Svetoslav Ganov | ff4adde5 | 2013-06-10 08:47:27 -0700 | [diff] [blame] | 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.graphics.Bitmap; |
| 20 | import android.graphics.Canvas; |
| 21 | import android.graphics.Matrix; |
| 22 | import android.graphics.Rect; |
| 23 | |
| 24 | import dalvik.system.CloseGuard; |
| 25 | |
| 26 | import java.io.OutputStream; |
| 27 | import java.util.ArrayList; |
| 28 | import java.util.Collections; |
| 29 | import java.util.List; |
| 30 | |
| 31 | /** |
| 32 | * <p> |
| 33 | * This class enables generating a PDF document from native Android content. You |
| 34 | * open a new document and then for every page you want to add you start a page, |
| 35 | * write content to the page, and finish the page. After you are done with all |
| 36 | * pages, you write the document to an output stream and close the document. |
| 37 | * After a document is closed you should not use it anymore. |
| 38 | * </p> |
| 39 | * <p> |
| 40 | * A typical use of the APIs looks like this: |
| 41 | * </p> |
| 42 | * <pre> |
| 43 | * // open a new document |
| 44 | * PdfDocument document = PdfDocument.open(); |
| 45 | * |
| 46 | * // crate a page description |
| 47 | * PageInfo pageInfo = new PageInfo.Builder(new Rect(0, 0, 100, 100), 1, 300).create(); |
| 48 | * |
| 49 | * // start a page |
| 50 | * Page page = document.startPage(pageInfo); |
| 51 | * |
| 52 | * // draw something on the page |
| 53 | * View content = getContentView(); |
| 54 | * content.draw(page.getCanvas()); |
| 55 | * |
| 56 | * // finish the page |
| 57 | * document.finishPage(page); |
| 58 | * . . . |
Svetoslav | 6283608 | 2013-07-17 14:52:35 -0700 | [diff] [blame] | 59 | * // add more pages |
Svetoslav Ganov | ff4adde5 | 2013-06-10 08:47:27 -0700 | [diff] [blame] | 60 | * . . . |
| 61 | * // write the document content |
| 62 | * document.writeTo(getOutputStream()); |
| 63 | * |
| 64 | * //close the document |
| 65 | * document.close(); |
| 66 | * </pre> |
| 67 | */ |
| 68 | public final class PdfDocument { |
| 69 | |
| 70 | private final byte[] mChunk = new byte[4096]; |
| 71 | |
| 72 | private final CloseGuard mCloseGuard = CloseGuard.get(); |
| 73 | |
| 74 | private final List<PageInfo> mPages = new ArrayList<PageInfo>(); |
| 75 | |
| 76 | private int mNativeDocument; |
| 77 | |
| 78 | private Page mCurrentPage; |
| 79 | |
| 80 | /** |
| 81 | * Opens a new document. |
| 82 | * <p> |
| 83 | * <strong>Note:</strong> You must close the document after you are |
| 84 | * done by calling {@link #close()} |
| 85 | * </p> |
| 86 | * |
| 87 | * @return The document. |
| 88 | * |
| 89 | * @see #close() |
| 90 | */ |
| 91 | public static PdfDocument open() { |
| 92 | return new PdfDocument(); |
| 93 | } |
| 94 | |
| 95 | /** |
| 96 | * Creates a new instance. |
| 97 | */ |
| 98 | private PdfDocument() { |
| 99 | mNativeDocument = nativeCreateDocument(); |
| 100 | mCloseGuard.open("close"); |
| 101 | } |
| 102 | |
| 103 | /** |
| 104 | * Starts a page using the provided {@link PageInfo}. After the page |
| 105 | * is created you can draw arbitrary content on the page's canvas which |
| 106 | * you can get by calling {@link Page#getCanvas()}. After you are done |
| 107 | * drawing the content you should finish the page by calling |
Svetoslav | fd90651 | 2013-06-24 09:04:48 -0700 | [diff] [blame] | 108 | * {@link #finishPage(Page)}. After the page is finished you should |
Svetoslav Ganov | ff4adde5 | 2013-06-10 08:47:27 -0700 | [diff] [blame] | 109 | * no longer access the page or its canvas. |
| 110 | * <p> |
| 111 | * <strong>Note:</strong> Do not call this method after {@link #close()}. |
| 112 | * </p> |
| 113 | * |
| 114 | * @param pageInfo The page info. |
| 115 | * @return A blank page. |
| 116 | * |
| 117 | * @see #finishPage(Page) |
| 118 | */ |
| 119 | public Page startPage(PageInfo pageInfo) { |
| 120 | throwIfClosed(); |
| 121 | if (pageInfo == null) { |
| 122 | throw new IllegalArgumentException("page cannot be null!"); |
| 123 | } |
| 124 | if (mCurrentPage != null) { |
| 125 | throw new IllegalStateException("Previous page not finished!"); |
| 126 | } |
| 127 | Canvas canvas = new PdfCanvas(nativeCreatePage(pageInfo.mPageSize, |
| 128 | pageInfo.mContentSize, pageInfo.mInitialTransform.native_instance), |
| 129 | pageInfo.mDensity); |
| 130 | mCurrentPage = new Page(canvas, pageInfo); |
| 131 | return mCurrentPage; |
| 132 | } |
| 133 | |
| 134 | /** |
| 135 | * Finishes a started page. You should always finish the last started page. |
| 136 | * <p> |
| 137 | * <strong>Note:</strong> Do not call this method after {@link #close()}. |
| 138 | * </p> |
| 139 | * |
| 140 | * @param page The page. |
| 141 | * |
| 142 | * @see #startPage(PageInfo) |
| 143 | */ |
| 144 | public void finishPage(Page page) { |
| 145 | throwIfClosed(); |
| 146 | if (page == null) { |
| 147 | throw new IllegalArgumentException("page cannot be null"); |
| 148 | } |
| 149 | if (page != mCurrentPage) { |
| 150 | throw new IllegalStateException("invalid page"); |
| 151 | } |
| 152 | mPages.add(page.getInfo()); |
| 153 | mCurrentPage = null; |
| 154 | nativeAppendPage(mNativeDocument, page.mCanvas.mNativeCanvas); |
| 155 | page.finish(); |
| 156 | } |
| 157 | |
| 158 | /** |
| 159 | * Writes the document to an output stream. |
| 160 | * <p> |
| 161 | * <strong>Note:</strong> Do not call this method after {@link #close()}. |
| 162 | * </p> |
| 163 | * |
| 164 | * @param out The output stream. |
| 165 | */ |
| 166 | public void writeTo(OutputStream out) { |
| 167 | throwIfClosed(); |
| 168 | if (out == null) { |
| 169 | throw new IllegalArgumentException("out cannot be null!"); |
| 170 | } |
| 171 | nativeWriteTo(mNativeDocument, out, mChunk); |
| 172 | } |
| 173 | |
| 174 | /** |
| 175 | * Gets the pages of the document. |
| 176 | * |
| 177 | * @return The pages. |
| 178 | */ |
| 179 | public List<PageInfo> getPages() { |
| 180 | return Collections.unmodifiableList(mPages); |
| 181 | } |
| 182 | |
| 183 | /** |
| 184 | * Closes this document. This method should be called after you |
| 185 | * are done working with the document. After this call the document |
| 186 | * is considered closed and none of its methods should be called. |
| 187 | */ |
| 188 | public void close() { |
| 189 | dispose(); |
| 190 | } |
| 191 | |
| 192 | @Override |
| 193 | protected void finalize() throws Throwable { |
| 194 | try { |
| 195 | mCloseGuard.warnIfOpen(); |
| 196 | dispose(); |
| 197 | } finally { |
| 198 | super.finalize(); |
| 199 | } |
| 200 | } |
| 201 | |
| 202 | private void dispose() { |
| 203 | if (mNativeDocument != 0) { |
| 204 | nativeFinalize(mNativeDocument); |
| 205 | mCloseGuard.close(); |
| 206 | mNativeDocument = 0; |
| 207 | } |
| 208 | } |
| 209 | |
| 210 | /** |
| 211 | * Throws an exception if the document is already closed. |
| 212 | */ |
| 213 | private void throwIfClosed() { |
| 214 | if (mNativeDocument == 0) { |
| 215 | throw new IllegalStateException("document is closed!"); |
| 216 | } |
| 217 | } |
| 218 | |
| 219 | private native int nativeCreateDocument(); |
| 220 | |
| 221 | private native void nativeFinalize(int document); |
| 222 | |
| 223 | private native void nativeAppendPage(int document, int page); |
| 224 | |
| 225 | private native void nativeWriteTo(int document, OutputStream out, byte[] chunk); |
| 226 | |
| 227 | private static native int nativeCreatePage(Rect pageSize, |
| 228 | Rect contentSize, int nativeMatrix); |
| 229 | |
| 230 | |
| 231 | private final class PdfCanvas extends Canvas { |
| 232 | |
| 233 | public PdfCanvas(int nativeCanvas, int density) { |
| 234 | super(nativeCanvas); |
| 235 | super.setDensity(density); |
| 236 | } |
| 237 | |
| 238 | @Override |
| 239 | public void setBitmap(Bitmap bitmap) { |
| 240 | throw new UnsupportedOperationException(); |
| 241 | } |
| 242 | |
| 243 | @Override |
| 244 | public void setDensity(int density) { |
| 245 | throw new UnsupportedOperationException(); |
| 246 | } |
| 247 | |
| 248 | @Override |
| 249 | public void setScreenDensity(int density) { |
| 250 | throw new UnsupportedOperationException(); |
| 251 | } |
| 252 | } |
| 253 | |
| 254 | /** |
| 255 | * This class represents meta-data that describes a PDF {@link Page}. |
| 256 | */ |
| 257 | public static final class PageInfo { |
| 258 | private Rect mPageSize; |
| 259 | private Rect mContentSize; |
| 260 | private Matrix mInitialTransform; |
| 261 | private int mPageNumber; |
| 262 | private int mDensity; |
| 263 | |
| 264 | /** |
| 265 | * Creates a new instance. |
| 266 | */ |
| 267 | private PageInfo() { |
| 268 | /* do nothing */ |
| 269 | } |
| 270 | |
| 271 | /** |
| 272 | * Gets the page size in pixels. |
| 273 | * |
| 274 | * @return The page size. |
| 275 | */ |
| 276 | public Rect getPageSize() { |
| 277 | return mPageSize; |
| 278 | } |
| 279 | |
| 280 | /** |
| 281 | * Get the content size in pixels. |
| 282 | * |
| 283 | * @return The content size. |
| 284 | */ |
| 285 | public Rect getContentSize() { |
| 286 | return mContentSize; |
| 287 | } |
| 288 | |
| 289 | /** |
| 290 | * Gets the initial transform which is applied to the page. This may be |
| 291 | * useful to move the origin to account for a margin, apply scale, or |
| 292 | * apply a rotation. |
| 293 | * |
| 294 | * @return The initial transform. |
| 295 | */ |
| 296 | public Matrix getInitialTransform() { |
| 297 | return mInitialTransform; |
| 298 | } |
| 299 | |
| 300 | /** |
| 301 | * Gets the page number. |
| 302 | * |
| 303 | * @return The page number. |
| 304 | */ |
| 305 | public int getPageNumber() { |
| 306 | return mPageNumber; |
| 307 | } |
| 308 | |
| 309 | /** |
| 310 | * Gets the density of the page in DPI. |
| 311 | * |
| 312 | * @return The density. |
| 313 | */ |
| 314 | public int getDesity() { |
| 315 | return mDensity; |
| 316 | } |
| 317 | |
| 318 | /** |
| 319 | * Builder for creating a {@link PageInfo}. |
| 320 | */ |
| 321 | public static final class Builder { |
| 322 | private final PageInfo mPageInfo = new PageInfo(); |
| 323 | |
| 324 | /** |
| 325 | * Creates a new builder with the mandatory page info attributes. |
| 326 | * |
| 327 | * @param pageSize The page size in pixels. |
| 328 | * @param pageNumber The page number. |
| 329 | * @param density The page density in DPI. |
| 330 | */ |
| 331 | public Builder(Rect pageSize, int pageNumber, int density) { |
| 332 | if (pageSize.width() == 0 || pageSize.height() == 0) { |
| 333 | throw new IllegalArgumentException("page width and height" + |
| 334 | " must be greater than zero!"); |
| 335 | } |
| 336 | if (pageNumber < 0) { |
| 337 | throw new IllegalArgumentException("pageNumber cannot be less than zero!"); |
| 338 | } |
| 339 | if (density <= 0) { |
| 340 | throw new IllegalArgumentException("density must be greater than zero!"); |
| 341 | } |
| 342 | mPageInfo.mPageSize = pageSize; |
| 343 | mPageInfo.mPageNumber = pageNumber; |
| 344 | mPageInfo.mDensity = density; |
| 345 | } |
| 346 | |
| 347 | /** |
| 348 | * Sets the content size in pixels. |
| 349 | * |
| 350 | * @param contentSize The content size. |
| 351 | */ |
| 352 | public Builder setContentSize(Rect contentSize) { |
| 353 | Rect pageSize = mPageInfo.mPageSize; |
| 354 | if (contentSize != null && (pageSize.left > contentSize.left |
| 355 | || pageSize.top > contentSize.top |
| 356 | || pageSize.right < contentSize.right |
| 357 | || pageSize.bottom < contentSize.bottom)) { |
| 358 | throw new IllegalArgumentException("contentSize does not fit the pageSize!"); |
| 359 | } |
| 360 | mPageInfo.mContentSize = contentSize; |
| 361 | return this; |
| 362 | } |
| 363 | |
| 364 | /** |
| 365 | * Sets the initial transform which is applied to the page. This may be |
| 366 | * useful to move the origin to account for a margin, apply scale, or |
| 367 | * apply a rotation. |
| 368 | * |
| 369 | * @param transform The initial transform. |
| 370 | */ |
| 371 | public Builder setInitialTransform(Matrix transform) { |
| 372 | mPageInfo.mInitialTransform = transform; |
| 373 | return this; |
| 374 | } |
| 375 | |
| 376 | /** |
| 377 | * Creates a new {@link PageInfo}. |
| 378 | * |
| 379 | * @return The new instance. |
| 380 | */ |
| 381 | public PageInfo create() { |
| 382 | if (mPageInfo.mContentSize == null) { |
| 383 | mPageInfo.mContentSize = mPageInfo.mPageSize; |
| 384 | } |
| 385 | if (mPageInfo.mInitialTransform == null) { |
| 386 | mPageInfo.mInitialTransform = new Matrix(); |
| 387 | } |
| 388 | return mPageInfo; |
| 389 | } |
| 390 | } |
| 391 | } |
| 392 | |
| 393 | /** |
| 394 | * This class represents a PDF document page. It has associated |
| 395 | * a canvas on which you can draw content and is acquired by a |
| 396 | * call to {@link #getCanvas()}. It also has associated a |
| 397 | * {@link PageInfo} instance that describes its attributes. |
| 398 | */ |
| 399 | public static final class Page { |
| 400 | private final PageInfo mPageInfo; |
| 401 | private Canvas mCanvas; |
| 402 | |
| 403 | /** |
| 404 | * Creates a new instance. |
| 405 | * |
| 406 | * @param canvas The canvas of the page. |
| 407 | * @param pageInfo The info with meta-data. |
| 408 | */ |
| 409 | private Page(Canvas canvas, PageInfo pageInfo) { |
| 410 | mCanvas = canvas; |
| 411 | mPageInfo = pageInfo; |
| 412 | } |
| 413 | |
| 414 | /** |
| 415 | * Gets the {@link Canvas} of the page. |
| 416 | * |
| 417 | * @return The canvas if the page is not finished, null otherwise. |
| 418 | * |
| 419 | * @see PdfDocument#finishPage(Page) |
| 420 | */ |
| 421 | public Canvas getCanvas() { |
| 422 | return mCanvas; |
| 423 | } |
| 424 | |
| 425 | /** |
| 426 | * Gets the {@link PageInfo} with meta-data for the page. |
| 427 | * |
| 428 | * @return The page info. |
| 429 | * |
| 430 | * @see PdfDocument#finishPage(Page) |
| 431 | */ |
| 432 | public PageInfo getInfo() { |
| 433 | return mPageInfo; |
| 434 | } |
| 435 | |
| 436 | private void finish() { |
| 437 | if (mCanvas != null) { |
| 438 | mCanvas.release(); |
| 439 | mCanvas = null; |
| 440 | } |
| 441 | } |
| 442 | } |
| 443 | } |