I'm developing an iOS6 app for iPad. The user can add a textfield, edit it, move and rotate it. I would like that when the user pinches the field, it gets bigger. I've tried it, but the text gets pixeled, because the font size doesn't change. How can I detect the actual font size so as to increase it? This is my actual code:
- (void)pinchDetected:(UIPinchGestureRecognizer*) pinchRecognizer {
CGFloat scale = pinchRecognizer.scale;
self.transform = CGAffineTransformScale(self.transform, scale, scale);
pinchRecognizer.scale = 1.0;
}
Thanks for your help!
Why not try this?
CGFloat currentFontSize = self.font.pointSize;
CGFloat newFontSize = currentFontSize * scale; //or anything you wish
self.font = [self.font fontWithSize:newFontSize];
Related
I have an issue with scroll view. I have implemnted two font resize buttons to increase or decrease text font size for the text view embedded in the scroll view. But after decreasing font size, I calculate the scroll view content and reize it to adapt to the new text view height. But every time I modify text font, it scrolls down for every step.
Here is the code:
- (IBAction)decreaseText:(id)sender {
int MyTextSizeMin = 8;
int MyTextSizeMax = 20;
// disable buttons when they're out of the range.
BOOL smallerEnabled = textFontSize > MyTextSizeMin;
BOOL biggerEnabled = textFontSize < MyTextSizeMax;
[self.decreaseText setEnabled:smallerEnabled];
[self.increaseText setEnabled:biggerEnabled];
height =0;
CGFloat secondLabelsize = texto.font.pointSize;
[texto setFont:[UIFont systemFontOfSize:(secondLabelsize-1)]];
CGRect frame = texto.frame;
frame.size.height = texto.contentSize.height;
self.texto.frame = frame;
height +=texto.contentSize.height;
height += self.imagen.image.size.height;
height += self.fecha.frame.size.height;
height += self.titulo.frame.size.height;
height += 200;
self.scrollView.contentSize=CGSizeMake(300.0,height);
[self.scrollView setNeedsDisplay];
}
How can I disable this undesired scroll?
Many thanks!
Try it may it help full for you.
[scrollView scrollRectToVisible:CGRect animated:BOOL];
I've been trying to get the converted CGRect of a UIView within a UIScrollView. It works fine if I'm not zoomed, but once I zoom, the new CGRect shifts. Here is the code that's gotten me close:
CGFloat zoomScale = (scrollView.zoomScale);
CGRect newRect = [self.view convertRect:widgetView.frame fromView:scrollView];
CGPoint newPoint = [self.view convertPoint:widgetView.center fromView:scrollView];
// Increase the size of the CGRect by multiplying by the zoomScale
CGSize newSize = CGSizeMake(newRect.size.width * zoomScale, newRect.size.height * zoomScale);
// Subtract the offset of the UIScrollView for proper positioning
CGPoint newCenter = CGPointMake(newPoint.x - scrollView.contentOffset.x, newPoint.y - scrollView.contentOffset.y);
// Create rect with the proper width/height (x and y set by center)
newRect = CGRectMake(0, 0, newSize.width, newSize.height);
[self.view addSubview:widgetView];
widgetView.frame = newRect;
widgetView.center = newCenter;
I'm fairly certain that my issue lies in the zoomScale - I should probably be modifying the x and y coordinates based on the zoomScale value. Everything I have tried thus far has been unsuccessful, though.
I received the following answer from user Brian2012 on the iOS dev forums:
What I did:
Created a UIScrollView that covers the view controller's main view.
Put a desktop view (a standard UIView) in the scroll view. The origin of the desktop is at 0,0 and the size is bigger than the scroll view so I could scroll around without having to zoom first.
Put some widget views (UIImageView) into the desktop view at various locations.
Set the contentSize of the scroll view to the size of the desktop view.
Implemented viewForZoomingInScrollView to return the desktop view as the view to scroll.
Put NSLogs in scrollViewDidZoom to print out the frame of the desktop view and one of the widget views.
What I found out:
The widget frame never changes from the initial value that I set. So for example, if a widget started at position 108, 108 with a size of 64x64, then the frame is always reported as 108,108,64,64 regardless of zooming or scrolling.
The desktop frame origin never changes. I put the origin of the desktop at 0,0 in the scroll view, and the origin is always reported as 0,0 regardless of zooming or scrolling.
The only thing that changes is the desktop view's frame size, and the size is just the original size multiplied by the scroll view's zoomScale.
Conclusion:
To figure out the location of a widget relative to the coordinate system of the view controller's main view, you need to do the math yourself. The convertRect method doesn't do anything useful in this case. Here's some code to try
- (CGRect)computePositionForWidget:(UIView *)widgetView fromView:(UIScrollView *)scrollView
{
CGRect frame;
float scale;
scale = scrollView.zoomScale;
// compute the widget size based on the zoom scale
frame.size.width = widgetView.frame.size.width * scale;
frame.size.height = widgetView.frame.size.height * scale;
// compute the widget position based on the zoom scale and contentOffset
frame.origin.x = widgetView.frame.origin.x * scale - scrollView.contentOffset.x + scrollView.frame.origin.x;
frame.origin.y = widgetView.frame.origin.y * scale - scrollView.contentOffset.y + scrollView.frame.origin.y;
// return the widget coordinates in the coordinate system of the view that contains the scroll view
return( frame );
}
I have also similar kind of issue, i fixed it by a different trick. i catch the zoom scale in a temporary variable, and set scrollView's zoom scale to minimum(1.0) and then calculate my frame using convertRect() and set the original zoom scale again
CGFloat actualZoomScal = self.baseVideoView.zoomScale;
CGPoint actualOffset = self.baseVideoView.contentOffset;
self.baseVideoView.zoomScale = 1.0;
CGRect iFrame = [[RGLayout layout] rectToPixels:[self recordingIndicatorFrame]];
self.recordIndicator = [[RiscoRecordingIndicatorView alloc] initWithFrame:[self convertRect:iFrame fromView:self.previewView]];
[self addSubview:self.recordIndicator] ;
[self bringSubviewToFront:self.recordIndicator] ;
self.baseVideoView.zoomScale = actualZoomScal;
self.baseVideoView.contentOffset = actualOffset;
I'm new to iPhone development, coming from a web application development background and I'm working on my first project. I chose to create a Navigation based project, since after reading it seemed to be the easiest way to get what I'm after. How do you change the width of the UITableView? Eventually, I'd like to have a top bar, UITableView, and bottom bar be 304px wide. I've tried the following in my RootViewController's viewDidLoad method, but I'm doing it wrong:
CGRect tableViewFrame = self.tableView.frame;
tableViewFrame.size.width = 200;
self.tableView.frame = tableViewFrame;
Thanks for any help in advance.
If you want to change the width of the tableViewCell.. go to cellForRowAtIndexPath, and assign it there.
You could also do -
CGFloat tableBorderLeft = 1;
CGFloat tableBorderRight = 1;
CGRect tableRect = self.view.frame;
tableRect.origin.x += tableBorderLeft; // make the table begin a few pixels right from its origin
tableRect.size.width -= tableBorderLeft + tableBorderRight; // reduce the width of the table
tableView.frame = tableRect;
For changing the size of header
-(CGFloat)tableView:(UITableView*)tableView heightForHeaderInSection:(NSInteger)section
{
return 150.0; //Give a value
}
For changing size of footer
-(CGFloat)tableView:(UITableView*)tableView heightForFooterInSection:(NSInteger)section
{
return 150.0;//Give a value
}
I am trying to rotate UITextField at 90 angle.It is rotationg perfectly..but text inside the UITextField, is displaced.I am unable to find out the reason behind it.
[InputField setTransform:CGAffineTransformMakeRotation(-M_PI / 2.0)];
[InputField setContentVerticalAlignment:UIControlContentVerticalAlignmentTop];
[InputField setContentHorizontalAlignment:UIControlContentHorizontalAlignmentCenter];
works for me!
What exactly is the problem? When I apply an CGAffineTransformation to an TextField, everything looks fine.
myTextField.transform = CGAffineTransformMakeRotation(M_PI_2);
Instead of setting the vertical and horizontal alignment (which produces the off-center edit window observed above), you could handle the editing rect manually. I overrided editingRectForBounds as follows. This centers the editing rect regardless of rotation:
-(CGRect)editingRectForBounds:(CGRect)bounds
{
// how tall is the font?
CGFloat fontHeight = [self.text sizeWithFont:self.font].height;
// compute pad
CGFloat pad = (bounds.size.height - fontHeight) / 2.0f;
// return rect with pad on top and bottom
return CGRectMake(bounds.origin.x, bounds.origin.y + pad, bounds.size.width, fontHeight);
}
I'm trying to get an effect like the zoomRectToVisible-method of UIScrollview.
But my method should be able to center the particular rect in the layer while zooming and it should be able to re-adjust after the device orientation changed.
I'm trying to write a software like the marvel-comic app and need a view that presents each panel in a page.
For my implementation I'm using CALayer and Core Animation to get the desired effect with CATransform3D-transformations. My problem is, I'm not able to get the zoomed rect/panel centered.
the structure of my implementation looks like this: I have a subclass of UIScrollview with a UIView added as subview. The UIView contains the image/page in it's CALayer.contents and I use core animations to get the zooming and centering effect. The zoom effect on each panel works correcty but the centering is off. I'm not able to compute the correct translate-transformation for centering.
My code for the implementation of the effect is like this:
- (void) zoomToRect:(CGRect)rect animated:(BOOL)animated {
CGSize scrollViewSize = self.bounds.size;
// get the current panel boundingbox
CGRect panelboundingBox = CGPathGetBoundingBox([comicPage panelAtIndex:currentPanel]);
// compute zoomfactor depending on the longer dimension of the panelboundingBox size
CGFloat zoomFactor = (panelboundingBox.size.height > panelboundingBox.size.width) ? scrollViewSize.height/panelboundingBox.size.height : scrollViewSize.width/panelboundingBox.size.width;
CGFloat translateX = scrollViewSize.width/2 - (panelboundingBox.origin.x/2 + panelboundingBox.size.width/2);
CGFloat translateY = scrollViewSize.height/2 - (panelboundingBox.size.height/2 - panelboundingBox.origin.y);
// move anchorPoint to panelboundingBox center
CGPoint anchor = CGPointMake(1/contentViewLayer.bounds.size.width * (panelboundingBox.origin.x + panelboundingBox.size.width/2), 1/contentViewLayer.bounds.size.height * (contentViewLayer.bounds.size.height - (panelboundingBox.origin.y + panelboundingBox.size.height/2)));
// create the nessesary transformations
CATransform3D translateMatrix = CATransform3DMakeTranslation(translateX, -translateY, 1);
CATransform3D scaleMatrix = CATransform3DMakeScale(zoomFactor, zoomFactor, 1);
// create respective core animation for transformation
CABasicAnimation *zoomAnimation = [CABasicAnimation animationWithKeyPath:#"transform"];
zoomAnimation.fromValue = (id) [NSValue valueWithCATransform3D:contentViewLayer.transform];
zoomAnimation.toValue = (id) [NSValue valueWithCATransform3D:CATransform3DConcat(scaleMatrix, translateMatrix)];
zoomAnimation.removedOnCompletion = YES;
zoomAnimation.duration = duration;
// create respective core animation for anchorpoint movement
CABasicAnimation *anchorAnimatione = [CABasicAnimation animationWithKeyPath:#"anchorPoint"];
anchorAnimatione.fromValue = (id)[NSValue valueWithCGPoint:contentViewLayer.anchorPoint];
anchorAnimatione.toValue = (id) [NSValue valueWithCGPoint:anchor];
anchorAnimatione.removedOnCompletion = YES;
anchorAnimatione.duration = duration;
// put them into an animation group
CAAnimationGroup *group = [CAAnimationGroup animation];
group.animations = [NSArray arrayWithObjects:zoomAnimation, anchorAnimatione, nil] ;
/////////////
NSLog(#"scrollViewBounds (w = %f, h = %f)", self.frame.size.width, self.frame.size.height);
NSLog(#"panelBounds (x = %f, y = %f, w = %f, h = %f)", panelboundingBox.origin.x, panelboundingBox.origin.y, panelboundingBox.size.width, panelboundingBox.size.height);
NSLog(#"zoomfactor: %f", zoomFactor);
NSLog(#"translateX: %f, translateY: %f", translateX, translateY);
NSLog(#"anchorPoint (x = %f, y = %f)", anchor.x, anchor.y);
/////////////
// add animation group to layer
[contentViewLayer addAnimation:group forKey:#"zoomAnimation"];
// trigger respective animations
contentViewLayer.anchorPoint = anchor;
contentViewLayer.transform = CATransform3DConcat(scaleMatrix, translateMatrix);
}
So the view requires the following points:
it should be able to zoom and center a rect/panel of the layer/view depending on the current device orientation. (zoomRectToVisible of UIScrollview does not center the rect)
if nessesary (either device orientation changed or panel requires rotation) the zoomed panel/rect should be able to rotate
the duration of the animation is depending on user preference. (I don't know whether I can change the default animation duration of zoomRectToVisible of UIScrollView ?)
Those points are the reason why I overwrite the zoomRectToVisible-method of UIScrollView.
So I have to know how I can correctly compute the translation parameters for the transformation.
I hope someone can guide me to get the correct parameters.
Just skimmed over your code and this line is probably not being calculated as you think:
CGPoint anchor = CGPointMake(1/contentViewLayer.bounds.size.width * (panelboundingBox.origin.x + panelboundingBox.size.width/2), 1/contentViewLayer.bounds.size.height * (contentViewLayer.bounds.size.height - (panelboundingBox.origin.y + panelboundingBox.size.height/2)));
You're likely to get 0 because of the 1/ at the start. C will do your multiplication before this division, resulting in values <1 - probably not what you're after. See this
You might find it more useful to breakdown your calculation so you know it's working in the right order (just use some temporary variables) - believe me it will help enormously in making your code easier to read (and debug) later. Or you could just use more brackets...
Hope this helps.