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 android.graphics.pdf; 18 19 import android.annotation.IntDef; 20 import android.annotation.NonNull; 21 import android.annotation.Nullable; 22 import android.graphics.Bitmap; 23 import android.graphics.Bitmap.Config; 24 import android.graphics.Matrix; 25 import android.graphics.Point; 26 import android.graphics.Rect; 27 import android.os.ParcelFileDescriptor; 28 import android.system.ErrnoException; 29 import android.system.OsConstants; 30 import dalvik.system.CloseGuard; 31 import libcore.io.Libcore; 32 33 import java.io.IOException; 34 import java.lang.annotation.Retention; 35 import java.lang.annotation.RetentionPolicy; 36 37 /** 38 * <p> 39 * This class enables rendering a PDF document. This class is not thread safe. 40 * </p> 41 * <p> 42 * If you want to render a PDF, you create a renderer and for every page you want 43 * to render, you open the page, render it, and close the page. After you are done 44 * with rendering, you close the renderer. After the renderer is closed it should not 45 * be used anymore. Note that the pages are rendered one by one, i.e. you can have 46 * only a single page opened at any given time. 47 * </p> 48 * <p> 49 * A typical use of the APIs to render a PDF looks like this: 50 * </p> 51 * <pre> 52 * // create a new renderer 53 * PdfRenderer renderer = new PdfRenderer(getSeekableFileDescriptor()); 54 * 55 * // let us just render all pages 56 * final int pageCount = renderer.getPageCount(); 57 * for (int i = 0; i < pageCount; i++) { 58 * Page page = renderer.openPage(i); 59 * 60 * // say we render for showing on the screen 61 * page.render(mBitmap, null, null, Page.RENDER_MODE_FOR_DISPLAY); 62 * 63 * // do stuff with the bitmap 64 * 65 * // close the page 66 * page.close(); 67 * } 68 * 69 * // close the renderer 70 * renderer.close(); 71 * </pre> 72 * 73 * <h3>Print preview and print output</h3> 74 * <p> 75 * If you are using this class to rasterize a PDF for printing or show a print 76 * preview, it is recommended that you respect the following contract in order 77 * to provide a consistent user experience when seeing a preview and printing, 78 * i.e. the user sees a preview that is the same as the printout. 79 * </p> 80 * <ul> 81 * <li> 82 * Respect the property whether the document would like to be scaled for printing 83 * as per {@link #shouldScaleForPrinting()}. 84 * </li> 85 * <li> 86 * When scaling a document for printing the aspect ratio should be preserved. 87 * </li> 88 * <li> 89 * Do not inset the content with any margins from the {@link android.print.PrintAttributes} 90 * as the application is responsible to render it such that the margins are respected. 91 * </li> 92 * <li> 93 * If document page size is greater than the printed media size the content should 94 * be anchored to the upper left corner of the page for left-to-right locales and 95 * top right corner for right-to-left locales. 96 * </li> 97 * </ul> 98 * 99 * @see #close() 100 */ 101 public final class PdfRenderer implements AutoCloseable { 102 /** 103 * Any call the native pdfium code has to be single threaded as the library does not support 104 * parallel use. 105 */ 106 final static Object sPdfiumLock = new Object(); 107 108 private final CloseGuard mCloseGuard = CloseGuard.get(); 109 110 private final Point mTempPoint = new Point(); 111 112 private final long mNativeDocument; 113 114 private final int mPageCount; 115 116 private ParcelFileDescriptor mInput; 117 118 private Page mCurrentPage; 119 120 /** @hide */ 121 @IntDef({ 122 Page.RENDER_MODE_FOR_DISPLAY, 123 Page.RENDER_MODE_FOR_PRINT 124 }) 125 @Retention(RetentionPolicy.SOURCE) 126 public @interface RenderMode {} 127 128 /** 129 * Creates a new instance. 130 * <p> 131 * <strong>Note:</strong> The provided file descriptor must be <strong>seekable</strong>, 132 * i.e. its data being randomly accessed, e.g. pointing to a file. 133 * </p> 134 * <p> 135 * <strong>Note:</strong> This class takes ownership of the passed in file descriptor 136 * and is responsible for closing it when the renderer is closed. 137 * </p> 138 * <p> 139 * If the file is from an untrusted source it is recommended to run the renderer in a separate, 140 * isolated process with minimal permissions to limit the impact of security exploits. 141 * </p> 142 * 143 * @param input Seekable file descriptor to read from. 144 * 145 * @throws java.io.IOException If an error occurs while reading the file. 146 * @throws java.lang.SecurityException If the file requires a password or 147 * the security scheme is not supported. 148 */ 149 public PdfRenderer(@NonNull ParcelFileDescriptor input) throws IOException { 150 if (input == null) { 151 throw new NullPointerException("input cannot be null"); 152 } 153 154 final long size; 155 try { 156 Libcore.os.lseek(input.getFileDescriptor(), 0, OsConstants.SEEK_SET); 157 size = Libcore.os.fstat(input.getFileDescriptor()).st_size; 158 } catch (ErrnoException ee) { 159 throw new IllegalArgumentException("file descriptor not seekable"); 160 } 161 162 mInput = input; 163 164 synchronized (sPdfiumLock) { 165 mNativeDocument = nativeCreate(mInput.getFd(), size); 166 mPageCount = nativeGetPageCount(mNativeDocument); 167 } 168 169 mCloseGuard.open("close"); 170 } 171 172 /** 173 * Closes this renderer. You should not use this instance 174 * after this method is called. 175 */ 176 public void close() { 177 throwIfClosed(); 178 throwIfPageOpened(); 179 doClose(); 180 } 181 182 /** 183 * Gets the number of pages in the document. 184 * 185 * @return The page count. 186 */ 187 public int getPageCount() { 188 throwIfClosed(); 189 return mPageCount; 190 } 191 192 /** 193 * Gets whether the document prefers to be scaled for printing. 194 * You should take this info account if the document is rendered 195 * for printing and the target media size differs from the page 196 * size. 197 * 198 * @return If to scale the document. 199 */ 200 public boolean shouldScaleForPrinting() { 201 throwIfClosed(); 202 203 synchronized (sPdfiumLock) { 204 return nativeScaleForPrinting(mNativeDocument); 205 } 206 } 207 208 /** 209 * Opens a page for rendering. 210 * 211 * @param index The page index. 212 * @return A page that can be rendered. 213 * 214 * @see android.graphics.pdf.PdfRenderer.Page#close() PdfRenderer.Page.close() 215 */ 216 public Page openPage(int index) { 217 throwIfClosed(); 218 throwIfPageOpened(); 219 throwIfPageNotInDocument(index); 220 mCurrentPage = new Page(index); 221 return mCurrentPage; 222 } 223 224 @Override 225 protected void finalize() throws Throwable { 226 try { 227 mCloseGuard.warnIfOpen(); 228 if (mInput != null) { 229 doClose(); 230 } 231 } finally { 232 super.finalize(); 233 } 234 } 235 236 private void doClose() { 237 if (mCurrentPage != null) { 238 mCurrentPage.close(); 239 } 240 synchronized (sPdfiumLock) { 241 nativeClose(mNativeDocument); 242 } 243 try { 244 mInput.close(); 245 } catch (IOException ioe) { 246 /* ignore - best effort */ 247 } 248 mInput = null; 249 mCloseGuard.close(); 250 } 251 252 private void throwIfClosed() { 253 if (mInput == null) { 254 throw new IllegalStateException("Already closed"); 255 } 256 } 257 258 private void throwIfPageOpened() { 259 if (mCurrentPage != null) { 260 throw new IllegalStateException("Current page not closed"); 261 } 262 } 263 264 private void throwIfPageNotInDocument(int pageIndex) { 265 if (pageIndex < 0 || pageIndex >= mPageCount) { 266 throw new IllegalArgumentException("Invalid page index"); 267 } 268 } 269 270 /** 271 * This class represents a PDF document page for rendering. 272 */ 273 public final class Page implements AutoCloseable { 274 275 private final CloseGuard mCloseGuard = CloseGuard.get(); 276 277 /** 278 * Mode to render the content for display on a screen. 279 */ 280 public static final int RENDER_MODE_FOR_DISPLAY = 1; 281 282 /** 283 * Mode to render the content for printing. 284 */ 285 public static final int RENDER_MODE_FOR_PRINT = 2; 286 287 private final int mIndex; 288 private final int mWidth; 289 private final int mHeight; 290 291 private long mNativePage; 292 293 private Page(int index) { 294 Point size = mTempPoint; 295 synchronized (sPdfiumLock) { 296 mNativePage = nativeOpenPageAndGetSize(mNativeDocument, index, size); 297 } 298 mIndex = index; 299 mWidth = size.x; 300 mHeight = size.y; 301 mCloseGuard.open("close"); 302 } 303 304 /** 305 * Gets the page index. 306 * 307 * @return The index. 308 */ 309 public int getIndex() { 310 return mIndex; 311 } 312 313 /** 314 * Gets the page width in points (1/72"). 315 * 316 * @return The width in points. 317 */ 318 public int getWidth() { 319 return mWidth; 320 } 321 322 /** 323 * Gets the page height in points (1/72"). 324 * 325 * @return The height in points. 326 */ 327 public int getHeight() { 328 return mHeight; 329 } 330 331 /** 332 * Renders a page to a bitmap. 333 * <p> 334 * You may optionally specify a rectangular clip in the bitmap bounds. No rendering 335 * outside the clip will be performed, hence it is your responsibility to initialize 336 * the bitmap outside the clip. 337 * </p> 338 * <p> 339 * You may optionally specify a matrix to transform the content from page coordinates 340 * which are in points (1/72") to bitmap coordinates which are in pixels. If this 341 * matrix is not provided this method will apply a transformation that will fit the 342 * whole page to the destination clip if provided or the destination bitmap if no 343 * clip is provided. 344 * </p> 345 * <p> 346 * The clip and transformation are useful for implementing tile rendering where the 347 * destination bitmap contains a portion of the image, for example when zooming. 348 * Another useful application is for printing where the size of the bitmap holding 349 * the page is too large and a client can render the page in stripes. 350 * </p> 351 * <p> 352 * <strong>Note: </strong> The destination bitmap format must be 353 * {@link Config#ARGB_8888 ARGB}. 354 * </p> 355 * <p> 356 * <strong>Note: </strong> The optional transformation matrix must be affine as per 357 * {@link android.graphics.Matrix#isAffine() Matrix.isAffine()}. Hence, you can specify 358 * rotation, scaling, translation but not a perspective transformation. 359 * </p> 360 * 361 * @param destination Destination bitmap to which to render. 362 * @param destClip Optional clip in the bitmap bounds. 363 * @param transform Optional transformation to apply when rendering. 364 * @param renderMode The render mode. 365 * 366 * @see #RENDER_MODE_FOR_DISPLAY 367 * @see #RENDER_MODE_FOR_PRINT 368 */ 369 public void render(@NonNull Bitmap destination, @Nullable Rect destClip, 370 @Nullable Matrix transform, @RenderMode int renderMode) { 371 if (destination.getConfig() != Config.ARGB_8888) { 372 throw new IllegalArgumentException("Unsupported pixel format"); 373 } 374 375 if (destClip != null) { 376 if (destClip.left < 0 || destClip.top < 0 377 || destClip.right > destination.getWidth() 378 || destClip.bottom > destination.getHeight()) { 379 throw new IllegalArgumentException("destBounds not in destination"); 380 } 381 } 382 383 if (transform != null && !transform.isAffine()) { 384 throw new IllegalArgumentException("transform not affine"); 385 } 386 387 if (renderMode != RENDER_MODE_FOR_PRINT && renderMode != RENDER_MODE_FOR_DISPLAY) { 388 throw new IllegalArgumentException("Unsupported render mode"); 389 } 390 391 if (renderMode == RENDER_MODE_FOR_PRINT && renderMode == RENDER_MODE_FOR_DISPLAY) { 392 throw new IllegalArgumentException("Only single render mode supported"); 393 } 394 395 final int contentLeft = (destClip != null) ? destClip.left : 0; 396 final int contentTop = (destClip != null) ? destClip.top : 0; 397 final int contentRight = (destClip != null) ? destClip.right 398 : destination.getWidth(); 399 final int contentBottom = (destClip != null) ? destClip.bottom 400 : destination.getHeight(); 401 402 final long transformPtr = (transform != null) ? transform.native_instance : 0; 403 404 synchronized (sPdfiumLock) { 405 nativeRenderPage(mNativeDocument, mNativePage, destination, contentLeft, 406 contentTop, contentRight, contentBottom, transformPtr, renderMode); 407 } 408 } 409 410 /** 411 * Closes this page. 412 * 413 * @see android.graphics.pdf.PdfRenderer#openPage(int) 414 */ 415 @Override 416 public void close() { 417 throwIfClosed(); 418 doClose(); 419 } 420 421 @Override 422 protected void finalize() throws Throwable { 423 try { 424 mCloseGuard.warnIfOpen(); 425 if (mNativePage != 0) { 426 doClose(); 427 } 428 } finally { 429 super.finalize(); 430 } 431 } 432 433 private void doClose() { 434 synchronized (sPdfiumLock) { 435 nativeClosePage(mNativePage); 436 } 437 mNativePage = 0; 438 mCloseGuard.close(); 439 mCurrentPage = null; 440 } 441 442 private void throwIfClosed() { 443 if (mNativePage == 0) { 444 throw new IllegalStateException("Already closed"); 445 } 446 } 447 } 448 449 private static native long nativeCreate(int fd, long size); 450 private static native void nativeClose(long documentPtr); 451 private static native int nativeGetPageCount(long documentPtr); 452 private static native boolean nativeScaleForPrinting(long documentPtr); 453 private static native void nativeRenderPage(long documentPtr, long pagePtr, Bitmap dest, 454 int destLeft, int destTop, int destRight, int destBottom, long matrixPtr, int renderMode); 455 private static native long nativeOpenPageAndGetSize(long documentPtr, int pageIndex, 456 Point outSize); 457 private static native void nativeClosePage(long pagePtr); 458 } 459