I have problems with NSScrollView, It is not displayed the way I want.
Yes I know there is a lot of post about it around the web, I need to override the isFlipped, in order to make it return YES, in my NSView subclass.
Ok, it's done, so now, my scrollView scroll from top to bottom, and not in the reverse way, as it was before overriding isFlipped.
But, this is the second part, my real problem, which I didn't found any answer on the web, how the hell I'm supposed to code, or create my view in interface builder, if everything is flipped? If I put something at the top, it is displayed a the bottom… do you have any magic trick to handle that?
And my last problem, is the NSScrollView frame. before setting the documentView of my scroll view, everything is fine, the scrollView is displayed at the place I choose, but, when I set the document view, it looks like the scrollview frame looks bigger, so I have to resize it…. is this a normal behavior?
Thank you very much.
The answer is usually to create an NSClipView subclass that returns YES from an override of isFlipped:
Then in IB, set the scroll view's content view (clip view) to your subclass.
Being flipped only applies its coordinate system to that exact view, not everything down the whole view hierarchy. So whatever you're putting directly into your flipped content view needs to be aware that it's flipped, but nothing else does.
And if you don't want it to work that way, just don't ask for it to be flipped! There's no rule that says that the document view of an NSScrollView has to be flipped, it's just very common for anything with variable-height content to be laid out top to bottom, which is easiest to do in a flipped view. If the layout you're doing works best as bottom-anchored, by all means, keep it unflipped, whatever's easiest. (And anything in Interface Builder should be fine anyway…did you actually see this problem, or are you just speculating that it might happen? I've never seen this issue…)
Setting the document view shouldn't change the size of the NSScrollView. You may have something else going on besides just that…
Related
I have a view controller that consists of two child UIContainerViews, one of which is fixed-width, and the other which dynamically adjusts its width based on portrait vs landscape mode. Both contain UITableViews.
For some reason, if the screen loads in portrait orientation it renders fine. However if it loads in landscape and then rotates to portrait, the second (dynamic) table gets all screwy and thinks it's wider than it is/should be, letting you scroll it horizontally which it should not be doing.
The cells of the tableView all size properly and stick to the left side of this "too wide" tableView. However, if I color the background of the tableview pink, I can see the whole thing is extending into this too wide zone.
It's baffling me what's going on here. Shouldn't autolayout be the same regardless of which orientation the view controller was loaded as?
If I log the widths in a viewDidRotate... handler, everything appears to have the correct width, yet it's still rendering in this bizarre way.
Is there perhaps I way I can just force the container view to re-lay it self out?
Update: It is the contentSize of the tableView that is getting messed up. All the other widths are correct when logged, but the contentSize.width is way off. The good news is I can just manually set this back to what it should be and everything works great! However it doesn't answer the question as to why it's happening in the first place or what I'm doing wrong (if anything).
Here's a screenshot:
In order to force a UITableView to (re)calculate its content size, you may use layoutIfNeeded method. It traverses through the view hierarchy and lays out the subviews immediately, so content size is set properly.
Instead of setting the size manually, call this method for your table view.
I have a scroll view with a image view inside. I was wondering whether it's possible to have the image inside the image view be much smaller than the resolution of the screen, and somehow be able to stretch it to fit the screen.
Set contentMode on the UIImageView and change its size.
[UIImageView setContentMode:UIViewContentModeScaleToFill];
Check the docs for more informations regarding UIViewContentMode:
http://developer.apple.com/library/ios/#documentation/uikit/reference/uiview_class/UIView/UIView.html#//apple_ref/doc/uid/TP40006816-CH3-SW69
Sure, just change the bounds of the imageView.
Am I missing something here?
Your UIImageView is within an UIScrollView I understand?
That would work by adjusting the scroll view plus adusting the image view appropriately. However that is not advisable to do. You will get lost in small errors with annoying effects.
I'd suggest to add an additional UIView that can match the bounds of the screen.
Add that view to the underlying "view" object and use the bringSubviewToFront method.
You could as well make sure that this new UIView is the first subview of the most underlying view object. You could achieve that by manipulating the subviews array structure - which I do not recommend in general wihout having fully understood everythng about the view hierarchy.
You can as well achieve that by adding the additional view at first before adding any other view. (Within IB just make sure that the new view is the topmost in the tree, coming next to the view controllers "view".) And then make it hidden until you actually need it. Then you unhide it. When it is not needed anymore then hide it again and neither delete it nor erase it from its superview.
I need to create a scrollable composite view on iOS. That is to say, the view will contain at least one image, possibly a button, and some text (that we may wish to format with bold fonts, etc). The amount of data, and particularly the amount of text, is variable, from maybe 4 lines to maybe 100. The data is "variable" to a degree, and in particular the image and text do not come joined at the hip.
This all needs to fit in a "pane" of about 280h x 115w pixels in a portrait-only layout.
A single UITextView doesn't provide the facilities to display an image or format the text.
A UIWebView provides the ability to display the image and formatted text, but the button is a problem (not even sure if it's doable).
A UIScrollView would easily allow the image and button, and then a UIWebView could be embedded in the scroll view for the text, but then scrolling becomes a problem -- I'd like the entire view to scroll as one, without having to resize the web view to contain it's content, and without the confusion of a scrollable within a scrollable (the doc warns of "unexpected behavior").
(I'm guessing your thoughts at this point are that I want too much.)
So, any suggestions? What's the best way to get close to what I need here?
In iOS5 the UIWebView has a scrollView property, which is a normal UIScrollView. You should be able to add a UIButton as a subview of the scrollView to achieve what you want, although positioning it correctly may be a challenge. Prior to iOS5 you could cycle through the subviews of the UIWebView to find the UIScrollView with isKindOfClass...
I suggest testing with a UIWebView inside your UIScrollView. I don't see any interference in the iOS 5.0 simulator. I don't know if there are problems in iOS 4.0.
If you find that there is interference, you can prevent it by setting the web view's userInteractionEnabled property to NO, either in the nib or in code. This will prevent the web view from receiving any touches, so the user also won't be able to pinch-zoom it, follow links in it, or copy text from it.
In the web view's delegate, implement webViewDidFinishLoad: to set the web view's size and the scroll view's contentSize. For example:
- (void)webViewDidFinishLoad:(UIWebView *)webView {
CGRect frame = self.webView.frame;
frame.size = [self.webView sizeThatFits:CGSizeMake(frame.size.width, HUGE_VALF)];
self.webView.frame = frame;
self.scrollView.contentSize = CGSizeMake(CGRectGetMaxX(frame), CGRectGetMaxY(frame));
}
When I did a similar thing, I had a dozen of views which I added to the UIScrollView and then calculated the frames of all the views. Granted, it was an extremely tedious work, given that some views could get hidden under various conditions. The layout code was actually pretty simple, laying out views from top to bottom, but ugly. The upshot is that it works like a charm, fast and reliably. You can even trivially wrap it in an animation block.
Couldn't find anything on the net about this and wondered if anyone on SO has a solution.
I have an NSView with several subviews that are centered by removing the left and right anchor points. When I resize my view, programatically or with the mouse, to a smaller width than the subviews: it pushes them off center. Has anyone come across this before and do you have a solution?
EDIT: I want to be able to resize my view to a zero width. The reason being, the view is actually part of a split view and I have hooked up a button to 'collapse' it. When it collapses all of the subviews are pushed off-center and aren't re-centered when the view is resized, effectively un-collapsing it.
I have solved my problem now and thought I would share incase anyone comes across this issue in the future.
No amount of playing with autosizing options or view layouts in Interface Builder seemed to stop my subviews from getting moved off center. I did manage to find this link here and from this page, the advice:
Springs and struts, as currently
implemented, are really no good for
anything but keeping either one or
both sides of a view "stuck" to the
nearest edge. Any sort of centering
behavior, division of gained/lost area
between multiple views, etc. has to be
done by hand.
Based on this I overrode my view's setFrame: method and manually laid out my subviews using their setFrame: method. This works great and gives me the results I'm looking for.
There is the same issue using NSSplitView, resizing here one Subview to be smaller than the Subview Subviews makes sense,e.g. having small charts in the upper subview, and an rss reader in the lower subview.
If you want to show only the rss reader in the lower subview, you can "hide" the upper subview, but after resizing the upper subview the NSImageView are not layed out the same as in the beginning. Check this nib/xCode Project and the following screenshot to see this behaviour.
Only workaroung is to override the resize function to stop getting smaller.
I have an NSScrollView with an IKImageView inside to display images. This seems to work.
However, if I make the window smaller than the image, the scrollbars appear as they should, but the BOTTOM of the image is locked to the bottom of the window, instead of the top of the image being locked to the top of the window. In other words, I want the image to not move on the screen when I re-size the window from the bottom right.
I understand why this is, because in All of these classes, the origin is in the lower left, not the upper left. However, It's still behaving wrong. If you look at any other product (including Preview, which I assume is written with some of these libraries) the image/content/whatever, is locked to the top not the bottom.
How do I do this?
I've looked for methods in the NSScrollView and IKImageView. I've considered capturing the scroller events and manually moving the image down or up as appropriate, but I haven't seen a way to do this (Set the selector to a method I write in the controller?) and anyway, that seems very messy...
Is there an easy way to do this?
thanks.
Solution for future reference:
Make a subclass of IKImageView with only one over-ridden method:
-isFlipped()
{
return YES;
}
This subclass will also prove useful if I find that I need to re-implement the rotate:(id) method and the setImage:(NSImage) method which exist in the class (and in the case of rotate are USED IN THE DEMO supplied by Apple) but not documented, and therefore not officially supported...