This is about a web browser.
I have a custom Class that handles the webpages.
SNBrowserView
SNBrowserViewPage
SNBrowserViewPages have two objects.
WKWebView
UIImageView // Snapshot of the WKWebView
A function either sustains or recovers a page for memory management.
(Testing) Whenever a page is selected I call a recovery function.
Selection:
- (void)browserView:(SNBrowserView *)browserView didSelectPage:(SNBrowserViewPage *)page
{
if (page.sustained) {
[page recoverAnimated:NO];
}
}
Sustain:
- (void)sustain
{
_sustained = YES;
if (_webView) {
_webView = nil;
[_webView removeFromSuperview];
}
_snapshotView = [[UIImageView alloc] init];
_snapshotView.frame = CGRectMake(0.0, 0.0, self.frame.size.width, self.frame.size.height);
_snapshotView.image = _snapshot;
[self addSubview:_snapshotView];
}
Recover:
- (void)recoverAnimated:(BOOL)animated
{
_sustained = NO;
_webView = [[WKWebView alloc] init];
_webView.frame = CGRectMake(0.0, 0.0, self.frame.size.width, self.frame.size.height);
_webView.navigationDelegate = self;
_webView.UIDelegate = self;
[self addSubview:_webView];
[self sendSubviewToBack:_webView];
[self loadURL:_initialURL]; // Start loading as early as possible.
if (animated) {
[UIView animateWithDuration:0.3
animations:^{
_snapshotView.alpha = 0.0;
}
completion:^(BOOL finished){
_snapshotView = nil;
[_snapshotView removeFromSuperview];
}];
}
else {
_snapshotView = nil;
[_snapshotView removeFromSuperview];
}
}
When I try to recover a page the snapshotView is not set to nil nor is it removed from the superview.
How is that even possible?
Even this won't work:
- (void)recoverAnimated:(BOOL)animated
{
_snapshotView = nil;
[_snapshotView removeFromSuperview];
}
The snapshotView is a subview, removeFromSuperview should always work, why is there MORE to it?
I suggest you try replace all of your
_view = nil;
[_view removeFromSuperview];
with
[_view removeFromSuperview];
_view = nil;
because what you are doing is setting the _view to nil and then removing nil from superview.
Related
Hi i am beginner in ios and in my project i am adding UIImage on UIScrollview and i have added tap gesture on UIImage
When we double click on UIImage then image should be zooming full screen size on view controller
After the full screen size image we can zoom it like any way what we want(i mean using like pinch zoom effect)here my requirement is when we double click on image then image need to set it's original position i have tried my level best but i did not get result please help me
my code is below:
#import "ViewController2.h"
#interface ViewController2 ()
{
UIScrollView * myScroll;
UITapGestureRecognizer *tap;
BOOL isFullScreen;
CGRect prevFrame;
UIImageView * _imageView;
}
#end
#implementation ViewController2
- (void)viewDidLoad
{
[super viewDidLoad];
isFullScreen = FALSE;
myScroll = [[UIScrollView alloc] init];
myScroll.frame = self.view.bounds;
myScroll.contentSize = CGSizeMake(_imageView.frame.size.width, _imageView.frame.size.height);
myScroll.maximumZoomScale = 4.0;
myScroll.minimumZoomScale = 1.0;
myScroll.clipsToBounds = YES;
myScroll.delegate = self;
myScroll.backgroundColor = [UIColor lightGrayColor];
[self.view addSubview:myScroll];
_imageView = [[UIImageView alloc] initWithFrame:CGRectMake(10, 10, 300, 200)];
_imageView.contentMode = UIViewContentModeScaleAspectFill;
[_imageView setClipsToBounds:YES];
_imageView.userInteractionEnabled = YES;
_imageView.image = [UIImage imageNamed:#"ram.jpeg"];
UITapGestureRecognizer *tapper = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(imgToFullScreen:)];
tapper.numberOfTapsRequired = 1;
[_imageView addGestureRecognizer:tapper];
[myScroll addSubview:_imageView];
}
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView {
return _imageView;
}
-(void)imgToFullScreen:(UITapGestureRecognizer*)sender {
if (!isFullScreen) {
[UIView animateWithDuration:0.5 delay:0 options:0 animations:^{
prevFrame = _imageView.frame;
[_imageView setFrame:[[UIScreen mainScreen] bounds]];
}completion:^(BOOL finished){
isFullScreen = TRUE;
}];
return;
}
else{
[UIView animateWithDuration:0.5 delay:0 options:0 animations:^{
[_imageView setFrame:prevFrame];
}completion:^(BOOL finished){
isFullScreen = FALSE;
}];
return;
}
}
#end
I did some modifications in your code as like below try it .Check it give your wanted output or not.
#interface ScrollViewController ()<UIScrollViewDelegate>{
UIScrollView * myScroll;
UITapGestureRecognizer *tap;
BOOL isFullScreen;
CGRect prevFrame;
UIImageView * _imageView;
CGAffineTransform trans;
}
#end
#implementation ScrollViewController
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view from its nib.
isFullScreen = FALSE;
myScroll = [[UIScrollView alloc] init];
myScroll.frame = [UIScreen mainScreen].bounds;
myScroll.contentSize = CGSizeMake(prevFrame.size.width, prevFrame.size.height);
myScroll.maximumZoomScale = 4.0;
myScroll.minimumZoomScale = 1.0;
myScroll.clipsToBounds = YES;
myScroll.delegate = self;
myScroll.backgroundColor = [UIColor lightGrayColor];
[self.view addSubview:myScroll];
_imageView = [[UIImageView alloc] initWithFrame:CGRectMake(10, 10, 300, 200)];
_imageView.contentMode = UIViewContentModeScaleAspectFill;
[_imageView setClipsToBounds:YES];
_imageView.userInteractionEnabled = YES;
_imageView.image = [UIImage imageNamed:#"img.png"];
UITapGestureRecognizer *tapper = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(imgToFullScreen:)];
tapper.numberOfTapsRequired = 2;
[_imageView addGestureRecognizer:tapper];
[myScroll addSubview:_imageView];
prevFrame = _imageView.frame;
trans = _imageView.transform;
}
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView {
return _imageView;
}
-(void)imgToFullScreen:(UITapGestureRecognizer*)sender {
if (!isFullScreen) {
myScroll.contentSize = prevFrame.size;
[UIView animateWithDuration:0.5 delay:0 options:0 animations:^{
_imageView.frame = [UIScreen mainScreen].bounds;
}completion:^(BOOL finished){
isFullScreen = TRUE;
}];
return;
}
else{
[UIView animateWithDuration:0.5 delay:0 options:0 animations:^{
myScroll.contentSize = CGSizeMake(prevFrame.size.width, prevFrame.size.height);
_imageView.transform = trans;
_imageView.frame = prevFrame;
NSLog(#"%# %#",NSStringFromCGSize(myScroll.contentSize),NSStringFromCGRect(prevFrame));
}completion:^(BOOL finished){
isFullScreen = FALSE;
}];
return;
}
}
I have a UISegmentedControl where the first control will display the text within a UITextView while the second control displays a scrollable UIImageView.
In the initial startup, if I switch to the second control, the image displays and switching back to the first control, the image disappears and the UITextView shows.
However, when I switch to the second control the 2nd time and switch back to the first control, the image is still there and I cannot get the UITextView to show anymore.
My code has it to where the image is hidden and the text is shown in the first control, and vice versa in the second control.
Why was it working the first time, but then not working the second time I switched between controls?
What am I doing wrong?
Thanks
-(void)viewDidLoad
{
self.scrollView.delegate = self;
self.textView.text = #"THIS IS A TEST. THIS IS A TEST. THIS IS A TEST. THIS IS A TEST. THIS IS A TEST. THIS IS A TEST.";
self.textView.hidden = NO;
}
-(void)setScroller
{
CGSize scrollableSize = CGSizeMake(self.view.frame.size.width, self.view.frame.size.height);
[self.scrollView setContentSize:scrollableSize];
self.imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"test.png"] ];
self.imageView.frame = CGRectMake(0, 0, self.scrollView.frame.size.width, self.view.frame.size.height);
self.scrollView.backgroundColor = [UIColor blackColor];
self.scrollView.minimumZoomScale = 1.0 ;
self.scrollView.maximumZoomScale = self.imageView.image.size.width / self.scrollView.frame.size.width;
//self.scrollView.zoomScale = 1.0;
[self.scrollView addSubview:self.imageView];
}
-(UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
return self.imageView;
}
- (IBAction)segmentedControl:(UISegmentedControl *)sender
{
if (self.segmentedControl.selectedSegmentIndex == 0)
{
// Display apppropriate info for About
self.imageView.hidden = YES;
self.textView.hidden = NO;
}
else
{
self.imageView.hidden = NO;
self.textView.hidden = YES;
[self setScroller];
}
}
You should remove [self setScroller]; from the - (IBAction)segmentedControl:(UISegmentedControl *)sender method, and put it in -(void)viewDidLoad instead. You're calling [self setScroller]; every time you switch to the second segment.
Your code should look like:
-(void)viewDidLoad
{
[super viewDidLoad];
self.scrollView.delegate = self;
[self setupScroller];
}
-(void)setupScroller
{
// Set contentSize
CGSize scrollableSize = CGSizeMake(self.view.frame.size.width, self.view.frame.size.height);
self.scrollView.contentSize = scrollableSize;
// Add textView
self.textView.text = #"THIS IS A TEST. THIS IS A TEST. THIS IS A TEST. THIS IS A TEST. THIS IS A TEST. THIS IS A TEST.";
self.textView.hidden = NO;
// Add ImageView
self.imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"test.png"]];
self.imageView.frame = CGRectMake(0, 0, self.scrollView.frame.size.width, self.view.frame.size.height);
self.imageView.hidden = YES;
[self.scrollView addSubview:self.imageView];
// Configure Zoom Scales and backgroundColor
self.scrollView.backgroundColor = [UIColor blackColor];
self.scrollView.minimumZoomScale = 1.0 ;
self.scrollView.maximumZoomScale = self.imageView.image.size.width / self.scrollView.frame.size.width;
}
-(UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
return self.imageView;
}
- (IBAction)segmentedControl:(UISegmentedControl *)sender
{
if (self.segmentedControl.selectedSegmentIndex == 0)
{
// Display appropriate info for About
self.imageView.hidden = YES;
self.textView.hidden = NO;
}
else
{
self.imageView.hidden = NO;
self.textView.hidden = YES;
}
}
Your problem probably is that you creating a lot of instances of "imageView"
To solve your problem I suggest:
-(void)setScroller
{
CGSize scrollableSize = CGSizeMake(self.view.frame.size.width, self.view.frame.size.height);
[self.scrollView setContentSize:scrollableSize];
if(self.imageView == nil) {
self.imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"test.png"]];
[self.scrollView addSubview:self.imageView];
}
self.imageView.frame = CGRectMake(0, 0, self.scrollView.frame.size.width, self.view.frame.size.height);
self.scrollView.backgroundColor = [UIColor blackColor];
self.scrollView.minimumZoomScale = 1.0 ;
self.scrollView.maximumZoomScale = self.imageView.image.size.width / self.scrollView.frame.size.width;
//self.scrollView.zoomScale = 1.0;
[self.imageView setNeedsDisplay];
[self.imageView setImage:[UIImage imageNamed: #"test.png"]];
}
I've put only the Alloc of the self.imageView + the addSubView to the if,
All the rest are out side,
Now it will work
I have a parent view that allows you to see post in a UITableView. In its Navigation Bar I have a post button that when pressed presents a UIView subclass and shows it on the top of the screen. I have an image on that UIView that when tapped I want to present the UIImagePickerController to allow users to pick an image to post to the service. How can I do this since my subview is not a view controller it cannot present the UIImagePickerController.
Below is my subview code.
#import "PostView.h"
#implementation PostView
#synthesize attachedLabel;
#synthesize postButton;
#synthesize textView;
#synthesize characterLimit;
#synthesize attachImage;
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
originalFrame = frame;
NSArray *xib = [[NSBundle mainBundle] loadNibNamed:#"PostView" owner:self options:nil];
PostView *view = [xib objectAtIndex:0];
[view setBackgroundColor:[UIColor whiteColor]];
[view setAlpha:0.7f];
attachedLabel = [[UILabel alloc] initWithFrame:CGRectMake(204, 212, 56, 21)];
attachedLabel.textColor = [UIColor blackColor];
[attachedLabel setText:#"Attached"];
attachedLabel.backgroundColor = [UIColor clearColor];
attachedLabel.font = [UIFont fontWithName:text_font_name size:12.0];
characterLimit = [[UILabel alloc] initWithFrame:CGRectMake(246, 13, 50, 21)];
[characterLimit setTextAlignment:NSTextAlignmentRight];
characterLimit.textColor = [UIColor blackColor];
characterLimit.backgroundColor = [UIColor clearColor];
characterLimit.font = [UIFont fontWithName:text_font_name size:12.0];
attachImage = [[UIImageView alloc] initWithFrame:CGRectMake(270, 208, 30, 30)];
[attachImage setImage:[UIImage imageNamed:#"attachphoto30x30.png"]];
[self.textView setDelegate:self];
[self.textView setAlpha:0.7f];
[self.textView setTextColor:[UIColor whiteColor]];
[self.textView setBackgroundColor:[UIColor clearColor]];
self.layer.cornerRadius = 10.0f;
self.layer.masksToBounds = YES;
[self addSubview:view];
[self addSubview:characterLimit];
[self addSubview:attachedLabel];
[self addSubview:attachImage];
}
return self;
}
- (IBAction)openCamera:(id)sender
{
UIImagePickerController *controller = [[UIImagePickerController alloc] init];
controller.delegate = self;
//[self presentViewController:controller animated:YES completion:nil];
NSLog(#"%#", #"Image Tapped");
}
-(void)imagePickerController:(UIImagePickerController*)picker didFinishPickingMediaWithInfo:(NSDictionary*)info
{
/*[picker dismissViewControllerAnimated:YES completion:nil];
UIImage *image = [info objectForKey: UIImagePickerControllerOriginalImage];
UIImage *scale = [image scaleToSize:CGSizeMake(320.0f, 548.0f)];
imageData = UIImageJPEGRepresentation(scale, 1);
encodedImage = [self Base64Encode:imageData];
[attachedLabel setHidden:NO];
*/
}
#pragma mark Custom alert methods
- (IBAction)postAction:(id)sender
{
[self hide];
}
- (void)show
{
//prepare attachImage
attachImage.userInteractionEnabled = YES;
UITapGestureRecognizer *tapAttach = [[UITapGestureRecognizer alloc]
initWithTarget:self action:#selector(openCamera:)];
tapAttach.numberOfTapsRequired = 1;
[self.attachImage addGestureRecognizer:tapAttach];
isShown = YES;
self.transform = CGAffineTransformMakeScale(0.1, 0.1);
self.alpha = 0;
[UIView beginAnimations:#"showAlert" context:nil];
[self setBackgroundColor:[UIColor clearColor]];
[UIView setAnimationDelegate:self];
self.transform = CGAffineTransformMakeScale(1.1, 1.1);
self.alpha = 1;
[UIView commitAnimations];
}
- (void)hide
{
isShown = NO;
[UIView beginAnimations:#"hideAlert" context:nil];
[UIView setAnimationDelegate:self];
[[NSNotificationCenter defaultCenter] postNotificationName:#"hidePostView_Notification" object:nil];
self.transform = CGAffineTransformMakeScale(0.1, 0.1);
self.alpha = 0;
[UIView commitAnimations];
}
- (void)toggle
{
if (isShown)
{
[self hide];
} else
{
[self show];
}
}
#pragma mark Animation delegate
- (void)animationDidStop:(NSString *)animationID finished:(NSNumber *)finished context:(void *)context
{
if ([animationID isEqualToString:#"showAlert"])
{
if (finished)
{
[UIView beginAnimations:nil context:nil];
self.transform = CGAffineTransformMakeScale(1.0, 1.0);
[UIView commitAnimations];
}
} else if ([animationID isEqualToString:#"hideAlert"])
{
if (finished)
{
self.transform = CGAffineTransformMakeScale(1.0, 1.0);
self.frame = originalFrame;
}
}
}
- (BOOL)textViewShouldBeginEditing:(UITextView *)textView
{
return YES;
}
- (BOOL)textView:(UITextView *)textViewer shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)string
{
if ([string isEqualToString:#"\n"])
{
[textViewer resignFirstResponder];
}
return [self isAcceptableTextLength:textViewer.text.length + string.length - range.length];
}
-(IBAction)checkIfCorrectLength:(id)sender
{
if (![self isAcceptableTextLength:self.textView.text.length])
{
// do something to make text shorter
}
}
- (BOOL)isAcceptableTextLength:(NSUInteger)length
{
return length <= 160;
}
- (void)textViewDidChange:(UITextView *)textViewer
{
NSString *characters = [[NSString stringWithFormat:#"%d", textViewer.text.length] stringByAppendingString:#"/160"];
NSLog(#"%#", characters);
[self updateDisplay:characters];
}
-(void) updateDisplay : (NSString *)str
{
[self.characterLimit performSelectorOnMainThread : # selector(setText : ) withObject:str waitUntilDone:YES];
}
#end
Yes, you can not present a viewcontroller from a UIView subclass.
To solve this problem, you can use your subview's superview's viewcontroller class. calling [self.superview nextResponder] in your subview will return you the superview's viewcontroller. Using that you can present your UIImagePicker view controller. To use the presentViewController method, you should cast [self.superview nextResponder] to your parentviewcontroller's class type. Also make sure you import parentview controller.h inside subview.m file
[(YourParentViewController *)[self.superview nextResponder] presentViewController:controller animated:YES completion:nil];
You should present a UIViewController subclass rather than a UIView subclass.
I would also say that UIViewController should be responsible for handling data and operational logic for its views. Check out some of the docs:
View Controller Basics:
http://developer.apple.com/library/ios/#featuredarticles/ViewControllerPGforiPhoneOS/AboutViewControllers/AboutViewControllers.html
UIViewController Class Reference:
http://developer.apple.com/library/ios/#featuredarticles/ViewControllerPGforiPhoneOS/AboutViewControllers/AboutViewControllers.html
I have a problem with an app that won't set frames outside -init and -viewWillLayoutSubviews methods. What should happen when one taps the editButton is an animation that will hide the editor view. Nonetheless, nothing happens as I test it. The problem doesn't come from the animation method since the -setFrame method as it - not included in the block - doesn't work neither.
Here is the code :
-(id)init {
if (self = [super init]) {
editButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemEdit target:self action:#selector(editButtonTapped)];
doneButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:#selector(doneButtonTapped)];
editor = [[UIView alloc] init];
[editor setBackgroundColor:[UIColor yellowColor]];
editor.clipsToBounds = YES;
editorIsOpen = YES;
portraitRegularModeEditorRect = CGRectMake(15, 59, 738, 100);
portraitClosedEditorEditorRect = CGRectMake(15, 59, 738, 0);
}
return self;
}
- (void)viewDidLoad {
[super viewDidLoad];
[[self view] addSubview:editor];
[[self view] setBackgroundColor:[UIColor blueColor]];
}
-(void)viewDidAppear:(BOOL)animated {
[self setForRegularMode];
}
-(void)viewWillLayoutSubviews {
UIInterfaceOrientation io = [[UIApplication sharedApplication] statusBarOrientation];
if (io == UIInterfaceOrientationPortrait || io == UIInterfaceOrientationPortraitUpsideDown) {
//portrait
[editor setFrame:portraitRegularModeEditorRect];
} else {
//landscape
}
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
-(void)editButtonTapped {
[self setForScenarioLinesEditingMode];
}
-(void)doneButtonTapped {
[self setForRegularMode];
}
-(void)setForRegularMode {
editingMode = CPRegularMode;
if (!editorIsOpen) {
[UIView animateWithDuration:0.3 delay:0 options:UIViewAnimationCurveEaseOut animations:^(void){
[editor setFrame:portraitRegularModeEditorRect];
} completion:^(BOOL finished) {
editorIsOpen = YES;
}];
}
[[self navigationItem] setRightBarButtonItems:[[NSArray alloc] initWithObjects:editButton,nil]];
}
-(void)setForScenarioLinesEditingMode {
editingMode = CPScenarioLinesEditingMode;
if (editorIsOpen) {
[UIView animateWithDuration:0.3 delay:0.0 options:UIViewAnimationCurveEaseOut animations:^(void){
[editor setFrame:portraitClosedEditorEditorRect];
} completion:^(BOOL finished) {
editorIsOpen = NO;
}];
}
[[self navigationItem] setRightBarButtonItems:[[NSArray alloc] initWithObjects:doneButton,nil]];
}
If anyone can help, thanks in advance ;)
I think that the problem in your case is the fact that in -(void)viewWillLayoutSubviews method you set, lets say the default frame of your view, if you try to change the frame in other methods after the setFrame is called on your view, the -(void)viewWillLayoutSubviews will also be called and the frame of the view will be the default one. Try to remove the setFrame from your -(void)viewWillLayoutSubviews.
Is your view controller set up in storyboards, and are you using Autolayout (which is on by default?) If so, setFrame won't work and you need to edit constraints after creating outlets to them from the storyboard.
Alternatively, you can turn off Autolayout in your storyboard, as shown here.
I am working on a reader app. when you read one magazine, it will display first five pages and download the rest pages one by one. there is a scrollview to view the thumbnail image of pages. At the beginning, if the page needs downloading, the corresponding thumbnail view's alpha value is set to 0.5 (the thumbnail images are in the file,no need to download). when the page is downloaded, i will update the thumbnail view's value to 1.0. I use one operation to download the page, and when one is downloaded i use delegate to set thumbnail view's alpha.
But when i update thumbnail view's alpha value, it still the same as the beginning. it seems the alpha has no effect. I wonder is there anything wrong with my code? some snippets are as follows:
In the PageViewController.m
- (void)loadView
{
[super loadView];
//...
[self createSlideUpViewIfNecessary];
[self downloadPages];
}
- (void)createSlideUpViewIfNecessary {
if (!slideUpView) {
[self createThumbScrollViewIfNecessary];
// create container view that will hold scroll view and label
CGRect frame = CGRectMake(CGRectGetMinX(self.view.bounds), CGRectGetMaxY(self.view.bounds), CGRectGetWidth(self.view.bounds), CGRectGetHeight(thumbScrollView.frame));
slideUpView = [[UIView alloc] initWithFrame:frame];
[slideUpView setBackgroundColor:[UIColor blackColor]];
[slideUpView setOpaque:NO];
[slideUpView setAlpha:0.75];
[[self view] addSubview:slideUpView];
// add subviews to container view
[slideUpView addSubview:thumbScrollView];
}
}
- (void)createThumbScrollViewIfNecessary {
if (!thumbScrollView) {
float scrollViewHeight = THUMB_HEIGHT + THUMB_V_PADDING;
float scrollViewWidth = CGRectGetWidth(self.view.bounds);
thumbScrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, scrollViewWidth, scrollViewHeight)];
[thumbScrollView setCanCancelContentTouches:NO];
[thumbScrollView setClipsToBounds:NO];
// now place all the thumb views as subviews of the scroll view
// and in the course of doing so calculate the content width
float xPosition = THUMB_H_PADDING;
for (int i = 0; i < magazine.pageNum ; i++) {
Page *page = [magazine.pages objectAtIndex:i];
NSString *name = page.pageName;
NSString *mfjName =[name stringByReplacingOccurrencesOfString:#".mfj" withString:#"Small.mfj"];
UIImage *thumbImage = nil;
if([mfjName hasSuffix:#".mfj"])
thumbImage = [Reader loadMfjFromSprOrCache:magazine MFJ:mfjName];
ThumbImageView *thumbView;
if (thumbImage) {// sometimes mfjname is 0 which means white page in normal and black thumbnail in thumbnail scrollview.
if (!mThumbnailSizeUpdated) {
mThumbnailWidth = thumbImage.size.width;
mThumbnailHeight = thumbImage.size.height;
mThumbnailSizeUpdated = YES;
}
thumbView = [[ThumbImageView alloc] initWithImage:thumbImage];
} else {
CGRect thumbFrame;
if (mThumbnailSizeUpdated) {
thumbFrame = CGRectMake(0, 0, mThumbnailWidth, mThumbnailHeight);
} else {
mThumbnailWidth = 80;
mThumbnailHeight = 100;
thumbFrame = CGRectMake(0, 0, mThumbnailWidth, mThumbnailHeight);
}
thumbView = [[ThumbImageView alloc] initWithFrame:thumbFrame];
}
NSString *mfjPath= [[magazine getDownloadPath] stringByAppendingPathComponent:name];
if (![magazine getFileInfo:name]&&![[NSFileManager defaultManager] fileExistsAtPath:mfjPath]) {
thumbView.alpha = 0.5;
}
[thumbView setBackgroundColor:[UIColor blackColor]];
[thumbView setTag:THUMBVIEW_OFFSET+i];
[thumbView setDelegate:self];
[thumbView setImageName:name];
CGRect frame = [thumbView frame];
frame.origin.y = THUMB_V_PADDING;
frame.origin.x = xPosition;
frame.size.width = frame.size.width+30;
frame.size.height = frame.size.height+40;
[thumbView setFrame:frame];
[thumbScrollView addSubview:thumbView];
UILabel *pageIndexLabel = [[UILabel alloc] initWithFrame:CGRectMake(xPosition, frame.origin.y+frame.size.height-THUMB_LABEL_HEIGHT, frame.size.width, THUMB_LABEL_HEIGHT)];
[pageIndexLabel setBackgroundColor:[UIColor clearColor]];
[pageIndexLabel setText:[NSString stringWithFormat:#"%d",(i+1)]];
[pageIndexLabel setTextColor:[UIColor whiteColor]];
[pageIndexLabel setTextAlignment:UITextAlignmentCenter];
[thumbScrollView addSubview:pageIndexLabel];
xPosition += (frame.size.width + THUMB_H_PADDING);
}
thumbScrollView.showsHorizontalScrollIndicator = NO;
[thumbScrollView setContentSize:CGSizeMake(xPosition, scrollViewHeight)];
}
}
- (void)downloadPages
{
DownloadOperation *op = [[DownloadOperation alloc] initWithMagazine:magazine];
op.delegate = self;
[[(AppDelegate *)[[UIApplication sharedApplication] delegate] sharedOperationQueue] addOperation:op];
}
- (void)downloadOperation:(DownloadOperation *)operation finishedAtIndex:(NSUInteger)index
{
if (thumbScrollView){
[thumbScrollView viewWithTag:THUMBVIEW_OFFSET+index].alpha = 1.0;
}
}
In DownloadOperation.m
- (void)main
{
// ...
NSUInteger index = 0;
for (Page *page in mMagazine.pages)
{
if (/*page doesn't exist*/){
// download the page;
if ([delegate respondsToSelector:#selector(downloadOperation:finishedAtIndex:)]) {
[delegate downloadOperation:self finishedAtIndex:index];
}
}
index++;
}
}
you're using operation queue to download images -> thus, your finish callbacks might arrive not on the main thread, but you are trying to update you UI anyway - try wrapping your UI interaction into dispatch_async on main thread:
dispatch_async(dispatch_get_main_queue), ^{
if (thumbScrollView){
[thumbScrollView viewWithTag:THUMBVIEW_OFFSET+index].alpha = 1.0;
}
});
Thanks to #Inafziger for clues on this.