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Unified Diff: pkg/args/lib/src/usage.dart

Issue 814113004: Pull args, intl, logging, shelf, and source_maps out of the SDK. (Closed) Base URL: https://dart.googlecode.com/svn/branches/bleeding_edge/dart
Patch Set: Also csslib. Created 6 years ago
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Index: pkg/args/lib/src/usage.dart
diff --git a/pkg/args/lib/src/usage.dart b/pkg/args/lib/src/usage.dart
deleted file mode 100644
index 11be54b38983900ea14ddf0c9223bcb20b2a6923..0000000000000000000000000000000000000000
--- a/pkg/args/lib/src/usage.dart
+++ /dev/null
@@ -1,243 +0,0 @@
-// Copyright (c) 2013, the Dart project authors. Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-library args.src.usage;
-
-import 'dart:math';
-
-import '../args.dart';
-
-/// Takes an [ArgParser] and generates a string of usage (i.e. help) text for
-/// its defined options.
-///
-/// Internally, it works like a tabular printer. The output is divided into
-/// three horizontal columns, like so:
-///
-/// -h, --help Prints the usage information
-/// | | | |
-///
-/// It builds the usage text up one column at a time and handles padding with
-/// spaces and wrapping to the next line to keep the cells correctly lined up.
-class Usage {
- static const NUM_COLUMNS = 3; // Abbreviation, long name, help.
-
- /// The parser this is generating usage for.
- final ArgParser args;
-
- /// The working buffer for the generated usage text.
- StringBuffer buffer;
-
- /// The column that the "cursor" is currently on.
- ///
- /// If the next call to [write()] is not for this column, it will correctly
- /// handle advancing to the next column (and possibly the next row).
- int currentColumn = 0;
-
- /// The width in characters of each column.
- List<int> columnWidths;
-
- /// The number of sequential lines of text that have been written to the last
- /// column (which shows help info).
- ///
- /// We track this so that help text that spans multiple lines can be padded
- /// with a blank line after it for separation. Meanwhile, sequential options
- /// with single-line help will be compacted next to each other.
- int numHelpLines = 0;
-
- /// How many newlines need to be rendered before the next bit of text can be
- /// written.
- ///
- /// We do this lazily so that the last bit of usage doesn't have dangling
- /// newlines. We only write newlines right *before* we write some real
- /// content.
- int newlinesNeeded = 0;
-
- Usage(this.args);
-
- /// Generates a string displaying usage information for the defined options.
- /// This is basically the help text shown on the command line.
- String generate() {
- buffer = new StringBuffer();
-
- calculateColumnWidths();
-
- args.options.forEach((name, option) {
- if (option.hide) return;
-
- write(0, getAbbreviation(option));
- write(1, getLongOption(option));
-
- if (option.help != null) write(2, option.help);
-
- if (option.allowedHelp != null) {
- var allowedNames = option.allowedHelp.keys.toList(growable: false);
- allowedNames.sort();
- newline();
- for (var name in allowedNames) {
- write(1, getAllowedTitle(name));
- write(2, option.allowedHelp[name]);
- }
- newline();
- } else if (option.allowed != null) {
- write(2, buildAllowedList(option));
- } else if (option.defaultValue != null) {
- if (option.isFlag && option.defaultValue == true) {
- write(2, '(defaults to on)');
- } else if (!option.isFlag) {
- write(2, '(defaults to "${option.defaultValue}")');
- }
- }
-
- // If any given option displays more than one line of text on the right
- // column (i.e. help, default value, allowed options, etc.) then put a
- // blank line after it. This gives space where it's useful while still
- // keeping simple one-line options clumped together.
- if (numHelpLines > 1) newline();
- });
-
- return buffer.toString();
- }
-
- String getAbbreviation(Option option) {
- if (option.abbreviation != null) {
- return '-${option.abbreviation}, ';
- } else {
- return '';
- }
- }
-
- String getLongOption(Option option) {
- var result;
- if (option.negatable) {
- result = '--[no-]${option.name}';
- } else {
- result = '--${option.name}';
- }
-
- if (option.valueHelp != null) result += "=<${option.valueHelp}>";
-
- return result;
- }
-
- String getAllowedTitle(String allowed) {
- return ' [$allowed]';
- }
-
- void calculateColumnWidths() {
- int abbr = 0;
- int title = 0;
- args.options.forEach((name, option) {
- if (option.hide) return;
-
- // Make room in the first column if there are abbreviations.
- abbr = max(abbr, getAbbreviation(option).length);
-
- // Make room for the option.
- title = max(title, getLongOption(option).length);
-
- // Make room for the allowed help.
- if (option.allowedHelp != null) {
- for (var allowed in option.allowedHelp.keys) {
- title = max(title, getAllowedTitle(allowed).length);
- }
- }
- });
-
- // Leave a gutter between the columns.
- title += 4;
- columnWidths = [abbr, title];
- }
-
- void newline() {
- newlinesNeeded++;
- currentColumn = 0;
- numHelpLines = 0;
- }
-
- void write(int column, String text) {
- var lines = text.split('\n');
-
- // Strip leading and trailing empty lines.
- while (lines.length > 0 && lines[0].trim() == '') {
- lines.removeRange(0, 1);
- }
-
- while (lines.length > 0 && lines[lines.length - 1].trim() == '') {
- lines.removeLast();
- }
-
- for (var line in lines) {
- writeLine(column, line);
- }
- }
-
- void writeLine(int column, String text) {
- // Write any pending newlines.
- while (newlinesNeeded > 0) {
- buffer.write('\n');
- newlinesNeeded--;
- }
-
- // Advance until we are at the right column (which may mean wrapping around
- // to the next line.
- while (currentColumn != column) {
- if (currentColumn < NUM_COLUMNS - 1) {
- buffer.write(padRight('', columnWidths[currentColumn]));
- } else {
- buffer.write('\n');
- }
- currentColumn = (currentColumn + 1) % NUM_COLUMNS;
- }
-
- if (column < columnWidths.length) {
- // Fixed-size column, so pad it.
- buffer.write(padRight(text, columnWidths[column]));
- } else {
- // The last column, so just write it.
- buffer.write(text);
- }
-
- // Advance to the next column.
- currentColumn = (currentColumn + 1) % NUM_COLUMNS;
-
- // If we reached the last column, we need to wrap to the next line.
- if (column == NUM_COLUMNS - 1) newlinesNeeded++;
-
- // Keep track of how many consecutive lines we've written in the last
- // column.
- if (column == NUM_COLUMNS - 1) {
- numHelpLines++;
- } else {
- numHelpLines = 0;
- }
- }
-
- String buildAllowedList(Option option) {
- var allowedBuffer = new StringBuffer();
- allowedBuffer.write('[');
- bool first = true;
- for (var allowed in option.allowed) {
- if (!first) allowedBuffer.write(', ');
- allowedBuffer.write(allowed);
- if (allowed == option.defaultValue) {
- allowedBuffer.write(' (default)');
- }
- first = false;
- }
- allowedBuffer.write(']');
- return allowedBuffer.toString();
- }
-}
-
-/// Pads [source] to [length] by adding spaces at the end.
-String padRight(String source, int length) {
- final result = new StringBuffer();
- result.write(source);
-
- while (result.length < length) {
- result.write(' ');
- }
-
- return result.toString();
-}
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