I init a scrollView's frame according to my imageView's frame, so does its contentSize. Then I set my imageView as his child in order to zoom out and it works well. But, The method below can only just get the (UIView *)view 's relative location to his father(scrollView).Actually, view.frame.origin = (0, 0), which is weird to me. How explain this situation? Can I get the zoomed imageView's absolute position(to rootview) ?
(void)scrollViewDidEndZooming:(UIScrollView *)scrollView withView:(UIView *)view atScale:(CGFloat)scale
Parameter view
What changes when UIScrollView is scrolling is its contentOffset & bounds not its subviews' frames.
Related
I have a UICollectionView with the frame of
[UIScreen mainScreen].bounds
and these attributes:
_collectionView.pagingEnabled = YES;
_collectionView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
A cell has also the size of the collection view. When I rotate, the contentOffset of the collection view does not fit to the new orientation. It has still the same offset as before the rotation.
To fix this, I changed the contentOffset manually in the didRotate method.
- (void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation {
_collectionView.contentOffset = CGPointMake(_newContentOffsetX, _collectionView.contentOffset.y);
}
This works, but it looks terrible. I also tried to scroll to the current IndexPath, but it hast the same ugly behaviour:
- (void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation {
[_collectionView scrollToItemAtIndexPath:_currentIndexPath atScrollPosition:UICollectionViewScrollPositionLeft animated:NO];
}
I need a clean transition and behaviour of updating the collection view's content offset when rotating the device.
Its better To use the
willAnimateRotationToInterfaceOrientation:duration:
When this method is called the bound of your view controllers view are already updated to the current device orientation. It seems that this method gets called inside of the rotation animation block. This means all the positions you will set inside of willAnimateRotationToInterfaceOrientation:duration: are animated.
This helps me a lot and I use it to update my view Controllers view content insets on rotation. Works like a charm! :-)
Instead of using didRotateFromInterfaceOrientation, try updating contentOffset in willRotateToInterfaceOrientation.
You'll need to make sure to compensate for using the other width/height dimension that you'll be rotating to since it won't have done the rotation yet.
- (void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration
_collectionView.contentOffset = CGPointMake(_newContentOffsetX, _collectionView.contentOffset.y);
}
I am developing Mac app. In this app, I am using a NSScrollView's instance as scrollView.
And I have set a customView which is an instance of NSView in this ScrollView as:
[scrollView setDocumentView:customView];
But, the NSScrollView's vertical Slider always points to the bottom of the view as:
I want that the slider always points to the top of the custom View as:
How can I make this change?
Plz help.
I have solved my problem by setting the scrollToPoint property of ScrollView's ContentView.
Here is the code:
[[scrollView verticalScroller] setFloatValue:0.0];
[[scrollView contentView] scrollToPoint:NSMakePoint(0.0, y)];
// here y = (difference b/w scrollView's content size height and scrollView's height)
I move a hidden uilabel to the tap point in a uiscrollview and then unhide it - works great. However when you pinch the uiscrollview to zoom in and tap again the label shows up in the wrong position. How can I scale the touchpoint by the scale of the uiscrollview to position it correctly?
-me
-(void)handleLongPress:(UILongPressGestureRecognizer*)sender {
CGPoint longTapPoint = [sender locationInView:self.view];
NSLog(#"LongTapPoint.x %f,LongTapPoint.y %f",longTapPoint.x,longTapPoint.y);
uil_tapBldgLabel.center = CGPointMake(longTapPoint.x, longTapPoint.y);
}
You may want to pass these touch events to the nextResponder so you do not get caught up with the scaling nuances.
I have a Cocoa window, whose content view contains an NSScrollView that, in turns, contains a fixed-size NSView.
Upon launching the program, the scroll bars displayed initially are too small, as if the content size was much larger than it actually is:
When I start playing with, e.g., the vertical scroll bar, and bring it back to the original position at the top, it gets resized to its expected size (which corresponds to the ratio of scroll view and content view sizes):
(Notice the horizontal bar, which still has incorrect size. If I then play with it, and bring it back to its leftmost position, it gets resized to the correct size.)
I also encountered the same problem, I have searched everywhere but it seems no one else experiences this problem. Fortunately I found a hack which solves the problem.
What I did notice was that when the window is resized or maximized the scrollbars resize to the expected size (autoresizing has to be enabled). This is because when the window resizes so does the scrollview and the length of the scroll bars gets recalculated and is calculated correctly. Possibly due to some bug the scroll bar lengths are not calculated correctly on initialization. Anyway to fix the problem, in your application delegate create an outlet to your window. Override the "applicationDidFinishLaunching" method and inside it call the method "frame" on the window outlet, which returns the current NSRect of the window. Using the returned value add one to the size.width and size.height. The call the method setFrame with display set to YES. This will resize the window and force the size of the scrollbars to be recalculated.
Here is the code for applicationDidFinishLaunching Below
(void)applicationDidFinishLaunching:(NSNotification *)aNotification
{
// Get the current rect
NSRect windowRect = [_window frame];`
// add one to the width and height to resize window
windowRect.size.width += 1;
windowRect.size.height += 1;
// resize window with display:YES to redraw window subviews
[_window setFrame:windowSize display:YES];
}
I encountered this issue when modifying an NSTextView textContainer size to toggle line wrapping. Resizing the enclosing view does cause the correct scroll view height to be used, however its a brutal solution.
NSScrollView supports -reflectScrolledClipView. Calling this directly in my case had no effect except when delayed on the runloop:
[textScrollView performSelector:#selector(reflectScrolledClipView:) withObject:textScrollView.contentView afterDelay:0];
The scroller position is correct but there is a scroller redraw. So it looks as if part of the view geometry is calculated when drawing. A better solution is therefore:
NSDisableScreenUpdates();
[textScrollView display];
[textScrollView reflectScrolledClipView:textScrollView.contentView];
[textScrollView display];
NSEnableScreenUpdates();
Building on the answer from jstuxx above, if you don't want the window to visibly resize, try:
NSRect windowRect = [[[self view] window] frame];
windowRect.size.width += 1;
windowRect.size.height += 1;
[[[self view] window] setFrame:windowRect display:YES];
windowRect.size.width -= 1;
windowRect.size.height -= 1;
[[[self view] window] setFrame:windowRect display:YES];
I had to put this code after where I was programmatically adding the scroll view to my interface.
I am developing Mac app. In this app, I am using a NSScrollView's instance as scrollView.
And I have set a customView which is an instance of NSView in this ScrollView as:
[scrollView setDocumentView:customView];
But, the NSScrollView's vertical Slider always points to the bottom of the view as:
I want that the slider always points to the top of the custom View as:
How can I make this change?
Plz help.
I have solved my problem by setting the scrollToPoint property of ScrollView's ContentView.
Here is the code:
[[scrollView verticalScroller] setFloatValue:0.0];
[[scrollView contentView] scrollToPoint:NSMakePoint(0.0, y)];
// here y = (difference b/w scrollView's content size height and scrollView's height)