com.google.gwt.safecss.shared.SafeStylesUtils Maven / Gradle / Ivy
/*
* Copyright 2011 Google Inc.
*
* 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.google.gwt.safecss.shared;
import com.google.gwt.core.shared.GWT;
import com.google.gwt.dom.client.Style.BorderStyle;
import com.google.gwt.dom.client.Style.Clear;
import com.google.gwt.dom.client.Style.Cursor;
import com.google.gwt.dom.client.Style.Display;
import com.google.gwt.dom.client.Style.Float;
import com.google.gwt.dom.client.Style.FontStyle;
import com.google.gwt.dom.client.Style.FontWeight;
import com.google.gwt.dom.client.Style.ListStyleType;
import com.google.gwt.dom.client.Style.OutlineStyle;
import com.google.gwt.dom.client.Style.Overflow;
import com.google.gwt.dom.client.Style.Position;
import com.google.gwt.dom.client.Style.TableLayout;
import com.google.gwt.dom.client.Style.TextAlign;
import com.google.gwt.dom.client.Style.TextDecoration;
import com.google.gwt.dom.client.Style.TextJustify;
import com.google.gwt.dom.client.Style.TextOverflow;
import com.google.gwt.dom.client.Style.TextTransform;
import com.google.gwt.dom.client.Style.Unit;
import com.google.gwt.dom.client.Style.VerticalAlign;
import com.google.gwt.dom.client.Style.Visibility;
import com.google.gwt.dom.client.Style.WhiteSpace;
import com.google.gwt.safehtml.shared.SafeUri;
/**
* Utility class containing static methods for creating {@link SafeStyles}.
*/
public final class SafeStylesUtils {
/**
* Standard implementation of this class.
*/
static class Impl {
public SafeStyles forOpacity(double value) {
return new SafeStylesString("opacity: " + value + ";");
}
}
/**
* Server implementation of this class.
*
*
* The server doesn't necessarily know the user agent of the client, so we
* combine the results of all other implementations.
*
*/
static class ImplServer extends Impl {
private ImplIE8 implIE = new ImplIE8();
@Override
public SafeStyles forOpacity(double value) {
SafeStylesBuilder sb = new SafeStylesBuilder();
sb.append(super.forOpacity(value));
sb.append(implIE.forOpacity(value));
return sb.toSafeStyles();
}
}
/**
* IE8 implementation of this class.
*/
static class ImplIE8 extends Impl {
@Override
public SafeStyles forOpacity(double value) {
// IE8 uses an alpha filter instead of opacity.
return new SafeStylesString("filter: alpha(opacity=" + (value * 100) + ");");
}
}
private static Impl impl;
/**
* Sets the background-image CSS property.
*
* @param uri the URI of the background image
* @return a {@link SafeStyles} instance
* @see #forTrustedBackgroundImage(String)
*/
public static SafeStyles forBackgroundImage(SafeUri uri) {
return fromTrustedNameAndValue("background-image", "url(\"" + uri.asString() + "\")");
}
/**
* Sets the border-style CSS property.
*/
public static SafeStyles forBorderStyle(BorderStyle value) {
return fromTrustedNameAndValue("border-style", value.getCssName());
}
/**
* Set the border-width css property.
*/
public static SafeStyles forBorderWidth(double value, Unit unit) {
return fromTrustedNameAndValue("border-width", value, unit);
}
/**
* Set the bottom css property.
*/
public static SafeStyles forBottom(double value, Unit unit) {
return fromTrustedNameAndValue("bottom", value, unit);
}
/**
* Sets the 'clear' CSS property.
*/
public static SafeStyles forClear(Clear value) {
return fromTrustedNameAndValue("clear", value.getCssName());
}
/**
* Sets the cursor CSS property.
*/
public static SafeStyles forCursor(Cursor value) {
return fromTrustedNameAndValue("cursor", value.getCssName());
}
/**
* Sets the display CSS property.
*/
public static SafeStyles forDisplay(Display value) {
return fromTrustedNameAndValue("display", value.getCssName());
}
/**
* Set the float css property.
*/
public static SafeStyles forFloat(Float value) {
return fromTrustedNameAndValue("float", value.getCssName());
}
/**
* Set the font-size css property.
*/
public static SafeStyles forFontSize(double value, Unit unit) {
return fromTrustedNameAndValue("font-size", value, unit);
}
/**
* Sets the font-style CSS property.
*/
public static SafeStyles forFontStyle(FontStyle value) {
return fromTrustedNameAndValue("font-style", value.getCssName());
}
/**
* Sets the font-weight CSS property.
*/
public static SafeStyles forFontWeight(FontWeight value) {
return fromTrustedNameAndValue("font-weight", value.getCssName());
}
/**
* Set the height css property.
*/
public static SafeStyles forHeight(double value, Unit unit) {
return fromTrustedNameAndValue("height", value, unit);
}
/**
* Set the left css property.
*/
public static SafeStyles forLeft(double value, Unit unit) {
return fromTrustedNameAndValue("left", value, unit);
}
/**
* Set the line-height css property.
*/
public static SafeStyles forLineHeight(double value, Unit unit) {
return fromTrustedNameAndValue("line-height", value, unit);
}
/**
* Sets the list-style-type CSS property.
*/
public static SafeStyles forListStyleType(ListStyleType value) {
return fromTrustedNameAndValue("list-style-type", value.getCssName());
}
/**
* Set the margin css property.
*/
public static SafeStyles forMargin(double value, Unit unit) {
return fromTrustedNameAndValue("margin", value, unit);
}
/**
* Set the margin-bottom css property.
*/
public static SafeStyles forMarginBottom(double value, Unit unit) {
return fromTrustedNameAndValue("margin-bottom", value, unit);
}
/**
* Set the margin-left css property.
*/
public static SafeStyles forMarginLeft(double value, Unit unit) {
return fromTrustedNameAndValue("margin-left", value, unit);
}
/**
* Set the margin-right css property.
*/
public static SafeStyles forMarginRight(double value, Unit unit) {
return fromTrustedNameAndValue("margin-right", value, unit);
}
/**
* Set the margin-top css property.
*/
public static SafeStyles forMarginTop(double value, Unit unit) {
return fromTrustedNameAndValue("margin-top", value, unit);
}
/**
* Set the opacity css property.
*/
public static SafeStyles forOpacity(double value) {
return impl().forOpacity(value);
}
/**
* Sets the outline-style CSS property.
*/
public static SafeStyles forOutlineStyle(OutlineStyle value) {
return fromTrustedNameAndValue("outline-style", value.getCssName());
}
/**
* Set the outline-width css property.
*/
public static SafeStyles forOutlineWidth(double value, Unit unit) {
return fromTrustedNameAndValue("outline-width", value, unit);
}
/**
* Sets the overflow CSS property.
*/
public static SafeStyles forOverflow(Overflow value) {
return fromTrustedNameAndValue("overflow", value.getCssName());
}
/**
* Sets the overflow-x CSS property.
*/
public static SafeStyles forOverflowX(Overflow value) {
return fromTrustedNameAndValue("overflow-x", value.getCssName());
}
/**
* Sets the overflow-y CSS property.
*/
public static SafeStyles forOverflowY(Overflow value) {
return fromTrustedNameAndValue("overflow-y", value.getCssName());
}
/**
* Set the padding css property.
*/
public static SafeStyles forPadding(double value, Unit unit) {
return fromTrustedNameAndValue("padding", value, unit);
}
/**
* Set the padding-bottom css property.
*/
public static SafeStyles forPaddingBottom(double value, Unit unit) {
return fromTrustedNameAndValue("padding-bottom", value, unit);
}
/**
* Set the padding-left css property.
*/
public static SafeStyles forPaddingLeft(double value, Unit unit) {
return fromTrustedNameAndValue("padding-left", value, unit);
}
/**
* Set the padding-right css property.
*/
public static SafeStyles forPaddingRight(double value, Unit unit) {
return fromTrustedNameAndValue("padding-right", value, unit);
}
/**
* Set the padding-top css property.
*/
public static SafeStyles forPaddingTop(double value, Unit unit) {
return fromTrustedNameAndValue("padding-top", value, unit);
}
/**
* Sets the position CSS property.
*/
public static SafeStyles forPosition(Position value) {
return fromTrustedNameAndValue("position", value.getCssName());
}
/**
* Set the right css property.
*/
public static SafeStyles forRight(double value, Unit unit) {
return fromTrustedNameAndValue("right", value, unit);
}
/**
* Set the table-layout CSS property.
*/
public static SafeStyles forTableLayout(TableLayout value) {
return fromTrustedNameAndValue("table-layout", value.getCssName());
}
/**
* Sets the 'text-align' CSS property.
*/
public static SafeStyles forTextAlign(TextAlign value) {
return fromTrustedNameAndValue("text-align", value.getCssName());
}
/**
* Sets the 'text-decoration' CSS property.
*/
public static SafeStyles forTextDecoration(TextDecoration value) {
return fromTrustedNameAndValue("text-decoration", value.getCssName());
}
/**
* Set the 'text-indent' CSS property.
*/
public static SafeStyles forTextIndent(double value, Unit unit) {
return fromTrustedNameAndValue("text-indent", value + unit.getType());
}
/**
* Set the 'text-justify' CSS3 property.
*/
public static SafeStyles forTextJustify(TextJustify value) {
return fromTrustedNameAndValue("text-justify", value.getCssName());
}
/**
* Set the 'text-overflow' CSS3 property.
*/
public static SafeStyles forTextOverflow(TextOverflow value) {
return fromTrustedNameAndValue("text-overflow", value.getCssName());
}
/**
* Set the 'text-transform' CSS property.
*/
public static SafeStyles forTextTransform(TextTransform value) {
return fromTrustedNameAndValue("text-transform", value.getCssName());
}
/**
* Set the top css property.
*/
public static SafeStyles forTop(double value, Unit unit) {
return fromTrustedNameAndValue("top", value, unit);
}
/**
*
* Returns a {@link SafeStyles} constructed from a trusted background color,
* i.e., without escaping the value. No checks are performed. The calling code
* should be carefully reviewed to ensure the argument will satisfy the
* {@link SafeStyles} contract when they are composed into the form:
* "<name>:<value>;".
*
*
* {@link SafeStyles} may never contain literal angle brackets. Otherwise, it
* could be unsafe to place a {@link SafeStyles} into a <style> tag
* (where it can't be HTML escaped). For example, if the {@link SafeStyles}
* containing "
* font: 'foo <style><script>evil</script>'" is
* used in a style sheet in a <style> tag, this could then break out of
* the style context into HTML.
*
*
* @param value the property value
* @return a {@link SafeStyles} instance
*/
public static SafeStyles forTrustedBackgroundColor(String value) {
return fromTrustedNameAndValue("background-color", value);
}
/**
*
* Returns a {@link SafeStyles} constructed from a trusted background image,
* i.e., without escaping the value. No checks are performed. The calling code
* should be carefully reviewed to ensure the argument will satisfy the
* {@link SafeStyles} contract when they are composed into the form:
* "<name>:<value>;".
*
*
* {@link SafeStyles} may never contain literal angle brackets. Otherwise, it
* could be unsafe to place a {@link SafeStyles} into a <style> tag
* (where it can't be HTML escaped). For example, if the {@link SafeStyles}
* containing "
* font: 'foo <style><script>evil</script>'" is
* used in a style sheet in a <style> tag, this could then break out of
* the style context into HTML.
*
*
* @param value the property value
* @return a {@link SafeStyles} instance
* @see #forBackgroundImage(SafeUri)
*/
public static SafeStyles forTrustedBackgroundImage(String value) {
return fromTrustedNameAndValue("background-image", value);
}
/**
*
* Returns a {@link SafeStyles} constructed from a trusted border color, i.e.,
* without escaping the value. No checks are performed. The calling code
* should be carefully reviewed to ensure the argument will satisfy the
* {@link SafeStyles} contract when they are composed into the form:
* "<name>:<value>;".
*
*
* {@link SafeStyles} may never contain literal angle brackets. Otherwise, it
* could be unsafe to place a {@link SafeStyles} into a <style> tag
* (where it can't be HTML escaped). For example, if the {@link SafeStyles}
* containing "
* font: 'foo <style><script>evil</script>'" is
* used in a style sheet in a <style> tag, this could then break out of
* the style context into HTML.
*
*
* @param value the property value
* @return a {@link SafeStyles} instance
*/
public static SafeStyles forTrustedBorderColor(String value) {
return fromTrustedNameAndValue("border-color", value);
}
/**
*
* Returns a {@link SafeStyles} constructed from a trusted font color, i.e.,
* without escaping the value. No checks are performed. The calling code
* should be carefully reviewed to ensure the argument will satisfy the
* {@link SafeStyles} contract when they are composed into the form:
* "<name>:<value>;".
*
*
* {@link SafeStyles} may never contain literal angle brackets. Otherwise, it
* could be unsafe to place a {@link SafeStyles} into a <style> tag
* (where it can't be HTML escaped). For example, if the {@link SafeStyles}
* containing "
* font: 'foo <style><script>evil</script>'" is
* used in a style sheet in a <style> tag, this could then break out of
* the style context into HTML.
*
*
* @param value the property value
* @return a {@link SafeStyles} instance
*/
public static SafeStyles forTrustedColor(String value) {
return fromTrustedNameAndValue("color", value);
}
/**
*
* Returns a {@link SafeStyles} constructed from a trusted outline color,
* i.e., without escaping the value. No checks are performed. The calling code
* should be carefully reviewed to ensure the argument will satisfy the
* {@link SafeStyles} contract when they are composed into the form:
* "<name>:<value>;".
*
*
* {@link SafeStyles} may never contain literal angle brackets. Otherwise, it
* could be unsafe to place a {@link SafeStyles} into a <style> tag
* (where it can't be HTML escaped). For example, if the {@link SafeStyles}
* containing "
* font: 'foo <style><script>evil</script>'" is
* used in a style sheet in a <style> tag, this could then break out of
* the style context into HTML.
*
*
* @param value the property value
* @return a {@link SafeStyles} instance
*/
public static SafeStyles forTrustedOutlineColor(String value) {
return fromTrustedNameAndValue("outline-color", value);
}
/**
* Sets the vertical-align CSS property.
*/
public static SafeStyles forVerticalAlign(double value, Unit unit) {
return fromTrustedNameAndValue("vertical-align", value, unit);
}
/**
* Sets the vertical-align CSS property.
*/
public static SafeStyles forVerticalAlign(VerticalAlign value) {
return fromTrustedNameAndValue("vertical-align", value.getCssName());
}
/**
* Sets the visibility CSS property.
*/
public static SafeStyles forVisibility(Visibility value) {
return fromTrustedNameAndValue("visibility", value.getCssName());
}
/**
* Set the 'white-space' CSS property.
*/
public static SafeStyles forWhiteSpace(WhiteSpace value) {
return fromTrustedNameAndValue("white-space", value.getCssName());
}
/**
* Set the width css property.
*/
public static SafeStyles forWidth(double value, Unit unit) {
return fromTrustedNameAndValue("width", value, unit);
}
/**
* Set the z-index css property.
*/
public static SafeStyles forZIndex(int value) {
return new SafeStylesString("z-index: " + value + ";");
}
/**
*
* Returns a {@link SafeStyles} constructed from a trusted name and a trusted
* value, i.e., without escaping the name and value. No checks are performed.
* The calling code should be carefully reviewed to ensure the argument will
* satisfy the {@link SafeStyles} contract when they are composed into the
* form: "<name>:<value>;".
*
*
* {@link SafeStyles} may never contain literal angle brackets. Otherwise, it
* could be unsafe to place a {@link SafeStyles} into a <style> tag
* (where it can't be HTML escaped). For example, if the {@link SafeStyles}
* containing "
* font: 'foo <style><script>evil</script>'" is
* used in a style sheet in a <style> tag, this could then break out of
* the style context into HTML.
*
*
*
* The name should be in hyphenated format, not camelCase format.
*
*
* @param name the property name
* @param value the value
* @param unit the units of the value
* @return a {@link SafeStyles} instance
*/
public static SafeStyles fromTrustedNameAndValue(String name, double value, Unit unit) {
SafeStylesHostedModeUtils.maybeCheckValidStyleName(name);
return new SafeStylesString(name + ":" + value + unit.getType() + ";");
}
/**
*
* Returns a {@link SafeStyles} constructed from a trusted name and a trusted
* value, i.e., without escaping the name and value. No checks are performed.
* The calling code should be carefully reviewed to ensure the argument will
* satisfy the {@link SafeStyles} contract when they are composed into the
* form: "<name>:<value>;".
*
*
* {@link SafeStyles} may never contain literal angle brackets. Otherwise, it
* could be unsafe to place a {@link SafeStyles} into a <style> tag
* (where it can't be HTML escaped). For example, if the {@link SafeStyles}
* containing "
* font: 'foo <style><script>evil</script>'" is
* used in a style sheet in a <style> tag, this could then break out of
* the style context into HTML.
*
*
*
* The name should be in hyphenated format, not camelCase format.
*
*
* @param name the property name
* @param value the property value
* @return a {@link SafeStyles} instance
*/
public static SafeStyles fromTrustedNameAndValue(String name, String value) {
SafeStylesHostedModeUtils.maybeCheckValidStyleName(name);
SafeStylesHostedModeUtils.maybeCheckValidStyleValue(value);
return fromTrustedString(name + ":" + value + ";");
}
/**
*
* Returns a {@link SafeStyles} constructed from a trusted string, i.e.,
* without escaping the string. No checks are performed. The calling code
* should be carefully reviewed to ensure the argument meets the
* {@link SafeStyles} contract.
*
*
* Generally, {@link SafeStyles} should be of the form
* {@code cssPropertyName:value;}, where neither the name nor the value
* contain malicious scripts.
*
*
* {@link SafeStyles} may never contain literal angle brackets. Otherwise, it
* could be unsafe to place a {@link SafeStyles} into a <style> tag
* (where it can't be HTML escaped). For example, if the {@link SafeStyles}
* containing "
* font: 'foo <style><script>evil</script>'" is
* used in a style sheet in a <style> tag, this could then break out of
* the style context into HTML.
*
*
* The following example values comply with this type's contract:
*
* width: 1em;height:1em;width: 1em;height: 1em;background:url('http://url');
* In addition, the empty string is safe for use in a CSS attribute.
*
*
* The following example values do not comply with this type's
* contract:
*
* background: red (missing a trailing semi-colon)background: (missing a value and a trailing semi-colon)1em (missing an attribute name, which provides context for
* the value)
*
* @param s the input String
* @return a {@link SafeStyles} instance
*/
public static SafeStyles fromTrustedString(String s) {
return new SafeStylesString(s);
}
/**
* Verify that the basic constraints of a {@link SafeStyles} are met. This
* method is not a guarantee that the specified css is safe for use in a CSS
* style attribute. It is a minimal set of assertions to check for common
* errors.
*
* @param styles the CSS properties string
* @throws NullPointerException if the css is null
* @throws AssertionError if the css does not meet the contraints
*/
static void verifySafeStylesConstraints(String styles) {
if (styles == null) {
throw new NullPointerException("css is null");
}
// CSS properties must end in a semi-colon or they cannot be safely
// composed with other properties.
assert ((styles.trim().length() == 0) || styles.endsWith(";")) : "Invalid CSS Property: '"
+ styles + "'. CSS properties must be an empty string or end with a semi-colon (;).";
assert !styles.contains("<") && !styles.contains(">") : "Invalid CSS Property: '" + styles
+ "'. CSS should not contain brackets (< or >).";
}
private static Impl impl() {
if (impl == null) {
if (GWT.isClient()) {
impl = GWT.create(Impl.class);
} else {
impl = new ImplServer();
}
}
return impl;
}
// prevent instantiation
private SafeStylesUtils() {
}
}