I created an UIView and then added the Anchor constraints but I have a problem when I want to read the values ...
In this case as you see, I created an NSLayoutConstraint property to get the Anchor Width of my uiview ... I then created a CGFloat that contains constraint but my NSLog always returns me a ZERO value.
where am I wrong? how can I get the width values of my UIView assigned to the Anchors?
UIView *trackLine = [[UIView alloc] init];
trackLine.backgroundColor = [self trackLineColor];
trackLine.translatesAutoresizingMaskIntoConstraints = NO;
[self addSubview:trackLine];
[trackLine.topAnchor constraintEqualToAnchor:mediaTitle.bottomAnchor constant:25].active = YES;
[trackLine.rightAnchor constraintEqualToAnchor:self.rightAnchor].active = YES;
[trackLine.heightAnchor constraintEqualToConstant:1].active = YES;
self.width = [trackLine.widthAnchor constraintEqualToAnchor:self.widthAnchor multiplier:.8];
self.width.active = YES;
CGFloat trackLineLenght = self.width.constant;
NSLog(#"TRACK LINE %f", trackLineLenght );
NSLog Result:
**2017-10-21 17:10:35.096562+0200 [5501:1994879] TRACK LINE 0.000000**
OK - a little confusion...
First, don't use "width" as a property name... very confusing, since width is used in so many places already.
So, let's assume you have:
#property NSLayoutConstraint *trackLineWidthConstraint;
A .widthAnchor doesn't really have a width in terms of "what's the width of the anchor." The way you are defining your constraints:
self.trackLineWidthConstraint = [trackLine.widthAnchor constraintEqualToAnchor:self.widthAnchor multiplier:.8];
Says "set the .trackLineWidthConstraint property to 80% of the width of self. So, whenever the actual width of self changes, the actual width of your trackLine view will change to 80% of the new width.
The .constant is Zero. If it was something other than zero, that value would be added after calculating 80%. For example:
self.trackLineWidthConstraint = [trackLine.widthAnchor constraintEqualToAnchor:self.widthAnchor multiplier:.8];
// if self is 200-pts wide, trackLine will be 160-pts
self.trackLineWidthConstraint.constant = 10
// trackLine width is now (200 * 0.8) + 10, or 170-pts
If you want to get the current width of trackLine, you can get it from its .frame (after auto-layout has finished).
Hopefully, that didn't just make it more confusing :)
Related
I have a UIView that displays like a bar and its width should change based on a NSNumber value displayed on a UILabel.
Image below shows the ui
For instance: As shown in the image, all 3 orange bars have different values. I need the bar's width should also be different based on the value. The bars with value 14 and 10 should be less in width than the bar with value 18.
Following is the code I wrote but it doesn't work.
//Get the value as string
NSString *countString = cell.numberOfTuneIn.text;
//MAximum size of the bar
CGSize maxSize = CGSizeMake(cell.numberOfTuneIn.bounds.size.width, CGFLOAT_MAX);
CGRect s = [countString boundingRectWithSize:maxSize options:NSStringDrawingUsesLineFragmentOrigin attributes:#{NSFontAttributeName:cell.numberOfTuneIn.font} context:nil];
//set the frame of the bar
CGRect rect = cell.barView.frame;
rect.size.width = s.size.width;
cell.barView.frame = rect;
Can someone please help with:
How do I change the width of the bar based on the value?
This is the basic logic you should follow:
Get bar number range (e.g. 0-100)
Get width pixel range (e.g. 0-320)
Create ratio (e.g. 320 / 100) or 3.2 pixels of width for each 1 you
increment...
So according to the example above:
If the bar is 100, it's width is 100 * 3.2 = 320 px width
If the bar is 50, it's width is 50 * 3.2 = 160 px width
Hope it helped.
- (CGFloat)getViewlWidth:(float)labelValue {
// Setup view bar settings, you can take those settings outside of this method if needed
int maxLabelValue = 100;
int viewMaxWidth = 320; // You can make it dynamic according to screen width
float widthPixelRatio = viewMaxWidth / maxLabelValue;
// Calculate width
CGFloat pixelsResult = labelValue * widthPixelRatio;
// Return value
return pixelsResult;
}
// Lets assume that here you get the label value from the server and you called it labelValue
NSString * labelValue = // Value from server
/*
Create UILabel here, showing the value from server
*/
// Get the width of the UIView to be
CGFloat myViewWidth = [self getViewlWidth:[labelValue floatValue]];
/*
Create the UIView here and set its witdh to the result of the CGFloat above (myViewWidth)
*/
I'm running into issues with my UI when adding a dynamic number of child UIView elements into a "container" UIView. Basically I need to be able to dynamically resize the container view (self.containerAView below) to fit the height of all the "children" subViews that have been added to it. All the attempts that I have done thus far to reset the frame haven't worked. It is worth noting that the initial size is defined in the *.xib file that is initially loading the containerAView (UIView) element with an initial size of 300x200 (w x h).
- (void)drawScreen {
// handle all screen presentation initialization here
// programatically create a dynamic number of child views to add to the container view
for (int i = 0; i < 3; i++) {
int childViewHeight = 60;
int childViewWidth = 300;
UIView *childView = [[UIView alloc] initWithFrame:CGRectMake(0, (i * childViewHeight) + (i * 10), childViewWidth, childViewHeight)];
childView.backgroundColor = [UIColor blackColor];
[self.containerAView addSubview:childView];
}
// build a mapping dictionary for all child elements in the container view
NSMutableDictionary *containerASubViewDictionary = [[NSMutableDictionary alloc] init];
for (int i = 0; i < [self.containerAView.subviews count]; i++) {
[containerASubViewDictionary setValue:self.containerAView.subviews[i] forKey:[NSString stringWithFormat:#"childView%d", i]];
}
// WHAT TO ADD HERE TO HANDLE RESIZING self.containerAView height???
}
Any sort of help on dynamically resizing the container view would be greatly appreciated as I have been unable to find any solution as of yet.
One way, which is probably the most up to date approach, would be to add 4 auto layout constraints to the containerview in interface builder.
Add the four constraints: x = 0, y = 0, width = 300 & height = 200
Now click on the width constraint in interface builder to highlight it and then control drag it into your .h file and give it a name, like containerWidth.
#property (strong, nonatomic) IBOutlet NSLayoutConstraint *containerWidth;
Repeat with the height.
In your .m file you can adjust the height and width in your drawScreen method by manipulating the contstraints.
self.containerWidth.constant = width; // your calculated new width
self.containerHeight.constant = height; // your calculated new height
You seem to be attempting to change the height of your container's frame. A frame has an origin and a size. Try manipulating these properties:
self.containerView.frame.origin.x
self.containerView.frame.origin.y
self.containerView.frame.size.height
self.containerView.frame.size.width
So I have setup a UIView that contains a UIScrollView (and child content view) that has sub views that are series of UILabels and UIViews that grow and shrink depending on the content contained in them, all using AutoLayout from the Storyboard. This works when I have something like Label - Label - Label - View w/o any issues, however if I put an empty UIView in-between two labels and insert sub views on the UIView, I'm not seeing the results I'm expecting. I have the following layout in a storyboard:
...where the teal and blue views are labels that grow to infinite height and the orange view (optionsPanel) is an empty UIVIew that I later inject sub views into. The rest of the stuff on the window is UILabels and UISegment controls. Between each row of views I have a Vertical Space constraint with a constant of 8. This all worked beautifully until I had to put in the empty UIView and programmatically inject sub views. The code I would expect to work would be something like (optionsPanel is the orange colored UIView)...
optionsPanel.translatesAutoresizingMaskIntoConstraints = YES;
NSArray *options = [product objectForKey:#"options"];
lastTop = 10;
for(int i=0;i<options.count; i++) {
NSDictionary *option = [options objectAtIndex:i];
NSArray *values = [option objectForKey:#"values"];
if([self hasNoneValue:values] && values.count == 2) {
NSDictionary *value = [self notNoneValue:values];
M13Checkbox *optionCheck = [[M13Checkbox alloc] initWithTitle:[option objectForKey:#"name"]];
optionCheck.frame = CGRectMake(0, lastTop, 280, 25);
[optionsPanel addSubview:optionCheck];
lastTop += 25;
} else {}
}
...where the orange UIView would magically grow and everything would just get pushed around accordingly, however this is what I'm seeing:
...the orange UIView does not grow at all, and the other two top UIView have gone somewhere off the screen. So my next guess was to turn off the Autoresizing Mask using...
optionsPanel.translatesAutoresizingMaskIntoConstraints = NO;
...but I'm getting a result where everything appears to be working but the orange UIView (optionsPanel) has no height for whatever reason and looks like:
This is getting closer to what I would expect, so I thought I would force the height of the orange UIView using code like...
frame = optionsPanel.frame;
frame.size.height = lastTop;
optionsPanel.frame = frame;
...but this appears to have no affect on anything.
Purely guessing, I found that this code almost works, if I arbitrary set the optionPanel's origin to something much larger than the space that is needed....
optionsPanel.translatesAutoresizingMaskIntoConstraints = YES;
NSArray *options = [product objectForKey:#"options"];
lastTop = 10;
for(int i=0;i<options.count; i++) {
NSDictionary *option = [options objectAtIndex:i];
NSArray *values = [option objectForKey:#"values"];
if([self hasNoneValue:values] && values.count == 2) {
NSDictionary *value = [self notNoneValue:values];
M13Checkbox *optionCheck = [[M13Checkbox alloc] initWithTitle:[option objectForKey:#"name"]];
optionCheck.frame = CGRectMake(0, lastTop, 280, 25);
[optionsPanel addSubview:optionCheck];
lastTop += 25;
} else {}
}
lastTop += 10;
frame = optionsPanel.frame;
frame.size.height = lastTop;
frame.origin.y += 300; //some arbitrarily large number
optionsPanel.frame = frame;
..which gives this result:
...but apparently the AutoLayout has decided that the name label needs to take up the extra space. Its an ugly approach but if I could figure out how much space I need then I could just push everything down, if I had to. What's the secret to having a dynamic UIView between two dynamically sized labels and everything just work???
As #Timothy says, you need to manually add constraints to the subviews of the orange view if you want it to resize based on its contents—views don’t do this by default.
In general, if you’re using autolayout in a window, you should never be manually setting the frame of any view. Autolayout overrides any frames you set the every time it’s called, so even if you manage to manually get it working for a second it’ll fail the next time anything triggers a layout.
For views created in code, it's perfectly fine to set their frames as long as their translatesAutoresizingMaskIntoConstraints property is YES (the default, by the way).
However, for a view instantiated in storyboard or a nib, you can not set its translatesAutoresizingMaskIntoConstraints to YES.
The is the first of several problems I'm having setting up some UIViews and subviews. I have a UIView that is dynamically positioned on screen at run time. That UIView (master) contains another UIView (child) which wraps a UIImageView and a UILabel. Here are the requirements I have for this arrangement:
The child UIView must stay centered in the master UIView when the device rotates.
The text in the UILabel can be very long or very short and the child UIView with the image and text must still remain centered.
I would like to avoid subclassing UIView to handle this scenario and I would also like to avoid any frame/positioning code in willRotateToInterfaceOrientation. I'd like to handle all of this with some autoresizingMask settings in I.B. and maybe a little forced resizing code, if possible.
This is the arrangement of controls in Interface Builder(highlighted in red):
With Interface Builder, the autoresizingMask properties have been set like so, for the described controls
UIView (master): Flexible top margin, Flexible left margin, Flexible right margin, Flexible width
UIView (child): Flexible top margin, Flexible bottom margin, Flexible left margin, Flexible right margin, Flexible width, Flexible height. (All modes, except None)
UIImageView: Flexible right margin
UILabel: Flexible right margin
This is the view (red bar with image and text) after it's been added programmatically at run time while in portrait mode:
The master UIView's background is a light-red colored image. The child UIView's background is slightly darker than that, and the UILabel's background is even darker. I colored them so that I could see their bounds as the app responded to rotation.
It's clear to me that:
It is not centered but ...
After changing the text from it's default value in I.B from "There is no data in this map extent." to "TEST1, 123." the label contracts correctly.
This is the view after it's been added while in portrait and then rotated to landscape mode:
From here I can see that:
It is still not centered and perhaps at its original frame origin prior to rotation
The UIView (child) has expanded to fill more of the screen when it shouldn't.
The UIView (master) has properly expanded to fill the screen width.
This is the code that got me where I am now. I call the method showNoDataStatusView from viewDidLoad:
// Assuming
#define kStatusViewHeight 20
- (void)showNoDataStatusView {
if (!self.noDataStatusView.superview) {
self.noDataStatusView.frame = CGRectMake(self.mapView.frame.origin.x,
self.mapView.frame.origin.y,
self.mapView.frame.size.width,
kStatusViewHeight);
self.noDataStatusView.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:#"bgRedStatus.png"]];
// Position the label view in the center
self.noDataStatusLabelView.center = CGPointMake(self.noDataStatusView.frame.size.width/2,
self.noDataStatusView.frame.size.height/2);
// Test different text
self.noDataStatusLabel.text = #"Testing, 123.";
// Size to fit label
[self.noDataStatusLabel sizeToFit];
// Test the status label view resizing
[self.noDataStatusLabelView resizeToFitSubviews];
// Add view as subview
[self.view addSubview:self.noDataStatusView];
}
}
Please note the following:
resizeToFitSubviews is a category I placed on UIView once I found that UIView's won't automatically resize to fit their subviews even when you call sizeToFit. This question, and this question explained the issue. See the code for the category, below.
I have thought about creating a UIView subclass that handles all this logic for me, but it seems like overkill. It should be simple to arrange this in I.B. right?
I have tried setting every resizing mask setting in the book, as well as adjusting the order in which the resizing of the label and view occur as well as the point at which the master view is added as a subview. Nothing seems to be working as I get odd results every time.
UIView resizeToFitSubviews category implementation method:
-(void)resizeToFitSubviews
{
float width = 0;
float height = 0;
// Loop through subviews to determine max height/width
for (UIView *v in [self subviews]) {
float fw = v.frame.origin.x + v.frame.size.width;
float fh = v.frame.origin.y + v.frame.size.height;
width = MAX(fw, width);
height = MAX(fh, height);
}
[self setFrame:CGRectMake(self.frame.origin.x, self.frame.origin.y, width, height)];
}
What I want to know is why the UIView (child) is not properly centered after it's superview is added to the view hierarchy. It looks as though its got the proper width, but is somehow retaining the frame it had in I.B. when the label read "There is no data in this map extent."
I want to also know why it's not centered after device rotation and whether or not the approach I'm taking here is wise. Perhaps this is causing the other issues I'm having. Any UIView layout help here would be greatly appreciated.
Thanks!
If you are able to target iOS 6 you could use the new Auto Layout functionality to make this much much easier to manage - I've been reading a great tutorial by Ray Wenderlich that seems to be perfect to solve the problem you are seeing.
The problem here is that my UIView (master) does not layout it's subviews automatically when the device rotates and the "springs & struts" layout method used to position the image and interior UIView was inefficient. I solved the problem by doing two things.
I got rid of the internal UIView (child) instance, leaving only the UIView (master) and inside of that a UILabel and UIImageView.
I then created a UIView subclass called StatusView and in it I implement the layoutSubviews method. In its constructor I add a UIImageView and UILabel and position them dynamically. The UILabel is positioned first based on the size of the text and then the UIImageView is placed just to the left of it and vertically centered. That's it. In layoutSubviews I ensure that the positions of the elements are adjusted for the new frame.
Additionally, since I need to swap the background, message and possibly the image in some circumstances, it made sense to go with a custom class. There may be memory issues here/there but I'll iron them out when I run through this with the profiling tool.
Finally, I'm not totally certain if this code is rock solid but it does work. I don't know if I need the layout code in my init method, either. Layout subviews seems to be called shortly after the view is added as a subview.
Here's my class header:
#import <UIKit/UIKit.h>
typedef enum {
StatusViewRecordCountType = 0,
StatusViewReachedMaxRecordCountType = 1,
StatusViewZoomInType = 2,
StatusViewConnectionLostType = 3,
StatusViewConnectionFoundType = 4,
StatusViewNoDataFoundType = 5,
StatusViewGeographyIntersectionsType = 6,
StatusViewRetreivingRecordsType = 7
} StatusViewType;
#interface StatusView : UIView
#property (strong, nonatomic) NSString *statusMessage;
#property (nonatomic) StatusViewType statusViewType;
- (id)initWithFrame:(CGRect)frame message:(NSString*)message type:(StatusViewType)type;
#end
... and implementation:
#import "StatusView.h"
#define kConstrainSizeWidthOffset 10
#define kImageBufferWidth 15
#interface StatusView ()
#property (nonatomic, strong) UILabel *statusMessageLabel;
#property (nonatomic, strong) UIFont *statusMessageFont;
#property (nonatomic, strong) UIImage *statusImage;
#property (nonatomic, strong) UIImageView *statusImageView;
#end
#implementation StatusView
#synthesize statusMessageLabel = _statusMessageLabel;
#synthesize statusMessageFont = _statusMessageFont;
#synthesize statusImageView = _statusImageView;
#synthesize statusMessage = _statusMessage;
#synthesize statusViewType = _statusViewType;
#synthesize statusImage = _statusImage;
- (id)initWithFrame:(CGRect)frame message:(NSString *)message type:(StatusViewType)type {
self = [super initWithFrame:frame];
if (self) {
if (message != nil) {
_statusMessage = message;
_statusMessageFont = [UIFont fontWithName:#"Avenir-Roman" size:15.0];
CGSize constrainSize = CGSizeMake(self.frame.size.width - kImageBufferWidth - kConstrainSizeWidthOffset, self.frame.size.height);
// Find the size appropriate for this message
CGSize messageSize = [_statusMessage sizeWithFont:_statusMessageFont constrainedToSize:constrainSize];
// Create label and position at center of status view
CGRect labelFrame = CGRectMake(self.frame.origin.x,
self.frame.origin.y,
messageSize.width,
messageSize.height);
_statusMessageLabel = [[UILabel alloc] initWithFrame:labelFrame];
_statusMessageLabel.backgroundColor = [UIColor clearColor];
_statusMessageLabel.textColor = [UIColor whiteColor];
_statusMessageLabel.font = _statusMessageFont;
// Set shadow and color
_statusMessageLabel.shadowOffset = CGSizeMake(0, 1);
_statusMessageLabel.shadowColor = [UIColor blackColor];
// Center the label
CGPoint centerPoint = CGPointMake(self.frame.size.width / 2, self.frame.size.height / 2);
_statusMessageLabel.center = centerPoint;
// Gets rid of fuzziness
_statusMessageLabel.frame = CGRectIntegral(_statusMessageLabel.frame);
// Flex both the width and height as well as left and right margins
_statusMessageLabel.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleLeftMargin | UIViewAutoresizingFlexibleRightMargin;
// Set label text
_statusMessageLabel.text = _statusMessage;
[self addSubview:_statusMessageLabel];
}
self.statusViewType = type;
if (_statusImage != nil) {
// Create image view
_statusImageView = [[UIImageView alloc] initWithImage:_statusImage];
// Vertically center the image
CGPoint centerPoint = CGPointMake(_statusMessageLabel.frame.origin.x - kImageBufferWidth,
self.frame.size.height / 2);
_statusImageView.center = centerPoint;
[self addSubview:_statusImageView];
}
}
return self;
}
- (void)layoutSubviews {
CGSize constrainSize = CGSizeMake(self.frame.size.width - kImageBufferWidth - kConstrainSizeWidthOffset, self.frame.size.height);
// Find the size appropriate for this message
CGSize messageSize = [_statusMessage sizeWithFont:_statusMessageFont constrainedToSize:constrainSize];
// Create label and position at center of status view
CGRect labelFrame = CGRectMake(self.frame.origin.x,
self.frame.origin.y,
messageSize.width,
messageSize.height);
_statusMessageLabel.frame = labelFrame;
// Center the label
CGPoint centerPoint = CGPointMake(self.frame.size.width / 2, self.frame.size.height / 2);
_statusMessageLabel.center = centerPoint;
// Gets rid of fuzziness
_statusMessageLabel.frame = CGRectIntegral(_statusMessageLabel.frame);
if (_statusImageView != nil) {
// Vertically center the image
CGPoint centerPoint = CGPointMake(_statusMessageLabel.frame.origin.x - kImageBufferWidth,
self.frame.size.height / 2);
_statusImageView.center = centerPoint;
}
}
#pragma mark - Custom setters
- (void)setStatusMessage:(NSString *)message {
if (_statusMessage == message) return;
_statusMessage = message;
_statusMessageLabel.text = _statusMessage;
// Force layout of subviews
[self setNeedsLayout];
[self layoutIfNeeded];
}
- (void)setStatusViewType:(StatusViewType)statusViewType {
_statusViewType = statusViewType;
UIColor *bgColor = nil;
switch (_statusViewType) {
// Changes background and image based on type
}
self.backgroundColor = bgColor;
if (_statusImageView != nil) {
_statusImageView.image = _statusImage;
}
}
#end
Then in my view controller I can do this:
CGRect statusFrame = CGRectMake(self.mapView.frame.origin.x,
self.mapView.frame.origin.y,
self.mapView.frame.size.width,
kStatusViewHeight);
self.staticStatusView = [[StatusView alloc] initWithFrame:statusFrame message:#"600 records found :)" type:StatusViewRecordCountType];
self.staticStatusView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleLeftMargin | UIViewAutoresizingFlexibleRightMargin;
[self.view addSubview:self.staticStatusView];
... and later on I can change it up by doing this:
self.staticStatusView.statusMessage = #"No data was found here";
self.staticStatusView.statusViewType = StatusViewNoDataFoundType;
Now I've got a reusable class rather than 12 UIView instances floating around my NIB with various settings and properties.
I've got a subclassed UITableViewCell. I'm dynamically adding a UILabel and UIButton to it.
Right now I've overridden layoutSubviews and am setting the x,y absolutely of the button and label. To be able to accommodate both screen layouts as well as larger screens I'd like to make this automatic. Is there a way to tell the label to "float left" and the button to "float right?" Ideally the label should use up all space that the button doesn't need (the button is going to be a fixed size for the most part).
this property of uiview should get you started
You can try something like this assuming cellLbl is the UILabel and cellBtn is the UIButton:
- (void) layoutSubviews
{
CGRect rctFrm;
CGFloat flW;
CGFloat flH;
int iSpacing = 4; // This could be fixed for a percentage of cell width
[super layoutSubviews];
flW = self.contentView.bounds.size.width;
flH = self.contentView.bounds.size.height;
rctFrm = self.cellBtn.frame;
flW -= rctFrm.size.width + iSpacing;
rctFrm.origin.x = flW; // Right justify button
rctFrm.origin.y = (flH - rctFrm.size.height) / 2; // Center button vertically
[self.cellBtn setFrame:rctFrm];
rctFrm = self.cellLbl.frame;
rctFrm.origin.x = iSpacing;
rctFrm.size.width = flW - (2 * iSpacing);
// You can adjust UILabel vertical position and height if desired
[self.cellLbl setFrame:rctFrm];
}