I'm trying to get an image of a view, so I can put it in a NSImageView.
I'm using NSViews bitmapImageRepForCachingDisplayInRect: method.
However, this method does only return the contents of the view, without background of the window.
How can I get the image of the whole view, as it looks on the screen, with background-color etc.?
Current Code
- (NSImage *)imageOfView:(NSView *)view {
NSBitmapImageRep* rep = [view bitmapImageRepForCachingDisplayInRect:view.bounds];
[view cacheDisplayInRect:view.frame toBitmapImageRep:rep];
return [[NSImage alloc] initWithCGImage:[rep CGImage] size:view.bounds.size];
}
This statement from the project
/* Get the index for the chosen display from the CGDirectDisplayID array. */
NSInteger displaysIndex = [menuItem tag];
/* Make a snapshot image of the current display. */
CGImageRef image = CGDisplayCreateImage(displays[displaysIndex]);
Related
I have an NSScrollView, whose documentView is a huge NSView, made of many many sub-NSImageViews, who act as tiles in a map. (The entire map is the NSView, and since it is way bigger than the screen size, its embedded in a scrollview).
I'm able to display the map with correct tile positions, and scroll around with the bars/gestures. However.. when I enable magnification to be able to zoom, the following happens:
Somehow I'm assuming auto-layout adds the tile borders below, and I don't know how to disable them. These are surely borders, since I have checked thousands of times that my tiles and subviews are the same size.. so where does this come from?
I have quite some experience with iOS development, but am completely lost with NSScrollView (Where are my delegate methods?). How do I disable this behavior of the scroll view?
Here's my subview code:
- (void)setupSubViews
{
NSLog(#"--------Creating subviews!-------");
//first we create the subviews..
//This is the key part, we traverse from top Left, and since OS X coordinates start at bottom left, we need to invert the rows!
for (int i=0; i< NUMBER_OF_COLUMNS; i++) {
for (int j=NUMBER_OF_ROWS-1; j>=0; j--) {
CGRect frame = CGRectMake(i*256, j*256, 256, 256);
NSImageView *newView = [[NSImageView alloc] initWithFrame:frame];
newView.focusRingType = NSFocusRingTypeNone; //I gave this focusRing a try, it didn't work :(
[self addSubview:newView];
}
}
}
And this is where I connect the subviews to the actual images..
-(void)updateMap:(id)tilesPassed{
if (downloadFinished) {
NSLog(#"--------DRAW RECT-------------");
NSImageView *subView;
NSInteger idx = 0;
for (int i =0; i<[self.subviews count]; i++) {
subView = [self.subviews objectAtIndex:i];
[subView setAllowsCutCopyPaste:NO];
[subView setImageFrameStyle:NSImageFrameNone]; //This doesnt work either :(
MapTile *tile = [tilesArray objectAtIndex:idx];
subView.image = tile.image;
idx++;
}
}
}
You probably don't want to use subviews for this. There is a CALayer subclass for exactly this purpose: CATiledLayer: https://developer.apple.com/library/mac/documentation/GraphicsImaging/Reference/CATiledLayer_class/Introduction/Introduction.html
With it you can even load different image tiles based on how far you are zoomed in, just like Google Maps. It will render without borders and the performance will be WAY better than using lots of subviews. Subviews are expensive, layers are (generally) cheap.
Update: This example will get you up and running: http://bill.dudney.net/roller/objc/entry/catiledlayer_example
As a quick work around without using CATiledLayer you can stitch all images as one image and add it to main view
Below is the sample code to stitch 2 images:
UIImage *bottomImage = [UIImage imageNamed:#"bottom.png"]; //first image
UIImage *image = [UIImage imageNamed:#"top.png"]; //foreground image
CGSize newSize = CGSizeMake(209, 260); //size of image view
UIGraphicsBeginImageContext( newSize );
// drawing 1st image
[bottomImage drawInRect:CGRectMake(0,0,newSize.width/2,newSize.height/2)];
// drawing the 2nd image after the 1st
[image drawInRect:CGRectMake(0,newSize.height/2,newSize.width/2,newSize.height/2)] ;
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
and directly add this newImage formed by stitching all your tiled images to the main view.
This is what I did:
#implementation BGUIActivityIndicator
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
// Initialization code
}
[self customInitialize];
return self;
}
-(id)initWithCoder:(NSCoder *)aDecoder
{
self = [super initWithCoder:aDecoder];
[self customInitialize];
return self;
}
-(void)customInitialize
{
UIView * theImageView= [self findASubViewforClass:[UIImageView class]];//
UIImageView * theImageView1 = (UIImageView *) theImageView;
theImageView1.image = [UIImage imageNamed:#"spinner_blue"];
[theImageView1.image saveScreenshot];
while (false) ;
}
/*
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect
{
// Drawing code
}
*/
#end
Everything seems perfect. [theImageView1.image saveScreenshot]; jot down both the old and new view perfectly.
However, nothing changes. Why?
I am not exactly asking how to change the image of UIActivityIndicator. There are tons of it already. I want to use it by subclassing UIActivityIndicator because I think it's the most elegant solution. I can't seem to do that.
In particular, I am asking why my approach, which works for changing background of search controller, for example, doesn't work for this.
According to the UIActivityIndicatorView Class Reference ,there is no way/ chance to change the image through sub-classing.
However you can change its activityIndicatorViewStyle , color of the activity indicator,UIActivityIndicatorStyle etc..
I think, without sub-classing, the class class UIImageView provides a very useful and simple way to implement such a thing. The only thing you have to do is to:
1.Provide a number of images that reflect your indicator animation.
2.Create a new UIImageView instance and set images and animation duration.
3.Position your custom activity indicator within your current view.
SAMPLE CODE:
//Create the first status image and the indicator view
UIImage *statusImage = [UIImage imageNamed:#"status1.png"];
UIImageView *activityImageView = [[UIImageView alloc]
initWithImage:statusImage];
//Add more images which will be used for the animation
activityImageView.animationImages = [NSArray arrayWithObjects:
[UIImage imageNamed:#"status1.png"],
[UIImage imageNamed:#"status2.png"],
[UIImage imageNamed:#"status3.png"],
[UIImage imageNamed:#"status4.png"],
[UIImage imageNamed:#"status5.png"],
[UIImage imageNamed:#"status6.png"],
[UIImage imageNamed:#"status7.png"],
[UIImage imageNamed:#"status8.png"],
nil];
//Set the duration of the animation (play with it
//until it looks nice for you)
activityImageView.animationDuration = 0.8;
//Position the activity image view somewhere in
//the middle of your current view
activityImageView.frame = CGRectMake(
self.view.frame.size.width/2
-statusImage.size.width/2,
self.view.frame.size.height/2
-statusImage.size.height/2,
statusImage.size.width,
statusImage.size.height);
//Start the animation
[activityImageView startAnimating];
//Add your custom activity indicator to your current view
[self.view addSubview:activityImageView];
See the full details Here
i have this method i use to load many images to scroll view, but when the images load from the url my scroll view is stuck and i can't understand how to load them in the background so the user will not feel it.
this method will call few times (8) in "for" cycle.
- (void)loadPhotosToLeftscroll{
//getting image information from JSON
NSMutableDictionary *photoDict;
photoDict = [leftPhotoArray lastObject];
//getting the photo
NSString *photoPath = [photoDict objectForKey:#"photos_path"];
NSLog(#"photo Path:%#",photoPath);
NSData * imageData = [[NSData alloc] initWithContentsOfURL:[NSURL URLWithString:photoPath]];
UIImage *image = [UIImage imageWithData:imageData];
// use the image how you like, say, as your button background
//calculating the hight of next photo
UIImageView *leftImage = [leftBlockScroll.subviews lastObject];
//allocating photoView
UIImageView *photoView = [[UIImageView alloc]initWithFrame:CGRectMake(5 , leftImage.frame.origin.y + leftImage.frame.size.height+5, image.size.width/2, image.size.height/2 )];
photoView.userInteractionEnabled=YES;
[photoView.layer setMasksToBounds:YES];
[photoView.layer setCornerRadius:3];
//getting items list
NSDictionary *sh_items = [photoDict objectForKey:#"items"];
//adding image button
UIButton *imageOverButton = [UIButton buttonWithType:UIButtonTypeCustom];
imageOverButton.frame = CGRectMake(0, 0, photoView.frame.size.width, photoView.frame.size.height);
[imageOverButton addTarget:self action:#selector(LeftimagePressed:) forControlEvents:UIControlEventTouchUpInside];
[imageOverButton setTag:[leftPhotoArray count]-1];
[photoView addSubview:imageOverButton];
//adding sh button to imageView
[self addThe_sh_signs:sh_items To_ImageView:photoView];
//subViewing the image to the scrollView
[self insert_Image:image toImageView:photoView in_Scroll:leftBlockScroll];
//calclulating the position of next imageView in scroll.
nextLeftPhotoHight = photoView.frame.size.height + photoView.frame.origin.y + 5;
//calculating the hight of the highest scroll view in both.
leftBlockScroll.contentSize = CGSizeMake(160, [self theSizeOfScrollViewHight]);
rightBlocScroll.contentSize = CGSizeMake(160, [self theSizeOfScrollViewHight]);
isLoadindContant = NO;
[self.view reloadInputViews];
[leftBlockScroll reloadInputViews];
}
please do not send me to some link that trying to explain how to use the asynchronous.
Try to explain according the method you see here.
Im here for any question, that you need to ask to help me.
You will have to do it asynchronously in a proper way. I do not think there is any way around that. I subclassed an UIImageView object and placed many instances of it within the cells of a talbe (in your case within the scroll view). The subclass objects are initialized with an url and load their image asynchronously (with some caching so that the image is not loaded every time).
This tutorial helped me much in the beginning:
http://www.markj.net/iphone-asynchronous-table-image/
You will just have to adopt that to your scroll view. The underlaying principle remains the same.
I am struggeling with my UIScrollview to get it to zoom-in the underlying UIImageView. In my view controller I set
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView {
return myImageView;
}
In the viewDidLoad method I try to set the zoomScale to 2 as follows (note the UIImageView and Image is set in Interface Builder):
- (void)viewDidLoad {
[super viewDidLoad];
myScrollView.contentSize = CGSizeMake(myImageView.frame.size.width, myImageView.frame.size.height);
myScrollView.contentOffset = CGPointMake(941.0, 990.0);
myScrollView.minimumZoomScale = 0.1;
myScrollView.maximumZoomScale = 10.0;
myScrollView.zoomScale = 0.7;
myScrollView.clipsToBounds = YES;
myScrollView.delegate = self;
NSLog(#"zoomScale: %.1f, minZoolScale: %.3f", myScrollView.zoomScale, myScrollView.minimumZoomScale);
}
I tried a few variations of this, but the NSLog always shows a zoomScale of 1.0.
Any ideas where I screw this one up?
I finally got this to work. what caused the problem was the delegate call being at the end. I now moved it up and .... here we go.
New code looks like this:
- (void)viewDidLoad {
[super viewDidLoad];
myScrollView.delegate = self;
myScrollView.contentSize = CGSizeMake(myImageView.frame.size.width, myImageView.frame.size.height);
myScrollView.contentOffset = CGPointMake(941.0, 990.0);
myScrollView.minimumZoomScale = 0.1;
myScrollView.maximumZoomScale = 10.0;
myScrollView.zoomScale = 0.7;
myScrollView.clipsToBounds = YES;
}
Here is another example I made. This one is using an image that is included in the resource folder. Compared to the one you have this one adds the UIImageView to the view as a subview and then changes the zoom to the whole view.
-(void)viewDidLoad{
[super viewDidLoad];
UIImage *image = [UIImage imageNamed:#"random.jpg"];
imageView = [[UIImageView alloc] initWithImage:image];
[self.view addSubview:imageView];
[(UIScrollView *) self.view setContentSize:[image size]];
[(UIScrollView *) self.view setMaximumZoomScale:2.0];
[(UIScrollView *) self.view setMinimumZoomScale:0.5];
}
I know this is quite late as answers go, but the problem is that your code calls zoomScale before it sets the delegate. You are right the other things in there don't require the delegate, but zoomScale does because it has to be able to call back when the zoom is complete. At least that's how I think it works.
My code must be completely crazy because the scale that I use is completely opposite to what tutorials and others are doing. For me, minScale = 1 which indicates that the image is fully zoomed out and fits the UIImageView that contains it.
Here's my code:
[self.imageView setImage:image];
// Makes the content size the same size as the imageView size.
// Since the image size and the scroll view size should be the same, the scroll view shouldn't scroll, only bounce.
self.scrollView.contentSize = self.imageView.frame.size;
// despite what tutorials say, the scale actually goes from one (image sized to fit screen) to max (image at actual resolution)
CGRect scrollViewFrame = self.scrollView.frame;
CGFloat minScale = 1;
// max is calculated by finding the max ratio factor of the image size to the scroll view size (which will change based on the device)
CGFloat scaleWidth = image.size.width / scrollViewFrame.size.width;
CGFloat scaleHeight = image.size.height / scrollViewFrame.size.height;
self.scrollView.maximumZoomScale = MAX(scaleWidth, scaleHeight);
self.scrollView.minimumZoomScale = minScale;
// ensure we are zoomed out fully
self.scrollView.zoomScale = minScale;
This works as I expect. When I load the image into the UIImageView, it is fully zoomed out. I can then zoom in and then I can pan the image.
I've created an NSScrollView which itself contains a NSClippedView as content view (this is all default, created by IB). Inside the contents view there is the (default) document view.
This NSScrollView has horizontal scroller disabled and vertical enabled and, most importantly auto hide scrollers enabled.
When I add new views (via code, runtime) to the document view the scroller does not unhide automatically, until the moment I vertically resize the window (and which in turn resizes the scrollview as well). 1px is enough. Just the new painting of the window seems enough.
What I am looking for is triggering this by code: so when I add views to the scrollviews' content view I would like the scrollbar to appear.
int numberOfChildViews = 10; //hard coded for example here
int childViewHeight = 80; //same as above
NSRect rect = NSMakeRect(0, 0, [[self.scrollView contentView] bounds].size.width, [numberOfChildViews*childViewHeight);
[[self.scrollView documentView] setFrame:rect];
[[self.scrollView documentView] setBounds:rect]; //just added to make sure
Then I added the custom views to the document view, like:
for (int i=0; i<numberOfChildViews; i++) {
NZBProgressViewController *item = [nzbProgressArray objectAtIndex:i];
int y=i*[[item view] bounds].size.height;
rect= NSMakeRect(0, y, [[scrollView contentView] frame].size.width, [[item view] bounds].size.height);
[[item view] setFrame:rect];
currentPosition++;
}
I am using a FlippedView so the origin will be displayed in left-top, like so:
#interface NSFlippedClipView : NSClipView {
}
#implementation NSFlippedClipView
- (BOOL)isFlipped {
return YES;
}
- (BOOL)isOpaque {
return YES;
}
#end
And added the following code to the awakeFromNib
NSFlippedClipView *documentView = [[NSFlippedClipView alloc] init];
[documentView setAutoresizingMask:NSViewWidthSizable];
[documentView setBackgroundColor:[self.scrollView backgroundColor]];
[self.scrollView setDocumentView:documentView];
[documentView release];
The scrollbars should become visible as soon as the document view is resized to be larger than the current viewport of the scroll view. Are you resizing the document view when you add your subviews to it?
Ahh, it's my own bad. For future reference: if you want to move the origin (0,0) to left-top use a NSView instead of NSClippedView extended class with IsFlipped method overriden to YES.
Thanks irsk for answering.