1 files changed, 169 insertions, 0 deletions
diff --git a/dx/src/com/android/dx/util/IndentingWriter.java b/dx/src/com/android/dx/util/IndentingWriter.java
new file mode 100644
index 0000000..3424e37
--- /dev/null
+++ b/dx/src/com/android/dx/util/IndentingWriter.java
@@ -0,0 +1,169 @@
+/*
+ * Copyright (C) 2007 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 com.android.dx.util;
+
+import java.io.FilterWriter;
+import java.io.IOException;
+import java.io.Writer;
+
+/**
+ * Writer that wraps another writer and passes width-limited and
+ * optionally-prefixed output to its subordinate. When lines are
+ * wrapped they are automatically indented based on the start of the
+ * line.
+ */
+public final class IndentingWriter extends FilterWriter {
+    /** {@code null-ok;} optional prefix for every line */
+    private final String prefix;
+
+    /** {@code > 0;} the maximum output width */
+    private final int width;
+
+    /** {@code > 0;} the maximum indent */
+    private final int maxIndent;
+
+    /** {@code >= 0;} current output column (zero-based) */
+    private int column;
+
+    /** whether indent spaces are currently being collected */
+    private boolean collectingIndent;
+
+    /** {@code >= 0;} current indent amount */
+    private int indent;
+
+    /**
+     * Constructs an instance.
+     *
+     * @param out {@code non-null;} writer to send final output to
+     * @param width {@code >= 0;} the maximum output width (not including
+     * {@code prefix}), or {@code 0} for no maximum
+     * @param prefix {@code non-null;} the prefix for each line
+     */
+    public IndentingWriter(Writer out, int width, String prefix) {
+        super(out);
+
+        if (out == null) {
+            throw new NullPointerException("out == null");
+        }
+
+        if (width < 0) {
+            throw new IllegalArgumentException("width < 0");
+        }
+
+        if (prefix == null) {
+            throw new NullPointerException("prefix == null");
+        }
+
+        this.width = (width != 0) ? width : Integer.MAX_VALUE;
+        this.maxIndent = width >> 1;
+        this.prefix = (prefix.length() == 0) ? null : prefix;
+
+        bol();
+    }
+
+    /**
+     * Constructs a no-prefix instance.
+     *
+     * @param out {@code non-null;} writer to send final output to
+     * @param width {@code >= 0;} the maximum output width (not including
+     * {@code prefix}), or {@code 0} for no maximum
+     */
+    public IndentingWriter(Writer out, int width) {
+        this(out, width, "");
+    }
+
+    /** {@inheritDoc} */
+    @Override
+    public void write(int c) throws IOException {
+        synchronized (lock) {
+            if (collectingIndent) {
+                if (c == ' ') {
+                    indent++;
+                    if (indent >= maxIndent) {
+                        indent = maxIndent;
+                        collectingIndent = false;
+                    }
+                } else {
+                    collectingIndent = false;
+                }
+            }
+
+            if ((column == width) && (c != '\n')) {
+                out.write('\n');
+                column = 0;
+                /*
+                 * Note: No else, so this should fall through to the next
+                 * if statement.
+                 */
+            }
+
+            if (column == 0) {
+                if (prefix != null) {
+                    out.write(prefix);
+                }
+
+                if (!collectingIndent) {
+                    for (int i = 0; i < indent; i++) {
+                        out.write(' ');
+                    }
+                    column = indent;
+                }
+            }
+
+            out.write(c);
+
+            if (c == '\n') {
+                bol();
+            } else {
+                column++;
+            }
+        }
+    }
+
+    /** {@inheritDoc} */
+    @Override
+    public void write(char[] cbuf, int off, int len) throws IOException {
+        synchronized (lock) {
+            while (len > 0) {
+                write(cbuf[off]);
+                off++;
+                len--;
+            }
+        }
+    }
+
+    /** {@inheritDoc} */
+    @Override
+    public void write(String str, int off, int len) throws IOException {
+        synchronized (lock) {
+            while (len > 0) {
+                write(str.charAt(off));
+                off++;
+                len--;
+            }
+        }
+    }
+
+    /**
+     * Indicates that output is at the beginning of a line.
+     */
+    private void bol() {
+        column = 0;
+        collectingIndent = (maxIndent != 0);
+        indent = 0;
+    }
+}