1 /* 2 * Copyright (C) 2014 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.android.inputmethod.keyboard.layout.expected; 18 19 import java.util.Arrays; 20 21 /** 22 * This class builds a keyboard that is a two dimensional array of elements <code>E</code>. 23 * 24 * A keyboard consists of an array of rows, and a row consists of an array of elements. Each row 25 * may have different number of elements. A element of a keyboard can be specified by a row number 26 * and a column number, both numbers starts from 1. 27 * 28 * @param <E> the type of a keyboard element. A keyboard element must be an immutable object. 29 */ 30 abstract class AbstractKeyboardBuilder<E> { 31 // A building array of rows. 32 private E[][] mRows; 33 34 // Returns an instance of default element. defaultElement()35 abstract E defaultElement(); 36 // Returns an <code>E</code> array instance of the <code>size</code>. newArray(final int size)37 abstract E[] newArray(final int size); 38 // Returns an <code>E[]</code> array instance of the <code>size</code>. newArrayOfArray(final int size)39 abstract E[][] newArrayOfArray(final int size); 40 41 /** 42 * Construct an empty builder. 43 */ AbstractKeyboardBuilder()44 AbstractKeyboardBuilder() { 45 mRows = newArrayOfArray(0); 46 } 47 48 /** 49 * Construct a builder from template keyboard. This builder has the same dimensions and 50 * elements of <code>rows</rows>. 51 * @param rows the template keyboard rows. The elements of the <code>rows</code> will be 52 * shared with this builder. Therefore a element must be an immutable object. 53 */ AbstractKeyboardBuilder(final E[][] rows)54 AbstractKeyboardBuilder(final E[][] rows) { 55 mRows = newArrayOfArray(rows.length); 56 for (int rowIndex = 0; rowIndex < rows.length; rowIndex++) { 57 final E[] row = rows[rowIndex]; 58 mRows[rowIndex] = Arrays.copyOf(row, row.length); 59 } 60 } 61 62 /** 63 * Return current constructing keyboard. 64 * @return the array of the array of the element being constructed. 65 */ build()66 E[][] build() { 67 return mRows; 68 } 69 70 /** 71 * Return the number of rows. 72 * @return the number of rows being constructed. 73 */ getRowCount()74 int getRowCount() { 75 return mRows.length; 76 } 77 78 /** 79 * Get the current contents of the specified row. 80 * @param row the row number to get the contents. 81 * @return the array of elements at row number <code>row</code>. 82 * @throws RuntimeException if <code>row</code> is illegal. 83 */ getRowAt(final int row)84 E[] getRowAt(final int row) { 85 final int rowIndex = row - 1; 86 if (rowIndex < 0 || rowIndex >= mRows.length) { 87 throw new RuntimeException("Illegal row number: " + row); 88 } 89 return mRows[rowIndex]; 90 } 91 92 /** 93 * Set an array of elements to the specified row. 94 * @param row the row number to set <code>elements</code>. 95 * @param elements the array of elements to set at row number <code>row</code>. 96 * @throws RuntimeException if <code>row</code> is illegal. 97 */ setRowAt(final int row, final E[] elements)98 void setRowAt(final int row, final E[] elements) { 99 final int rowIndex = row - 1; 100 if (rowIndex < 0) { 101 throw new RuntimeException("Illegal row number: " + row); 102 } 103 final E[][] newRows = (rowIndex < mRows.length) ? mRows 104 : Arrays.copyOf(mRows, rowIndex + 1); 105 newRows[rowIndex] = elements; 106 mRows = newRows; 107 } 108 109 /** 110 * Set or insert an element at specified position. 111 * @param row the row number to set or insert the <code>element</code>. 112 * @param column the column number to set or insert the <code>element</code>. 113 * @param element the element to set or insert at <code>row,column</code>. 114 * @param insert if true, the <code>element</code> is inserted at <code>row,column</code>. 115 * Otherwise the <code>element</code> replace the element at <code>row,column</code>. 116 * @throws RuntimeException if <code>row</code> or <code>column</code> is illegal. 117 */ setElementAt(final int row, final int column, final E element, final boolean insert)118 void setElementAt(final int row, final int column, final E element, final boolean insert) { 119 final E[] elements = getRowAt(row); 120 final int columnIndex = column - 1; 121 if (columnIndex < 0) { 122 throw new RuntimeException("Illegal column number: " + column); 123 } 124 if (insert) { 125 if (columnIndex >= elements.length + 1) { 126 throw new RuntimeException("Illegal column number: " + column); 127 } 128 final E[] newElements = Arrays.copyOf(elements, elements.length + 1); 129 // Shift the remaining elements. 130 System.arraycopy(newElements, columnIndex, newElements, columnIndex + 1, 131 elements.length - columnIndex); 132 // Insert the element at <code>row,column</code>. 133 newElements[columnIndex] = element; 134 // Replace the current row with one. 135 setRowAt(row, newElements); 136 return; 137 } 138 final E[] newElements = (columnIndex < elements.length) ? elements 139 : Arrays.copyOf(elements, columnIndex + 1); 140 newElements[columnIndex] = element; 141 setRowAt(row, newElements); 142 } 143 } 144