I'd like to center an NSCollectionView in its enclosing scroll view (horizontally & vertically).
How can I determine the ideal size of the collection view so that all item views fit?
It appears that a collection view will always resize itself to fill the entire document view when enclosed in a scroll view.
Also, if not enclosed in a scroll view, the collection view won't change its frame when new items are added.
I would suggest you to customise the NSCollection View. All you can do is override "drawRect" Method of NSCollectionView and inset its own rect. Below is what will fix your issue
Steps to implement:
Create a Class "NSModifiedCollectionView" Where it inherits from NSCollection View and do the following.
#interface NSModifiedCollectionView : NSCollectionView
#end
#implementation NSModifiedCollectionView
- (void) drawRect:(NSRect)dirtyRect
{
//You can inset more than 9.0 as per your needs but this will make you fit exactly
NSRect insetRec = NSInsetRect(dirtyRect, 9.0, 9.0);
[super drawRect:insetRec];}
2: Drag and Drop a NSCollectionView from you object list to the Xib and modify its custom class to "NSModifiedCollectionView". Now Run and check it should work as you expect.
Related
Is there a way for a custom NSView to know whether it is embedded in a NSScrollView or not?
I am creating a custom NSView for displaying some content.
When my view is placed in a window or another view, its size is fixed and the content is clipped to available size.
When my view is placed in a NSScrollView its size must be adjusted according to content so it can be scrolled if necessary.
I know I can add a member in my view that specifies the NSScrollView that hosts my view and set this member manually in code, but I was wondering if there is another way?
You didn't check the methods of NSView?
#property(readonly, strong) NSScrollView *enclosingScrollView;
or
var enclosingScrollView: NSScrollView? { get }
The nearest ancestor scroll view that contains the current view.
If the current view is not embedded inside a scroll view, the value of this property is nil. This property does not contain the current view if the current view is itself a scroll view. It always contains an ancestor scroll view.
I have a view-based NSTableView. I positioned the textField and other elements in an NSTableCellView in Interface Builder with autolayout. How can I get the height for the cell based on its autolayout parameters?
This answer is the closest I have found to what I am looking for, but it is written for iOS and the systemLayoutSizeFittingSize method does not exist on NSView.
You could put the views inside your table cell view into a separate NSView (let's call this view contentView). Set Auto Layout constraints for the contentView so that it aligns to its parent view at the left (leading), top and right (trailing). Make sure the subviews of contentView resize their parent view. Create an IBOutlet on that view in your NSTableCellView subclass. To calculate the height, call fittingSize on contentView which should get you the minimal size of your subviews based on the constraints.
I would like to figure out how to perform drag and drop from strings in a table view onto a collection view. I know there are delegate methods for collectionView drag and drop but can't find any examples of how to implement them. I have my collection view set up, it seems to be working correctly but don't know how to finish.
Any help is appreciated.
Update: The collection view setup I am working with has 3 NSTextFields and 2 check boxes for each collection item. There is also a tableView in the same view. The table view is passed an a MutableArray of strings. I want to be able to drag string values from the table view rows into the appropriate textFields in the collection view item.
This is different from the typical way drag and drop is used for collection views.
I am going to answer my own question because I spent quite a bit of time today trying to figure this out, Many people struggle with this procedure and mostly because I feel bad I keep asking the Stack community all these collection view questions all week:
I discovered the default behavior of the NSTextField actually allows a drop if it is in focus. The problem is that I need the appropriate NSTextField to auto focus on mouse enetered event. So as things turned out, I did not even need the NSCollectionView drag and drop delegates. I needed the NSTableView drag delegates and I needed to subclass the NSTextField and implement mouse event (drop) delegates in it.
so my class for the original collectionViewItem look like this:
//someClass.h
#interface SomeClass : NSObject{
IBOutlet NSTextField *field1_;
IBOutlet NSTextField *field2_;
IBOutlet NSTextField *field3_;
IBOutlet NSButton *chkBox1_;
IBOutlet NSButton *chkBox2_;
}
#porperty(readwrite, copy) NSTextField *filed1_;
properties are made for all 5 outlets for binding purposes. If you follow the tutorial on the Mac OSX Dev Library ; Collection View Programming Guide, it walks you through the process of setting up a collection View but it uses bindings.
So now the key is to set up a textField sub class
//MyNSTextField.h
#import
#interface MyNSTextField : NSTextField{
//mouse positioning
unsigned long last_;
}
//MyNSTextField.m
#import "MtTextField.h"
#implementation
-(void)dealloc{
[super dealloc];
}
-(void)awakeFromNib{
//register for dragged types
//any other nib stuff
}
//three required mouse events
-(unsigned long)draggingEntered:(id<NSDraggingInfo>)sender{
//this forces the textfield to focus before drop
[self.window makeFirstResponder: self];
NSPasebord *pBoard;
self->last_ = DragOperationNone;
pBoard = [sender draggingPastboard];
return self->last_;
}
-(unsigned long)draggingUpdated:(id<NSDraggingInfo>)sender{
return self->last_;
}
-(void)draggingExited:sender{
if([sender draggingSource] != self){
self->last = NSDragOperationNone;
}
}
}// end class
now just go back to the original class and change the name of your textField outlets from NSTextField to MyNSTextField and in the collection view, select each textfield and assign it the new class name in the inspector and as long as you had your tableview drag delegates set up, or if your are dragging from some other source, make sure you have the appropriate dragging source delegates set and it should work.
Is it a chance to programatically change the background color of NSCollectionView?
I was trying subclassing.. but not working..
#interface CollectionViewBg : NSCollectionView
in .m
[self setBackgroundColors:[NSArray arrayWithObjects:[NSColor blueColor], nil]];
In .m, remove this line :
[self setBackgroundColors:[NSArray arrayWithObjects:[NSColor blueColor], nil]];
And use this code:
- (void)drawRect:(NSRect)dirtyRect{
[[NSColor blueColor] setFill];
NSRectFill(dirtyRect);
}
Also don't forget to change class of NSCollectionView object in IB to CollectionViewBg.
Hope this helps :)
Guess subclassing isn't a great idea, because most of Cocoa controls provide various techniques to avoid subclassing in order to customize appearance and behavior.
In this particular case, you can set backgroundView property to your NSCollectionView and provide a custom view that is dedicated for drawing a custom background.
If you need to change only background color, then you can consider take advantage of the fact that collection view usually resists inside scroll view. Just set backgroundColor and drawsBackground properties of NSScrollView.
Here's a more modern solution. First, make yourself an NSView subclass that draws the effect you want to achieve. Here's a simple one that paints a block colour:
class ColouredView: NSView {
#IBInspectable var color: NSColor = .windowBackgroundColor
override func draw(_ dirtyRect: NSRect) {
color.setFill()
dirtyRect.fill()
}
}
Now go to your nib or storyboard and drag a custom view onto the left bar. We don't want it to be part of the view hierarchy, but we do want it to be listed under the view controller containing the collection view. Just drag it in below 'First Responder'. You can then set up any important properties or relationships - in my case, the background colour.
Finally, right-click your collection view and connect its 'background view' outlet to your custom view. This lets you do all the setup in your storyboard. If you like you can make your custom view #IBDesignable but I find that usually causes more trouble than it's worth.
I need fixed-size NSTextViews inside a larger scrolling window. IB requires that the textviews be inside their own NSScrollViews, even though their min/max sizes are fixed so that they won’t actually scroll. When trackpad gestures are made within the textview frames (regardless of whether they have focus), they are captured by the textviews’ scrollviews, so nothing happens.
How do I tell the textviews’ scrollviews to pass scroll events up to the window’s main scrollview? (Or perhaps I should be asking how I tell the window’s main scrollview to handle these events itself and not pass them on to its child scrollviews.)
The IB structure is like this:
window
window’s content view
big scrollview for window (desired target for scroll events)
box
swappable content view in separate xib
scrollview for textview
textview
And, yes, the window does scroll correctly when the textviews do not have focus.
You needn't create a outlet "svActive" to track your super scrollview. Just write this sentence in scrollWheel event:
[[self nextResponder] scrollWheel:event];
this will pass the event to next responder in the responder chain.
IB does not require you have a text view inside a NSScrollView; this is just the default, because most of the time you'll want your view to scroll. Select the NSTextView and choose Layout > Unembed Objects. Note that after this point, you can no longer move or resize your view in IB. This seems to be a bug.
Here's an example of how to put two NSTextViews in a single NSScrollView.
Add two text views next to each other; put some text in them so you can see what's happening.
Select the views; choose Layout > Embed Objects In > Scroll View. This puts them in a generic NSView inside a NSScrollView.
Select the text views; choose Layout > Unembed Objects.
Turn off the springs and struts (autosizing) for each text view, so they don't resize when you shrink the scroll view.
Take note of the height of the document view (here it's 175).
Make the scroll view smaller. This also resizes the document view (NSView).
Restore the document view to its original size (I set the height back to 175).
Done! Scrolling works as you'd expect.
This is really embarrassing. After weeks of putting it off, I made a first attempt to get a subclassed NSScrollView to behave passively — and it turned out to be a no brainer.
Here’s the subclass:
h file:
#import <Cocoa/Cocoa.h>
#interface ScrollViewPassive : NSScrollView {
// This property is assigned a ref to windowController’s main scrollview.
NSScrollView *svActive;
}
#property (nonatomic, retain) NSScrollView *svActive;
#end
m file:
#import "ScrollViewPassive.h"
#implementation ScrollViewPassive
#synthesize svActive;
// Pass any gesture scrolling up to the main, active scrollview.
- (void)scrollWheel:(NSEvent *)event {
[svActive scrollWheel:event];
}
#end
There’s no need to make outlets for these passive scrollviews; I give them their refs to the main scrollview right after their xibs are assigned as content to the NSBox:
[self.boxDisplayingTextViews setContentView:self.subviewCtllr1.view];
// A textview's superview's superview is its scrollview:
((ScrollViewPassive *)[[self.subviewCtllr1.textview1 superview] superview]).svActive = self.scrollviewMain;
That’s it. Works like a charm.
I find that IB3 and Xcode4 both fight you if you try to do this directly, but you can do it indirectly. First, drag the textview out of the scrollview and delete the scrollview. You'll wind up with an orphaned textview. I don't know any way to get IB to allow you to put this into your window, but it'll be in your NIB. Now, attach an IBOutlet to it, and at runtime do a addSubview: and adjust its frame to move it into whatever scrollview you wanted it to be in.
In my experience, NIBs are a good thing, but every complex NIB I've ever worked with needed some final rearranging in code.
Based on #phaibin's answer, here's how you'd do it in Swift 4.2.
First, subclass NSScrollView and override scrollWheel:
class ScrollThingy: NSScrollView{
override func scrollWheel(with event: NSEvent) {
self.nextResponder?.scrollWheel(with: event)
}
}
Then place the ScrollThingy class (or whatever you name it) on the NSScrollView that is wrapped around your NSTextView. The parent NSScrollView will get the scroll event thereafter.