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/*
 * Copyright (c) 1997, 2021 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Distribution License v. 1.0, which is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

package com.sun.codemodel;

import java.util.ArrayList;
import java.util.List;
import java.util.Collections;

/**
 * A block of Java code, which may contain statements and local declarations.
 *
 * 

* {@link JBlock} contains a large number of factory methods that creates new * statements/declarations. Those newly created statements/declarations are * inserted into the {@link #pos() "current position"}. The position advances * one every time you add a new instruction. */ public final class JBlock implements JGenerable, JStatement { /** * Declarations and statements contained in this block. * Either {@link JStatement} or {@link JDeclaration}. */ private final List content = new ArrayList<>(); /** * Whether or not this block must be braced and indented */ private boolean bracesRequired = true; private boolean indentRequired = true; /** * Current position. */ private int pos; public JBlock() { this(true,true); } public JBlock(boolean bracesRequired, boolean indentRequired) { this.bracesRequired = bracesRequired; this.indentRequired = indentRequired; } /** * Returns a read-only view of {@link JStatement}s and {@link JDeclaration} * in this block. */ public List getContents() { return Collections.unmodifiableList(content); } private T insert( T statementOrDeclaration ) { content.add(pos,statementOrDeclaration); pos++; return statementOrDeclaration; } /** * Gets the current position to which new statements will be inserted. * * For example if the value is 0, newly created instructions will be * inserted at the very beginning of the block. * * @see #pos(int) */ public int pos() { return pos; } /** * Sets the current position. * * @return * the old value of the current position. * @throws IllegalArgumentException * if the new position value is illegal. * * @see #pos() */ public int pos(int newPos) { int r = pos; if(newPos>content.size() || newPos<0) throw new IllegalArgumentException(); pos = newPos; return r; } /** * Returns true if this block is empty and does not contain * any statement. */ public boolean isEmpty() { return content.isEmpty(); } /** * Adds a local variable declaration to this block * * @param type * JType of the variable * * @param name * Name of the variable * * @return Newly generated JVar */ public JVar decl(JType type, String name) { return decl(JMod.NONE, type, name, null); } /** * Adds a local variable declaration to this block * * @param type * JType of the variable * * @param name * Name of the variable * * @param init * Initialization expression for this variable. May be null. * * @return Newly generated JVar */ public JVar decl(JType type, String name, JExpression init) { return decl(JMod.NONE, type, name, init); } /** * Adds a local variable declaration to this block * * @param mods * Modifiers for the variable * * @param type * JType of the variable * * @param name * Name of the variable * * @param init * Initialization expression for this variable. May be null. * * @return Newly generated JVar */ public JVar decl(int mods, JType type, String name, JExpression init) { JVar v = new JVar(JMods.forVar(mods), type, name, init); insert(v); bracesRequired = true; indentRequired = true; return v; } /** * Creates an assignment statement and adds it to this block. * * @param lhs * Assignable variable or field for left hand side of expression * * @param exp * Right hand side expression */ public JBlock assign(JAssignmentTarget lhs, JExpression exp) { insert(new JAssignment(lhs, exp)); return this; } public JBlock assignPlus(JAssignmentTarget lhs, JExpression exp) { insert(new JAssignment(lhs, exp, "+")); return this; } /** * Creates an invocation statement and adds it to this block. * * @param expr * JExpression evaluating to the class or object upon which * the named method will be invoked * * @param method * Name of method to invoke * * @return Newly generated JInvocation */ public JInvocation invoke(JExpression expr, String method) { JInvocation i = new JInvocation(expr, method); insert(i); return i; } /** * Creates an invocation statement and adds it to this block. * * @param expr * JExpression evaluating to the class or object upon which * the method will be invoked * * @param method * JMethod to invoke * * @return Newly generated JInvocation */ public JInvocation invoke(JExpression expr, JMethod method) { return insert(new JInvocation(expr, method)); } /** * Creates a static invocation statement. */ public JInvocation staticInvoke(JClass type, String method) { return insert(new JInvocation(type, method)); } /** * Creates an invocation statement and adds it to this block. * * @param method * Name of method to invoke * * @return Newly generated JInvocation */ public JInvocation invoke(String method) { return insert(new JInvocation((JExpression)null, method)); } /** * Creates an invocation statement and adds it to this block. * * @param method * JMethod to invoke * * @return Newly generated JInvocation */ public JInvocation invoke(JMethod method) { return insert(new JInvocation((JExpression)null, method)); } /** * Adds a statement to this block * * @param s * JStatement to be added * * @return This block */ public JBlock add(JStatement s) { // ## Needed? insert(s); return this; } /** * Create an If statement and add it to this block * * @param expr * JExpression to be tested to determine branching * * @return Newly generated conditional statement */ public JConditional _if(JExpression expr) { return insert(new JConditional(expr)); } /** * Create a For statement and add it to this block * * @return Newly generated For statement */ public JForLoop _for() { return insert(new JForLoop()); } /** * Create a While statement and add it to this block * * @return Newly generated While statement */ public JWhileLoop _while(JExpression test) { return insert(new JWhileLoop(test)); } /** * Create a switch/case statement and add it to this block */ public JSwitch _switch(JExpression test) { return insert(new JSwitch(test)); } /** * Create a Do statement and add it to this block * * @return Newly generated Do statement */ public JDoLoop _do(JExpression test) { return insert(new JDoLoop(test)); } /** * Create a Try statement and add it to this block * * @return Newly generated Try statement */ public JTryBlock _try() { return insert(new JTryBlock()); } /** * Create a return statement and add it to this block */ public void _return() { insert(new JReturn(null)); } /** * Create a return statement and add it to this block */ public void _return(JExpression exp) { insert(new JReturn(exp)); } /** * Create a throw statement and add it to this block */ public void _throw(JExpression exp) { insert(new JThrow(exp)); } /** * Create a break statement and add it to this block */ public void _break() { _break(null); } public void _break(JLabel label) { insert(new JBreak(label)); } /** * Create a label, which can be referenced from * continue and break statements. */ public JLabel label(String name) { JLabel l = new JLabel(name); insert(l); return l; } /** * Create a continue statement and add it to this block */ public void _continue(JLabel label) { insert(new JContinue(label)); } public void _continue() { _continue(null); } /** * Create a sub-block and add it to this block */ public JBlock block() { JBlock b = new JBlock(); b.bracesRequired = false; b.indentRequired = false; return insert(b); } /** * Creates a "literal" statement directly. * *

* Specified string is printed as-is. * This is useful as a short-cut. * *

* For example, you can invoke this method as: * directStatement("a=b+c;"). */ public JStatement directStatement(final String source) { JStatement s = new JStatement() { @Override public void state(JFormatter f) { f.p(source).nl(); } }; add(s); return s; } @Override public void generate(JFormatter f) { if (bracesRequired) f.p('{').nl(); if (indentRequired) f.i(); generateBody(f); if (indentRequired) f.o(); if (bracesRequired) f.p('}'); } void generateBody(JFormatter f) { for (Object o : content) { if (o instanceof JDeclaration) f.d((JDeclaration) o); else f.s((JStatement) o); } } /** * Creates an enhanced For statement based on j2se 1.5 JLS * and add it to this block * * @return Newly generated enhanced For statement per j2se 1.5 * specification */ public JForEach forEach(JType varType, String name, JExpression collection) { return insert(new JForEach( varType, name, collection)); } @Override public void state(JFormatter f) { f.g(this); if (bracesRequired) f.nl(); } }