I have properly setup an NSOutlineView with its data source and it's working great.
It's actually a basic File explorer, showing the folder structure of a particular path (folders, subfolders, etc). The subfolders are loaded on demand (when a folder item is expanded only then are its contents loaded, for speed reasons).
What I want is to know HOW I could EASILY add support to what I already have for the ImageAndTextCell class, so that I can put e.g. a folder/file icon next to each entry...
Any help is appreciated. (Please don't point me to documentation; I've studied almost all of it; what I need is advice by some who has done it, so that I just ADD to my existing code; without having to rewrite from scratch or totally change the logic...)
Thanks
Here's *My Code * (I had some trouble formatting it for SO... so I posted it on Snippet.MX)
Did what suggested and all the outline view items' names are suddenly NOT appearing...
Documentation is your friend but I understand sometime is so huge.
BTW
You need to set the ImageAndTextCell for your outline view, you can do it on you window controller init or awakeFromNib method or directly (if needed) on your NSOutlineView subclass.
On my project I've a NSOutlineView subclass as shown below
// myOutlineView subclass
- (void)awakeFromNib {
self.imageCell = [[ImageAndTextCell alloc] init];
[self.imageCell setEditable: NO];
NSTableColumn* leftColumn = [[self tableColumns] objectAtIndex:0];
[leftColumn setDataCell: self.imageCell];
}
Then you need to implement willDisplayCell delegate method where you set the image for your specific column as shown below (folder icon, file txt icon, jpg icon).
On the code shown below I get it from my singleton VDIconUtils but you can simply return a NSImage
- (void)outlineView:(NSOutlineView *)outlineView willDisplayCell:(id)cell forTableColumn:(NSTableColumn *)tableColumn item:(id)item {
[cell setDrawsBackground:NO];
if ([[tableColumn identifier] isEqualToString:#"mycellname"]) {
[cell setImage:[[VDIconUtils sharedIconUtils] iconForFolderStatus:fs :16 :[outlineView isItemExpanded:item]]];
}
}
Related
I understand this might be covered in parts in answers to other questions (see references) I've seen on the site, but due to my limited experience I haven't been able to understand each part as it relates to my code. Please forgive me for any duplications.
I have a PFQueryTableViewController (essentially a UITableViewController) called threadsViewController that sources cell information from a Parse backend. The table view consists of threads similar to what you would see on a web forum.
I then have a separate class postsViewController which is another PFQueryTableViewController that I wish to display a table of all the responses ('posts') to that particular thread.
The functionality I'm looking for is for a user tapping on a thread (left screen in the image) to be presented with a postsViewController (right screen) containing only those posts/responses related to that thread. (See basic diagram below).
What I do know from my research:
The Parse backend is established with classes for Thread and Post.
I'm probably going to use the didSelectRowAtIndexPath delegate method
What I need help with:
How can I know which thread cell a user tapped on, and then pass that on so that the postsViewController only displays posts from that Thread?
A layman's description of how to use indexPath.row etc
I understand how to complete PFQueries etc to get the data for the cells, I just don't know how to implement the navigation and how to tell postsViewController which posts to show.
In case it helps somehow, here is my implementation so far. I have tried addign a property to the postsViewController called fromThread to somehow store the thread but apart from that I'm out of ideas!
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
[super tableView:tableView didSelectRowAtIndexPath:indexPath];
postsViewController *postsVC = [[postsViewController alloc] init];
postsVC.fromThread = //?
[self performSegueWithIdentifier:#"threadsToPosts" sender:self];
}
References
How to filter a Parse query by an tableview index?
Pass Index Number between UITableView List segue
didSelectRowAtIndexPath and prepareForSegue implementation
You're on the right track. You need know how to do two things: (1) access your parse objects by indexPath, and (2) push a new view controller in a navigation controller.
(1) is simpler: PFQueryTableVC provides a method called objectAtIndexPath: that does just what you need.
// indexPath is the indexPath parameter to the didSelectRow delegate method
PFObject *fromThread = [self objectAtIndexPath:indexPath];
(2) is simple, too. But more complicated because there are a couple ways to do it. Segue is the more modern way, but I think the old way is simpler, and certainly easier to describe in code. View Controllers are given storyboard ids on the "Identity" tab in the storyboard editor. Give your Posts-presenting VC a storyboard id like "PostVC".
To get a new instance, use that storyboard id as follows:
MyPostVC *postVC = [self.storyboard instantiateViewControllerWithIdentifier:#"PostVC"];
// initialize it with the PFObject we got above
postVC.fromThread = fromThread;
// present it on the navigation stack
[self.navigationController pushViewController:postVC animated:YES];
And fromThread is just what the PostVC will need to form a query for posts associated with the selected thread.
You can pass data of cell to next ViewController in prepareForSegue with something like this
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
if ([segue.identifier isEqualToString:#"threadsToPosts"]) {
UINavigationController *navCon = segue.destinationViewController;
postsViewController *postsViewController = [navCon.viewControllers objectAtIndex:0];
// Whatever you are populating your tableView with
Thread *thread = [self.thread objectAtIndex:self.tableView.indexPathForSelectedRow.row];
postsViewController.thread = thread;
}
}
Just getting into NSOutlineViews and see them a useful control.
Is it possible to show a Xib as the root item??
Fritzables.
Yes, when you use a view based NSOutlineView. First register the nib you want to display for a cell using registerNib:forIdentifier: (windowDidLoad in a window controller would be a good place, awakeFromNib is also a possibility).
NSNib *cellNib = [[NSNib alloc] initWithNibNamed:#"MyCell" bundle:nil];
[self.outlineView registerNib:cellNib forIdentifier:#"MyIdentifier"];
Next in your outlineView:viewForTableColumn:item: you get a (possibly recycled) instance of your nib by using the earlier specified identifier:
- (NSView *)outlineView:(NSOutlineView *)outlineView viewForTableColumn:(NSTableColumn *)tableColumn item:(id)item
{
NSView *cellView = [outlineView makeViewWithIdentifier:#"MyIdentifier" owner:self];
// optional configuration here
return cellView;
}
I've got a blog post + mac app sample code that demonstrates this.
Yes. You just have to switch it to use view based cells.
In your delegate, implement outlineView:viewForTableColumn:item: to provide the correct XIB.
Yes it is Possible, NSOutlineView is another great visual control available in Mac OS X. Being descendant of the NSTableView It represents the hierarchical data. You can collapse and expand nodes, see parents and their children. In this article we will describe how to use NSOutlineView to show DASchema object which by its nature is a good example of the tree-like data.
For more info check Here
Is there a way to get a reference to the view controller of my superview?
There were several instances that I needed this on the past couple of months, but didn't know how to do it. I mean, if I have a custom button on a custom cell, and I wish to get a reference of the table view controller that controls the cell I`m currently in, is there a code snippet for that? Or is it something that I should just solve it by using better design patterns?
Thanks!
Your button should preferably not know about its superviews view controller.
However, if your button really needs to message objects that it shouldn't know the details about, you can use delegation to send the messages you want to the buttons delegate.
Create a MyButtonDelegate protocol and define the methods that everyone that conforms to that protocol need to implement (the callback). You can have optional methods as well.
Then add a property on the button #property (weak) id<MyButtonDelegate> so that any class of any kind can be set as the delegate as long as it conforms to your protocol.
Now the view controller can implement the MyButtonDelegate protocol and set itself as the delegate. The parts of the code that require knowledge about the view controller should be implemented in the delegate method (or methods).
The view can now send the protocol messages to its delegate (without knowing who or what it is) and the delegate can to the appropriate thing for that button. This way the same button could be reused because it doesn't depend on where it is used.
When I asked this question I was thinking of, in a situation where I have custom cells with buttons on them, how can the TableViewController know which cell's button was tapped.
More recently, reading the book "iOS Recipes", I got the solution:
-(IBAction)cellButtonTapped:(id)sender
{
NSLog(#"%s", __FUNCTION__);
UIButton *button = sender;
//Convert the tapped point to the tableView coordinate system
CGPoint correctedPoint = [button convertPoint:button.bounds.origin toView:self.tableView];
//Get the cell at that point
NSIndexPath *indexPath = [self.tableView indexPathForRowAtPoint:correctedPoint];
NSLog(#"Button tapped in row %d", indexPath.row);
}
Another solution, a bit more fragile (though simpler) would be:
- (IBAction)cellButtonTapped:(id)sender
{
// Go get the enclosing cell manually
UITableViewCell *parentCell = [[sender superview] superview];
NSIndexPath *pathForButton = [self.tableView indexPathForCell:parentCell];
}
And the most reusable one would be to add this method to a category of UITableView
- (NSIndexPath *)prp_indexPathForRowContainingView:(UIView *)view
{
CGPoint correctedPoint = [view convertPoint:view.bounds.origin toView:self];
return [self indexPathForRowAtPoint:correctedPoint];
}
And then, on your UITableViewController class, just use this:
- (IBAction)cellButtonTapped:(id)sender
{
NSIndexPath *pathForButton = [self.tableView indexPathForRowContainingView:sender];
}
If you know which class is the superview of your view controller, you can just iterate through the subviews array and typecheck for your superclass.
eg.
UIView *view;
for(tempView in self.subviews) {
if([tempView isKindOfClass:[SuperViewController class] ])
{
// you got the reference, do waht you want
}
}
I have an NSView subclass which registers for drag files in init method like this:
[self registerForDraggedTypes:[NSArray arrayWithObject:NSFilenamesPboardType]];
The drag drop works perfectly fine, but if I add a subview to this view with the exact same frame, it doesn't work any more. My guess is that the subview is block the drag event to go to super view. Can can I avoid that? Thanks
Also, I know I am asking two questions, but I don't want to create a new topic just for this: When I am dragging, my cursor doesn't change to the "+" sign like with other drags, how can I do that?
Thanks again.
UPDATE:
Here's the how I have it set up in my IB:
The DrawView is the custom class I was talking about that registered for draggedtypes. And the Image view simply is a subview, I dragged an image from the media section...
If it helps, here's my relevant code for DragView:
- (NSDragOperation)draggingEntered:(id <NSDraggingInfo>)sender {
return NSDragOperationCopy;
}
- (BOOL)performDragOperation:(id <NSDraggingInfo>)sender {
NSPasteboard *pboard;
pboard = [sender draggingPasteboard];
NSArray *list = [pboard propertyListForType:NSFilenamesPboardType];
if ([list count] == 1) {
BOOL isDirectory = NO;
NSString *fileName = [list objectAtIndex:0];
[[NSFileManager defaultManager] fileExistsAtPath:fileName
isDirectory: &isDirectory];
if (isDirectory) {
NSLog(#"AHH YEA");
} else {
NSLog(#"NOO");
}
}
return YES;
}
The answer to the second part of your question is this:
- (NSDragOperation)draggingEntered:(id <NSDraggingInfo>)sender{
return NSDragOperationCopy;
}
if you return NSDragOperationCopy, you get the mouse badge for a copy operation. (You can and should, of course, not just return NSDragOperationCopy unconditionally; check the objects on the pasteboard to see if you can accept them.)
I'm not sure what the answer to the first part of your question is, because I'm unable to recreate the subview blocking effect.
Okay, the answer is unfortunately that you can't. The image you dragged is contained in an NSImageView, and NSImageViews accept drag events themselves, so it's grabbing the drag event and not doing anything with it. If your subview was a custom class, you could either a) not implement drag and drop, in which case the drags would be passed through; b) implement drag and drop to accept drags for the subview. In this case, you're using a class over which you don't have any control. If all you want it to do is display an image, you should be able to make another NSView subclass that does nothing but draw the image in drawRect:
As mentioned in the comments, NSImageViews have their own drag and drop enabled by default (used for accepting images that are dragged onto the NSImageView). If you don't want to use this behavior and instead want to use the super view's drag and drop behavior, you'll want to unregister the dragging behavior in the NSImageView.
Objc:
[imageView unregisterDraggedTypes];
Swift:
imageView.unregisterDraggedTypes()
(in case anyone else stumbled across this question first and not the linked one in the comments)
I'm making an app that includes the same group of buttons in many different contexts. The buttons send their actions to a different object in each context. I'd like to be able to design a single NSView in IB containing the buttons, and then be able to put copies of that view in many places in my nibs, while maintaining the link, so changes propagate. I'd like to connect each of those instances to different objects, and have the buttons send their actions to whatever object their parent view is connected to.
I thought of creating a subclass of NSView which, when loaded, replaces itself with another view which it loads from a nib file, setting the connected object as File's Owner, but I'm not convinced this is the cleanest method. Here's my implementation of that idea (which -does- work):
#implementation AVNViewFromNib
- (void)awakeFromNib
{
//Load the nib whose name is specified by the "nibFile" key
NSNib* viewNib = [[NSNib alloc] initWithNibNamed:[self valueForKey:#"nibFile"] bundle:[NSBundle mainBundle]];
NSMutableArray* topLevelObjects = [NSMutableArray new];
[viewNib instantiateNibWithOwner:relatedObject topLevelObjects:&topLevelObjects];
//Find our replacement view in that nib
for (id currentObject in topLevelObjects)
{
if ([currentObject isKindOfClass:NSClassFromString(#"AVNReplacementView")])
{
representedView = currentObject;
break;
}
}
//Copy appropriate properties from us to our representedView
[representedView setAutoresizingMask:[self autoresizingMask]];
[representedView setFrame:[self frame]];
[[self superview] addSubview:representedView];
//We were never here. :)
[self removeFromSuperview];
[viewNib autorelease];
}
#end
#implementation AVNReplacementView
#end
Is that the cleanest method? Is there a standard way of going about this?
You can create the view with the buttons in it in IB, then drag that view into the Library window and save it. The catch is, there's no “link” between them; editing one won't change anything about the others.
If you want that, you'll need to make a subclass of NSView instead.
I thought of creating a subclass of NSView which, when loaded, replaces itself with another view which it loads from a nib file, setting the connected object as File's Owner, but I'm not convinced this is the cleanest method.
That could work. I don't think that's really all that dirty; the reason init methods return an object is that they explicitly can return a different object. However, I'm not sure how you'd handle views of different frames, since the loaded view will have whatever frame it has in the nib.
Another way would be to load the buttons from a nib, but you'd have to adjust their frames before adding them as subviews.