1 files changed, 70 insertions, 0 deletions
diff --git a/java/src/org/kelar/inputmethod/latin/AssetFileAddress.java b/java/src/org/kelar/inputmethod/latin/AssetFileAddress.java
new file mode 100644
index 000000000..c8508f91d
--- /dev/null
+++ b/java/src/org/kelar/inputmethod/latin/AssetFileAddress.java
@@ -0,0 +1,70 @@
+/*
+ * Copyright (C) 2011 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 org.kelar.inputmethod.latin;
+
+import org.kelar.inputmethod.latin.common.FileUtils;
+
+import java.io.File;
+
+/**
+ * Immutable class to hold the address of an asset.
+ * As opposed to a normal file, an asset is usually represented as a contiguous byte array in
+ * the package file. Open it correctly thus requires the name of the package it is in, but
+ * also the offset in the file and the length of this data. This class encapsulates these three.
+ */
+public final class AssetFileAddress {
+    public final String mFilename;
+    public final long mOffset;
+    public final long mLength;
+
+    public AssetFileAddress(final String filename, final long offset, final long length) {
+        mFilename = filename;
+        mOffset = offset;
+        mLength = length;
+    }
+
+    public static AssetFileAddress makeFromFile(final File file) {
+        if (!file.isFile()) return null;
+        return new AssetFileAddress(file.getAbsolutePath(), 0L, file.length());
+    }
+
+    public static AssetFileAddress makeFromFileName(final String filename) {
+        if (null == filename) return null;
+        return makeFromFile(new File(filename));
+    }
+
+    public static AssetFileAddress makeFromFileNameAndOffset(final String filename,
+            final long offset, final long length) {
+        if (null == filename) return null;
+        final File f = new File(filename);
+        if (!f.isFile()) return null;
+        return new AssetFileAddress(filename, offset, length);
+    }
+
+    public boolean pointsToPhysicalFile() {
+        return 0 == mOffset;
+    }
+
+    public void deleteUnderlyingFile() {
+        FileUtils.deleteRecursively(new File(mFilename));
+    }
+
+    @Override
+    public String toString() {
+        return String.format("%s (offset=%d, length=%d)", mFilename, mOffset, mLength);
+    }
+}