/*
* Copyright (C) 2006 The Android Open Source Project
*
* 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 android.util;
/**
* A collection of attributes, as found associated with a tag in an XML
* document. Often you will not want to use this interface directly, instead
* passing it to {@link android.content.res.Resources.Theme#obtainStyledAttributes(AttributeSet, int[], int, int)
* Resources.Theme.obtainStyledAttributes()}
* which will take care of parsing the attributes for you. In particular,
* the Resources API will convert resource references (attribute values such as
* "@string/my_label" in the original XML) to the desired type
* for you; if you use AttributeSet directly then you will need to manually
* check for resource references
* (with {@link #getAttributeResourceValue(int, int)}) and do the resource
* lookup yourself if needed. Direct use of AttributeSet also prevents the
* application of themes and styles when retrieving attribute values.
*
* <p>This interface provides an efficient mechanism for retrieving
* data from compiled XML files, which can be retrieved for a particular
* XmlPullParser through {@link Xml#asAttributeSet
* Xml.asAttributeSet()}. Normally this will return an implementation
* of the interface that works on top of a generic XmlPullParser, however it
* is more useful in conjunction with compiled XML resources:
*
* <pre>
* XmlPullParser parser = resources.getXml(myResouce);
* AttributeSet attributes = Xml.asAttributeSet(parser);</pre>
*
* <p>The implementation returned here, unlike using
* the implementation on top of a generic XmlPullParser,
* is highly optimized by retrieving pre-computed information that was
* generated by aapt when compiling your resources. For example,
* the {@link #getAttributeFloatValue(int, float)} method returns a floating
* point number previous stored in the compiled resource instead of parsing
* at runtime the string originally in the XML file.
*
* <p>This interface also provides additional information contained in the
* compiled XML resource that is not available in a normal XML file, such
* as {@link #getAttributeNameResource(int)} which returns the resource
* identifier associated with a particular XML attribute name.
*/
public interface AttributeSet {
/**
* Returns the number of attributes available in the set.
*
* @return A positive integer, or 0 if the set is empty.
*/
public int getAttributeCount();
/**
* Returns the name of the specified attribute.
*
* @param index Index of the desired attribute, 0...count-1.
*
* @return A String containing the name of the attribute, or null if the
* attribute cannot be found.
*/
public String getAttributeName(int index);
/**
* Returns the value of the specified attribute as a string representation.
*
* @param index Index of the desired attribute, 0...count-1.
*
* @return A String containing the value of the attribute, or null if the
* attribute cannot be found.
*/
public String getAttributeValue(int index);
/**
* Returns the value of the specified attribute as a string representation.
* The lookup is performed using the attribute name.
*
* @param namespace The namespace of the attribute to get the value from.
* @param name The name of the attribute to get the value from.
*
* @return A String containing the value of the attribute, or null if the
* attribute cannot be found.
*/
public String getAttributeValue(String namespace, String name);
/**
* Returns a description of the current position of the attribute set.
* For instance, if the attribute set is loaded from an XML document,
* the position description could indicate the current line number.
*
* @return A string representation of the current position in the set,
* may be null.
*/
public String getPositionDescription();
/**
* Return the resource ID associated with the given attribute name. This
* will be the identifier for an attribute resource, which can be used by
* styles. Returns 0 if there is no resource associated with this
* attribute.
*
* <p>Note that this is different than {@link #getAttributeResourceValue}
* in that it returns a resource identifier for the attribute name; the
* other method returns this attribute's value as a resource identifier.
*
* @param index Index of the desired attribute, 0...count-1.
*
* @return The resource identifier, 0 if none.
*/
public int getAttributeNameResource(int index);
/**
* Return the index of the value of 'attribute' in the list 'options'.
*
* @param namespace Namespace of attribute to retrieve.
* @param attribute Name of attribute to retrieve.
* @param options List of strings whose values we are checking against.
* @param defaultValue Value returned if attribute doesn't exist or no
* match is found.
*
* @return Index in to 'options' or defaultValue.
*/
public int getAttributeListValue(String namespace, String attribute,
String[] options, int defaultValue);
/**
* Return the boolean value of 'attribute'.
*
* @param namespace Namespace of attribute to retrieve.
* @param attribute The attribute to retrieve.
* @param defaultValue What to return if the attribute isn't found.
*
* @return Resulting value.
*/
public boolean getAttributeBooleanValue(String namespace, String attribute,
boolean defaultValue);
/**
* Return the value of 'attribute' as a resource identifier.
*
* <p>Note that this is different than {@link #getAttributeNameResource}
* in that it returns the value contained in this attribute as a
* resource identifier (i.e., a value originally of the form
* "@package:type/resource"); the other method returns a resource
* identifier that identifies the name of the attribute.
*
* @param namespace Namespace of attribute to retrieve.
* @param attribute The attribute to retrieve.
* @param defaultValue What to return if the attribute isn't found.
*
* @return Resulting value.
*/
public int getAttributeResourceValue(String namespace, String attribute,
int defaultValue);
/**
* Return the integer value of 'attribute'.
*
* @param namespace Namespace of attribute to retrieve.
* @param attribute The attribute to retrieve.
* @param defaultValue What to return if the attribute isn't found.
*
* @return Resulting value.
*/
public int getAttributeIntValue(String namespace, String attribute,
int defaultValue);
/**
* Return the boolean value of 'attribute' that is formatted as an
* unsigned value. In particular, the formats 0xn...n and #n...n are
* handled.
*
* @param namespace Namespace of attribute to retrieve.
* @param attribute The attribute to retrieve.
* @param defaultValue What to return if the attribute isn't found.
*
* @return Resulting value.
*/
public int getAttributeUnsignedIntValue(String namespace, String attribute,
int defaultValue);
/**
* Return the float value of 'attribute'.
*
* @param namespace Namespace of attribute to retrieve.
* @param attribute The attribute to retrieve.
* @param defaultValue What to return if the attribute isn't found.
*
* @return Resulting value.
*/
public float getAttributeFloatValue(String namespace, String attribute,
float defaultValue);
/**
* Return the index of the value of attribute at 'index' in the list
* 'options'.
*
* @param index Index of the desired attribute, 0...count-1.
* @param options List of strings whose values we are checking against.
* @param defaultValue Value returned if attribute doesn't exist or no
* match is found.
*
* @return Index in to 'options' or defaultValue.
*/
public int getAttributeListValue(int index, String[] options, int defaultValue);
/**
* Return the boolean value of attribute at 'index'.
*
* @param index Index of the desired attribute, 0...count-1.
* @param defaultValue What to return if the attribute isn't found.
*
* @return Resulting value.
*/
public boolean getAttributeBooleanValue(int index, boolean defaultValue);
/**
* Return the value of attribute at 'index' as a resource identifier.
*
* <p>Note that this is different than {@link #getAttributeNameResource}
* in that it returns the value contained in this attribute as a
* resource identifier (i.e., a value originally of the form
* "@package:type/resource"); the other method returns a resource
* identifier that identifies the name of the attribute.
*
* @param index Index of the desired attribute, 0...count-1.
* @param defaultValue What to return if the attribute isn't found.
*
* @return Resulting value.
*/
public int getAttributeResourceValue(int index, int defaultValue);
/**
* Return the integer value of attribute at 'index'.
*
* @param index Index of the desired attribute, 0...count-1.
* @param defaultValue What to return if the attribute isn't found.
*
* @return Resulting value.
*/
public int getAttributeIntValue(int index, int defaultValue);
/**
* Return the integer value of attribute at 'index' that is formatted as an
* unsigned value. In particular, the formats 0xn...n and #n...n are
* handled.
*
* @param index Index of the desired attribute, 0...count-1.
* @param defaultValue What to return if the attribute isn't found.
*
* @return Resulting value.
*/
public int getAttributeUnsignedIntValue(int index, int defaultValue);
/**
* Return the float value of attribute at 'index'.
*
* @param index Index of the desired attribute, 0...count-1.
* @param defaultValue What to return if the attribute isn't found.
*
* @return Resulting value.
*/
public float getAttributeFloatValue(int index, float defaultValue);
/**
* Return the value of the "id" attribute or null if there is not one.
* Equivalent to getAttributeValue(null, "id").
*
* @return The id attribute's value or null.
*/
public String getIdAttribute();
/**
* Return the value of the "class" attribute or null if there is not one.
* Equivalent to getAttributeValue(null, "class").
*
* @return The class attribute's value or null.
*/
public String getClassAttribute();
/**
* Return the integer value of the "id" attribute or defaultValue if there
* is none.
* Equivalent to getAttributeResourceValue(null, "id", defaultValue);
*
* @param defaultValue What to return if the "id" attribute isn't found.
* @return int Resulting value.
*/
public int getIdAttributeResourceValue(int defaultValue);
/**
* Return the value of the "style" attribute or 0 if there is not one.
* Equivalent to getAttributeResourceValue(null, "style").
*
* @return The style attribute's resource identifier or 0.
*/
public int getStyleAttribute();
}
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