find the location {x,y} of text in uilabel - objective-c

I have a string coming from server which I am displaying on UILabel multiligne. It is within that string, I am identifying some particular substring. I want to place a button on that substring(button will be a subview of UILabel). For this I require substring coordinates. I went through this but I am not able to understand it. Suppose my complete string is abc, 567-324-6554, New York. I want 567-324-6554 to be displayed on button for which I need its coordinates.
How can I use above link to find coordinates of substring?
Thanks,

UILabel doesn't have any methods for doing this. You can do it with UITextView, because it implements the UITextInput protocol. You will want to set the text view's editable property to NO.
Something like this untested code should work:
- (CGRect)rectInTextView:(UITextView *)textView stringRange:(CFRange)stringRange {
UITextPosition *begin = [textView positionFromPosition:textView.beginningOfDocument offset:stringRange.location];
UITextPosition *end = [textView positionFromPosition:begin offset:stringRange.length];
UITextRange *textRange = [textView textRangeFromPosition:begin toPosition:end];
return [textView firstRectForRange:textRange];
}
That should return a CGRect (in the text view's coordinate system) that covers the substring specified by stringRange. You can set the button's frame to this rectangle, if you make the button a subview of the text view.
If the substring spans multiple lines, the rectangle will only cover the first line.

Related

UITextField -- Adding UIView for leftView - Can't get Focus

The UITextFields in my app have placeholder text defined (in Interface Builder), and I cannot cause these fields to acquire focus (i.e. show the keyboard and allow editing) when I tap on the area occupied by the placeholder text. If I tap on the textfields in an area just outside the that of placeholder text (though still within the bounds of the textfiled itself), it acts as normal (i.e. the keyboard pops up and I can edit the content of the textfield). How can I fix this?
Thanks.
EDIT 1
Ok, I think I've got it. I'm also setting a blank view to the "leftView" property of these UITextFields. If I remove this, you can touch the UITextFields in the area of the placeholder text and it reacts as expected; I need this view for the leftView though. If you change the background color of this spacer view to red, you can see that it doesn't get in the way at all, so I don't know what's going wrong.
Why does this code cause this problem?
Thanks.
+(UIView*)getTextFieldLeftSpacerViewWithBackgroundColor:(UIColor*)backgroundColor andHeight:(CGFloat)height
{
UIView *leftWrapper = [[UIView alloc] initWithFrame:CGRectMake(0.0f, 0.0f, 8.0f, height)];
leftWrapper.autoresizingMask = UIViewAutoresizingNone;
[leftWrapper setOpaque:YES];
if(backgroundColor){leftWrapper.backgroundColor = backgroundColor;}
else{leftWrapper.backgroundColor = [UIColor clearColor];}
return [leftWrapper autorelease];
}
+(void)setTextFieldLeftSpacerForTextFieled:(UITextField*)textField
{
if(textField)
{
UIView *spacer = [MYViewController getTextFieldLeftSpacerViewWithBackgroundColor:nil andHeight:textField.bounds.size.height];
textField.leftView = spacer;
textField.leftViewMode = UITextFieldViewModeAlways;
}
}
Just ran into the same problem and didn't want to subclass, just had to use :
leftWrapper.userInteractionEnabled = NO;
I abandoned this approach. Instead of using an invisible view to offset the text, I opted to subclass UITextField and provide offset CGRects for the bounds of the text within theUITextField. The following SO post was very helpful:
Indent the text in a UITextField

location of a button/textfield in a view in cocoa

I'm sorry to ask such a question, but I can't seem to find the answer for it from the wild web.
I want to find out the location of a NSTextField in my custom view, so I can add other textfields under it programmatically.
The reason I don't just add other textfields in IB, is because I need to be able to dynamically create them.
The NSTextField is linked to an IBOutlet.
So the main question is: How do I find out the location of a NSTextField (or NSButton, it doesn't really matter atm) in a custom view (I need to get the coordinates of the item)?
Make an instance Variable with the NSTextField and then call these methods on it to get the four values you want.
NSRect textFieldFrame = [textField frame];
NSPoint textFieldLocation = textFieldFrame.origin;
NSSize textFieldSize = textFieldFrame.size;
NSInteger x = textFieldLocation.x;
NSInteger y = textFieldLocation.y;
NSInteger width = textFieldSize.width;
NSInteger height = textFieldSize.height;
Every kind of view or control (like NSButton, NSTextField, etc.) that inherits from NSView has a -frame method that contains the positioning information.
If your custom view has an IBOutlet connected up to the NSTextField, you could do the following:
NSRect textFieldFrame = [textField frame];
That NSRect contains all of the information for where the text field is positioned.
See the following 2 guides for more information:
View Programming Guide: Understanding a View's Frame and Bounds
Cocoa Drawing Guide: Coordinate Systems and Transforms
Any view has both a bounds and a frame property. bounds is the rectangle that encloses the view in that view's own coordinate space; frame is the enclosing rectangle in the superview's coordinate space. In this case, you want the text view's frame, i.e. its location and size in the view that contains it, so that you can locate other text views in the same superview.

How to make height of OHAttributedLabel scale with content height?

I use an OHAttributedLabel called demoLbl for displaying text with formatted areas. This label is laid out with Interface Builder and is connected to a property in my ViewController. After setting the attributedText to the label I want all the text to be displayed in the label.
If I don't resize the label then the text is cropped at the end of the label so the rest of the text is missing.
If I use [demoLbl sizeToFit]; then the height of the label is larger or smaller in height than the text (about 10 point, varying with the text's length) thus giving me blank areas at the bottom of my view (after scrolling) plus the width of the label is increased by about 2 points.
If I calculate the height of the original text (NSString) before putting it in a NSAttributedString and adding it to the label's attributedText property then the calculated height is way too small for setting it as the label's height.
Is there a hack or trick I can apply so that the label's height is adjusted according to the NSAttributedString's height?
PS: To be more specific I wanted to add OHAttributedLabel as a tag but it's not allowed to me yet.
I'm the author of OHattributedLabel.
I made some fixes recently about my computation of the size. Please check it out it will probably solve your issue.
I also added a method named sizeConstrainedToSize:fitRange: in NSAttributedString+Attributes.h that returns the CGSize of a given NSAttributedString (quite the same way UIKit's sizeWithFont:constrainedToSize: works, but for Attributed strings and CoreText and not plain stings an UIKit)
Actually OHAttributedLabel's sizeThatFits: calls this method itself now.
You can see if this category gives you a more reliable height.
https://gist.github.com/1071565
Usage
attrLabel.frame.size.height = [attrLabel.attributedString boundingHeightForWidth:attrLabel.frame.size.width];
I added this code to the implementation of the OHAttributedLabel class:
// Toni Soler - 02/09/2011
// Overridden of the UILabel::sizeToFit method
- (void)sizeToFit
{
// Do not call the standard method of the UILabel class, this resizes the frame incorrectly
//[super sizeToFit];
CGSize constraint = CGSizeMake(self.frame.size.width, 20000.0f);
CGRect frame = self.frame;
frame.size = [self sizeThatFits:constraint];
[self setFrame:frame];
}
// End Toni Soler - 02/09/2011
Thank you Olivier for sharing your code!

Getting NSTextView to perfectly fit its contents

I have a view that contains a button and a textview. When the button is clicked, the textview's hidden status will change and be shown on the view. Springs and struts have been configured so the textview expands vertically with the view. All this is done in IB
I then insert text into the textview programmatically, but I need the textview to show all its contents without the user needing to scroll.
This is the code I use to calculate the height of the text in the textview:
- (float) getTextViewHeight {
//based on http://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/TextLayout/Tasks/StringHeight.html%23//apple_ref/doc/uid/20001809-CJBGBIBB
[textview.textContainer setLineFragmentPadding:0.0];
[textview.layoutManager glyphRangeForTextContainer:textview.textContainer];
return [textview.layoutManager usedRectForTextContainer:self.interactionData.textContainer].size.height;
}
With or without that call to -sizeToFit on the textview, it will either be too big or too small (depending on its contents).
I need to get the height of the textview with all the contents showing so I can adjust the view's size.
I know I could probably use a NSTextField as a label, but I need a NSTextView for its added functionality (specifically using the enclosing scrollview's rulerview).
Does anybody have any suggestions?
NSTextView generally will resize itself if its string over-runs the container width. I think this is because the contained cell has a default behavior for text over-run, called "Line Wrap" or something. My gut feeling is you could just ask the TextView for it's height after it's been loaded and adjust the containing view accordingly, all without needing a layout manager. And obviously make sure the auto-resizing mask is set (oh, you're doing this in IB so no worries there). I could be wrong, and I didn't do any tests... but yeah, you could try it! :P
Her's how I do it and it works well:
// Help text.
NSBundle* mainBundle = [NSBundle mainBundle];
NSString* path = [mainBundle pathForResource: #"category-analysis-help" ofType: #"rtf"];
NSAttributedString* text = [[NSAttributedString alloc] initWithPath: path documentAttributes: NULL];
[helpText setAttributedStringValue: text];
NSRect bounds = [text boundingRectWithSize: NSMakeSize(helpText.bounds.size.width, 0) options: NSStringDrawingUsesLineFragmentOrigin];
helpContentView.frame = NSMakeRect(0, 0, helpText.bounds.size.width + 20, bounds.size.height + 20);
helpContentView is just a container for helpText to add some marging around the text. helpText resizes with its container.
It should be obvious that for the correct height a fixed width is necessary, since the height depends on what fits on the lines.
If you want to omit the scroll view entirely (e.g., make a text view that is attached to another superview and sizes itself to fit its text), you might take a look at NSText. It is, AFAICT, basically a NSTextView without the superview (scroll view parts), and can automagically resize itself.

What is the best way to implement a variable-sized multi-line UITableCell?

I'm trying to display a table full of twitter statuses (yes, this is the Stanford Presence 2 assignment), which are variably sized. I can relatively easily determine the appropriate height for my rows with code that approximates (from accompanying lecture 9):
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *) indexPath
{
NSString *text = ...;
UIFont *font = [UIFont systemFontOfSize:...];
CGSize withinSize = CGSizeMake(tableView.width, 1000];
CGSize size = [text sizeWithFont:font constrainedToSize:withinSize lineBreakMode:UILineBreakModeWordWrap];
return size.height + somePadding;
}
I have tried two approaches (and some tweaks to both) to get a multi-line word-wrapping field of text into my table row.
Add a UILabel as a subview to my custom UITableCell subclass, and set the numberOfLines property to either a calculated number based on the height above (say, 6), or to 0 (theoretically unlimited). The numberOfLines is ignored; I see either 1 or 2 lines, and no more.
Add a read-only UITextView as a subview. This has the problem that the UITextView eats my scrolling; I end up scrolling inside a UITextView row instead of moving smoothly from row to row. If I disable scrolling on the UITextView, I end up being unable to scroll at all.
This is a pretty common thing to do; what's the best way to accomplish it?
You might want to look at the userInteractionEnabled property of the UITextView. That should allow input to be passed through to the UITableView so you get scrolling.
Here's a link to a blog I posted on this subject. I used a UILabel with numberOfLInes = 0. I hope this will be of some help.
Sample Project with Variable Sized UITableViewCell
While playing with userInteractionEnabled=NO, scrollEnabled=NO, and getting the right autosizing parameters set in IB worked, I think that going with a UILabel with numberOfLines=0 and the same autosizing parameters is ultimately a better idea, for the next person.