NSTableView odd display bug when selection row changes - cocoa

I've got a weird drawing bug happening. I have a view based NSTableView with simple rows or text cells. When I press the down arrow, selecting a row, all the text in the tableview shifts 1 pixel to the left, and then when I select the next row, it goes back. Very odd.
I pulled out any subclassing of rows or cells that I have and replace them with standard stuff, but it still happens.
Anyone seen this before?

This can happen if you subclass "NSTableRowView" and use that to hi-light the "selected row".
This usually happens when there's a border to the left or to the right.
As per apples example called "TableViewPlaygound" (which can be found here: https://developer.apple.com/library/mac/samplecode/TableViewPlayground/Introduction/Intro.html#//apple_ref/doc/uid/DTS40010727), this is what they use and I use it often for quick and dirty copy and paste hi-lighting:
- (void)drawSelectionInRect:(NSRect)dirtyRect {
NSColor *primaryColor = [[NSColor alternateSelectedControlColor] colorWithAlphaComponent:0.4];
NSColor *secondarySelectedControlColor = [[NSColor secondarySelectedControlColor] colorWithAlphaComponent:0.4];
// Implement our own custom alpha drawing
switch (self.selectionHighlightStyle) {
case NSTableViewSelectionHighlightStyleRegular: {
if (self.selected) {
if (self.emphasized) {
[primaryColor set];
} else {
[secondarySelectedControlColor set];
}
NSRect bounds = self.bounds;
const NSRect *rects = NULL;
NSInteger count = 0;
[self getRectsBeingDrawn:&rects count:&count];
for (NSInteger i = 0; i < count; i++) {
NSRect rect = NSIntersectionRect(bounds, rects[i]);
NSRectFillUsingOperation(rect, NSCompositeSourceOver);
}
}
break;
}
default: {
// Do super's drawing
[super drawSelectionInRect:dirtyRect];
break;
}
}
}
-(void)drawSeparatorInRect:(NSRect)dirtyRect
{
NSRect sepRect = self.bounds;
sepRect.origin.y = NSMaxY(sepRect) - 1;
sepRect.size.height = 1;
sepRect = NSIntersectionRect(sepRect, dirtyRect);
if (!NSIsEmptyRect(sepRect)) {
[[NSColor gridColor] set];
NSRectFill(sepRect);
}
}

Related

UILabel align to Top Left in Xamarin iOS [duplicate]

I have a UILabel with space for two lines of text. Sometimes, when the text is too short, this text is displayed in the vertical center of the label.
How do I vertically align the text to always be at the top of the UILabel?
There's no way to set the vertical-align on a UILabel, but you can get the same effect by changing the label's frame. I've made my labels orange so you can see clearly what's happening.
Here's the quick and easy way to do this:
[myLabel sizeToFit];
If you have a label with longer text that will make more than one line, set numberOfLines to 0 (zero here means an unlimited number of lines).
myLabel.numberOfLines = 0;
[myLabel sizeToFit];
Longer Version
I'll make my label in code so that you can see what's going on. You can set up most of this in Interface Builder too. My setup is a View-Based App with a background image I made in Photoshop to show margins (20 points). The label is an attractive orange color so you can see what's going on with the dimensions.
- (void)viewDidLoad
{
[super viewDidLoad];
// 20 point top and left margin. Sized to leave 20 pt at right.
CGRect labelFrame = CGRectMake(20, 20, 280, 150);
UILabel *myLabel = [[UILabel alloc] initWithFrame:labelFrame];
[myLabel setBackgroundColor:[UIColor orangeColor]];
NSString *labelText = #"I am the very model of a modern Major-General, I've information vegetable, animal, and mineral";
[myLabel setText:labelText];
// Tell the label to use an unlimited number of lines
[myLabel setNumberOfLines:0];
[myLabel sizeToFit];
[self.view addSubview:myLabel];
}
Some limitations of using sizeToFit come into play with center- or right-aligned text. Here's what happens:
// myLabel.textAlignment = NSTextAlignmentRight;
myLabel.textAlignment = NSTextAlignmentCenter;
[myLabel setNumberOfLines:0];
[myLabel sizeToFit];
The label is still sized with a fixed top-left corner. You can save the original label's width in a variable and set it after sizeToFit, or give it a fixed width to counter these problems:
myLabel.textAlignment = NSTextAlignmentCenter;
[myLabel setNumberOfLines:0];
[myLabel sizeToFit];
CGRect myFrame = myLabel.frame;
// Resize the frame's width to 280 (320 - margins)
// width could also be myOriginalLabelFrame.size.width
myFrame = CGRectMake(myFrame.origin.x, myFrame.origin.y, 280, myFrame.size.height);
myLabel.frame = myFrame;
Note that sizeToFit will respect your initial label's minimum width. If you start with a label 100 wide and call sizeToFit on it, it will give you back a (possibly very tall) label with 100 (or a little less) width. You might want to set your label to the minimum width you want before resizing.
Some other things to note:
Whether lineBreakMode is respected depends on how it's set. NSLineBreakByTruncatingTail (the default) is ignored after sizeToFit, as are the other two truncation modes (head and middle). NSLineBreakByClipping is also ignored. NSLineBreakByCharWrapping works as usual. The frame width is still narrowed to fit to the rightmost letter.
Mark Amery gave a fix for NIBs and Storyboards using Auto Layout in the comments:
If your label is included in a nib or storyboard as a subview of the view of a ViewController that uses autolayout, then putting your sizeToFit call into viewDidLoad won't work, because autolayout sizes and positions the subviews after viewDidLoad is called and will immediately undo the effects of your sizeToFit call. However, calling sizeToFit from within viewDidLayoutSubviews will work.
My Original Answer (for posterity/reference):
This uses the NSString method sizeWithFont:constrainedToSize:lineBreakMode: to calculate the frame height needed to fit a string, then sets the origin and width.
Resize the frame for the label using the text you want to insert. That way you can accommodate any number of lines.
CGSize maximumSize = CGSizeMake(300, 9999);
NSString *dateString = #"The date today is January 1st, 1999";
UIFont *dateFont = [UIFont fontWithName:#"Helvetica" size:14];
CGSize dateStringSize = [dateString sizeWithFont:dateFont
constrainedToSize:maximumSize
lineBreakMode:self.dateLabel.lineBreakMode];
CGRect dateFrame = CGRectMake(10, 10, 300, dateStringSize.height);
self.dateLabel.frame = dateFrame;
Set the new text:
myLabel.text = #"Some Text"
Set the maximum number of lines to 0 (automatic):
myLabel.numberOfLines = 0
Set the frame of the label to the maximum size:
myLabel.frame = CGRectMake(20,20,200,800)
Call sizeToFit to reduce the frame size so the contents just fit:
[myLabel sizeToFit]
The labels frame is now just high and wide enough to fit your text. The top left should be unchanged. I have tested this only with the top left-aligned text. For other alignments, you might have to modify the frame afterward.
Also, my label has word wrapping enabled.
Refering to the extension solution:
for(int i=1; i< newLinesToPad; i++)
self.text = [self.text stringByAppendingString:#"\n"];
should be replaced by
for(int i=0; i<newLinesToPad; i++)
self.text = [self.text stringByAppendingString:#"\n "];
Additional space is needed in every added newline, because iPhone UILabels' trailing carriage returns seems to be ignored :(
Similarly, alignBottom should be updated too with a #" \n#%" in place of "\n#%" (for cycle initialization must be replaced by "for(int i=0..." too).
The following extension works for me:
// -- file: UILabel+VerticalAlign.h
#pragma mark VerticalAlign
#interface UILabel (VerticalAlign)
- (void)alignTop;
- (void)alignBottom;
#end
// -- file: UILabel+VerticalAlign.m
#implementation UILabel (VerticalAlign)
- (void)alignTop {
CGSize fontSize = [self.text sizeWithFont:self.font];
double finalHeight = fontSize.height * self.numberOfLines;
double finalWidth = self.frame.size.width; //expected width of label
CGSize theStringSize = [self.text sizeWithFont:self.font constrainedToSize:CGSizeMake(finalWidth, finalHeight) lineBreakMode:self.lineBreakMode];
int newLinesToPad = (finalHeight - theStringSize.height) / fontSize.height;
for(int i=0; i<newLinesToPad; i++)
self.text = [self.text stringByAppendingString:#"\n "];
}
- (void)alignBottom {
CGSize fontSize = [self.text sizeWithFont:self.font];
double finalHeight = fontSize.height * self.numberOfLines;
double finalWidth = self.frame.size.width; //expected width of label
CGSize theStringSize = [self.text sizeWithFont:self.font constrainedToSize:CGSizeMake(finalWidth, finalHeight) lineBreakMode:self.lineBreakMode];
int newLinesToPad = (finalHeight - theStringSize.height) / fontSize.height;
for(int i=0; i<newLinesToPad; i++)
self.text = [NSString stringWithFormat:#" \n%#",self.text];
}
#end
Then call [yourLabel alignTop]; or [yourLabel alignBottom]; after each yourLabel text assignment.
Just in case it's of any help to anyone, I had the same problem but was able to solve the issue simply by switching from using UILabel to using UITextView. I appreciate this isn't for everyone because the functionality is a bit different.
If you do switch to using UITextView, you can turn off all the Scroll View properties as well as User Interaction Enabled... This will force it to act more like a label.
No muss, no fuss
#interface MFTopAlignedLabel : UILabel
#end
#implementation MFTopAlignedLabel
- (void)drawTextInRect:(CGRect) rect
{
NSAttributedString *attributedText = [[NSAttributedString alloc] initWithString:self.text attributes:#{NSFontAttributeName:self.font}];
rect.size.height = [attributedText boundingRectWithSize:rect.size
options:NSStringDrawingUsesLineFragmentOrigin
context:nil].size.height;
if (self.numberOfLines != 0) {
rect.size.height = MIN(rect.size.height, self.numberOfLines * self.font.lineHeight);
}
[super drawTextInRect:rect];
}
#end
No muss, no Objective-c, no fuss but Swift 3:
class VerticalTopAlignLabel: UILabel {
override func drawText(in rect:CGRect) {
guard let labelText = text else { return super.drawText(in: rect) }
let attributedText = NSAttributedString(string: labelText, attributes: [NSFontAttributeName: font])
var newRect = rect
newRect.size.height = attributedText.boundingRect(with: rect.size, options: .usesLineFragmentOrigin, context: nil).size.height
if numberOfLines != 0 {
newRect.size.height = min(newRect.size.height, CGFloat(numberOfLines) * font.lineHeight)
}
super.drawText(in: newRect)
}
}
Swift 4.2
class VerticalTopAlignLabel: UILabel {
override func drawText(in rect:CGRect) {
guard let labelText = text else { return super.drawText(in: rect) }
let attributedText = NSAttributedString(string: labelText, attributes: [NSAttributedString.Key.font: font])
var newRect = rect
newRect.size.height = attributedText.boundingRect(with: rect.size, options: .usesLineFragmentOrigin, context: nil).size.height
if numberOfLines != 0 {
newRect.size.height = min(newRect.size.height, CGFloat(numberOfLines) * font.lineHeight)
}
super.drawText(in: newRect)
}
}
Easiest approach using Storyboard:
Embed Label in a StackView and set the following two attributes of StackView in the Attribute Inspector:
1- Axis to Horizontal,
2- Alignment to Top
Like the answer above, but it wasn't quite right, or easy to slap into code so I cleaned it up a bit. Add this extension either to it's own .h and .m file or just paste right above the implementation you intend to use it:
#pragma mark VerticalAlign
#interface UILabel (VerticalAlign)
- (void)alignTop;
- (void)alignBottom;
#end
#implementation UILabel (VerticalAlign)
- (void)alignTop
{
CGSize fontSize = [self.text sizeWithFont:self.font];
double finalHeight = fontSize.height * self.numberOfLines;
double finalWidth = self.frame.size.width; //expected width of label
CGSize theStringSize = [self.text sizeWithFont:self.font constrainedToSize:CGSizeMake(finalWidth, finalHeight) lineBreakMode:self.lineBreakMode];
int newLinesToPad = (finalHeight - theStringSize.height) / fontSize.height;
for(int i=0; i<= newLinesToPad; i++)
{
self.text = [self.text stringByAppendingString:#" \n"];
}
}
- (void)alignBottom
{
CGSize fontSize = [self.text sizeWithFont:self.font];
double finalHeight = fontSize.height * self.numberOfLines;
double finalWidth = self.frame.size.width; //expected width of label
CGSize theStringSize = [self.text sizeWithFont:self.font constrainedToSize:CGSizeMake(finalWidth, finalHeight) lineBreakMode:self.lineBreakMode];
int newLinesToPad = (finalHeight - theStringSize.height) / fontSize.height;
for(int i=0; i< newLinesToPad; i++)
{
self.text = [NSString stringWithFormat:#" \n%#",self.text];
}
}
#end
And then to use, put your text into the label, and then call the appropriate method to align it:
[myLabel alignTop];
or
[myLabel alignBottom];
An even quicker (and dirtier) way to accomplish this is by setting the UILabel's line break mode to "Clip" and adding a fixed amount of newlines.
myLabel.lineBreakMode = UILineBreakModeClip;
myLabel.text = [displayString stringByAppendingString:"\n\n\n\n"];
This solution won't work for everyone -- in particular, if you still want to show "..." at the end of your string if it exceeds the number of lines you're showing, you'll need to use one of the longer bits of code -- but for a lot of cases this'll get you what you need.
Instead of UILabel you may use UITextField which has vertical alignment option:
textField.contentVerticalAlignment = UIControlContentVerticalAlignmentCenter;
textField.userInteractionEnabled = NO; // Don't allow interaction
I've struggled with this one for a long time and I wanted to share my solution.
This will give you a UILabel that will autoshrink text down to 0.5 scales and vertically center the text. These options are also available in Storyboard/IB.
[labelObject setMinimumScaleFactor:0.5];
[labelObject setBaselineAdjustment:UIBaselineAdjustmentAlignCenters];
Create a new class
LabelTopAlign
.h file
#import <UIKit/UIKit.h>
#interface KwLabelTopAlign : UILabel {
}
#end
.m file
#import "KwLabelTopAlign.h"
#implementation KwLabelTopAlign
- (void)drawTextInRect:(CGRect)rect {
int lineHeight = [#"IglL" sizeWithFont:self.font constrainedToSize:CGSizeMake(rect.size.width, 9999.0f)].height;
if(rect.size.height >= lineHeight) {
int textHeight = [self.text sizeWithFont:self.font constrainedToSize:CGSizeMake(rect.size.width, rect.size.height)].height;
int yMax = textHeight;
if (self.numberOfLines > 0) {
yMax = MIN(lineHeight*self.numberOfLines, yMax);
}
[super drawTextInRect:CGRectMake(rect.origin.x, rect.origin.y, rect.size.width, yMax)];
}
}
#end
Edit
Here's a simpler implementation that does the same:
#import "KwLabelTopAlign.h"
#implementation KwLabelTopAlign
- (void)drawTextInRect:(CGRect)rect
{
CGFloat height = [self.text sizeWithFont:self.font
constrainedToSize:rect.size
lineBreakMode:self.lineBreakMode].height;
if (self.numberOfLines != 0) {
height = MIN(height, self.font.lineHeight * self.numberOfLines);
}
rect.size.height = MIN(rect.size.height, height);
[super drawTextInRect:rect];
}
#end
In Interface Builder
Set UILabel to size of biggest possible Text
Set Lines to '0' in Attributes Inspector
In your code
Set the text of the label
Call sizeToFit on your label
Code Snippet:
self.myLabel.text = #"Short Title";
[self.myLabel sizeToFit];
For Adaptive UI(iOS8 or after) , Vertical Alignment of UILabel is to be set from StoryBoard by Changing the properties
noOfLines=0` and
Constraints
Adjusting UILabel LefMargin, RightMargin and Top Margin Constraints.
Change Content Compression Resistance Priority For Vertical=1000` So that Vertical>Horizontal .
Edited:
noOfLines=0
and the following constraints are enough to achieve the desired results.
Create a subclass of UILabel. Works like a charm:
// TopLeftLabel.h
#import <Foundation/Foundation.h>
#interface TopLeftLabel : UILabel
{
}
#end
// TopLeftLabel.m
#import "TopLeftLabel.h"
#implementation TopLeftLabel
- (id)initWithFrame:(CGRect)frame
{
return [super initWithFrame:frame];
}
- (CGRect)textRectForBounds:(CGRect)bounds limitedToNumberOfLines:(NSInteger)numberOfLines
{
CGRect textRect = [super textRectForBounds:bounds limitedToNumberOfLines:numberOfLines];
textRect.origin.y = bounds.origin.y;
return textRect;
}
-(void)drawTextInRect:(CGRect)requestedRect
{
CGRect actualRect = [self textRectForBounds:requestedRect limitedToNumberOfLines:self.numberOfLines];
[super drawTextInRect:actualRect];
}
#end
As discussed here.
What I did in my app was to set the UILabel's line property to 0 as well as to create a bottom constraint of the UILabel and make sure it is being set to >= 0 as shown in the image below.
Use textRect(forBounds:limitedToNumberOfLines:).
class TopAlignedLabel: UILabel {
override func drawText(in rect: CGRect) {
let textRect = super.textRect(forBounds: bounds, limitedToNumberOfLines: numberOfLines)
super.drawText(in: textRect)
}
}
I wrote a util function to achieve this purpose. You can take a look:
// adjust the height of a multi-line label to make it align vertical with top
+ (void) alignLabelWithTop:(UILabel *)label {
CGSize maxSize = CGSizeMake(label.frame.size.width, 999);
label.adjustsFontSizeToFitWidth = NO;
// get actual height
CGSize actualSize = [label.text sizeWithFont:label.font constrainedToSize:maxSize lineBreakMode:label.lineBreakMode];
CGRect rect = label.frame;
rect.size.height = actualSize.height;
label.frame = rect;
}
.How to use? (If lblHello is created by Interface builder, so I skip some UILabel attributes detail)
lblHello.text = #"Hello World! Hello World! Hello World! Hello World! Hello World! Hello World! Hello World! Hello World!";
lblHello.numberOfLines = 5;
[Utils alignLabelWithTop:lblHello];
I also wrote it on my blog as an article:
http://fstoke.me/blog/?p=2819
I took a while to read the code, as well as the code in the introduced page, and found that they all try to modify the frame size of label, so that the default center vertical alignment would not appear.
However, in some cases we do want the label to occupy all those spaces, even if the label does have so much text (e.g. multiple rows with equal height).
Here, I used an alternative way to solve it, by simply pad newlines to the end of label (pls note that I actually inherited the UILabel, but it is not necessary):
CGSize fontSize = [self.text sizeWithFont:self.font];
finalHeight = fontSize.height * self.numberOfLines;
finalWidth = size.width; //expected width of label
CGSize theStringSize = [self.text sizeWithFont:self.font constrainedToSize:CGSizeMake(finalWidth, finalHeight) lineBreakMode:self.lineBreakMode];
int newLinesToPad = (finalHeight - theStringSize.height) / fontSize.height;
for(int i = 0; i < newLinesToPad; i++)
{
self.text = [self.text stringByAppendingString:#"\n "];
}
I took the suggestions here and created a view which can wrap a UILabel and will size it and set the number of lines so that it is top aligned. Simply put a UILabel as a subview:
#interface TopAlignedLabelContainer : UIView
{
}
#end
#implementation TopAlignedLabelContainer
- (void)layoutSubviews
{
CGRect bounds = self.bounds;
for (UILabel *label in [self subviews])
{
if ([label isKindOfClass:[UILabel class]])
{
CGSize fontSize = [label.text sizeWithFont:label.font];
CGSize textSize = [label.text sizeWithFont:label.font
constrainedToSize:bounds.size
lineBreakMode:label.lineBreakMode];
label.numberOfLines = textSize.height / fontSize.height;
label.frame = CGRectMake(0, 0, textSize.width,
fontSize.height * label.numberOfLines);
}
}
}
#end
You can use TTTAttributedLabel, it supports vertical alignment.
#property (nonatomic) TTTAttributedLabel* label;
<...>
//view's or viewController's init method
_label.verticalAlignment = TTTAttributedLabelVerticalAlignmentTop;
I've found the answers on this question are now a bit out-of-date, so adding this for the auto layout fans out there.
Auto layout makes this issue pretty trivial. Assuming we're adding the label to UIView *view, the following code will accomplish this:
UILabel *label = [[UILabel alloc] initWithFrame:CGRectZero];
[label setText:#"Some text here"];
[label setTranslatesAutoresizingMaskIntoConstraints:NO];
[view addSubview:label];
[view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"H:|[label]|" options:0 metrics:nil views:#{#"label": label}]];
[view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"V:|[label]" options:0 metrics:nil views:#{#"label": label}]];
The label's height will be calculated automatically (using it's intrinsicContentSize) and the label will be positioned edge-to-edge horizontally, at the top of the view.
I've used a lot of the methods above, and just want to add a quick-and-dirty approach I've used:
myLabel.text = [NSString stringWithFormat:#"%#\n\n\n\n\n\n\n\n\n",#"My label text string"];
Make sure the number of newlines in the string will cause any text to fill the available vertical space, and set the UILabel to truncate any overflowing text.
Because sometimes good enough is good enough.
I wanted to have a label which was able to have multi-lines, a minimum font size, and centred both horizontally and vertically in it's parent view. I added my label programmatically to my view:
- (void) customInit {
// Setup label
self.label = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, self.frame.size.width, self.frame.size.height)];
self.label.numberOfLines = 0;
self.label.lineBreakMode = UILineBreakModeWordWrap;
self.label.textAlignment = UITextAlignmentCenter;
// Add the label as a subview
self.autoresizesSubviews = YES;
[self addSubview:self.label];
}
And then when I wanted to change the text of my label...
- (void) updateDisplay:(NSString *)text {
if (![text isEqualToString:self.label.text]) {
// Calculate the font size to use (save to label's font)
CGSize textConstrainedSize = CGSizeMake(self.frame.size.width, INT_MAX);
self.label.font = [UIFont systemFontOfSize:TICKER_FONT_SIZE];
CGSize textSize = [text sizeWithFont:self.label.font constrainedToSize:textConstrainedSize];
while (textSize.height > self.frame.size.height && self.label.font.pointSize > TICKER_MINIMUM_FONT_SIZE) {
self.label.font = [UIFont systemFontOfSize:self.label.font.pointSize-1];
textSize = [ticker.blurb sizeWithFont:self.label.font constrainedToSize:textConstrainedSize];
}
// In cases where the frame is still too large (when we're exceeding minimum font size),
// use the views size
if (textSize.height > self.frame.size.height) {
textSize = [text sizeWithFont:self.label.font constrainedToSize:self.frame.size];
}
// Draw
self.label.frame = CGRectMake(0, self.frame.size.height/2 - textSize.height/2, self.frame.size.width, textSize.height);
self.label.text = text;
}
[self setNeedsDisplay];
}
Hope that helps someone!
FXLabel (on github) does this out of the box by setting label.contentMode to UIViewContentModeTop. This component is not made by me, but it is a component I use frequently and has tons of features, and seems to work well.
for anyone reading this because the text inside your label is not vertically centered, keep in mind that some font types are not designed equally. for example, if you create a label with zapfino size 16, you will see the text is not perfectly centered vertically.
however, working with helvetica will vertically center your text.
Subclass UILabel and constrain the drawing rectangle, like this:
- (void)drawTextInRect:(CGRect)rect
{
CGSize sizeThatFits = [self sizeThatFits:rect.size];
rect.size.height = MIN(rect.size.height, sizeThatFits.height);
[super drawTextInRect:rect];
}
I tried the solution involving newline padding and ran into incorrect behavior in some cases. In my experience, it's easier to constrain the drawing rect as above than mess with numberOfLines.
P.S. You can imagine easily supporting UIViewContentMode this way:
- (void)drawTextInRect:(CGRect)rect
{
CGSize sizeThatFits = [self sizeThatFits:rect.size];
if (self.contentMode == UIViewContentModeTop) {
rect.size.height = MIN(rect.size.height, sizeThatFits.height);
}
else if (self.contentMode == UIViewContentModeBottom) {
rect.origin.y = MAX(0, rect.size.height - sizeThatFits.height);
rect.size.height = MIN(rect.size.height, sizeThatFits.height);
}
[super drawTextInRect:rect];
}
If you are using autolayout, set the vertical contentHuggingPriority to 1000, either in code or IB. In IB you may then have to remove a height constraint by setting it's priority to 1 and then deleting it.
As long as you are not doing any complex task, you can use UITextView instead of UILabels.
Disable the scroll.
If you want the text to be displayed completely just user sizeToFit and sizeThatFits: methods
In swift,
let myLabel : UILabel!
To make your text of your Label to fit to screen and it's on the top
myLabel.sizeToFit()
To make your font of label to fit to the width of screen or specific width size.
myLabel.adjustsFontSizeToFitWidth = YES
and some textAlignment for label :
myLabel.textAlignment = .center
myLabel.textAlignment = .left
myLabel.textAlignment = .right
myLabel.textAlignment = .Natural
myLabel.textAlignment = .Justified
This is an old solution, use the autolayout on iOS >= 6
My solution:
Split lines by myself (ignoring label wrap settings)
Draw lines by myself (ignoring label alignment)
#interface UITopAlignedLabel : UILabel
#end
#implementation UITopAlignedLabel
#pragma mark Instance methods
- (NSArray*)splitTextToLines:(NSUInteger)maxLines {
float width = self.frame.size.width;
NSArray* words = [self.text componentsSeparatedByCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
NSMutableArray* lines = [NSMutableArray array];
NSMutableString* buffer = [NSMutableString string];
NSMutableString* currentLine = [NSMutableString string];
for (NSString* word in words) {
if ([buffer length] > 0) {
[buffer appendString:#" "];
}
[buffer appendString:word];
if (maxLines > 0 && [lines count] == maxLines - 1) {
[currentLine setString:buffer];
continue;
}
float bufferWidth = [buffer sizeWithFont:self.font].width;
if (bufferWidth < width) {
[currentLine setString:buffer];
}
else {
[lines addObject:[NSString stringWithString:currentLine]];
[buffer setString:word];
[currentLine setString:buffer];
}
}
if ([currentLine length] > 0) {
[lines addObject:[NSString stringWithString:currentLine]];
}
return lines;
}
- (void)drawRect:(CGRect)rect {
if ([self.text length] == 0) {
return;
}
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetFillColorWithColor(context, self.textColor.CGColor);
CGContextSetShadowWithColor(context, self.shadowOffset, 0.0f, self.shadowColor.CGColor);
NSArray* lines = [self splitTextToLines:self.numberOfLines];
NSUInteger numLines = [lines count];
CGSize size = self.frame.size;
CGPoint origin = CGPointMake(0.0f, 0.0f);
for (NSUInteger i = 0; i < numLines; i++) {
NSString* line = [lines objectAtIndex:i];
if (i == numLines - 1) {
[line drawAtPoint:origin forWidth:size.width withFont:self.font lineBreakMode:UILineBreakModeTailTruncation];
}
else {
[line drawAtPoint:origin forWidth:size.width withFont:self.font lineBreakMode:UILineBreakModeClip];
}
origin.y += self.font.lineHeight;
if (origin.y >= size.height) {
return;
}
}
}
#end

How to change size and font of custom NSTextField?

I followed answer here:
https://stackoverflow.com/a/3233802/3850487
I was able to use #Dave code and it works great.
The only thing is I cannot seem to find a way to change font or size of my label.
[self.rssLabel setText:fullString];
[self.rssLabel setSpeed:0.03f];
[[self rssLabel] setFont:[NSFont boldSystemFontOfSize:100]];//NOT WORKING
Nothing happens at all , it's like it is not being affected.
The closest I got was when I added some code to - (void)drawRect:(NSRect)dirtyRect
- (void)drawRect:(NSRect)dirtyRect {
// Drawing code here.
[[NSColor grayColor] set];//changed the background of the view
NSRectFill(dirtyRect); //not text color
...
}
I tried to contact dave, but I cannot comment yet, please advise.
That's right you need to do the change in drawRect:(NSRect)dirtyRect.
Example:
- (void)drawRect:(NSRect)dirtyRect {
// Drawing code here.
NSFont *font = [NSFont fontWithName:#"Courier" size: 15.0f];
//add more custom stuff, then assign attributes
NSDictionary *attributes = #{ NSFontAttributeName: font};
if (point.x + stringWidth < 0) {
point.x += dirtyRect.size.width;
}
[text drawAtPoint:point withAttributes:attributes];//assign!
if (point.x < 0) {
NSPoint otherPoint = point;
otherPoint.x += dirtyRect.size.width;
[text drawAtPoint:otherPoint withAttributes:attributes];//assign!
}
}

View-Based NSTableView

I have been beating my head against the wall trying to come up with an understanding of tableView:heightOfRow: and I guess I need help. I want to do dynamic row heights for a textView inside the row, and cannot seem to get a handle on the approach. I've read everything I can find, which really isn't much. I can get the rows to size like I want using this method, but only if the table is resized. Rows that are not in view won't be sized right until they are visible and the table is resized.
I've added the tableView:didAddRowView:forRow method and using the same basic idea it ends up squishing the row size to a single line. Doesn't work the same as tableView:heightOfRow: at all, even though it's the same code. I'm guessing that the tableView:didAddRowView:forRow method setting the textView bounds is somehow getting scaled.
Here's my (hopefully relevant) code:
- (CGFloat)tableView:(NSTableView *)tv heightOfRow:(NSInteger)row {
if (tv == dataTableView) {
NSInteger valueCol = [tv columnWithIdentifier:#"value"];
NSTableCellView *valueView = [tv viewAtColumn:valueCol row:row makeIfNecessary:NO];
if (valueView) {
// Working on the interesting column and this row is visible
NSRect bounds = [[valueView textField] bounds];
id value = [[valueView textField] stringValue];
NSFont *fieldFont = [[valueView textField] font];
CGFloat adjustedHeight = [value heightForWidth:bounds.size.width font:fieldFont];
CGFloat rowHeight = [tv rowHeight];
if (adjustedHeight <= rowHeight) adjustedHeight = rowHeight;
return adjustedHeight;
}
}
return [tv rowHeight];
}
- (void)tableView:(NSTableView *)tv didAddRowView:(NSTableRowView *)rowView forRow:(NSInteger)row {
if (tv == dataTableView) {
NSInteger valueCol = [tv columnWithIdentifier:#"value"];
NSTableCellView *colView = [rowView viewAtColumn:valueCol];
NSRect textFieldViewBounds = [[colView textField] bounds];
NSTextField *colTextField = [colView textField];
NSFont *colFont = [colTextField font];
id value = [colTextField stringValue];
CGFloat newHeight = [value heightForWidth:textFieldViewBounds.size.width font:colFont];
NSSize colViewSize = colView.bounds.size;
colViewSize.height = newHeight;
textFieldViewBounds.size.height = newHeight;
[colTextField setBounds:textFieldViewBounds];
}
}
UPDATE: new code is working better, but still has glitches on initial load and sometimes on scroll:
- (CGFloat)tableView:(NSTableView *)tv heightOfRow:(NSInteger)row {
if (tv == dataTableView) {
NSInteger valueCol = [tv columnWithIdentifier:#"value"];
NSTableCellView *valueView = [tv viewAtColumn:valueCol row:row makeIfNecessary:NO];
if (valueView) {
// Working on the interesting column
NSRect bounds = [[valueView textField] bounds];
id value = [[valueView textField] stringValue];
NSFont *fieldFont = [[valueView textField] font];
CGFloat adjustedHeight = [value heightForWidth:bounds.size.width font:fieldFont];
CGFloat rowHeight = [tv rowHeight];
if (adjustedHeight <= rowHeight) adjustedHeight = rowHeight;
return adjustedHeight;
}
}
return [tv rowHeight];
}
- (void) tableView:(NSTableView *)tv didAddRowView:(NSTableRowView *)rowView forRow:(NSInteger)row {
if (tv == dataTableView) {
[dataTableView noteHeightOfRowsWithIndexesChanged:[NSIndexSet indexSetWithIndexesInRange:NSMakeRange(row, 1)]];
}
}
From your code, I'm guessing you want row height to change based on a the number of lines in a textfield cell, right? So the height should change if you resize a column or the table, or if you enter new text...?
IMO you don't need to do anything in -tableView:didAddRowViewForRow: It's too late for that and the row view should already have it's final height. Trying to modify view frame there may cause exceptions of bugs. Since your text field is in a NSTableCellView (assuming appropriate layout constraints, the default ones should be ok), it should display as intended given your design in IB and the row height returned by -tableView:heigthOfRow:
-tableView:heigthOfRow: is indeed the method where you need to determine row height. But you need to return an appropriate value for all rows for which to method is called or else rows won't display at the right height when they enter the visible rect during scrolling. So I would choose YES for the makeIfNecessary: argument of the viewAtColumn method.
Then you need to have the table update the row height when necessary (resizing a column, the view, maybe entering new text...). This could be done for instance in -tableViewColumnDidResize (using the userinfo dictionary to get the resized column) or when the text field is edited.
There, you need to call -noteHeightOfRowsWithIndexesChanged: on the table view. If the column is resized, you call it for all rows and the -tableView:heigthOfRow: will return all the heights. If the text field is edited, you may want to call it only for its row (but even calling the method for all rows should do it).
I hope it helped.

How to NSTableView cell add padding to cell?

I've got an NSTableView which stretches from edge to edge on my window, but the data in the cells on the edge of the table really need some padding. The window doesn't look good if I leave a gutter on the edges, so I'd like to try to add some padding inside some of the cells so the data isn't right up against the edge.
I can't find anything in Interface Builder or in the code documentation about adding padding or insets to the cells.
Any suggestions?
You can subclass NSTextFieldCell and override the drawInteriorWithFrame:inView: method to custom draw the string.
- (void)drawInteriorWithFrame:(NSRect)cellFrame inView:(NSView *)controlView
{
NSRect titleRect = [self titleRectForBounds:cellFrame];
NSAttributedString *aTitle = [self attributedStringValue];
if ([aTitle length] > 0) {
[aTitle drawInRect:titleRect];
}
}
where titleRectForBounds: adds some space
- (NSRect)titleRectForBounds:(NSRect)bounds
{
NSRect titleRect = bounds;
titleRect.origin.x += 5;
titleRect.origin.y += 5;
NSAttributedString *title = [self attributedStringValue];
if (title) {
titleRect.size = [title size];
} else {
titleRect.size = NSZeroSize;
}
// We don't want the width of the string going outside the cell's bounds
CGFloat maxX = NSMaxX(bounds);
CGFloat maxWidth = maxX - NSMinX(titleRect);
if (maxWidth < 0) {
maxWidth = 0;
}
titleRect.size.width = MIN(NSWidth(titleRect), maxWidth);
return titleRect;
}
There's a more full example at http://comelearncocoawithme.blogspot.com/2011/09/custom-cells-in-nstableview-part-1.html
Easy way: add spaces before your text strings.
Better way: embed a view inside your cell and put all other UI objects inside that.
in your cellforrowAtIndexPath you need to implement this.
cell.textLabel.text = [NSString stringWithFormat:#" %#",sometext];
or else
take a label and setframe to it.Then add it to cell

How to stop NSScrollView from scrolling to top when horizontally resizing contained NSTextView?

I have a NSTextView that I want to display a horizontal scroll bar. Following some leads on the internet, I have most of it working, except that I am having problems with the vertical scroll bar.
What I have done is to find the width of the longest line (in pixels with the given font) and then I resize the NSTextContainer and the NSTextView appropriately. This way the horizontal scroll bar is representative of the width and scrolling to the right will scroll to the end of the longest line of text.
After doing this work, I noticed that my NSScrollView would show and hide the vertical scroll bar as I typed. I've 'fixed' this problem by setting autohidesScrollers to NO before the resize and then YES afterwards. However, there still remains another problem where, as I type, the vertical scrollbar thumb jumps to the top of the scrollbar and back to the proper place as I type. I type 'a' <space>, it jumps to the top, I press the <space> again and it jumps back to the proper location.
Any thoughts?
Here is some sample code:
- (CGFloat)longestLineOfText
{
CGFloat longestLineOfText = 0.0;
NSRange lineRange;
NSString* theScriptText = [myTextView string];
NSDictionary* attributesDict = [NSDictionary dictionaryWithObject:scriptFont forKey:NSFontAttributeName]; //scriptFont is a instance variable
NSUInteger characterIndex = 0;
NSUInteger stringLength = [theScriptText length];
while (characterIndex < stringLength) {
lineRange = [theScriptText lineRangeForRange:NSMakeRange(characterIndex, 0)];
NSSize lineSize = [[theScriptText substringWithRange:lineRange] sizeWithAttributes:attributesDict];
longestLineOfText = max(longestLineOfText, lineSize.width);
characterIndex = NSMaxRange(lineRange);
}
return longestLineOfText;
}
// ----------------------------------------------------------------------------
- (void)updateMyTextViewWidth
{
static CGFloat previousLongestLineOfText = 0.0;
CGFloat currentLongestLineOfText = [self longestLineOfText];
if (currentLongestLineOfText != previousLongestLineOfText) {
BOOL shouldStopBlinkingScrollBar = (previousLongestLineOfText < currentLongestLineOfText);
previousLongestLineOfText = currentLongestLineOfText;
NSTextContainer* container = [myTextView textContainer];
NSScrollView* scrollView = [myTextView enclosingScrollView];
if (shouldStopBlinkingScrollBar) {
[scrollView setAutohidesScrollers:NO];
}
CGFloat padding = [container lineFragmentPadding];
NSSize size = [container containerSize];
size.width = currentLongestLineOfText + padding * 2;
[container setContainerSize:size];
NSRect frame = [myTextView frame];
frame.size.width = currentLongestLineOfText + padding * 2;
[myTextView setFrame:frame];
if (shouldStopBlinkingScrollBar) {
[scrollView setAutohidesScrollers:YES];
}
}
}
Thanks to Ross Carter's post on the Cocoa-Dev list, I resolved this issue.
A. You have to set up your text view to support horizontal scrolling:
- (void)awakeFromNib {
[myTextView setHorizontallyResizable:YES];
NSSize tcSize = [[myTextView textContainer] containerSize];
tcSize.width = FLT_MAX;
[[myTextView textContainer] setContainerSize:tcSize];
[[myTextView textContainer] setWidthTracksTextView:NO];
}
B. You have to update the width of the text view as it changes, otherwise the horizontal scroll-bar doesn't update properly:
- (void)textDidChange:(NSNotification *)notification
{
[self updateTextViewWidth];
}
- (CGFloat)longestLineOfText
{
CGFloat longestLineOfText = 0.0;
NSLayoutManager* layoutManager = [myTextView layoutManager];
NSRange lineRange;
NSUInteger glyphIndex = 0;
NSUInteger glyphCount = [layoutManager numberOfGlyphs];
while (glyphIndex < glyphCount) {
NSRect lineRect = [layoutManager lineFragmentUsedRectForGlyphAtIndex:glyphIndex
effectiveRange:&lineRange
withoutAdditionalLayout:YES];
longestLineOfText = max(longestLineOfText, lineRect.size.width);
glyphIndex = NSMaxRange(lineRange);
}
return longestLineOfText;
}
// ----------------------------------------------------------------------------
- (void)updateTextViewWidth
{
static CGFloat previousLongestLineOfText = 0.0;
CGFloat currentLongestLineOfText = [self longestLineOfText];
if (currentLongestLineOfText != previousLongestLineOfText) {
previousLongestLineOfText = currentLongestLineOfText;
NSTextContainer* container = [myTextView textContainer];
CGFloat padding = [container lineFragmentPadding];
NSRect frame = [myTextView frame];
frame.size.width = currentLongestLineOfText + padding * 2;
[myTextView setFrame:frame];
}
}

Resources