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/*
* Copyright 2000-2013 Vaadin Ltd.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package com.vaadin.client;
import com.google.gwt.core.client.JavaScriptObject;
import com.google.gwt.dom.client.Element;
public class ComputedStyle {
protected final JavaScriptObject computedStyle;
private final Element elem;
/**
* Gets this element's computed style object which can be used to gather
* information about the current state of the rendered node.
*
* Note that this method is expensive. Wherever possible, reuse the returned
* object.
*
* @param elem
* the element
* @return the computed style
*/
public ComputedStyle(Element elem) {
computedStyle = getComputedStyle(elem);
this.elem = elem;
}
private static native JavaScriptObject getComputedStyle(Element elem)
/*-{
if(elem.nodeType != 1) {
return {};
}
if($wnd.document.defaultView && $wnd.document.defaultView.getComputedStyle) {
return $wnd.document.defaultView.getComputedStyle(elem, null);
}
if(elem.currentStyle) {
return elem.currentStyle;
}
}-*/;
/**
*
* @param name
* name of the CSS property in camelCase
* @return the value of the property, normalized for across browsers (each
* browser returns pixel values whenever possible).
*/
public final native String getProperty(String name)
/*-{
var cs = [email protected]::computedStyle;
var elem = [email protected]::elem;
// Border values need to be checked separately. The width might have a
// meaningful value even if the border style is "none". In that case the
// value should be 0.
if(name.indexOf("border") > -1 && name.indexOf("Width") > -1) {
var borderStyleProp = name.substring(0,name.length-5) + "Style";
if(cs.getPropertyValue)
var borderStyle = cs.getPropertyValue(borderStyleProp);
else // IE
var borderStyle = cs[borderStyleProp];
if(borderStyle == "none")
return "0px";
}
if(cs.getPropertyValue) {
// Convert name to dashed format
name = name.replace(/([A-Z])/g, "-$1").toLowerCase();
var ret = cs.getPropertyValue(name);
} else {
var ret = cs[name];
var style = elem.style;
// From the awesome hack by Dean Edwards
// http://erik.eae.net/archives/2007/07/27/18.54.15/#comment-102291
// If we're not dealing with a regular pixel number
// but a number that has a weird ending, we need to convert it to pixels
if ( !/^\d+(px)?$/i.test( ret ) && /^\d/.test( ret ) ) {
// Remember the original values
var left = style.left, rsLeft = elem.runtimeStyle.left;
// Put in the new values to get a computed value out
elem.runtimeStyle.left = cs.left;
style.left = ret || 0;
ret = style.pixelLeft + "px";
// Revert the changed values
style.left = left;
elem.runtimeStyle.left = rsLeft;
}
}
// Normalize margin values. This is not totally valid, but in most cases
// it is what the user wants to know.
if(name.indexOf("margin") > -1 && ret == "auto") {
return "0px";
}
// Some browsers return undefined width and height values as "auto", so
// we need to retrieve those ourselves.
if (name == "width" && ret == "auto") {
ret = elem.clientWidth + "px";
} else if (name == "height" && ret == "auto") {
ret = elem.clientHeight + "px";
}
return ret;
}-*/;
public final int getIntProperty(String name) {
Integer parsed = parseInt(getProperty(name));
if (parsed != null) {
return parsed.intValue();
}
return 0;
}
/**
* Get current margin values from the DOM. The array order is the default
* CSS order: top, right, bottom, left.
*/
public final int[] getMargin() {
int[] margin = { 0, 0, 0, 0 };
margin[0] = getIntProperty("marginTop");
margin[1] = getIntProperty("marginRight");
margin[2] = getIntProperty("marginBottom");
margin[3] = getIntProperty("marginLeft");
return margin;
}
/**
* Get current padding values from the DOM. The array order is the default
* CSS order: top, right, bottom, left.
*/
public final int[] getPadding() {
int[] padding = { 0, 0, 0, 0 };
padding[0] = getIntProperty("paddingTop");
padding[1] = getIntProperty("paddingRight");
padding[2] = getIntProperty("paddingBottom");
padding[3] = getIntProperty("paddingLeft");
return padding;
}
/**
* Get current border values from the DOM. The array order is the default
* CSS order: top, right, bottom, left.
*/
public final int[] getBorder() {
int[] border = { 0, 0, 0, 0 };
border[0] = getIntProperty("borderTopWidth");
border[1] = getIntProperty("borderRightWidth");
border[2] = getIntProperty("borderBottomWidth");
border[3] = getIntProperty("borderLeftWidth");
return border;
}
/**
* Takes a String value e.g. "12px" and parses that to int 12.
*
* @param String
* a value starting with a number
* @return int the value from the string before any non-numeric characters.
* If the value cannot be parsed to a number, returns
* null.
*/
public static native Integer parseInt(final String value)
/*-{
var number = parseInt(value, 10);
if (isNaN(number))
return null;
else
// $entry not needed as function is not exported
return @java.lang.Integer::valueOf(I)(number);
}-*/;
}