Dynamic CCLabelTTF font size in a specified rectangle - cocos2d - ios

Question

I am trying to create a text box that is specified by x, y, w, and h that can accept any string and adjust the font size to be as big as possible and still fit in the box. I have been trying several approaches, but it doesn't quite work. Here is my closest attempt:
+ (CCLabelTTF*) wrap_text :(id)not_self :(NSString *)label :(double)x :(double)y : (double)w :(double)h :(float) fontScale :(ccColor3B) color_front
{
CGSize size;
size = [[CCDirector sharedDirector] winSize];
int boxWidth = (w - x) * size.width;
int boxHeight = (h - y) * size.height;
double middleX = ((w-x)/2 + x);
double middleY = (1 - y);
middleX *= size.width;
middleY *= size.height;
//float font_size = size.height * h * fontScale;
int font_min = 5;
int font_max = 300;
int font_size = 5;
int font_size_final = -1;
int max_interations = 10;
int i;
NSString *hello = label;
UIFont *font = [UIFont fontWithName:GLOBAL_FONT size:font_size];
CGSize realSize = [hello sizeWithFont:font constrainedToSize:CGSizeMake(boxWidth, boxHeight) lineBreakMode:UILineBreakModeWordWrap ];
i = 0;
while ( true ) {
if(realSize.width < boxWidth && realSize.height < boxHeight){
//we found a good value, let's record it and try to go bigger
font_size_final = font_size;
font_min = font_size;
font_size = (font_max - font_min) / 2 + font_min;
}else if(realSize.width > boxWidth || realSize.height > boxHeight){
//too big, let's try a smaller font
font_max = font_size;
font_size = (font_max - font_min) / 2 + font_min;
}
if(font_max == font_min || i >= max_interations)
break;
font = [UIFont fontWithName:GLOBAL_FONT size:font_size];
realSize = [hello sizeWithFont:font constrainedToSize:CGSizeMake(boxWidth, boxHeight) lineBreakMode:UILineBreakModeWordWrap ];
i++;
}
G_label = [CCLabelTTF labelWithString:label fontName:GLOBAL_FONT fontSize:font_size dimensions:CGSizeMake(boxWidth, boxHeight) hAlignment:UITextAlignmentCenter];
G_label.color = color_front;
G_label.anchorPoint = ccp(0.5f, 1);
G_label.position = ccp( middleX , middleY );
[not_self addChild:G_label];
return G_label;
}
If I change boxWidth and boxHeight to 200, I get slightly better results, but I don't understand why and it's still not perfect. Can somebody tell me where I am going astray? Thanks.

Answer 1

*This answer is not mine: original answer is posted here - https://stackoverflow.com/a/9060833/1590951
above post gives credit to http://www.11pixel.com/blog/28/resize-multi-line-text-to-fit-uilabel-on-iphone/
I have only made minor edits it to make it easier to test in cocos2d (tested on ancient cc2d 1.1 so if you have a different version you'll have to make the relevant edits)
You could try the following as a test to see if this will work for your needs:
NSString *fontString = #"Arial";
CGSize targetSize = CGSizeMake(300.0f, 300.0f);
int i;
int fontSizeStep = 1;
int fontSizeMin = 6;
int fontSizeMax = 28;
CCSprite *bg = [CCSprite spriteWithFile:#"Default.png"];
[bg setScaleX: targetSize.width / bg.contentSize.width];
[bg setScaleY: targetSize.height / bg.contentSize.height];
[bg setPosition:ccp(s.width / 2.0f, s.height / 2.0f)];
[bg setColor:ccc3(128, 128, 128)];
[self addChild:bg];
NSString *sampleText = #"Now the way that the book winds up is this: Tom and me found the money that the robbers hid in the cave, and it made us rich. We got six thousand dollars apiece -­ all gold. It was an awful sight of money when it was piled up. Well, Judge Thatcher he took it and put it out at interest, and it fetched us a dollar a day apiece all the year round -­ more than a body could tell what to do with. The Widow Douglas she took me for her son, and allowed she would sivilize me; but it was rough living in the house all the time, considering how dismal regular and decent the widow was in all her ways; and so when I couldn't stand it no longer I lit out. I got into my old rags and my sugar-hogshead again, and was free and satisfied. But Tom Sawyer he hunted me up and said he was going to start a band of robbers, and I might join if I would go back to the widow and be respectable. So I went back.";
// NSString *sampleText = #"Once upon a midnight dreary, while I pondered, weak and weary, Over many a quaint and curious volume of forgotten lore— While I nodded, nearly napping, suddenly there came a tapping, As of some one gently rapping, rapping at my chamber door— \"'Tis some visitor,\" I muttered, \"tapping at my chamber door— Only this and nothing more.";
UIFont *font = [UIFont fontWithName:fontString size:fontSizeMax];
/* Time to calculate the needed font size.
This for loop starts at the largest font size, and decreases by two point sizes (i=i-2)
Until it either hits a size that will fit or hits the minimum size we want to allow (i > 10) */
for(i = fontSizeMax; i > fontSizeMin; i-=fontSizeStep)
{
// Set the new font size.
font = [font fontWithSize:i];
// You can log the size you're trying: NSLog(#"Trying size: %u", i);
/* This step is important: We make a constraint box
using only the fixed WIDTH of the UILabel. The height will
be checked later. */
CGSize constraintSize = CGSizeMake(targetSize.width, MAXFLOAT);
// This step checks how tall the label would be with the desired font.
CGSize labelSize = [sampleText sizeWithFont:font constrainedToSize:constraintSize lineBreakMode:CCLineBreakModeWordWrap];
/* Here is where you use the height requirement!
Set the value in the if statement to the height of your UILabel
If the label fits into your required height, it will break the loop
and use that font size. */
if(labelSize.height <= targetSize.height)
{
NSLog(#"Break on: %u", i);
break;
}
}
if(i == fontSizeMin)
{
NSLog(#"* possibly truncated text *");
}
// You can see what size the function is using by outputting: NSLog(#"Best size is: %u", i);
CCLabelTTF *label = [CCLabelTTF labelWithString:sampleText dimensions:targetSize alignment:CCTextAlignmentLeft fontName:fontString fontSize:i];
[label setPosition:ccp(s.width / 2.0f, s.height / 2.0f)];
[self addChild:label];