/*
* Copyright (C) 2008 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.gxp.compiler.alerts;
import com.google.common.base.Objects;
import com.google.common.base.Preconditions;
import com.google.gxp.compiler.fs.FileRef;
/**
* An Alert indicates something that has (potentially) gone wrong, along with
* the location (if any) where it went wrong.
*
* <p>Like {@link java.lang.Throwable}, Alert is meant to be subclassed for
* each type of "alert". Subclasses may either subclass {@code Alert} directly,
* or may extend one of {@link InfoAlert}, {@link WarningAlert} or
* {@link ErrorAlert} if their {@code defaultSeverity} is invariant..
*/
public abstract class Alert {
/**
* Variety of alert severities.
*/
public enum Severity {
/**
* Indicates that the {@code Alert} is merely informative, and does not
* suggest that there is any kind of problem.
*/
INFO,
/**
* Indicates a possible programming error, or otherwise "suspicious"
* situation, but which isn't severe enough to be considered an error.
*/
WARNING,
/**
* Indicates an error condition: something is definitely wrong.
*/
ERROR
}
private final SourcePosition sourcePosition;
private final String message;
private final Severity defaultSeverity;
// Package private, because all direct subclasses are in this package.
public Alert(SourcePosition sourcePosition, Severity defaultSeverity,
String message) {
this.sourcePosition = Preconditions.checkNotNull(
sourcePosition, "sourcePosition is null");
this.defaultSeverity = Preconditions.checkNotNull(
defaultSeverity, "defaultSeverity is null");
this.message = Preconditions.checkNotNull(message, "alert message is null");
}
/**
* @return the {@link FileRef} that this {@code Alert} pertains to.
*/
public final FileRef getSource() {
return sourcePosition.getSource();
}
/**
* @return the SourcePosition this Alert took place at.
*/
public final SourcePosition getSourcePosition() {
return sourcePosition;
}
/**
* @return English plaintext message explaining what went wrong.
*/
public final String getMessage() {
return message;
}
/**
* Returns the default severity of this {@code Alert}. Note that you should
* generally use an {@link AlertPolicy} to determine the actual severity of
* an {@code Alert}.
*/
public final Severity getDefaultSeverity() {
return defaultSeverity;
}
/**
* @return human-readable representation of this Alert.
*/
@Override
public final String toString() {
return sourcePosition.toString() + ": " + getMessage();
}
@Override
public final boolean equals(Object that) {
return this == that
|| ((that instanceof Alert) && equals((Alert) that));
}
private boolean equals(Alert that) {
return getSourcePosition().equals(that.getSourcePosition())
&& getMessage().equals(that.getMessage())
&& getDefaultSeverity().equals(that.getDefaultSeverity());
}
@Override
public final int hashCode() {
return Objects.hashCode(
getSourcePosition(),
getMessage(),
getDefaultSeverity());
}
}
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