我正在使用textarea弹性插件JQuery。 这是插件
(function(jQuery){
jQuery.fn.extend({
elastic: function() {
// We will create a div clone of the textarea
// by copying these attributes from the textarea to the div.
var mimics = [
'paddingTop',
'paddingRight',
'paddingBottom',
'paddingLeft',
'fontSize',
'lineHeight',
'fontFamily',
'width',
'fontWeight'];
return this.each( function() {
// Elastic only works on textareas
if ( this.type != 'textarea' ) {
return false;
}
var $textarea = jQuery(this),
$twin = jQuery('<div />').css({'position': 'absolute','display':'none','word-wrap':'break-word'}),
lineHeight = parseInt($textarea.css('line-height'),10) || parseInt($textarea.css('font-size'),'10'),
minheight = parseInt($textarea.css('height'),10) || lineHeight*3,
maxheight = parseInt($textarea.css('max-height'),10) || Number.MAX_VALUE,
goalheight = 0,
i = 0;
// Opera returns max-height of -1 if not set
if (maxheight < 0) { maxheight = Number.MAX_VALUE; }
// Append the twin to the DOM
// We are going to meassure the height of this, not the textarea.
$twin.appendTo($textarea.parent());
// Copy the essential styles (mimics) from the textarea to the twin
var i = mimics.length;
while(i--){
$twin.css(mimics[i].toString(),$textarea.css(mimics[i].toString()));
}
// Sets a given height and overflow state on the textarea
function setHeightAndOverflow(height, overflow){
curratedHeight = Math.floor(parseInt(height,10));
if($textarea.height() != curratedHeight){
$textarea.css({'height': curratedHeight + 'px','overflow':overflow});
}
}
// This function will update the height of the textarea if necessary
function update() {
// Get curated content from the textarea.
var textareaContent = $textarea.val().replace(/&/g,'&').replace(/ /g, ' ').replace(/<|>/g, '>').replace(/\n/g, '<br />');
var twinContent = $twin.html();
if(textareaContent+' ' != twinContent){
// Add an extra white space so new rows are added when you are at the end of a row.
$twin.html(textareaContent+' ');
// Change textarea height if twin plus the height of one line differs more than 3 pixel from textarea height
if(Math.abs($twin.height()+lineHeight/3 - $textarea.height()) > 3){
var goalheight = $twin.height()+lineHeight/3;
if(goalheight >= maxheight) {
setHeightAndOverflow(maxheight,'auto');
} else if(goalheight <= minheight) {
setHeightAndOverflow(minheight,'hidden');
} else {
setHeightAndOverflow(goalheight,'hidden');
}
}
}
}
// Hide scrollbars
$textarea.css({'overflow':'hidden'});
// Update textarea size on keyup
$textarea.keyup(function(){ update(); });
$textarea.focus(function(){ update(); });
// And this line is to catch the browser paste event
$textarea.live('input paste',function(e){ setTimeout( update, 250); });
// Run update once when elastic is initialized
update();
});
}
});
})(jQuery的);
如何从插件外部调用内部的更新功能?
答案 0 :(得分:3)
你看底部,它与keyup
和focus
事件绑定在一起:
$textarea.keyup(function(){ update(); });
$textarea.focus(function(){ update(); });
//this should be just $textarea.keyup(update); but that's a another question :)
您可以使用.triggerHandler()
为这些事件处理程序触发update()
功能,如下所示:
$('textarea').triggerHandler('keyup');