I am developing a Ui which has a look & feel like a speedometer of vehicle which has a needle which is fixed from one end & rotate with some angle with that fixed end.
I have done some sort of code for that
self.SIV_Needle.transform =CGAffineTransformMakeRotation((CGFloat(M_PI_2)/180.0) * 80)
Its working but the imageView loss its original x & y coordinates from one end.I have tried lot of things like changing anchor point , center but doesn't seems to work well.
Responding to my comment, OP said the issue was that the control was not rotating around the desired axis. OP was not (I think) clear about what the desired axis is, nor about what the current axis is (I am using axis interchangeably to mean pivot point). There are a few potential fixes.
1) This needle thing is an ImageView, so you could do a simple hack and just make your image bigger or smaller to fix the rotation. To explain: if your needle is rotating around the center of the needle and not the ball part, then simply double the width of the image, such that the needle only takes up the right side and thus the "ball" of the needle is the pivot point.
2) Set the anchor property of the transform to wherever you want it to be rotating around. See this similar SO question & answer.
You need to translate the UI , to compensate the position change comes due to roatation
Try to change the anchor point of the needle imageView and then add the Rotation. I have not tried it, but i think it should work.
You can archive this by putting your pin image in a UIView at desired position and rotating your main UIView.
like;
let myView:UIIView = UIIView(); //set frame of UIView
let pinImgView:UIVImageView(); // set pin image and frame of required position
//--
myView.addSubview(pinImgView);
//--
myView.transform =CGAffineTransformMakeRotation((CGFloat(M_PI_2)/180.0) * 80);
I have made a sample project for this. you can take idea from it;
http://www.filedropper.com/stackover
or
http://wikisend.com/download/263926/StackOver.zip
Related
I have the following problem: I'm scanning a QR Code with AVFoundation. This works quite well and I can also create a border around the code by adding a subview and set the frame attribute by subview.frame = qrCodeObject.bounds. This only has the problem that the border is only a rectangle and dismisses the perspective of the QR code.
I know that the qrCodeObject has a property corners which incorporates the top right, top left, bottom right and bottom left points of the QR code detected.
My question is now: how can I apply those corner points to the "border" view to make this border to have the same perspective as the QR code? Or in other words: how to "transform" the view according to the corner points?
Thanks a lot in advance!
UPDATE:
Here you can see the problem: the red box is a UIView, having it's frame property set to the QR codes bounds property. This misses perspective. I would like to transform the UIView (the red box) to following the corners property of the QR code, which includes the top right, top left, bottom right and bottom left points (CGPoint) of the QR code. It is important to apply this to a UIView, because I later want to apply it to an ImageView. Also a mask is not usable, as it just hides part of the view, but does not stretch or transform the content of the view.
I found a solution: AGGeometryKit did the trick: https://github.com/hfossli/AGGeometryKit/
Thanks everybody for helping!
You can't transform a CGRect that way, as far as I know. (At least I'm unaware of any framework that can do that kind of image processing.)
What you can do is to draw a polygon using the points of the qrCodeObject.
In drawRect of your UIView, change use CGContext and CGPath to draw the path you'd like.
You want your drawing UIView to be the same size as the one showing the QR code so that you don't have to translate the points onto a second coordinate space.
This answer has directions if you need more guidance on how to do that.
Ok, the problem you are facing is that a CGRect can only represent a rectangle that is not tilted or distorted. What you are dealing with is an image that has different kinds of perspective distortion.
I haven't tried to do this, but it sounds like AVFoundation gives you 4 CGPoint objects for a reason. You need to draw those 4 CGPoints using a UIBezierPath rather than trying to draw a CGRect. Simply create a bezier path that moves to the first point, then draws lines to each subsequent point, and finally, back to the first point. That will give you a quadrilateral that takes into account the distortion of your QR code.
CATransform3DRotate could be your friend, here.
https://guides.codepath.com/ios/Using-Perspective-Transforms might be a good starting point.
Is it possible to rotate UILabels or similar about a clockface?
For example, if I had an array of numbers from one to twelve, it would render as such in a circular manner. However, with a touch event I could move the labels about the face of the clock i.e. I could move 12 in a rightward motion until it reached 6, with all other numbers remaining in their positions.
I have considered UIPicker, but that follows a 'top to bottom' approach. I need a solution to move the label about a point while maintaining the order of the other labels.
It's simply a matter of opposing rotation transforms. Rotate the clock face while at the same time rotating all the subview numbers the same amount in the opposite direction.
Recommended:
1 Clock without small & Big handle (As Image) set it in ImageView.
2 Another two image view one for Small hand another one for Big hand.
3 Rotate the hands(UIImageView) by using the below code as you needed.
#define DEGREES_TO_RADIANS(angle) ((angle) / 180.0 * M_PI)
UIImageView *smallHand = set your smallHand image view here;
UIImageView *bigHand = set your bigHand image view here;
// Small hand
CGAffineTransform smallHandTransform = CGAffineTransformRotate(self.transform, (DEGREES_TO_RADIANS(1)));
// Big hand
CGAffineTransform bigHandTransform = CGAffineTransformRotate(self.transform, (DEGREES_TO_RADIANS(1*0.60)));
// Apply rotation
smallHand.transform = smallHandTransform;
bigHand.transform = bigHandTransform;
I knew that question was rotating the label, if you need it apply this transform on UILabel.
I hope somebody will make use of this idea. Good luck :)
Here is the example project
displaycontent = display.newImageRect (rawdata[currentpath][3], screenW*1.1, ((screenW*1.1/1654)*rawdata[currentpath][6]))
displaycontent.anchorY = 0
displaycontent.y = screenH*0.78
My program loads an image from a database to be displayed on the mobile phone's screen, everything works correctly apart from being able to position it with the y coordinates.
The only thing that changes its position is the anchor point 0 puts the top of the image in the centre of the screen, and values from 0.1 - 1 all position it higher. Changing the y position via object.y has zero effect regardless of what I set it as.
(the size settings probably look a bit weird in the first line, but this is because the images are different sizes and need to show the correct proportions on different screen types).
Btw I am using a tabbar widget as the UI (in case that is relevant)
Any help would be appreciated.
Edit: I am aware that displaycontent is bad name for a variable because of its similarity to things like display.contentCenterY for example, this will be changed to prevent any confusion when I look over the code in future.
I went through my code and tried disabling sections to find the culprit and a content mask was preventing me from setting the position of the loaded images within it.
I will look over my masking code and fix it (should be straight forward now I know where the problem started).
If anyone else has a similar problem (where an image or object wont position itself on given coordinates) check your content mask as that may be the issue!
I'm trying to rotate UIImageView for certain degrees with CGAffineTransformMakeRotation() function, but it end with imageView only rotates, but when I moved to another coordinates then imageView stretched or change height and width. I have no clue why this happens.
Here is a code:
double a = atan2(dx,dy);
bowImageView.transform = CGAffineTransformMakeRotation(a);
WHen you apply a transform to a view the geometry changes. If you wish to move that view rotated, the simplest solution is to set the transform back to CGAffineTransformIdentity, move the view and reapply the rotation.
The other way is to work out the movement based on the current rotation.....but I find the first solution easier!
I am having some issues understanding and using anchorPoint. As I understand it, the default anchor is (.5,.5) which applies transforms about the center of objects. However, when I placed a UIButton into a CCUIViewWrapper, I noticed that scaling it would scale about the right side of the object (i.e. if I scaled from 0 to 1, it would grow from right to left).
I wasn't sure what to make of this, but with tinkering found that I had to adjust the anchor point to (0,0) in order to make scaling occur about the center of the object. Why would this happen?
Further more, while I expect that to make the anchor be the bottom left of the object because Cocos2d is bottom left oriented for (0,0), it did not and in fact aligned the top left with my wrapper's position value.
In the end, what worked to scale about the center was to make the anchor point (0,0) and position the wrapper using the top left of the object, almost as if it were using the UIView coordinates to place the object. I'm not certain if this behavior is something occurring strictly with wrapped UIViews in CCUIViewWrappers nor do I know if this is simply correct behavior and I'm completely misunderstanding it.
Can someone clarify and explain?
I've had a similar problem with the wrapper. One of the issue here is that the wrapper attaches the view to the root window instead of the director's OpenGL view, which means it wont respect whatever autorotation the OpenGL view is using. The code looks like it is trying compensate for the difference between UIView and Cocos2d coordinates but doesn't seem to do it properly when it comes to anchor points. I ended up just using UIView coordinates in the end but I did experiment with an alternate method for setting the anchor point by using:
uiItem.center = ccp((self.anchorPoint.x - 0.5f) * self.contentSize.width, (self.anchorPoint.y - 0.5f) * self.contentSize.height);
At the start of the updateUIViewTransform method in CCUIViewWrappers before setting the view's transform. This makes anchor points behave as expected, at least for views attached directly to a layer.
Instead of using:
uiItem.center = ccp((self.anchorPoint.x - 0.5f) * self.contentSize.width, (self.anchorPoint.y - 0.5f) * self.contentSize.height);
which set the anchor point to the bottom right, I used:
uiItem.center = ccp(-uiItem.bounds.size.height/2, uiItem.bounds.size.width/2);
which set it to the center.
The reason the x and y are flipped, I'm guessing it's because my item is rotated by 90.