I have the following hierarchy:
view
scrollview(with scroll and zoom enabled)
containerview
imageview (with a map)
views for buttons
views for navigation panel
Over the image view I have to put some point of interest (depending on the category the user selects):
The problems are:
if i attach them to the container view, they getting the correct position is very easy,
but when zooming they will zoom with the image, and they should keep the same size (1)
if i attach them to the scrollview I don’t see nothing..
If I attach them to the main view, I have two problems:
1 to find their hierarchy position in between scrollview and view for buttons, etc (they get at the top of the application and should be just over the map but below the control panels, buttons, etc
2 to coordinate with the zoom and scroll- done with convertPoint:toView
If I add a view (sibling of container view under the scrollview) they show fine, but I have no user input on them (They don’t receive
touches)
If I convert that sibling subview to a CALayer, I don’t get the sublayers (POIs) to shown.
(1) Ive tried to subclass container view and override setTransform by applying CGAffineTransform invertedTransform = CGAffineTransformInvert(transform); but I had problems passing it an array with views references to it
What would you recommend to do in this case?
Thank you very much!
S.
I've finally added subviews to containerView and I've subclassed it:
- (void)setTransform:(CGAffineTransform)transform
{
[super setTransform:transform];
CGAffineTransform invertedTransform = CGAffineTransformInvert(transform);
for (UIView *view in self.subviews)
{
if ([view isKindOfClass:[MarkerClass class]]) {
[view setTransform:invertedTransform];
}
}
}
The only problem is that before I zoom the containerView, a short sized version of the markers appear on the screen.
After passing some time, I've found I would override addSubview too, to get an initial transform in this way:
-(void)addSubview:(UIView *)view {
[super addSubview:view];
if ([view isKindOfClass:[MarkerClass class]]) {
CGAffineTransform invertedTransform = CGAffineTransformInvert(self.transform);
[view setTransform:invertedTransform];
}
}
Related
When a UITextField is added to a UIScrollview the scroll view automatically adjusts its contentOffset so that the view will not be obscured by the keyboard.
I have a custom UIControl which also presents a keyboard when it becomes the first responder by assigning its inputView property. The same scrolling behavior does not work. Is there a way to configure a UIControl such that a scroll view will keep it visible when the keyboard is presented?
My guess is that it could be possible by overriding a property defined in one of the protocols UITextField and other classes which this behavior conform to. But these can be a bit of a maze. Also note, the issue here has nothing to do with the scroll view's contentInset property. The scroll view can scroll to show the custom control, it just doesn't do it automatically when the control becomes the first responder.
It looks like this is handled by an internal private method that Apple utilizes [UIFieldEditor scrollSelectionToVisible] as noted on this blog: http://sugarrushva.my03.com/712423-disable-uiscrollview-scrolling-when-uitextfield-becomes-first-responder.html
It appears to do this by stepping back up through the view hierarchy and if it finds a parent UIScrollView, it scrolls the view to bring the UITextField into visible view. You'll need to implement the scrolling manually on your custom control when it becomes first responder, or handle it by introspecting the parent views.
I was pointed in the right direction by #markflowers.
Based on that, here's what I've written into the control to get the desired behavior:
- (BOOL)becomeFirstResponder {
if ([super becomeFirstResponder]) {
[self scrollParentViewToFrame];
return YES;
}
return NO;
}
- (void)scrollParentViewToFrame {
UIScrollView *scrollView = self.parentScrollView;
CGRect frame = [scrollView convertRect:self.bounds fromView:self];
[self.parentScrollView scrollRectToVisible:frame animated:YES];
}
- (UIScrollView *)parentScrollView {
return (UIScrollView *) [self closestParentWithClass:[UIScrollView class]];
}
Note that the frame attribute is not used in case the control is not a direct descendant of the scroll view. Instead convert the bounds to the scroll view's coordinate space.
The scroll adjustment is also needs to be performed after [super becomeFirstResponder] is called for it to interact properly with keyboard notifications that are being used to adjust the insets of the scroll view.
I defined the method to search for the closest parent scroll view in a UIView category which made it easier to recursively search up the hierarchy.
- (UIView *)closestParentWithClass:(Class)class {
if ([self isKindOfClass:class]) {
return self;
}
// Recursively searches up the view hierarchy, returns nil if a view
// has no superview.
return [self.superview closestParentWithClass:class];
}
I am trying to develop a new custom UIView (to allow for horizontal date selection). I want to do all the UI design in XIB files.
The custom UI view contains a scrollview and then two 'week' views. The idea is that as the scrolling occurs, I will move the two 'week' views in place and reconfigure them to the right dates to create an 'infinite' scroll for date selections.
I can load the UIView, which then loads scrollview and week views (all designed in a XIB).
My DatePickerView class, derived from the UIView class does an addSubview of the scroll view (which contains the two week views). The scroll view is 320 wide and the contentSize is set to 640 wide. UserInteraction is enabled. Horizonal Scrolling is enabled.
This all works and displays on the screen. The week views each contain 7 buttons. I can press them and they get the touch. However, the scrollview does not seem to want to scroll.
I set my custom view to be a UIScrollViewDelegate. No calls occur to scrollViewDidScroll.
For each of the week views, I have a 'container' view and then the buttons. I added the following to the container view (again derived from a UIView).
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
DDLogInfo(#"Began. Next Responder: %#", self.nextResponder);
[self.nextResponder touchesBegan:touches withEvent:event];
}
(and comparable ones for the other touch events, touchesMoved, touchesEnded, touchesCancelled),
I print out the nextResponder, which is the UIScrollView, so I know that I am sending the touch to the view, but I never see the scrollview want to scroll.
Is my method of passing the touchEvents up the responder chain correct?
Is there anything else I need to configure to get the scrolling to work?
Any help is appreciated.
Charlie
If I understand correctly, you want infinite scroll with just three pages of scroll view. I achieved it with similar effects in my calendar view project.
You can checkout from here DPCalendar
In a nutshell, I created a view like
#interface DPCalendarMonthlyView : UIScrollView
And initial it like this
self.showsHorizontalScrollIndicator = NO;
self.clipsToBounds = YES;
self.contentInset = UIEdgeInsetsZero;
self.pagingEnabled = YES;
self.delegate = self;
I create three views like this
[self.pagingViews addObject:[self singleMonthViewInFrame:self.bounds]];
[self.pagingViews addObject:[self singleMonthViewInFrame:CGRectMake(self.bounds.size.width, 0, self.bounds.size.width, self.bounds.size.height)]];
[self.pagingViews addObject:[self singleMonthViewInFrame:CGRectMake(self.bounds.size.width * 2, 0, self.bounds.size.width, self.bounds.size.height)]];
Then I set the content size and also scroll it to the middle
[self setContentSize:CGSizeMake(self.bounds.size.width * 3, self.bounds.size.height)];
[self scrollRectToVisible:((UIView *)[self.pagingViews objectAtIndex:1]).frame animated:NO];
In the scrollview delegate function, i need to do
- (void)scrollViewDidEndDecelerating:(UIScrollView *)sender
{
//If scroll right
if(self.contentOffset.x > self.frame.size.width)
{
//do something if scroll right
} else if(self.contentOffset.x < self.frame.size.width)
{
//do something else if scroll left
} else {
return;
}
//scroll back to the middle
[self scrollRectToVisible:((UICollectionView *)[self.pagingViews objectAtIndex:1]).frame animated:NO];
}
Hopefully it is useful to you.
For those that follow down this path, I figured this out and it was a silly error. I forgot to turn off AutoLayout. I keep forgetting that Apple put autoLayout as an enable/disable option under the 'document'-level of a NIB (so I forget to look there).
Turned it off and it works as designed. Looks like autoLayout was causing the views to be rearranged to not need to be scrolled, or something equivalent.
So i have a UIView setup on the Ipad for a small project i am working on. I will be displaying an image or a view on that page. I wanted to know if is it possible to create an invisible border (say 1") around the view that will be unclickable ?
I was thinking of adding a button and disabling it, but i think that would not allow the image to be shown full screen.
I have already setup a recognizer, because i want a three finger swipe to go to the next image. What would be the best approach for this ?
Use a custom UIView class and override hitTest:withEvent:.
- UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event {
CGRect frame = CGRectInset(self.bounds, 25, 25);
return CGRectContainsPoint(frame, point) ? self : nil;
}
Adjust the inset to meet your needs.
I have created a relatively simple app which allows the user to drag an imageview from a 'tray' UIView at the bottom of the screen, and when the view is dropped, it adds itself to a subview of a 'target' UIView.
My problem is, when I drop the imageview into the target view, the frame is totally wrong, and the imageview jumps (seemingly randomly) to another position in the target view.
I've torn my hair out over this, and am having a massive brainfart. Is there a way to just get the coordinates of the dragged view in the superview, and then translate that into coordinates of the target view?
As you can see, i'm taking the icon out of the 'tray' view, and into the main view when the dragging begins. When it ends, I simply add the icon into the target view.
if (gesture.state == UIGestureRecognizerStateBegan){
if (icon.superview == viewTray) {
[self closeTray:nil];
[self.view addSubview:icon];
}
}
if (gesture.state == UIGestureRecognizerStateEnded) {
[viewTarget addSubview:icon];
}
An image of the basics of the xib:
use the gesture recognizer to figure out where the finger touches in the viewTarget's frame by:
CGPoint p = [gesture locationInView:viewTarget];
then set the icon's center to be that point, and you are done:
icon.center = p;
[icon removeFromSuperView];
[viewTarget addSubview:icon];
The problem is that the frame is in the bounds of its superView. So when you drop it into a new superView its not the same. You need to convert it.
This code will convert its from from its superView coordinate system to its targetView coordinate system. You should probably do this right after [viewTarget addSubview:icon];
[viewTarget convertRect:icon.frame fromView:icon.superView];
I have two UIScrollViews on my screen and I need to be able to drag a UIView from one scrollview to the other.
At the moment, I have a UILongGestureRecognizer on the UIView that I want to move, such that when the user starts dragging it, I make the view follow the touch:
- (void)dragChild:(UILongPressGestureRecognizer *)longPress {
[[longPress view] setCenter:[longPress locationInView:[[longPress view] superview]]];
}
But when I get the boundary of the starting UIScrollView, the view disappears because it's locked into that scrollview's bounds.
Is there a way to "pop" it out of the scrollview when I start dragging such that I can carry it over to the other scrollview?
Also, how do I test for the "drop" location? I want to know if it's been dropped over a certain other view.
Or am I going about this all the wrong way?
Thanks guys
If you will need to drag it from a scroll view to another do the following (pseudo code)
when you start dragging do the following
//scrollView1 is the scroll view that currently contains the view
//Your view is the view you want to move
[scrollView1.superView addSubView:yourView];
now when dropping the view, you will need to know if it is inside the other scrollview
//scrollView2 is the second scroll view that you want to move it too
//Your view is the view you want to move
CGPoint point = yourView.center;
CGRect rect = scrollView2.frame;
if(CGRectContainsPoint(rect, point))
{
//Yes Point is inside add it to the new scroll view
[scrollView2 addSubView:yourView];
}
else
{
//Point is outside, return it to the original view
[scrollView1 addSubView:yourView];
}
Here is an untested idea:
When the drag begins, move the dragging-view out of the scroll view (as a subview) and into the mutual superview of both scroll views.
When the drag ends, move the dragging-view out of the superview and into the new scroll view.
You'll probably have to be careful with coordinate systems, using things like [UIView convertPoint:toView:] to convert between the views' different perspectives when moving things around.