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);
}
Related
I'm using a MTKView to draw Metal content. It's configured as follows:
mtkView = MTKView(frame: self.view.frame, device: device)
mtkView.colorPixelFormat = .bgra8Unorm
mtkView.delegate=self
mtkView.sampleCount=4
mtkView.isPaused=true
mtkView.enableSetNeedsDisplay=true
setFrameSize is overriden to trigger a redisplay.
Whenever the view resizes it scales its old content before it redraws everything. This gives a jittering feeling.
I tried setting the contentGravity property of the MTKView's layer to a non-resizing value, but that totally messes up the scale and position of the content. It seems MTKView doesn't want me to fiddle with that parameter.
How can I make sure that during a resize the content is always properly redrawn?
In my usage of Metal and MTKView, I tried various combinations of presentsWithTransaction and waitUntilScheduled without success. I still experienced occasional frames of stretched content in between frames of properly rendered content during live resize.
Finally, I dropped MTKView altogether and made my own NSView subclass that uses CAMetalLayer and resize looks good now (without any use of presentsWithTransaction or waitUntilScheduled). One key bit is that I needed to set the layer's autoresizingMask to get the displayLayer method to be called every frame during window resize.
Here's the header file:
#import <Cocoa/Cocoa.h>
#interface MyMTLView : NSView<CALayerDelegate>
#end
Here's the implementation:
#import <QuartzCore/CAMetalLayer.h>
#import <Metal/Metal.h>
#implementation MyMTLView
- (id)initWithFrame:(NSRect)frame
{
if (!(self = [super initWithFrame:frame])) {
return self;
}
// We want to be backed by a CAMetalLayer.
self.wantsLayer = YES;
// We want to redraw the layer during live window resize.
self.layerContentsRedrawPolicy = NSViewLayerContentsRedrawDuringViewResize;
// Not strictly necessary, but in case something goes wrong with live window
// resize, this layer placement makes it more obvious what's going wrong.
self.layerContentsPlacement = NSViewLayerContentsPlacementTopLeft;
return self;
}
- (CALayer*)makeBackingLayer
{
CAMetalLayer* metalLayer = [CAMetalLayer layer];
metalLayer.device = MTLCreateSystemDefaultDevice();
metalLayer.delegate = self;
// *Both* of these properties are crucial to getting displayLayer to be
// called during live window resize.
metalLayer.autoresizingMask = kCALayerHeightSizable | kCALayerWidthSizable;
metalLayer.needsDisplayOnBoundsChange = YES;
return metalLayer;
}
- (CAMetalLayer*)metalLayer
{
return (CAMetalLayer*)self.layer;
}
- (void)setFrameSize:(NSSize)newSize
{
[super setFrameSize:newSize];
self.metalLayer.drawableSize = newSize;
}
- (void)displayLayer:(CALayer*)layer
{
// Do drawing with Metal.
}
#end
For reference, I do all my Metal drawing in MTKView's drawRect method.
I have the same problem with glitches on view resizing. You can even reproduce it in the HelloTriangle example from the Apple's developer site. However the effect is minimized because the triangle is drawn near the middle of the screen, and it's the content closest to the edge of the window, opposite the corner that drags, that is effected worst. The developer notes regarding use of presentsWithTransaction and waitUntilScheduled do not work for me either.
My solution was to add a Metal layer beneath the window.contentView.layer, and to make that layer large enough that it rarely needs to be resized. The reason this works is that, unlike the window.contentView.layer, which sizes itself automatically to the view (in turn maintaining the window size), you have explicit control of the sublayer size. This eliminates the flickering.
This helped me - https://github.com/trishume/MetalTest
He uses MetalLayer and careful setting of various properties. Everything is pretty smooth even with two side by side in synchronised scroll views with 45megapixel images.
A link to my original problem How do I position an image correctly in MTKView?
How does one go about having auto-layout automatically wrap an NSTextField to multiple lines as the width of the NSTextField changes?
I have numerous NSTextFields displaying static text (i.e.: labels) in an inspector pane. As the inspector pane is resized by the user, I would like the right hand side labels to reflow to multiple lines if need be.
(The Finder's Get Info panel does this.)
But I haven't been able to figure out the proper combination of auto layout constraints to allow this behavior. In all case, the NSTextFields on the right refuse to wrap. (Unless I explicitly add a height constraint that would allow it to.)
The view hierarchy is such that each gray band is a view containing two NSTextFields, the property name on the left and the property value on the right. As the user resizes the inspector pane, I would like the property value label to auto-resize it's height as need-be.
Current situation:
What I would like to have happen:
(Note that this behavior is different than most Stack Overflow questions I came across regarding NSTextFields and auto layout. Those questions wanted the text field to grow while the user is typing. In this situation, the text is static and the NSTextField is configured to look like a label.)
Update 1.0
Taking #hamstergene's suggestion, I subclassed NSTextField and made a little sample application. For the most part, it now works, but there's now a small layout issue that I suspect is a result of the NSTextField's frame not being entirely in sync with what auto-layout expects it to be. In the screenshot below, the right-hand side labels are all vertically spaced with a top constraint. As the window is resized, the Where field is getting properly resized and wrapped. However, the Kind text field does not get pushed down until I resize the window "one more pixel".
Example: If I resize the window to just the right width that the Where textfield does it's first wrap, then I get the results in the middle image. If I resize the window one more pixel, then the Kind field's vertical location is properly set.
I suspect that's because auto-layout is doing it's pass and then the frames are getting explicitly set. I imagine auto-layout doesn't see that on that pass but does it it on the next pass, and updates the positions accordingly.
Assuming that's the issue, how do I inform auto-layout of these changes I'm doing in setFrameSize so that it can run the layout again. (And, most importantly, not get caught in recursive state of layout-setFrameSize-layout-etc...)
Solution
I've come up with a solution that appears to work exactly how I was hoping. Instead of subclassing NSTextField, I just override layout in the superview of the NSTextField in question. Within layout, I set the preferredMaxLayoutWidth on the text field and then trigger a layout pass. That appears to be enough to get it mostly working, but it leaves the annoying issue of the layout being briefly "wrong". (See note above).
The solution to that appears to be to call setNeedsDisplay and then everything Just Works.
- (void)layout {
NSTextField *textField = ...;
NSRect oldTextFieldFrame = textField.frame;
[textField setPreferredMaxLayoutWidth:NSWidth(self.bounds) - NSMinX(textField.frame) - 12.0];
[super layout];
NSRect newTextFieldFrame = textField.frame;
if (oldTextFieldFrame.size.height != newTextFieldFrame.size.height) {
[self setNeedsDisplay:YES];
}
}
The simplest way to get this working, assuming you're using an NSViewController-based solution is this:
- (void)viewDidLayout {
[super viewDidLayout];
self.aTextField.preferredMaxLayoutWidth = self.aTextField.frame.size.width;
[self.view layoutSubtreeIfNeeded];
}
This simply lets the constraint system solve for the width (height will be unsolvable on this run so will be what ever you initially set it to), then you apply that width as the max layout width and do another constraint based layout pass.
No subclassing, no mucking with a view's layout methods, no notifications. If you aren't using NSViewController you can tweak this solution so that it works in most cases (subclassing textfield, in a custom view, etc.).
Most of this came from the swell http://www.objc.io/issue-3/advanced-auto-layout-toolbox.html (look at the Intrinsic Content Size of Multi-Line Text section).
If inspector pane width will never change, just check "First Runtime Layout Width" in IB (note it's 10.8+ feature).
But allowing inspector to have variable width at the same time is not possible to achieve with constraints alone. There is a weak point somewhere in AutoLayout regarding this.
I was able to achieve reliable behaviour by subclassing the text field like this:
- (NSSize) intrinsicContentSize;
{
const CGFloat magic = -4;
NSSize rv;
if ([[self cell] wraps] && self.frame.size.height > 1)
rv = [[self cell] cellSizeForBounds:NSMakeRect(0, 0, self.bounds.size.width + magic, 20000)];
else
rv = [super intrinsicContentSize];
return rv;
}
- (void) layout;
{
[super layout];
[self invalidateWordWrappedContentSizeIfNeeded];
}
- (void) setFrameSize:(NSSize)newSize;
{
[super setFrameSize:newSize];
[self invalidateWordWrappedContentSizeIfNeeded];
}
- (void) invalidateWordWrappedContentSizeIfNeeded;
{
NSSize a = m_previousIntrinsicContentSize;
NSSize b = self.intrinsicContentSize;
if (!NSEqualSizes(a, b))
{
[self invalidateIntrinsicContentSize];
}
m_previousIntrinsicContentSize = b;
}
In either case, the constraints must be set the obvious way (you have probably already tried it): high vertical hugging priority, low horizontal, pin all four edges to superview and/or sibling views.
Set in the size inspector tab in section Text Field Preferred Width to "First Runtime layout Width"
This works for me and is a bit more elegant. Additionally i've made a little sample project on Github
public class DynamicTextField: NSTextField {
public override var intrinsicContentSize: NSSize {
if cell!.wraps {
let fictionalBounds = NSRect(x: bounds.minX, y: bounds.minY, width: bounds.width, height: CGFloat.greatestFiniteMagnitude)
return cell!.cellSize(forBounds: fictionalBounds)
} else {
return super.intrinsicContentSize
}
}
public override func textDidChange(_ notification: Notification) {
super.textDidChange(notification)
if cell!.wraps {
validatingEditing()
invalidateIntrinsicContentSize()
}
}
}
I've a vertical NSSplitView, the bottom subview contains a custom view (eg NSView) and a NSTextView.
The NSView contains inside it two NSButtons.
When I resize the splitView, making it smaller, the NSView containing the buttons is resized, too.
I don't want this behavior.
To better explain my problem please view the attached image.
Image 1: the window at application startup, everything is ok
Image 2: I've resized making smaller the split view, only a little part of buttons is visible
Image 3: I've enlarged again the split view but as you can see the NSView remains smaller and buttons are no longer visible (if I resize the splitView to bottom the NSView 'disappears')
This is a vicious problem that's based on the legacy workings of Cocoa views. The best solution I've seen is to constrain the minimum dimension of any portion of the split view. If the subviews never collapse, their metrics don't cross into another dimension and they should re-enlarge just fine.
To do this, set up a delegate for your split view, which will implement - splitView:constrainMaxCoordinate:ofSubviewAt:. The split view will call your delegate method hoping it can leave the max divider position at the height of the split view (passing this in as the second argument), but you can simply subtract some quantity from that value (say, 60) to return it as the minimum height for the bottom view.
- (CGFloat)splitView:(NSSplitView *)aSplitView
constrainMaxCoordinate:(CGFloat)proposedMin
ofSubviewAt:(NSInteger)dividerIndex {
return proposedMin - 60;
}
Of course, you'll probably want to do more checking in this method to make sure you're talking about the right split view, and the right subview, to avoid overreaching effects, but this is the basic idea.
(See also this fabulicious article on the subject.)
Constraining the divider position did not help in my case, as I'm animating the subviews and subviews can be collapsed.
I managed to achieve an acceptable solution by implementing the splitView delegate method -splitviewWillResizeSubviews: (means, you have to connect the delegate property from the split view to your controller in IB or in code) to maintain a minimum width by setting the subview to hidden instead of shrinking it to zero:
- (void)splitViewWillResizeSubviews:(NSNotification *)notification {
NSUInteger divider = [[[notification userInfo] valueForKey:#"NSSplitViewDividerIndex"] intValue];
NSView *subview = nil;
if(divider == SPLITVIEW_DIVIDER_SIDEBAR) {
subview = (NSView*)[self.splitView.subviews objectAtIndex:SPLITVIEW_SIDEBAR_INDEX];
}
if(subview) {
if(subview.frame.size.width < SPLITVIEW_MINIMUM_SIDEBAR_WIDTH) {
CGRect correctedFrame = subview.frame;
correctedFrame.size.width = SPLITVIEW_MINIMUM_SIDEBAR_WIDTH;
subview.frame = correctedFrame;
subview.hidden = YES;
} else {
subview.hidden = NO;
}
}
}
Re-asking the question:
When you add an animation for the contents key, a CATransitionAnimation is apparently being triggered that fades the original contents property to the first value in the animation's values array, resulting in a .25 second fade. And it looks bad! I have suppressed every animatable property using all the methods discussed here (returning null animations through a delegate, into the actions dictionary, using CATransaction), but none of these seem to be targeting this particular transition animation.
I have been looking into what property could possibly be responsible for this, but cannot figure it out.
I need to suppress the transition animation that is occurring when you add an animation to the contents key.
As I'm at such a loss, I will put the keyframe animation that is being added for you to see. I figure maybe I am doing something wrong here? Just a note, that array is just an array of 6 CGImageRefs (the frames of the animation).
+ (CAKeyframeAnimation *)moveLeftAnimation {
CAKeyframeAnimation *animation = [CAKeyframeAnimation animationWithKeyPath:#"contents"];
animation.values = [NSArray arrayWithArray:[Setzer walkingLeftSprite]];
animation.duration = 0.5f;
animation.keyTimes = [NSArray arrayWithObjects:
[NSNumber numberWithFloat:0.0],
[NSNumber numberWithFloat:0.2],
[NSNumber numberWithFloat:0.4],
[NSNumber numberWithFloat:0.6],
[NSNumber numberWithFloat:0.8],
[NSNumber numberWithFloat:1.0],
nil];
animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];
return animation;
}
Also, I have an animation that handles the position key, in the sprite's action dictionary:
+ (CABasicAnimation *)moveAnimation {
CABasicAnimation *moveAnimation = [CABasicAnimation animation];
moveAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];
moveAnimation.duration = 0.5f;
return moveAnimation;
}
I am thinking maybe this transition is occurring when you change the layer's position? I don't know...
Please help! This is driving me NUTS!
You can do something along the lines of what I describe in this answer, where I disable the implicit animations for various layer properties by setting the appropriate values in the actions dictionary on that layer.
In your case, I believe something like
NSMutableDictionary *newActions = [[NSMutableDictionary alloc] initWithObjectsAndKeys:
[NSNull null], #"contents",
nil];
layer.actions = newActions;
[newActions release];
should prevent the implicit animation of a layer's contents property until you explicitly animate it.
To prevent any animation, you could set an object as the delegate of your CALayer and then implement the ‑actionForLayer:forKey: delegate method and return a null object:
- (id<CAAction>)actionForLayer:(CALayer*)layer forKey:(NSString*)key
{
if(layer == yourLayer)
{
if([key isEqualToString:#"contents"])
{
return (id<CAAction>)[NSNull null];
}
}
return nil;
}
Here are a few notes on how this puzzle was solved, and how everyone's answers provided a piece of the puzzle.
To restate the problem: when I added a keyframe animation to the #contents key of a CALayer, there appeared to be a .25 second fade transition between the original contents property and the first frame of the keyframe animation. This looked bad, and I wanted to get rid of it.
At first, I thought surely that by using a CATransaction I could suppress this implicit transition animation, as that is what Apple's docs lead you to believe. Using a transaction, I suppressed in every possible way you could imagine, and yet it was still happening. Then I tried returning NULL animations for every animatable property via a dictionary. No luck. Then I did the same thing, but with a delegate. Still no luck.
What I didn't mention is that at the same time the animation was being added and the layer was being moved, two sublayers beneath it were being removed from the their superlayers. I tried adding custom animations for the onOrderOut key, but to no avail. Then I stumbled upon another question here on StackOverflow, about adding a custom animation for the onOrderOut key. It turns out, quite simply, that you can't, and that if you wan to implement some other animation for when a sublayer is removed, you have to use the delagate method animationDidStop. How can I use custom animations for onOrderOut in Core Animation?
So at this point I was convinced that this ghost image had nothing to do with the actual layer in question, the sprite itself. To test this, I just didn't add the sublayers that went beneath it. Sure enough, there was no lingering ghost when I moved the sprite around. It looked perfect. Then I added the layers beneath there was the ghost. It was almost like the sprite's contents were drawn into the layers beneath it, so that when they were removed, there was a sort of imprint.
Instead of removing the sublayers, I just tried hiding them. Bingo. It was perfect. The same fade transition occurred, but there was no imprint of the sprite left. I still don't understand why this is so.
Then, because I still needed to remove those layers, I implemented the animationDidStop delegate method for the sprite's various movement animations to remove them.
This is the original:
This is the new version:
So while I don't understand, technically, why there appears to be an imprint, I am all but certain that it concerns what goes on behind the scenes when you remove a sublayer. Also, for interest sake, I still wanted that sublayer to be hidden on animation start, so I just set it to hidden and provided my own transition animation.
So thanks to everyone for their help. This is a strange use case, I know, but if you are ever thinking of making a 2d sprites-based Final Fantasy Tactics ripoff, then hopefully my pain will be to your benefit!
class AnimationLayer: CALayer {
override class func defaultAction(forKey event: String) -> CAAction? {
let transition = CATransition()
transition.duration = 0
return transition
}
}
I am looking to inset the contents of an NSTableView so that there is a gap between the top of the table view and the first cell.
On iOS this is easy with UITableView - achieved by using setContentInset:.
Turn headers back on and substitute the header view with your own subclass. Override its -drawRect: to draw only your background color. Also override -headerRectOfColumn: to prevent any of the column headers from being drawn. I'm not sure if this prevents column dragging or sorting but I'll bet it does.
The question asked how to adjust content insets similar to iOS. The currently selected answer shows how to move the first row down, but that's not quite the same thing. Adjusting the content insets will also move the start of the scrollbar to the inset position, just like iOS. This is useful when placing content underneath a "vibrant" or transparent toolbar.
An NSTableView itself does not have content insets. On macOS content insets are usually part of NSScrollView. To get access to the scroll view of NSTableView's view controller you can use the enclosingScrollview method of NSView, disable automatic adjustment and set the insets like this:
(warning old school Obj-C here)
self.enclosingScrollView.automaticallyAdjustsContentInsets = NO;
self.enclosingScrollView.contentInsets = NSEdgeInsetsMake(50.f,0.f,0.f,0.f);
Calling these from viewDidLoad is usually fine, however some types of table views will override your values with their own.
NSOutlineView set to source-list mode comes with lots of default values overridden to make the view look like the Finder sidebar.
There is no "clean" way to set the content-insets of these views. They stubbornly override your values, I've found that if you subclass NSOutlineView and overload setFrameSize: it will do the trick. So like this (inside the NSOutlineView subclass):
- (void)setFrameSize:(NSSize)newSize {
[super setFrameSize:newSize];
self.enclosingScrollView.automaticallyAdjustsContentInsets = NO;
self.enclosingScrollView.contentInsets = NSEdgeInsetsMake(100.f,0.f,0.f,0.f);
}
This will do the trick, but the initial scroll position will be strange. Calling scrollToBeginningOfDocument: from the initWithCoder: method of the subclass will scroll it to the correct initial position.
It's not very clean but you can achieve that by having the first row higher than the rest. Implement heightOfRow table delegate method:
- (CGFloat)tableView:(NSTableView *)tableView heightOfRow:(NSInteger)row
{
if (row == 0) {
return normalRowHeight + topPadding;
} else {
return normalRowHeight;
}
}
The drawback is that you would also need to implement custom highlighting and custom cell drawing to take into account the extra space for the first row.
scrollView.automaticallyAdjustsContentInsets = false
scrollView.contentInsets = NSEdgeInsets(top: 40, left: 0, bottom: 0, right: 0)