I have an NSScrollView with a custom NSImageView as its document view set up in the xib file. My problem comes when I want to magnify the NSScrollView. I would like it to behave like the Preview app on Mac, and I can get it to magnify just fine, but I want it to magnify with the cursor as the centered point.
I have this code in my custom NSScrollView class:
//Informs the receiver that the user has begun a pinch gesture.
- (void)magnifyWithEvent:(NSEvent *)event {
NSPoint conViewPoint =[[self contentView] convertPoint:[event locationInWindow] fromView:nil];
[self setMagnification:[event magnification]+[self magnification] centeredAtPoint:conViewPoint];
}
This works, however it also causes the scroll view to scroll down as it magnifies (though it doesn't move sideways at all). It's more noticeable when zooming in and out multiple times without lifting from the trackpad.
A similar problem seems to be in this question, however I'm using a pinch gesture and not buttons. I've been trying to offset the y axis scrolling as suggested for that question with
[[self documentView] scrollPoint:scrollPoint]
but I haven't been able to figure out a working formula for scrollPoint that accounts for the changing content view bounds to keep the point under the cursor in the same place. So, I'm wondering if there is a more proper approach to this or if the scrolling really is needed and I just need to figure out the math.
Thanks for any help with this
EDIT:
So I finally figured out the scrolling math. It took a while and way more complicated attempts, but is pretty simple in the end:
- (void)magnifyWithEvent:(NSEvent *)event {
NSPoint docViewPoint =[[self documentView] convertPoint:[event locationInWindow] fromView:nil];
NSPoint docRectOri=[self documentVisibleRect].origin;
float widthGapSize=-docRectOri.x;
float heightGapSize=-docRectOri.y;
if([event phase]==NSEventPhaseBegan){
startDocPoint=docViewPoint;
startPoint.x=(docViewPoint.x+widthGapSize)*[self magnification];
startPoint.y=(docViewPoint.y+heightGapSize)*[self magnification];
}
scrollPoint.x=startDocPoint.x-(startPoint.x/[self magnification]);
scrollPoint.y=startDocPoint.y-(startPoint.y/[self magnification]);
[self setMagnification:[event magnification]+[self magnification] centeredAtPoint:docViewPoint];
[[self documentView] scrollPoint:scrollPoint];
}
I still don't understand why setMagnification:centeredAtPoint: doesn't just work and am still wondering if anyone has some input on this as my workaround is very jittery on magnification because of the scrolling.
Related
I'm experience the strangest thing. I'm working on a project that I started noticing this issue, so I created a sandboxed test to simplify the problem and see if I can figure it out.
I have document based application with a single window controller. inside that are these objects:
Subclassed NSScrollView with isFlipped=YES
Subclassed NSView with isFlipped=YES, this is the documentView in the above scrollview.
An NSImage in the document view
Then I try and fade the image to alpha 0 like this:
- (void)windowDidLoad {
[super windowDidLoad];
[NSTimer scheduledTimerWithTimeInterval:2 target:self selector:#selector(test) userInfo:nil repeats:FALSE];
}
- (void) test {
[NSAnimationContext beginGrouping];
[[NSAnimationContext currentContext] setDuration:4];
self.errorOutline.animator.alphaValue = 0;
[NSAnimationContext endGrouping];
}
This is how it looks in Xcode:
This is what happens when it starts animating:
I've noticed that if I resize the window continually while it's animating, I get a ghosting image like effect where I an see the rest of the image.
Another strange issue is that if I set isFlipped=NO, then the issue doesn't happen. Which is not an option - the whole reason I'm flipping the view is so it's easier to manage adding cells to it without calculating positions and heights backwards.
Update: I've filed a radar bug as this is a really strange issue. http://openradar.appspot.com/20680289
Im using Xcode to make an application that has a NSImageView that I have made into an NSScrollView (I think) by means of selecting it in my .xib, going to the editor menu in Xcode then embedded in > scrollView.
I have an image in my NSScrollView that is larger than the window it is opened in, I can scroll using the scroll bars fine and have even turned on the autoscroll: function in my mouseDragged: method.
I would like to be able to simply pan around the image without touching the edges of the screen using mouseDragged:. So far my code for mouseDragged: in my panning.m(subclass of NSImageView) is such:
-(void)mouseDragged:(NSEvent *)theEvent{
NSPoint p = [theEvent locationInWindow];
[self scrollRectToVisible:NSMakeRect(p.x - self.visibleRect.origin.x, p.y - self.visibleRect.origin.y, self.visibleRect.size.width, self.visibleRect.size.height)];
[self autoscroll:theEvent];
}
This works to some degree, however there is a lot of jittering. Maybe because I am not restricting the bounds?
I was wondering if I am on the right track or is there a better/more efficient way.
Any help is appreciated.
Cheers.
I have an NSTextView inside an NSScrollView. I put text in the NSTextView and scroll it to the bottom programatically, which works OK, but the scrollbar stays at the top. Using the mouse to position the scrollbar causes it to jump to the bottom, where it belongs, and from that point it operates OK.
My code:
textView.string = s;
[textView scrollToEndOfDocument:self];
Don't get hung up on the scrollToEndOfDocument method--I also tried:
[textView scrollRangeToVisible:NSMakeRange(s.length, 0)];
and:
[[scrollViewText contentView] scrollToPoint:NSMakePoint(0, textView.frame.size.height)];
[scrollViewText reflectScrolledClipView:[scrollViewText contentView]];
with exactly the same problem, shown here:
I fixed the problem by adding one line:
textView.string = s;
[[NSRunLoop currentRunLoop] runUntilDate:[NSDate distantPast]];
[textView scrollToEndOfDocument:self];
That runUntilDate call shouldn't be necessary. My theory is that it gives the NSScrollView a chance to catch up and synchronize itself, somehow.
This is all on Lion. I tried it with the System Preference set to both the Lion "backwards" scrolling and the the traditional pre-Lion scrolling, with identical results.
Any ideas about:
Why that call I added helped, and
How to make it work without that call?
Try NSScrollView's reflectScrolledClipView:
Edit: How about replacing
[[scrollViewText contentView] scrollToPoint:NSMakePoint(0, textView.frame.size.height)];
with
[scrollView.contentView scrollToPoint:NSMakePoint(0, scrollView.documentView.frame.size.height-scrollView.contentSize.height)];
Because as it stands I believe you're scrolling past the document view's frame.
Whenever I try to create a custom window using NSBorderlessWindowMask and set an NSView (for example an NSImageView) as its contentView, I get a 1px gray border around the NSView and I don't seem to be able to get rid of it.
I have followed several approaches including Apple's RoundTransparentWindow sample code as well as several suggestions on StackOverflow.
I suspect the gray border is either coming from the window itself or the NSView.
Have any of you experienced this problem or do you have a possible solution?
The code is fairly straightforward. This is the init method of the custom window:
- (id)initWithContentRect:(NSRect)contentRect styleMask:(NSUInteger)aStyle backing:(NSBackingStoreType)bufferingType defer:(BOOL)flag {
self = [super initWithContentRect:contentRect styleMask:NSBorderlessWindowMask backing:NSBackingStoreBuffered defer:YES];
if (self != nil) {
[self setAlphaValue:1.0];
[self setBackgroundColor:[NSColor clearColor]];
[self setOpaque:NO];
}
return self;
}
To test this, in IB I place an NSImageView in that custom window WITHOUT border and yet the image in the NSImageView has a border. The same goes for other NSView subclasses, such as NSTextField, NSTableView.
In addition, I also noticed that the same is happening with the sample application (RoundTransparentWindow) of Apple. Is it even possible to draw an NSView in a custom window without a 1px border?
Thanks
Are you sure this happens when you use a regular NSView with no drawing? I bet not. Other controls (like NSImageView)have borders. Maybe you should double check to make sure they're turned off whe possible.
Update - How do you get your view into your window? You don't include that code. I created a basic test project (download it here) with an image well and it works just fine. See for yourself.
I have a NSTextView with a sizeable quantity of text. Whenever I scroll however, the view isn't updated properly. There are some artifacts that remain at the top or the bottom of the view. It appears that the view doesn't refresh itself often enough. If I scroll very slowly the view updates correctly though. If I add a border to the view everything works perfectly, borderless view is the one that has a problem. Here's a link to a screenshot:
Thanks
Have you set the setDrawsBackground and copiesOnScroll propertes for either the NSScrollView or the NSClipView?
The first thing I would suggest is turning off the "draws background" property of the NSScrollView:
[myScrollView setDrawsBackground:NO];
Note that this should be set on the NSScrollView, and not on the embedded NSClipView.
The following excerpt from the documentation may be relevant:
If your NSScrollView encloses an NSClipView sending a setDrawsBackground: message with a parameter of NO to the NSScrollView has the added effect of sending the NSClipView a setCopiesOnScroll: message with a parameter of NO. The side effect of sending the setDrawsBackground: message directly to the NSClipView instead would be the appearance of “trails” (vestiges of previous drawing) in the document view as it is scrolled.
Looks like the text field isn't even in the scrolling-area... Are you sure something isnt overlapping it?
I had a similar trouble - artifacts develop when the NSTextView is embedded in another scrollview (ie. a NSTableView).
I actually turned on the setdrawsbackground, and then added a nice color to make it disappear again.
-(void)awakeFromNib{
NSScrollView *scroll = [self enclosingScrollView];
[scroll setBorderType:NSNoBorder];
[scroll setDrawsBackground:YES];
[scroll setBackgroundColor:[NSColor windowBackgroundColor]];
}
This in combination with a scrollWheel event let me use the NSTextView in a NSTableView.
-(void)scrollWheel:(NSEvent *)theEvent{
NSScrollView *scroll = [self enclosingScrollView];
[[scroll superview] scrollWheel:theEvent];
}
I had the same trouble some time ago. I don't remember how I solved it.
Try to place the NSTextView to another view if the superview is a custom view. Just to see what will happen.