text: /**
   * @license
   * Visual Blocks Editor
   *
   * Copyright 2012 Google Inc.
   * https://developers.google.com/blockly/
   *
   * 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.
   */
  
  /**
   * @fileoverview Object representing an input (value, statement, or dummy).
   * @author fraser@google.com (Neil Fraser)
   */
  'use strict';
  
  goog.provide('Blockly.Input');
  
  goog.require('Blockly.Connection');
  goog.require('Blockly.FieldLabel');
  goog.require('goog.asserts');
  
  
  /**
   * Class for an input with an optional field.
   * @param {number} type The type of the input.
   * @param {string} name Language-neutral identifier which may used to find this
   *     input again.
   * @param {!Blockly.Block} block The block containing this input.
   * @param {Blockly.Connection} connection Optional connection for this input.
   * @constructor
   */
  Blockly.Input = function(type, name, block, connection) {
    if (type != Blockly.DUMMY_INPUT && !name) {
      throw 'Value inputs and statement inputs must have non-empty name.';
    }
    /** @type {number} */
    this.type = type;
    /** @type {string} */
    this.name = name;
    /**
     * @type {!Blockly.Block}
     * @private
     */
    this.sourceBlock_ = block;
    /** @type {Blockly.Connection} */
    this.connection = connection;
    /** @type {!Array.<!Blockly.Field>} */
    this.fieldRow = [];
  };
  
  /**
   * Alignment of input's fields (left, right or centre).
   * @type {number}
   */
  Blockly.Input.prototype.align = Blockly.ALIGN_LEFT;
  
  /**
   * Is the input visible?
   * @type {boolean}
   * @private
   */
  Blockly.Input.prototype.visible_ = true;
  
  /**
   * Add a field (or label from string), and all prefix and suffix fields, to the
   * end of the input's field row.
   * @param {string|!Blockly.Field} field Something to add as a field.
   * @param {string=} opt_name Language-neutral identifier which may used to find
   *     this field again.  Should be unique to the host block.
   * @return {!Blockly.Input} The input being append to (to allow chaining).
   */
  Blockly.Input.prototype.appendField = function(field, opt_name) {
    this.insertFieldAt(this.fieldRow.length, field, opt_name);
    return this;
  };
  
  /**
   * Inserts a field (or label from string), and all prefix and suffix fields, at
   * the location of the input's field row.
   * @param {number} index The index at which to insert field.
   * @param {string|!Blockly.Field} field Something to add as a field.
   * @param {string=} opt_name Language-neutral identifier which may used to find
   *     this field again.  Should be unique to the host block.
   * @return {number} The index following the last inserted field.
   */
  Blockly.Input.prototype.insertFieldAt = function(index, field, opt_name) {
    if (index < 0 || index > this.fieldRow.length) {
      throw new Error('index ' + index + ' out of bounds.');
    }
  
    // Empty string, Null or undefined generates no field, unless field is named.
    if (!field && !opt_name) {
      return index;
    }
    // Generate a FieldLabel when given a plain text field.
    if (goog.isString(field)) {
      field = new Blockly.FieldLabel(/** @type {string} */ (field));
    }
    field.setSourceBlock(this.sourceBlock_);
    if (this.sourceBlock_.rendered) {
      field.init();
    }
    field.name = opt_name;
  
    if (field.prefixField) {
      // Add any prefix.
      index = this.insertFieldAt(index, field.prefixField);
    }
    // Add the field to the field row.
    this.fieldRow.splice(index, 0, field);
    ++index;
    if (field.suffixField) {
      // Add any suffix.
      index = this.insertFieldAt(index, field.suffixField);
    }
  
    if (this.sourceBlock_.rendered) {
      this.sourceBlock_.render();
      // Adding a field will cause the block to change shape.
      this.sourceBlock_.bumpNeighbours_();
    }
    return index;
  };
  
  /**
   * Remove a field from this input.
   * @param {string} name The name of the field.
   * @throws {goog.asserts.AssertionError} if the field is not present.
   */
  Blockly.Input.prototype.removeField = function(name) {
    for (var i = 0, field; field = this.fieldRow[i]; i++) {
      if (field.name === name) {
        field.dispose();
        this.fieldRow.splice(i, 1);
        if (this.sourceBlock_.rendered) {
          this.sourceBlock_.render();
          // Removing a field will cause the block to change shape.
          this.sourceBlock_.bumpNeighbours_();
        }
        return;
      }
    }
    goog.asserts.fail('Field "%s" not found.', name);
  };
  
  /**
   * Gets whether this input is visible or not.
   * @return {boolean} True if visible.
   */
  Blockly.Input.prototype.isVisible = function() {
    return this.visible_;
  };
  
  /**
   * Sets whether this input is visible or not.
   * Used to collapse/uncollapse a block.
   * @param {boolean} visible True if visible.
   * @return {!Array.<!Blockly.Block>} List of blocks to render.
   */
  Blockly.Input.prototype.setVisible = function(visible) {
    var renderList = [];
    if (this.visible_ == visible) {
      return renderList;
    }
    this.visible_ = visible;
  
    var display = visible ? 'block' : 'none';
    for (var y = 0, field; field = this.fieldRow[y]; y++) {
      field.setVisible(visible);
    }
    if (this.connection) {
      // Has a connection.
      if (visible) {
        renderList = this.connection.unhideAll();
      } else {
        this.connection.hideAll();
      }
      var child = this.connection.targetBlock();
      if (child) {
        child.getSvgRoot().style.display = display;
        if (!visible) {
          child.rendered = false;
        }
      }
    }
    return renderList;
  };
  
  /**
   * Change a connection's compatibility.
   * @param {string|Array.<string>|null} check Compatible value type or
   *     list of value types.  Null if all types are compatible.
   * @return {!Blockly.Input} The input being modified (to allow chaining).
   */
  Blockly.Input.prototype.setCheck = function(check) {
    if (!this.connection) {
      throw 'This input does not have a connection.';
    }
    this.connection.setCheck(check);
    return this;
  };
  
  /**
   * Change the alignment of the connection's field(s).
   * @param {number} align One of Blockly.ALIGN_LEFT, ALIGN_CENTRE, ALIGN_RIGHT.
   *   In RTL mode directions are reversed, and ALIGN_RIGHT aligns to the left.
   * @return {!Blockly.Input} The input being modified (to allow chaining).
   */
  Blockly.Input.prototype.setAlign = function(align) {
    this.align = align;
    if (this.sourceBlock_.rendered) {
      this.sourceBlock_.render();
    }
    return this;
  };
  
  /**
   * Initialize the fields on this input.
   */
  Blockly.Input.prototype.init = function() {
    if (!this.sourceBlock_.workspace.rendered) {
      return;  // Headless blocks don't need fields initialized.
    }
    for (var i = 0; i < this.fieldRow.length; i++) {
      this.fieldRow[i].init();
    }
  };
  
  /**
   * Sever all links to this input.
   */
  Blockly.Input.prototype.dispose = function() {
    for (var i = 0, field; field = this.fieldRow[i]; i++) {
      field.dispose();
    }
    if (this.connection) {
      this.connection.dispose();
    }
    this.sourceBlock_ = null;
  };
  