1 /* 2 * Copyright (C) 2013 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 android.print.pdf; 18 19 import android.content.Context; 20 import android.graphics.Rect; 21 import android.graphics.pdf.PdfDocument; 22 import android.graphics.pdf.PdfDocument.Page; 23 import android.graphics.pdf.PdfDocument.PageInfo; 24 import android.print.PrintAttributes; 25 import android.print.PrintAttributes.Margins; 26 import android.print.PrintAttributes.MediaSize; 27 28 /** 29 * This class is a helper for creating a PDF file for given print 30 * attributes. It is useful for implementing printing via the native 31 * Android graphics APIs. 32 * <p> 33 * This class computes the page width, page height, and content rectangle 34 * from the provided print attributes and these precomputed values can be 35 * accessed via {@link #getPageWidth()}, {@link #getPageHeight()}, and 36 * {@link #getPageContentRect()}, respectively. The {@link #startPage(int)} 37 * methods creates pages whose {@link PageInfo} is initialized with the 38 * precomputed values for width, height, and content rectangle. 39 * <p> 40 * A typical use of the APIs looks like this: 41 * </p> 42 * <pre> 43 * // open a new document 44 * PrintedPdfDocument document = new PrintedPdfDocument(context, 45 * printAttributes); 46 * 47 * // start a page 48 * Page page = document.startPage(0); 49 * 50 * // draw something on the page 51 * View content = getContentView(); 52 * content.draw(page.getCanvas()); 53 * 54 * // finish the page 55 * document.finishPage(page); 56 * . . . 57 * // add more pages 58 * . . . 59 * // write the document content 60 * document.writeTo(getOutputStream()); 61 * 62 * //close the document 63 * document.close(); 64 * </pre> 65 */ 66 public class PrintedPdfDocument extends PdfDocument { 67 private static final int MILS_PER_INCH = 1000; 68 private static final int POINTS_IN_INCH = 72; 69 70 private final int mPageWidth; 71 private final int mPageHeight; 72 private final Rect mContentRect; 73 74 /** 75 * Creates a new document. 76 * <p> 77 * <strong>Note:</strong> You must close the document after you are 78 * done by calling {@link #close()}. 79 * </p> 80 * 81 * @param context Context instance for accessing resources. 82 * @param attributes The print attributes. 83 */ PrintedPdfDocument(Context context, PrintAttributes attributes)84 public PrintedPdfDocument(Context context, PrintAttributes attributes) { 85 MediaSize mediaSize = attributes.getMediaSize(); 86 87 // Compute the size of the target canvas from the attributes. 88 mPageWidth = (int) (((float) mediaSize.getWidthMils() / MILS_PER_INCH) 89 * POINTS_IN_INCH); 90 mPageHeight = (int) (((float) mediaSize.getHeightMils() / MILS_PER_INCH) 91 * POINTS_IN_INCH); 92 93 // Compute the content size from the attributes. 94 Margins minMargins = attributes.getMinMargins(); 95 final int marginLeft = (int) (((float) minMargins.getLeftMils() / MILS_PER_INCH) 96 * POINTS_IN_INCH); 97 final int marginTop = (int) (((float) minMargins.getTopMils() / MILS_PER_INCH) 98 * POINTS_IN_INCH); 99 final int marginRight = (int) (((float) minMargins.getRightMils() / MILS_PER_INCH) 100 * POINTS_IN_INCH); 101 final int marginBottom = (int) (((float) minMargins.getBottomMils() / MILS_PER_INCH) 102 * POINTS_IN_INCH); 103 mContentRect = new Rect(marginLeft, marginTop, mPageWidth - marginRight, 104 mPageHeight - marginBottom); 105 } 106 107 /** 108 * Starts a new page. The page is created using width, height and content 109 * rectangle computed from the print attributes passed in the constructor 110 * and the given page number to create an appropriate {@link PageInfo}. 111 * <p> 112 * After the page is created you can draw arbitrary content on the page's 113 * canvas which you can get by calling {@link Page#getCanvas() Page.getCanvas()}. 114 * After you are done drawing the content you should finish the page by calling 115 * {@link #finishPage(Page)}. After the page is finished you should no longer 116 * access the page or its canvas. 117 * </p> 118 * <p> 119 * <strong>Note:</strong> Do not call this method after {@link #close()}. 120 * Also do not call this method if the last page returned by this method 121 * is not finished by calling {@link #finishPage(Page)}. 122 * </p> 123 * 124 * @param pageNumber The page number. Must be a positive value. 125 * @return A blank page. 126 * 127 * @see #finishPage(Page) 128 */ startPage(int pageNumber)129 public Page startPage(int pageNumber) { 130 PageInfo pageInfo = new PageInfo 131 .Builder(mPageWidth, mPageHeight, pageNumber) 132 .setContentRect(mContentRect) 133 .create(); 134 return startPage(pageInfo); 135 } 136 137 /** 138 * Gets the page width. 139 * 140 * @return The page width in PostScript points (1/72th of an inch). 141 */ getPageWidth()142 public int getPageWidth() { 143 return mPageWidth; 144 } 145 146 /** 147 * Gets the page height. 148 * 149 * @return The page height in PostScript points (1/72th of an inch). 150 */ getPageHeight()151 public int getPageHeight() { 152 return mPageHeight; 153 } 154 155 /** 156 * Gets the content rectangle. This is the area of the page that 157 * contains printed data and is relative to the page top left. 158 * 159 * @return The content rectangle. 160 */ getPageContentRect()161 public Rect getPageContentRect() { 162 return mContentRect; 163 } 164 } 165