UIWebView change line spacing for text in source
-
11-06-2021 - |
문제
I have a javascript method to pass in to stringByEvaluatingJavaScriptFromString: in a UIWebView subclass.
var head = document.getElementsByTagName('head')[0],
style = document.createElement('style'),
rules = document.createTextNode('* { line-height: 20px !important; }');
style.type = 'text/css';
if(style.styleSheet)
style.styleSheet.cssText = rules.nodeValue;
else style.appendChild(rules);
head.appendChild(style);
I've added it to the stringByEvaluatingJavaScriptFromString: method and as long as I specify a pixel value, the code works. If I use a variable like the code below, it doesn't do anything. What am I doing wrong?
I'm using the largerBool to tell me if the spacing needs to increase or decrease. Then I'm setting max and min, and using line height as the variable.
- (void)changeLineSpacingLarger:(BOOL)largerBool {
if (largerBool == YES) { // A+
lineHeight = (lineHeight < 100) ? lineHeight +10 : lineHeight;
}
else if (largerBool == NO) { // A-
lineHeight = (lineHeight > 20) ? lineHeight -10 : lineHeight;
}
NSString *jsString = [[NSString alloc] initWithFormat:@"var head = document.getElementsByTagName('head')[0], style = document.createElement('style'), rules = document.createTextNode('* { line-height: '%d%%'px !important; }'); style.type = 'text/css'; if(style.styleSheet) style.styleSheet.cssText = rules.nodeValue; else style.appendChild(rules); head.appendChild(style);", lineHeight];
[self stringByEvaluatingJavaScriptFromString:jsString];
}
I'm also using the didFinishLoading delegate method of UIWebView to save the current line spacing value.
- (void)updateLineSpacingValue {
NSString *jsString = [[NSString alloc] initWithFormat:@"var element = document.getElementsByTagName('h1')[0], style = window.getComputedStyle(element), lh = style.getPropertyValue('line-height'); return lh;", textFontSize];
NSString *stringValue = [self stringByEvaluatingJavaScriptFromString:jsString];
lineHeight = [stringValue intValue];
NSLog(@"Line Height: %i", lineHeight);
}
All I get is '0' in the Log.
Thanks in advance!
올바른 솔루션이 없습니다
다른 팁
First, line-height: '%d%%'px
should be line-height: '%d'px
. Otherwise, you will build something like line-height: '12%%'px
, which won't be parsed when the source is rendered.
Second, stringValue
will be something like "12px", so you cannot directly convert it to a number without removing "px".