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      1 /*
      2  * Copyright (C) 2007 The Android Open Source Project
      3  *
      4  * Licensed under the Eclipse Public License, Version 1.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.eclipse.org/org/documents/epl-v10.php
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.android.ide.eclipse.adt.internal.resources.configurations;
     18 
     19 import org.eclipse.swt.graphics.Image;
     20 
     21 /**
     22  * Base class for resource qualifiers.
     23  * <p/>The resource qualifier classes are designed as immutable.
     24  */
     25 public abstract class ResourceQualifier implements Comparable<ResourceQualifier> {
     26 
     27     /**
     28      * Returns the human readable name of the qualifier.
     29      */
     30     public abstract String getName();
     31 
     32     /**
     33      * Returns a shorter human readable name for the qualifier.
     34      * @see #getName()
     35      */
     36     public abstract String getShortName();
     37 
     38     /**
     39      * Returns the icon for the qualifier.
     40      */
     41     public abstract Image getIcon();
     42 
     43     /**
     44      * Returns whether the qualifier has a valid filter value.
     45      */
     46     public abstract boolean isValid();
     47 
     48     /**
     49      * Returns whether the qualifier has a fake value.
     50      * <p/>Fake values are used internally and should not be used as real qualifier value.
     51      */
     52     public abstract boolean hasFakeValue();
     53 
     54     /**
     55      * Check if the value is valid for this qualifier, and if so sets the value
     56      * into a Folder Configuration.
     57      * @param value The value to check and set. Must not be null.
     58      * @param config The folder configuration to receive the value. Must not be null.
     59      * @return true if the value was valid and was set.
     60      */
     61     public abstract boolean checkAndSet(String value, FolderConfiguration config);
     62 
     63     /**
     64      * Returns a string formated to be used in a folder name.
     65      * <p/>This is declared as abstract to force children classes to implement it.
     66      */
     67     public abstract String getFolderSegment();
     68 
     69     /**
     70      * Returns whether the given qualifier is a match for the receiver.
     71      * <p/>The default implementation returns the result of {@link #equals(Object)}.
     72      * <p/>Children class that re-implements this must implement
     73      * {@link #isBetterMatchThan(ResourceQualifier, ResourceQualifier)} too.
     74      * @param qualifier the reference qualifier
     75      * @return true if the receiver is a match.
     76      */
     77     public boolean isMatchFor(ResourceQualifier qualifier) {
     78         return equals(qualifier);
     79     }
     80 
     81     /**
     82      * Returns true if the receiver is a better match for the given <var>reference</var> than
     83      * the given <var>compareTo</var> comparable.
     84      * @param compareTo The {@link ResourceQualifier} to compare to. Can be null, in which
     85      * case the method must return <code>true</code>.
     86      * @param reference The reference qualifier value for which the match is.
     87      * @return true if the receiver is a better match.
     88      */
     89     public boolean isBetterMatchThan(ResourceQualifier compareTo, ResourceQualifier reference) {
     90         // the default is to always return false. This gives less overhead than always returning
     91         // true, as it would only compare same values anyway.
     92         return false;
     93     }
     94 
     95     @Override
     96     public String toString() {
     97         return getFolderSegment();
     98     }
     99 
    100     /**
    101      * Returns a string formatted for display purpose.
    102      */
    103     public abstract String getShortDisplayValue();
    104 
    105     /**
    106      * Returns a string formatted for display purpose.
    107      */
    108     public abstract String getLongDisplayValue();
    109 
    110     /**
    111      * Returns <code>true</code> if both objects are equal.
    112      * <p/>This is declared as abstract to force children classes to implement it.
    113      */
    114     @Override
    115     public abstract boolean equals(Object object);
    116 
    117     /**
    118      * Returns a hash code value for the object.
    119      * <p/>This is declared as abstract to force children classes to implement it.
    120      */
    121     @Override
    122     public abstract int hashCode();
    123 
    124     public final int compareTo(ResourceQualifier o) {
    125         return toString().compareTo(o.toString());
    126     }
    127 }
    128