My iOS has registered for device orientation change notifications via NSNotificationCenter, and has a method that responds to the different orientation changes. The following code is called to change the orientation and location of a view when rotating the phone to "landscape-left".
camAngle = [(NSNumber *)[_cameraToggleButton valueForKeyPath:#"layer.transform.rotation.z"] floatValue];
camDegrees = (RADIANS_TO_DEGREES(camAngle));
if (!(camDegrees == 90)) {
_cameraToggleButton.alpha = 0.0;
_cameraToggleButton.transform = CGAffineTransformMakeRotation(DEGREES_TO_RADIANS(90));
_cameraToggleButton.frame = CGRectMake(274, 350, 66, 54);
[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:0.4];
[UIView setAnimationCurve:UIViewAnimationCurveLinear];
_cameraToggleButton.alpha = 1.0;
[UIView commitAnimations];
}
And my equations to convert radians and degrees:
#define RADIANS_TO_DEGREES(radians) ((radians) * (180.0 / M_PI))
#define DEGREES_TO_RADIANS(angle) ((angle) / 180.0 * M_PI)
The view rotates correctly and assumes the correct position on screen, but the sides of the image are suddenly squashed, making the image look condensed. This only happens when rotating the phone into landscape position (left or right). Rotating to upside down or back to portrait translates and rotates the view fine, with essentially the same code. What could cause this skewing of the images in landscape position?
You should not set the frame of the _cameraToggleButton after you set the rotation transform on it. To re-position the _cameraToggleButton after you set the rotation, you should change it's center like so:
_cameraToggleButton.center = CGPointMake(274, 350);
Also, as someone else suggested, use UIViewContentModeScaleAspectFit instead of UIViewContentModeScaleToFill.
Related
I have a UIView that I rotate with this code:
helpView.transform = CGAffineTransformMakeRotation(degreesToRadians( rotationAngle ));
Where degreeToRadians just is a macro to convert from degrees to radians.
This works fine as long as the view is visible, eg alpha = 1. When I hide it (alpha = 0, which I animate) it does not rotate any more. I guess this is a smart way for the devices to "save" on drawing time, but is there any way I can force it to be drawn even when alpha is 0? Otherwise I will have to rotate it before I show it again.
Any good ideas?
Thanks
Edit: This is the code I use to show/hide the view.
-(void)showHelp
{
bool helpAlpha = !helpView.alpha;
CGFloat newScale;
if (helpView.alpha) {
newScale = kHelpSmall;
helpView.transform = CGAffineTransformMakeScale(kHelpBig, kHelpBig);
} else {
newScale = kHelpBig;
helpView.transform = CGAffineTransformMakeScale(kHelpSmall, kHelpSmall);
}
[UIView animateWithDuration:(kAnimationTimeShort / 2) animations:^(void) {
[helpView setAlpha:helpAlpha];
helpView.transform = CGAffineTransformMakeScale(newScale, newScale);
}];
}
As you see I also scale it for a nicer effect. Works perfect when visible, does not rotate when alpha = 0. Rotation is done in another method, where I would prefer to keep it as I also rotate some other views there.
You are resetting the transform every time you use CGAffineTransformMake*. If you do this, you will get either a rotated transform or a scaled one. I am assuming the scaled one is after the rotated one and hence you aren't able to see the view rotated. If you need both the effects to remain, you will have to use CGAffineTransformRotate. So a scale and rotate will be
helpView.transform = CGAffineTransformMakeScale(kHelpSmall, kHelpSmall);
helpView.transform = CGAffineTransformRotate(helpView.transform, degreesToRadians(rotationAngle));
The order might vary.
I am trying to get the window coordinates of a table view using the following code:
[self.tableView.superview convertRect:self.tableView.frame toView:nil]
It reports the correct coordinates while in portrait mode, but when I rotate to landscape it no longer reports correct coordinates. First off, it flips the x, y coordinates and the width and height. That's not really the problem though. The real problem is that the coordinates are incorrect. In portrait the window coordinates for the table view's frame are {{0, 114}, {320, 322}}, while in landscape the window coordinates are {{32, 0}, {204, 480}}. Obviously the x-value here is incorrect, right? Shouldn't it be 84? I'm looking for a fix to this problem, and if anybody knows how to get the correct window coordinates of a view in landscape mode, I would greatly appreciate it if you would share that knowledge with me.
Here are some screenshots so you can see the view layout.
Portrait: http://i.stack.imgur.com/IaKJc.png
Landscape: http://i.stack.imgur.com/JHUV6.png
I've found what I believe to be the beginnings of the solution. It seems the coordinates you and I are seeing are being based on the bottom left or top right, depending on whether the orientation is UIInterfaceOrientationLandscapeRight or UIInterfaceOrientationLandscapeLeft.
I don't know why yet, but hopefully that helps. :)
[UPDATE]
So I guess the origin of the window is 0,0 in normal portrait mode, and rotates with the ipad/iphone.
So here's how I solved this.
First I grab my orientation, window bounds and the rect of my view within the window (with the wonky coordinates)
UIInterfaceOrientation orientation = [[UIApplication sharedApplication] statusBarOrientation];
CGRect windowRect = appDelegate.window.bounds;
CGRect viewRectAbsolute = [self.guestEntryTableView convertRect:self.guestEntryTableView.bounds toView:nil];
Then if the orientation is landscape, I reverse the x and y coordinates and the width and height
if (UIInterfaceOrientationLandscapeLeft == orientation ||UIInterfaceOrientationLandscapeRight == orientation ) {
windowRect = XYWidthHeightRectSwap(windowRect);
viewRectAbsolute = XYWidthHeightRectSwap(viewRectAbsolute);
}
Then I call my function for fixing the origin to be based on the top left no matter the rotation of the ipad/iphone.
It fixes the origin depending on where 0,0 currently lives (depending on the orientation)
viewRectAbsolute = FixOriginRotation(viewRectAbsolute, orientation, windowRect.size.width, windowRect.size.height);
Here are the two functions I use
CGRect XYWidthHeightRectSwap(CGRect rect) {
CGRect newRect;
newRect.origin.x = rect.origin.y;
newRect.origin.y = rect.origin.x;
newRect.size.width = rect.size.height;
newRect.size.height = rect.size.width;
return newRect;
}
CGRect FixOriginRotation(CGRect rect, UIInterfaceOrientation orientation, int parentWidth, int parentHeight) {
CGRect newRect;
switch(orientation)
{
case UIInterfaceOrientationLandscapeLeft:
newRect = CGRectMake(parentWidth - (rect.size.width + rect.origin.x), rect.origin.y, rect.size.width, rect.size.height);
break;
case UIInterfaceOrientationLandscapeRight:
newRect = CGRectMake(rect.origin.x, parentHeight - (rect.size.height + rect.origin.y), rect.size.width, rect.size.height);
break;
case UIInterfaceOrientationPortrait:
newRect = rect;
break;
case UIInterfaceOrientationPortraitUpsideDown:
newRect = CGRectMake(parentWidth - (rect.size.width + rect.origin.x), parentHeight - (rect.size.height + rect.origin.y), rect.size.width, rect.size.height);
break;
}
return newRect;
}
This is a hack, but it works for me:
UIView *toView = [UIApplication sharedApplication].keyWindow.rootViewController.view;
[self.tableView convertRect:self.tableView.bounds toView:toView];
I am not sure this is the best solution. It may not work reliably if your root view controller doesn't support the same orientations as the current view controller.
You should be able to get the current table view coordinates from self.tableView.bounds
Your code should be:
[tableView convertRect:tableView.bounds toView:[UIApplication sharedApplication].keyWindow];
That will give you the view's rectangle in the window's coordinate system. Be sure to use "bounds" and not "frame". frame is the rectangle of the view in its parent view coordinate system already. "bounds" is the view rectangle in its own system. So the above code asks the table view to convert its own rectangle from its own system to the window's system. Your previous code was asking the table's parent view to convert the table's rectangle from the parent coordinate system to nothing.
Try bounds instead of frame
self.parentViewController.view.bounds
for it gives me adjusted coords according to the current orientation
I am writing an iPhone programer, and
I want to make a button with is rotate 180 degree, I try to use the multi-touch track pad to rotate a UIbutton, but it don't success, how can I do it? or I need to do it by code?
You can't do it from Interface Builder. You have to rotate it from your code, using the transform property of your UIButton, which is a CGAffineTransform struct.
You can use the CGAffineTransformMakeRotation() to set it.
myButton.transform = CGAffineTransformMakeRotation( ( 180 * M_PI ) / 180 );
The first 180 in the code is the angle in degrees. The operation converts it to radians.
I was wanting to do this same thing - rotate a button 180 degrees when tapped - but do it using an animation. Neurofluxation's answer does the 180 degree rotation with an animation, but it isn't permanent. Macmade's answer does the 180 degree rotation, but doesn't do it with an animation. So if you're like me and would like to do a 180 degree rotation with animation use this code:
[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:0.35];
// (180 * M_PI) / 180 == M_PI, so just use M_PI
myButton.transform = CGAffineTransformMakeRotation(M_PI);
[UIView commitAnimations];
As well, if you want to rotate back to the starting position (ie 0 degree rotation) then put the following in between the animation code like above:
myButton.transform = CGAffineTransformMakeRotation(0);
As to a use case for such a button, Evernote's show/hide keyboard button does a really slick 180 degree rotation which can be recreated using the above code.
Well, here we go:
CABasicAnimation *halfTurn;
halfTurn = [CABasicAnimation animationWithKeyPath:#"transform.rotation"];
halfTurn.fromValue = [NSNumber numberWithFloat:0];
halfTurn.toValue = [NSNumber numberWithFloat:((360*M_PI)/180)];
halfTurn.duration = 0.5;
halfTurn.repeatCount = 1;
[myButton addAnimation:halfTurn forKey:#"180"];
Hope that helps... Im typing from my PC though, not my Mac - So I hope that's right!
I have the following code in a UIView subclass that will move it off the screen with an animation:
float currentX = xposition; //variables that store where the UIView is located
float currentY = yposition;
float targetX = -5.0f - self.width;
float targetY = -5.0f - self.height;
moveX = targetX - currentX; //stored as an instance variable so I can hang on to it and move it back
moveY = targetY - currentY;
[UIView beginAnimations:#"UIBase Hide" context:nil];
[UIView setAnimationDuration:duration];
self.transform = CGAffineTransformMakeTranslation(moveX,moveY);
[UIView commitAnimations];
It works just great. I've changed targetX/Y to 0 to see if it does indeed move to the specified point, and it does.
The problem is when I try and move the view back to where it was originally:
moveX = -moveX;
moveY = -moveY;
[UIView beginAnimations:#"UIBase Show" context:nil];
[UIView setAnimationDuration:duration];
self.transform = CGAffineTransformMakeTranslation(moveX,moveY);
[UIView commitAnimations];
This puts the UIView about 3x as far as it should. So the view usually gets put off the right side of the screen (depending on where it is).
Is there something with the CGAffineTransforMakeTranslation function that I should know? I read the documentation, and from what I can tell, it should be doing what I'm expecting it to do.
Anyone have a suggestion of how to fix this? Thanks.
Assigning to a transform will cause the old one to disappear. To return to the original position, assign the identity transform to it.
self.transform = CGAffineTransformIdentity;
(Or better, just change the .frame instead of changing the .transform.)
UIView transform isn't additive; I suggest that to move it back you instead do:
self.transform = CGAffineTransformIdentity;
The docs say (about updating the frame):
"Warning: If this property is not the identity transform, the value of the frame property is undefined and therefore should be ignored."
Sorry if this is obvious or covered elsewhere, but i've been googling all day and haven't found a solution that actually worked.
My problem is as follows: I am currently drawing an image in a full screen UIView, for examples sake we'll say the image is in the bottom right corner of the UIView. I'd like to do a rotation transform(CGAffineTransformMakeRotation) at the center of that image, however, by default the rotation command rotates around the center of the UIView it self. As a result, my image moves around the screen when i rotate instead of it staying in place and rotating around its own center.
From what i've gathered, i need to translate my context so that the origin(center of the UIView) is at the center of my image, Rotate, and then restore the context by translating back to the original spot.
The following is the closest thing i've gotten to work, but the problem is that while the image is rotating, it moves downward while it's rotating. I think this is caused by animation tweening the 1st step translate and 3rd step translate instead of just realizing that the beginning and end point on the translates would be the same...
// Before this i'd make a call to a function that draws a path to a passed in context
CGAffineTransform inverseTranslation = CGAffineTransformMakeTranslation( transX, transY );
CGAffineTransform translation = CGAffineTransformMakeTranslation( -transX, -transY );
CGAffineTransform rot = CGAffineTransformMakeRotation( 3.14 );
CGAffineTransform final = CGAffineTransformConcat( CGAffineTransformConcat( inverseTranslation, rot ), translation );
// Then i apply the transformation animation like normal using self.transform = final etc etc
I've also tried stuff like CGContextTranslateCTM and CGContextSaveGState/UIGraphicsPushContext, but these seem to have little effect.
I've been fighting with this for days and my current solution seems close, but i have no clue how to get rid of that translating tweening. Does anyone have a solution for this or a better way to go about this?
[update]
For the time being i'm drawing my image centered at the UIview's center and then setting the UIView.center property to the origin i'd like to rotate and then doing the rotate command. Seems like a bit of a hack, but until i can get the real translates working it's my only choice.
Thanks!
duncanwilcox' answer is the right one, but he left out the part where you change the anchor of the view's layer to the point you want to rotate around.
CGSize sz = theview.bounds.size;
// Anchorpoint coords are between 0.0 and 1.0
theview.layer.anchorPoint = CGPointMake(rotPoint.x/sz.width, rotPoint.y/sz.height);
[UIView beginAnimations:#"rotate" context:nil];
theview.transform = CGAffineTransformMakeRotation( 45. / 180. * M_PI );
[UIView commitAnimations];
This is documented here: http://developer.apple.com/documentation/Cocoa/Conceptual/CoreAnimation_guide/Articles/Layers.html
This is also an option: a simple change of basis ;-)
CGAffineTransform transform = CGAffineTransformMakeTranslation(x, y);
transform = CGAffineTransformRotate(transform, angle);
transform = CGAffineTransformTranslate(transform,-x,-y);
where (x,y) is the rotation center you like
Rotation happens around the anchorPoint of the view's layer. The default for the anchorPoint is the center (0.5, 0.5), so the rotation alone without the translations should suffice.
Did a quick test and this works for me:
[UIView beginAnimations:#"rotate" context:nil];
self.transform = CGAffineTransformMakeRotation( 45. / 180. * 3.14 );
[UIView commitAnimations];
If you don't want an animation to occur, but just set the new rotation, you can use this:
CGFloat newRotation = 3.14f
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:0.0]; // no tweening
CGAffineTransform transform = CGAffineTransformMakeRotation(newRotation);
self.transform = transform;
[UIView commitAnimations];
The rotation should indeed take place around the center of the UIView. Setting the animationDuration to zero garantees no tweening should happen.
Be sure though you don't do this 60 times a second. It's very tempting to create game like animations with these tools. These kind of animations aren't exactly meant for a frame to frame based, "lots of sprites flying everywhere" game.
For that - and I've been down that road - the only way to go, is OpenGL.