- * Return a unique TextMetrics instance that can be bound directly to an element and reused. This reduces
- * the overhead of multiple calls to initialize the style properties on each measurement.
- * @param {String/HTMLElement} el The element, dom node or id that the instance will be bound to
- * @param {Number} fixedWidth (optional) If the text will be multiline, you have to set a fixed width
- * in order to accurately measure the text height
- * @return {Ext.util.TextMetrics.Instance} instance The new instance
- */
- createInstance : function(el, fixedWidth){
- return Ext.util.TextMetrics.Instance(el, fixedWidth);
- }
- };
-}();
-
-Ext.util.TextMetrics.Instance = function(bindTo, fixedWidth){
- var ml = new Ext.Element(document.createElement('div'));
- document.body.appendChild(ml.dom);
- ml.position('absolute');
- ml.setLeftTop(-1000, -1000);
- ml.hide();
-
- if(fixedWidth){
- ml.setWidth(fixedWidth);
- }
-
- var instance = {
- /**
- * Returns the size of the specified text based on the internal element's style and width properties
- * @param {String} text The text to measure
- * @return {Object} An object containing the text's size {width: (width), height: (height)}
- */
- getSize : function(text){
- ml.update(text);
- var s = ml.getSize();
- ml.update('');
- return s;
- },
-
- /**
- * Binds this TextMetrics instance to an element from which to copy existing CSS styles
- * that can affect the size of the rendered text
- * @param {String/HTMLElement} el The element, dom node or id
- */
- bind : function(el){
- ml.setStyle(
- Ext.fly(el).getStyles('font-size','font-style', 'font-weight', 'font-family','line-height', 'text-transform', 'letter-spacing')
- );
- },
-
- /**
- * Sets a fixed width on the internal measurement element. If the text will be multiline, you have
- * to set a fixed width in order to accurately measure the text height.
- * @param {Number} width The width to set on the element
- */
- setFixedWidth : function(width){
- ml.setWidth(width);
- },
-
- /**
- * Returns the measured width of the specified text
- * @param {String} text The text to measure
- * @return {Number} width The width in pixels
- */
- getWidth : function(text){
- ml.dom.style.width = 'auto';
- return this.getSize(text).width;
- },
+ * Destroy the TextMetrics instance created by {@link #measure}.
+ */
+ destroy: function(){
+ var me = this;
+ Ext.destroy(me.shared);
+ me.shared = null;
+ }
+ },
+
+ /**
+ * Creates new TextMetrics.
+ * @param {Mixed} bindTo The element to bind to.
+ * @param {Number} fixedWidth (optional) A fixed width to apply to the measuring element.
+ */
+ constructor: function(bindTo, fixedWidth){
+ var measure = this.measure = Ext.getBody().createChild({
+ cls: 'x-textmetrics'
+ });
+ this.el = Ext.get(bindTo);
+
+ measure.position('absolute');
+ measure.setLeftTop(-1000, -1000);
+ measure.hide();