.
You can see that memory allocation increases as I just push segue and press back button repeatedly. Things that just keep increasing are CFData, CALayer, CABackingStore, UITableView. I doubt these are things that are created after segue, and they are not being released... Please help!
You're probably going to want some sort of image caching strategy to avoid re-downloading images. And UIImageView+AFNetworking category does cache images for you. But you may also have the responses being cached in the in-memory URL cache, which in this case is somewhat redundant.
So you might consider reducing or turning off the in-memory URL cache. I had the issue you're describing and the following reduced my memory issues quite a bit:
NSURLCache *sharedCache = [[NSURLCache alloc] initWithMemoryCapacity:0 diskCapacity:0 diskPath:nil];
[NSURLCache setSharedURLCache:sharedCache];
AFNetworking automatically stores images in an NSCache collection, which automatically removes some or all of the images from memory on a low memory warning. AFNetworking is probably not your issue.
In fact, I don't think displaying images is your issue unless you're downloading lots of very large images and displaying them simultaneously. (If this is the case, you should try optimizing your images for display on the device so they don't need to be resized.)
One issue I see is that you are adding a gesture recognizer to the cell every time it comes into the view, but cells are reused, so when a cell comes in again you are adding unnecessary gesture recognizers to it. You could resolve this by subclassing UITableViewCell and assigning the gesture recognizers as properties. You could also resolve this by checking flipView1 and flipView2 to see if they have gesture recognizers attached before adding them. (I'm not sure if this is enough to cause a memory warning though.)
I'd recommend going to Build -> Profile and selecting the Allocations instrument. On the left, select Objective C only, and hide system calls. Then, scroll through your collection view and look at the instrument to see what's taking up all the memory.
UPDATE
Here's a screenshot of the Allocations tool:
Ok guys, I am fairly new to objective C. I have an app that downloads a list of images from my web server and displays the appropriate ones in a UIImage view with swipe gestures to go forward or backwards for the next/previous pic to be displayed. Current naming format for the pictures is like this:
uploaded_141_admin1.png
uploaded_141_admin2.png
uploaded_141_interior1.png
uploaded_141_interior2.png
uploaded_141_exterior1.png
The current code loads every picture into the view that has 141 in the middle part of the filename (or whatever record the user in on... 141 is variable in this instance, just showing here for an example of the format). The problem is, there seems to be no rhyme or reason as to what order they are displayed in. I would like it to use the last part of the filename to sort alphabetically (or even the whole filename, as it would achieve the same result). In the example above, it would display the downloaded pics in the following order when swiping through the uiimageiew:
uploaded_141_admin1.png
uploaded_141_admin2.png
uploaded_141_exterior1.png
uploaded_141_interior1.png
uploaded_141_interior2.png
I've search and can't find what I am looking for (maybe because I'm using the wrong search criteria). Here is my existing code that downloads and displays the images in the UIImageView. I assume the "sort" code would go in here somewhere:
-(void)downloadPictures:(NSArray *)picPaths {
ELog(#"Downloading pictures: %#",picPaths);
// wait indicator
[[WaitingView sharedInstance] setMessage:LocStr(#"Loading pictures... The more pictures there are, the longer this will take. Please be patient.")];
[[WaitingView sharedInstance] showIndicator:YES];
[[WaitingView sharedInstance] displayOn:[self view]];
[[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:YES];
// queue download operation
NSOperationQueue *queue = [[NSOperationQueue alloc] init];
NSInvocationOperation *downloadOp = [[NSInvocationOperation alloc] initWithTarget:self selector:#selector(downloadOperation:) object:picPaths];
[queue addOperation:downloadOp];
}
-(void)downloadOperation:(NSArray *)picPaths {
NSMutableArray *allPictures = [[NSMutableArray alloc] init];
for(NSString *path in picPaths) {
NSURL *url = [NSURL URLWithString:[NSString stringWithFormat:#"http://%#%#/%#/%#",SERVER_ADDRESS,SERVER_PORT,SERVER_PHOTOS,path]];
NSData *picData = [NSData dataWithContentsOfURL:url];
if(picData!=nil) {
UIImage *img = [UIImage imageWithData:picData];
if(img!=nil) {
[allPictures addObject:img];
} else {
ELog(#"Failed to convert data to image from url %#",url);
}
} else {
ELog(#"Failed to download image from url %#",url);
}
}
[[WaitingView sharedInstance] performSelectorOnMainThread:#selector(remove) withObject:nil waitUntilDone:NO];
[[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:NO];
self.pictures=allPictures;
if([self.pictures count]==0) {
[self performSelectorOnMainThread:#selector(downloadErrorMessage) withObject:nil waitUntilDone:NO];
} else {
self.currentIndex=0;
[self performSelectorOnMainThread:#selector(showPicture) withObject:nil waitUntilDone:NO];
}
}
-(void)downloadErrorMessage {
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Oooops!" message:LocStr(#"Pictures download failed") delegate:nil cancelButtonTitle:LocStr(#"Close") otherButtonTitles:nil];
[alert show];
[alert release];
[self goBack];
}
-(void)showPicture {
UIImage *image = [self.pictures objectAtIndex:self.currentIndex];
ELog(#"Now displaying image with index %d: %#",self.currentIndex,image);
self.picture.image=image;
[self.picture setNeedsLayout];
}
In your downloadPictures: method you should sort your picPaths array to be the order you want the images before you start the download operation. You can do this by creating a new sorted array using the NSArray method sortedArrayUsingSelector:. Using caseInsensitiveCompare: as the selector for the sort will order the NSStrings in the array alphabetically.
NSArray *sortedPicPaths = [picPaths sortedArrayUsingSelector:#selector(caseInsensitiveCompare:)];
Then when you init your NSInvocationOperation, pass the sorted array as the object.
CD's been an enormous learning curve for me and there's still a bit for me to go, but any help on the following could enable me to lift the current weight on my shoulders!
I'm trying to write a method that implements a "Save As.." for the user in my CD app.
So far I've got:
[saveAsPanel beginSheetModalForWindow:window completionHandler:^(NSInteger userResult)
{
if (userResult == NSOKButton) {
NSPersistentStoreCoordinator *psc = [self persistentStoreCoordinator];
NSURL *oldURL = [self URLOfInternalStore]; //returns the current store's URL
NSURL *newURL = [saveAsPanel URL];
NSError *error = nil;
NSPersistentStore *oldStore = [psc persistentStoreForURL:oldURL];
NSPersistentStore *sqLiteStore = [psc migratePersistentStore:oldStore
toURL:newURL
options:nil
withType:NSXMLStoreType
error:&error];
}
}];
Unfortunately, I just get the error:
Object's persistent store is not reachable from this NSManagedObjectContext's coordinator.
Should I 'remove' and then 'addPersistentStore...' to update it to the new URL? The doc's seem to suggest that all will be handled with in the 'migrate' method.
Thanks in advance!
Edit:
Ok, well, I've come up with my own 'dirty' method. I can imagine that this isn't an approved way of doing things, but there's no error thrown up and the app works as expected at all times (not often I can say that, either!):
-(IBAction)saveAsAction:(id)sender
{
NSSavePanel *saveAsPanel = [NSSavePanel savePanel];
[saveAsPanel beginSheetModalForWindow:window completionHandler:^(NSInteger userResult)
{
if (userResult == NSOKButton) {
[self saveAction:#"saveAsCalling"];
NSURL *newURL = [saveAsPanel URL];
NSError *error = nil;
[[NSFileManager defaultManager] copyItemAtURL:[NSURL fileURLWithPath:internalStore] toURL:newURL error:&error];
//internalStore is a hard-wired NSString that holds the path to the bundle's database
}
}];
}
-(IBAction)loadAction:(id)sender
{
NSOpenPanel *loadPanel = [NSOpenPanel openPanel];
[loadPanel beginSheetModalForWindow:window completionHandler:^(NSInteger userResult)
{
if (userResult == NSOKButton) {
[self saveAction:#"loadCalling"];
NSURL *newURL = [loadPanel URL];
NSURL *oldURL = [NSURL fileURLWithPath:internalStore];
NSError *error = nil;
NSPersistentStoreCoordinator *psc = [SELF_MOC persistentStoreCoordinator];
[psc removePersistentStore:[[self persistentStoreCoordinator] persistentStoreForURL:oldURL] error:&error];
[psc addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:newURL options:nil error:&error];
[[NSFileManager defaultManager] removeItemAtURL:oldURL error:&error];
[[NSFileManager defaultManager] copyItemAtURL:newURL toURL:oldURL error:&error];
[psc removePersistentStore:[[self persistentStoreCoordinator] persistentStoreForURL:newURL] error:&error];
[psc addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:oldURL options:nil error:&error];
}
}];
}
The basic reasoning is this: to do a 'SaveAs...' I simply copy out the SQLLite store file in the mainBundle to wherever the user selects and rename it to what they want - as per TechZen's suggestion.
To do a 'Load' then I first removePersistentStore from the bundle's file, add the one that the user's just chosen. Delete the bundle store (which in theory isn't now being used) and then copy the user's choice back into the bundle. Finally, the two operations of remove and addPersistentStore are performed to point the app back to it's bundle's file which is now the user's choice.
Hope that makes sense. If anyone has any thoughts on just how unprofessional a methodology this is then please - be kind as I'm fairly new - let me know. I can't find anything that is more elegant.
I know Apple don't like you using removePersistentStore and addPersistentStore but, as I say no errors are reported (in my actual code I scattered NSLog lines throughout to report what error is holding).
You only use a SaveAs... in a document based app. If you use Core Data as your model, you need to use NSPersistentDocument to save your data. It provide the SaveAs... functionality you seek.
Straight Core Data is used for more database-like apps in which the entire app operates from one data set (more or less.)
I'd like to adjust the NSApplicationIcon image that gets shown automatically in all alerts to be something different than what is in the app bundle.
I know that it's possible to set the dock icon with [NSApplication setApplicationIconImage:] -- but this only affects the dock, and nothing else.
I'm able to work around this issue some of the time: I have an NSAlert *, I can call setIcon: to display my alternate image.
Unfortunately, I have a lot of nibs that have NSImageView's with NSApplicationIcon, that I would like to affect, and it would be a hassle to create outlets and put in code to change the icon. And for any alerts that I'm bringing up with the BeginAlert... type calls (which don't give an NSAlert object to muck with), I'm completely out of luck.
Can anybody think of a reasonable way to globally (for the life of a running application) override the NSApplicationIcon that is used by AppKit, with my own image, so that I can get 100% of the alerts replaced (and make my code simpler)?
Swizzle the [NSImage imageNamed:] method? This method works at least on Snow Leopard, YMMV.
In an NSImage category:
#implementation NSImage (Magic)
+ (void)load {
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
// have to call imageNamed: once prior to swizzling to avoid infinite loop
[[NSApplication sharedApplication] applicationIconImage];
// swizzle!
NSError *error = nil;
if (![NSImage jr_swizzleClassMethod:#selector(imageNamed:) withClassMethod:#selector(_sensible_imageNamed:) error:&error])
NSLog(#"couldn't swizzle imageNamed: application icons will not update: %#", error);
[pool release];
}
+ (id)_sensible_imageNamed:(NSString *)name {
if ([name isEqualToString:#"NSApplicationIcon"])
return [[NSApplication sharedApplication] applicationIconImage];
return [self _sensible_imageNamed:name];
}
#end
With this hacked up (untested, just wrote it) jr_swizzleClassMethod:... implementation:
+ (BOOL)jr_swizzleClassMethod:(SEL)origSel_ withClassMethod:(SEL)altSel_ error:(NSError**)error_ {
#if OBJC_API_VERSION >= 2
Method origMethod = class_getClassMethod(self, origSel_);
if (!origMethod) {
SetNSError(error_, #"original method %# not found for class %#", NSStringFromSelector(origSel_), [self className]);
return NO;
}
Method altMethod = class_getClassMethod(self, altSel_);
if (!altMethod) {
SetNSError(error_, #"alternate method %# not found for class %#", NSStringFromSelector(altSel_), [self className]);
return NO;
}
id metaClass = objc_getMetaClass(class_getName(self));
class_addMethod(metaClass,
origSel_,
class_getMethodImplementation(metaClass, origSel_),
method_getTypeEncoding(origMethod));
class_addMethod(metaClass,
altSel_,
class_getMethodImplementation(metaClass, altSel_),
method_getTypeEncoding(altMethod));
method_exchangeImplementations(class_getClassMethod(self, origSel_), class_getClassMethod(self, altSel_));
return YES;
#else
assert(0);
return NO;
#endif
}
Then, this method to illustrate the point:
- (void)doMagic:(id)sender {
static int i = 0;
i = (i+1) % 2;
if (i)
[[NSApplication sharedApplication] setApplicationIconImage:[NSImage imageNamed:NSImageNameBonjour]];
else
[[NSApplication sharedApplication] setApplicationIconImage:[NSImage imageNamed:NSImageNameDotMac]];
// any pre-populated image views have to be set to nil first, otherwise their icon won't change
// [imageView setImage:nil];
// [imageView setImage:[NSImage imageNamed:NSImageNameApplicationIcon]];
NSAlert *alert = [[[NSAlert alloc] init] autorelease];
[alert setMessageText:#"Shazam!"];
[alert runModal];
}
A couple of caveats:
Any image view already created must have setImage: called twice, as seen above to register the image changing. Don't know why.
There may be a better way to force the initial imageNamed: call with #"NSApplicationIcon" than how I've done it.
Try [myImage setName:#"NSApplicationIcon"] (after setting it as the application icon image in NSApp).
Note: On 10.6 and later, you can and should use NSImageNameApplicationIcon instead of the string literal #"NSApplicationIcon".