I have a custom NSCell with various elements inside of it (images, various text pieces) and one of those text blocks may have various clickable links inside of it. I have my NSAttributedString correctly identifying the links and coloring them blue however I can't figure out how to get the cursor to turn into a hand and allow a user to actually click on them.
Right now I have my attributed string drawn right to the cell which obviously isn't clickable, but I'm not sure how to add it any other way since NSCell doesn't inherit from NSView. Normally I'd just add an NSTextField as a subview but I can't do it like that in this case.
Any thoughts?
The only solution I can think of is via manual hit testing and mouse tracking within your NSCell. The hardest part (which I don't have the answer to) is how to determine the rect of the link text ... hopefully someone can answer that?
Once you know the rect of the url text it's possible to implement the clicking action by implementing hitTestForEvent. I think you'd do it something like this;
// If the event is a mouse down event and the point is inside the rect trigger the url
- (NSUInteger)hitTestForEvent:(NSEvent *)event inRect:(NSRect)frame ofView:(NSView *)controlView {
NSPoint point = [controlView convertPoint:[event locationInWindow] fromView:nil];
// Check that the point is over the url region
if (NSPointInRect(point, urlFrame)) {
// If event is mousedown activate url
// Insert code here to activate url
return NSCellHitTrackableArea;
} else {
return [super hitTestForEvent:event inRect:frame ofView:controlView];
}
}
Based on talks with Ira Cooke and other folks I've decided to go for the following solution:
Draw directly to the NSCell
When the mouse enters an NSCell, I will immediately add a custom NSView subview to the NSTableView at the same position as the NSCell that was hovered over.
Their designs match pixel for pixel so there's no discernible difference
This NSView will have an NSTextView (or Field, haven't decided) that will display the attributed string with links in it allowing it to be clickable.
When you hover out of the NSCell its mirror NSView is destroyed
If all goes according to plan then I should only have 1 NSView attached to the NSTableView at a time and most of the time none at all. I'll come back and report my results once I get it working.
Related
Context:
Apple has "soft-deprecated" NSCell on macOS. I'm trying to reduce the use of it in my custom NSControl subclasses and, instead, use CALayers to handle my drawing. To do this, I make my NSButton subclass layer-backed:
self.wantsLayer = YES;
And then I attempt to handle my drawing using the "updateLayer" path instead of "drawRect":
- (BOOL) wantsUpdateLayer {
return YES;
}
- (void) updateLayer {
// Change layer background/border colors if pressed, disabled, etc.
// Change text color of a CATextLayer sublayer for button's title.
}
The Problem:
If I use -updateLayer, the NSCell still receives drawing commands and draws its title, resulting in a "blurry" title string in my control because the string is being drawn twice—once in my textLayer and once by the Cell.
If, however, I do the exact same work as above in -drawRect: instead of -updateLayer, then the cell does NOT do any drawing (because I don't call down into it with [self.cell drawInteriorWithFrame:ControlView:])
I cannot, for the life of me, figure out what's firing the cell drawing when the associated controlView (my button subclass) has opted into -updateLayer instead of -drawRect:.
I have looked at all the methods on NSControl.h and NSView.h. I've overridden all of the -updateCell and associated methods. None of those are the culprit. I cannot simply set self.cell=nil because NSControl still relies on NSCell for event handling, etc.
Can someone tell me how to stop NSCell from drawing when its associated controlView is using -updateLayer instead of -drawRect:?
In -[NSButtonCell layoutLayerWithFrame:inView:], the cell adds a NSTextField to draw the title. Override titleRectForBounds: and return NSZeroRect to remove the title.
I'm creating a NSCell subclass that draws some objects directly onto the view (using drawInRect:fromRect:operation:fraction:respectFlipped:hints:) and also draws an NSButton instance simply using NSView's addSubview: selector.
While objects drawn using the first method all draw correclty, I'm having problems with drawing the NSButton correctly. The issue is that my NSButton instances will draw in the right places, but multiple times over.
I've researched this on the internet for a while and some people suggested using a cache, but I'm not sure if this is efficient. (going an array containing buttons using a for loop will definately cause slow scrolling since I display a lot of data...)
How would you do this? Am I barking up the wrong tree?
This is the relevant code:
- (void)drawInteriorWithFrame:(NSRect)cellFrame inView:(NSView *)controlView
{
NSRect _controlRect = cellFrame;
float _Y = cellFrame.origin.y;
NSRect _accessoryRect = NSMakeRect(_controlRect.size.width - 70.0f, _Y + 9.0f, 50.0f, 23.0f);
_switch = [self _choiceSwitch];
[_switch setFrame:_accessoryRect];
[controlView addSubview:_switch];
}
Long story short: Friends don't let friends addSubview, while drawing.
This a fundamental, and not particularly well-explained aspect of managing control interfaces, but is important to come to grips with.
Let your controllers dictate the "order" of subviews, and you can sleep tight knowing that that button shouldn't get overtly mucked about (which is NOT the case if it's getting jostled around inside your custom drawing routines).
It's easy to get trapped in this alley, cause, like, hey, I added an NSImageView in my initWithFrame and everything seems to be okay… But it's just sort of not how you're supposed to do it, I guess… and when you start subclassing NSControl, etc. is when you start to realize why.
Updated: Here's a really good write up on designing custom controls with an equally as great sample project attached - which embodies the kind of code organization that can help avoid this type of issue. For example.. you'll notice in the controller class how he's keeping each button seperate, unique, and independent of other views' business…
for (int butts = 0; butts < 3; butts++) {
NSRect buttFrame = NSMakeRect(0, butts * 10, 69, 10);
ExampleButt *butt = [[ExampleButt alloc]initWithFrame:buttFrame];
[mainView addSubview:butt];
}
“Drawing” NSButton by adding its instance into the view hierarchy each time you draw the cell itself is definitely a bad idea. Instead, create an NSButtonCell and configure it up to your taste. Then, in your -[NSCell drawInteriorWithFrame:inView:] use a cell ivar to draw its appearance.
If you want to have a clickable NSButton instance in each cell of the table view, try to avoid a call to addSubview: when possible. Each time you do this, the control view may invalidate its layout and re-draw everything from scratch making some kind of a recursion in your case.
I'm using an NSImageView to display an image on an NSWindow. The image will be on top of the area where the user can normally drag the window.
The window is styled in such a way that it's not easily apparent that you can drag the window... I thus need this little image to indicate that you can in fact drag the window.
Unfortunately, I can't figure out how to make a click on the image drag the window! It needs this. Dragging anywhere else in the window's title area works fine.
How can I make clicking and holding the image drag the entire window?
Bonus points if you can tell me how to give the mouse a "drag icon" cursor while hovered on this image.
I think the easiest way is to subclass NSImageView and return YES to mouseDownCanMoveWindow (which it inherits from NSView).
-(BOOL)mouseDownCanMoveWindow {
return YES;
}
You can set a new cursor when the mouse enters the image view by overriding resetCursorRects like this in the NSImageView subclass (I don't know what you mean by "drag icon" cursor, so this example uses the pointing hand cursor:
- (void)resetCursorRects {
[self addCursorRect:self.bounds cursor:[NSCursor pointingHandCursor]];
}
NSImageViews have their own mouse handling. To change the way that view behaves, you will have to subclass, either NSView or NSImageView.
I am trying to add a UIButton to the view of a MPMoviePlayerController along with the standard controls. The button appears over the video and works as expected receiving touch events, but I would like to have it fade in and out with the standard controls in response to user touches.
I know I could accomplish this by rolling my own custom player controls, but it seems silly since I am just trying to add one button.
EDIT
If you recursively traverse the view hierarchy of the MPMoviePlayerController's view eventually you will come to a view class called MPInlineVideoOverlay. You can add any additional controls easily to this view to achieve the auto fade in/out behavior.
There are a few gotchas though, it can sometimes take awhile (up to a second in my experience) after you have created the MPMoviePlayerController and added it to a view before it has initialized fully and created it's MPInlineVideoOverlay layer. Because of this I had to create an instance variable called controlView in the code below because sometimes it doesn't exist when this code runs. This is why I have the last bit of code where the function calls itself again in 0.1 seconds if it isn't found. I couldn't notice any delay in the button appearing on my interface despite this delay.
-(void)setupAdditionalControls {
//Call after you have initialized your MPMoviePlayerController (probably viewDidLoad)
controlView = nil;
[self recursiveViewTraversal:movie.view counter:0];
//check to see if we found it, if we didn't we need to do it again in 0.1 seconds
if(controlView) {
UIButton *backButton = [UIButton buttonWithType:UIButtonTypeCustom];
[controlView addSubview:backButton];
} else {
[self performSelector:#selector(setupAdditionalControls) withObject:nil afterDelay:0.1];
}
}
-(void)recursiveViewTraversal:(UIView*)view counter:(int)counter {
NSLog(#"Depth %d - %#", counter, view); //For debug
if([view isKindOfClass:NSClassFromString(#"MPInlineVideoOverlay")]) {
//Add any additional controls you want to have fade with the standard controls here
controlView = view;
} else {
for(UIView *child in [view subviews]) {
[self recursiveViewTraversal:child counter:counter+1];
}
}
}
It isn't the best solution, but I am posting it in case someone else is trying to do the same thing. If Apple was to change the view structure or class names internal to the control overlay it would break. I am also assuming you aren't playing the video full screen (although you can play it fullscreen with embeded controls). I also had to disable the fullscreen button using the technique described here because the MPInlineVideoOverlay view gets removed and released when it is pressed: iPad MPMoviePlayerController - Disable Fullscreen
Calling setupAdditionalControls when you receive the fullscreen notifications described above will re-add your additional controls to the UI.
Would love a more elegant solution if anyone can suggest something other than this hackery I have come up with.
My solution to the same problem was:
Add the button as a child of the MPMoviePlayerController's view;
fade the button in and out using animation of its alpha property, with the proper durations;
handle the player controller's touchesBegan, and use that to toggle the button's visibility (using its alpha);
use a timer to determine when to hide the button again.
By trial-and-error, I determined that the durations that matched the (current) iOS ones are:
fade in: 0.1s
fade out: 0.2s
duration on screen: 5.0s (extend that each time the view is touched)
Of course this is still fragile; if the built-in delays change, mine will look wrong, but the code will still run.
I have a button that sits on top of an NSScrollView, not within. When the scrollview scrolls, the button get's clipped with part of the button going along with the scrolling and the other part staying positioned.
To better describe the issue here's a video of the issue:
http://dl.dropbox.com/u/170068/ScrollTest.mov
The planned goal was to have a button sit in the top right corner of a text view but stay there when the text view scrolls. So if anyone has any thoughts on how to achieve this it would be greatly appreciated.
You should subclass NSScrollView and override "tile" method to position sub-controls of the scroll view.
- (void)tile
{
[super tile];
if (subControl)
{
NSRect subControlFrame = [subControl frame];
// adjust control position here in the scrollview coordinate space
// move controls
[subControl setFrame:subControlFrame];
}
}
I have used this way to implement a custom ScrollView with zoom control and background color selector embedded.
Overlapping views isn't recommended for non-layer-backed views. I think Interface Builder will even warn you about this. The easiest way to work around this would be to make your button layer-backed.