#121 Initial version (work in progress)

src/main/java/picocli/AutoComplete.java

@@ -0,0 +1,120 @@
+/*
+   Copyright 2017 Remko Popma
+
+   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 picocli;
+
+import java.lang.reflect.Field;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Generates a bash auto-complete script.
+ */
+public class AutoComplete {
+    private final CommandLine commandLine;
+
+    AutoComplete(Object annotatedObject) {
+        this(new CommandLine(annotatedObject));
+    }
+    AutoComplete(CommandLine commandLine) {
+        if (commandLine == null) { throw new NullPointerException("commandLine"); }
+        this.commandLine = commandLine;
+    }
+
+    private static final String HEADER = "" +
+            "#!bash\n" +
+            "#\n" +
+            "# %1s Bash Completion\n" +
+            "# =======================\n" +
+            "#\n" +
+            "# Bash completion support for %1s,\n" +
+            "# generated by [picocli](http://picocli.info/).\n" +
+            "#\n" +
+            "# Installation\n" +
+            "# ------------\n" +
+            "#\n" +
+            "# 1. Place it in a `bash-completion.d` folder:\n" +
+            "#\n" +
+            "#   * /etc/bash-completion.d\n" +
+            "#   * /usr/local/etc/bash-completion.d\n" +
+            "#   * ~/bash-completion.d\n" +
+            "#\n" +
+            "# 2. Open new bash, and type `%1s [TAB][TAB]`\n" +
+            "#\n" +
+            "# Documentation\n" +
+            "# -------------\n" +
+            "# The script is called by bash whenever [TAB] or [TAB][TAB] is pressed after\n" +
+            "# '%1s (..)'. By reading entered command line parameters, it determines possible\n" +
+            "# bash completions and writes them to the COMPREPLY variable. Bash then\n" +
+            "# completes the user input if only one entry is listed in the variable or\n" +
+            "# shows the options if more than one is listed in COMPREPLY.\n" +
+            "#\n" +
+            "# The script first determines the current parameter ($cur), the previous\n" +
+            "# parameter ($prev), the first word ($firstword) and the last word ($lastword).\n" +
+            "# Using the $firstword variable (= the command) and a giant switch/case,\n" +
+            "# completions are written to $complete_words and $complete_options.\n" +
+            "#\n" +
+            "# If the current user input ($cur) starts with '-', only $command_options are\n" +
+            "# displayed/completed, otherwise only $command_words.\n" +
+            "#\n" +
+            "# References\n" +
+            "# ----------\n" +
+            "# [1] http://stackoverflow.com/a/12495480/1440785\n" +
+            "# [2] http://tiswww.case.edu/php/chet/bash/FAQ\n" +
+            "#\n" +
+            "\n" +
+            "shopt -s progcomp\n" +
+            "_%1s() {\n";
+
+    String bash() {
+        final Map<String, Object> commands = commandLine.getCommands();
+        Object annotated = commandLine.getAnnotatedObject();
+        List<Field> requiredFields = new ArrayList<Field>();
+        Map<String, Field> optionName2Field = new HashMap<String, Field>();
+        Map<String, Field> singleCharOption2Field = new HashMap<String, Field>();
+        List<Field> positionalParameterFields = new ArrayList<Field>();
+        Class<?> cls = annotated.getClass();
+        while (cls != null) {
+            CommandLine.init(cls, requiredFields, optionName2Field, singleCharOption2Field, positionalParameterFields);
+            cls = cls.getSuperclass();
+        }
+        String result = "";
+        result += String.format(HEADER, scriptName);
+        result += commandListDeclaration(commands);
+        result += globalOptionDeclaration(optionName2Field);
+
+        return result;
+    }
+
+    private String commandListDeclaration(final Map<String, Object> commands) {
+        StringBuilder result = new StringBuilder("    GLOBAL_COMMANDS=\"\\\n");
+        for (String key : commands.keySet()) {
+            result.append("        ").append(key).append("\\\n");
+        }
+        result.setCharAt(result.length() - 2, '\"');
+        return result.toString();
+    }
+
+    private String globalOptionDeclaration(final Map<String, ?> options) {
+        StringBuilder result = new StringBuilder("    GLOBAL_OPTIONS=\"\\\n");
+        for (String key : options.keySet()) {
+            result.append("        ").append(key).append("\\\n");
+        }
+        result.setCharAt(result.length() - 2, '\"');
+        return result.toString();
+    }
+}