I have a very simple Collection View working exactly as expected. But, the underlying collection can get fairly long. The ItemViews themselves arent very wide. So, rather than have the Collection View run off the screen in a scrollable container, I would like to try and wrap the view from left to right maximizing the available screen width.
I have seen grid like views implemented with Composite Views, that are based on the table element. But I am wondering if there isnt just some magical way to make Collection View wrap left to right with css?
There is the CSS3 'columns' properties that may be what you're looking for: https://css-tricks.com/almanac/properties/c/columns/
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I am building an app, which will draw a representation of column-based data. I need both interactable cells and headers, so instead of adding suppplementary views for each column, I made another NSCollectionView that contains headers only.
The issue is that I would like to share selection rectangle state between these collection views, but I am not sure if there's some good way to achieve that or I have to hack whole controller.
Initially I was thinking about making an overlay on whole window, that would register in first responder chain, but it would use methods like draggedMouse only in my own methods and I would override built-in to pass the events to views behind, then if the view detected that user would like to draw a selection rectangle (select multiple items), that event would be moved to overlay view.
I thought also about making first row of items as sections (I am using compositional collection view layout, so it isn't that hard), but I think it would make features like drag and drop a huge pain in the bottom.
On the image you can see part of these collection views and how it looks now.
I have an NSCollectionView in an NSScrollView.
The scroll view scrolls horizontally to move along the line of items.
Inside each each collection item is a vertically scrolling NSOutlineView.
I have NSButton objects for opening and closing collection items - as supplementary views in my collection.
I set up NSTrackingAreas on these buttons to support mouse over effects.
This works correctly, until I scroll, at which point the NSTrackingArea areas are clearly left behind (the mouse over effects happen when the mouse is where the button was, not where it is).
I rebuild my tracking areas in updateTrackingAreas in my button class, and this is called, but not often enough.
I have tried using .inVisibleRect when setting up my tracking areas, rather than explicitly rebuilding them, but that doesn't improve the tracking update.
I have tried calling updateTrackingAreas on the NSCollectionView when scroll occurs, but it is never passed down to the child views as I expected it would.
As a side note, I also have NSTextViews in my collection view items with toolTips that are very flakey too. They are often left hanging. Pointing hand cursors over links are often misaligned.
It feels as though the default updateTrackingArea is over-optimised and is not being called as often as it should.
So, I am about to embark on building my own tracking-area-tracker to register and update my views when they are not updated by default...
...but maybe someone can see something obvious that I am missing? Thank you.
The tracking area setup can be subtly broken when nesting scroll views incorrectly. See the answers regarding nesting scroll views here for details:
NSScrollView inside another NSScrollView
It's really strange. The Prototype-Cell in my second UITableView isn't on top as it should be:
If I start moving it, than it's on top again, but after i drop it on my View, it is still in this strange way.
How can I change that?
As you see, the first Cell is okay, but the second isn't.
Well, it's difficult to understand using only an image, but I will give you some possible causes for that:
Have you applied a table header view by accident in the second table view? If you did, removing it will be the solution
Have you applied the proper view constraints in the table view and its cells?
If I were you, I would not try to embed two UITableViews in the same view controller this way, especially since you use storyboards with iOS 7. What I would do is to use embed segues. Just drag a container view for each of your view table views, and connect their embed segues to their appropriate table view controllers ( you need to create in the storyboard those, two). That way, you can set the constraints much easier, separate the logic between the two and have a cleaner interface. You can do that and see if that helps.
I am trying to create a view for a kind of brainstorming application like, for example, OmniGraffle, with elements that contain textviews and can be dragged around. (Also, the should be connectable with arrows, but that is not (yet) the problem)
I did my homework and searched via google and read books about cocoa, but there seems to be no similar example around.
Since I am also new to cocoa, I’m a bit helpless here.
The thing I am sure of is, that I need a custom view in which I can create my elements - what I tried until now to do that is:
First, I searched for the syntax to add subwindows to a window to create my elements. Subwindows, I imagined, would automatically be movable and come to front and so on.
The problem: As the experienced Cocoa-programmers of you probably are not surprised, I was stunned to find nothing about anything like that - this seems to be something, that is just not intended in Cocoa?!
Then I thought about creating subviews that contain a custom view for the title bar drawing (where the user can click to drag the element) and a NSTextView.
Problems:
I read, that it is not so clever to create dozens of subviews in a window because that would be very slow (or would that be not so bad in this case because all the subviews would be instances of always the same class?).
Also I can’t find out how to load a subview from a nib- or xib-file. Would I need a viewController? Or would that make the dozens-of-instances-problem even worse?
And Apple tells you not to overlap subviews (okay, that would be not so important, but I really wonder how the guys at OmniGroup made OmniGraffle...)
Because of that, I now wanted to do the title-bar-drawing in the surrounding custom view and create the textview programmatically (as I understand, a text-“view“ ist not really a view and takes its functionality from NSCell to reduce all the effort with the views?).
Problems:
Even that failed because I was not able to create a textview that doesn’t fill the complete window (the initWithFrame: of the [[NSScrollView alloc] initWithFrame: aRect] just seems to be ignored or do I get that wrong?).
Also, there should be some buttons on each element in the final application. I imagine that would be easier to accomplish with a subview from a nib-file for each element?
Well, now that nothing works and the more I read, the more problems seem to occur, I am pretty confused and frustrated.
How could I realize such a program? Could someone please push me in the right direction?
I created a class for the draggable elements where I save position, size and text in instance variables. In my view, every new element instance is added to an array (for now, this works without a controller). The array is used to draw all the elements in a loop in drawRect:. For the text of the element I just use a NSTextFieldCell which is set to the saved text from every element in the same loop.
That way it is also possible to overlap the elements.
Let's say I have a split view, and I want to fill half of it with a table view (a fairly common use case, I would think). Is there any way to tell the table view to size itself to fit the split view or do I really have to size it manually?
I've done this, the way Jon Hess mentions first. Assuming you're using Interface Builder version 3:
Drag and resize your GUI (tableview from what I understand?) component to fit into the enclosing area the way you want it.
Click it to select it.
Press Command-Shift-I to open the inspector window for this GUI component. The inspector window should now actually show that you've selected a "Scroll View".
Click the "ruler" heading to be able to set the sizing. You'll see to the right an animated representation of how your GUI component will behave within its enclosing GUI component, and to the left another represenation of the same, without animation, but with four springs and two struts that you can turn on or off.
Turn all six things on, making them red.
Voilà :-)
It's generally easier to create the subviews first, then use the Layout/Embed Objects In/Split View menu item to create the split view around them.
As far as I know, doing it manually is the only way to go. However, if you turn on "snap to cocoa guidelines", the inner view will snap to the edges of the enclosing view as you drag towards them. This makes it easier than having to manually mouse the edges into place, or manually edit the sizes to match.
You can set all of the springs and struts of the table view to "on" in the size inspector and that will cause the table view to fill the split view. Alternatively, you can use the outline view in the main document window to place the tableview's enclosing scroll view directly into the splitview instead of in an intermediary custom view.