ShapeDrawable.java revision f0e06784609bd3a62cbf86499b4348f4521b6de6
1/* 2 * Copyright (C) 2007 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 17package android.graphics.drawable; 18 19import android.graphics.*; 20import android.graphics.drawable.shapes.Shape; 21import android.content.res.Resources; 22import android.content.res.TypedArray; 23import android.util.AttributeSet; 24 25import org.xmlpull.v1.XmlPullParser; 26import org.xmlpull.v1.XmlPullParserException; 27 28import java.io.IOException; 29 30/** 31 * A Drawable object that draws primitive shapes. 32 * A ShapeDrawable takes a {@link android.graphics.drawable.shapes.Shape} 33 * object and manages its presence on the screen. If no Shape is given, then 34 * the ShapeDrawable will default to a 35 * {@link android.graphics.drawable.shapes.RectShape}. 36 * 37 * <p>This object can be defined in an XML file with the <code><shape></code> element.</p> 38 * 39 * <div class="special reference"> 40 * <h3>Developer Guides</h3> 41 * <p>For more information about how to use ShapeDrawable, read the 42 * <a href="{@docRoot}guide/topics/graphics/2d-graphics.html#shape-drawable"> 43 * Canvas and Drawables</a> document. For more information about defining a ShapeDrawable in 44 * XML, read the 45 * <a href="{@docRoot}guide/topics/resources/drawable-resource.html#Shape">Drawable Resources</a> 46 * document.</p></div> 47 * 48 * @attr ref android.R.styleable#ShapeDrawablePadding_left 49 * @attr ref android.R.styleable#ShapeDrawablePadding_top 50 * @attr ref android.R.styleable#ShapeDrawablePadding_right 51 * @attr ref android.R.styleable#ShapeDrawablePadding_bottom 52 * @attr ref android.R.styleable#ShapeDrawable_color 53 * @attr ref android.R.styleable#ShapeDrawable_width 54 * @attr ref android.R.styleable#ShapeDrawable_height 55 */ 56public class ShapeDrawable extends Drawable { 57 private ShapeState mShapeState; 58 private boolean mMutated; 59 60 /** 61 * ShapeDrawable constructor. 62 */ 63 public ShapeDrawable() { 64 this((ShapeState) null); 65 } 66 67 /** 68 * Creates a ShapeDrawable with a specified Shape. 69 * 70 * @param s the Shape that this ShapeDrawable should be 71 */ 72 public ShapeDrawable(Shape s) { 73 this((ShapeState) null); 74 75 mShapeState.mShape = s; 76 } 77 78 private ShapeDrawable(ShapeState state) { 79 mShapeState = new ShapeState(state); 80 } 81 82 /** 83 * Returns the Shape of this ShapeDrawable. 84 */ 85 public Shape getShape() { 86 return mShapeState.mShape; 87 } 88 89 /** 90 * Sets the Shape of this ShapeDrawable. 91 */ 92 public void setShape(Shape s) { 93 mShapeState.mShape = s; 94 updateShape(); 95 } 96 97 /** 98 * Sets a ShaderFactory to which requests for a 99 * {@link android.graphics.Shader} object will be made. 100 * 101 * @param fact an instance of your ShaderFactory implementation 102 */ 103 public void setShaderFactory(ShaderFactory fact) { 104 mShapeState.mShaderFactory = fact; 105 } 106 107 /** 108 * Returns the ShaderFactory used by this ShapeDrawable for requesting a 109 * {@link android.graphics.Shader}. 110 */ 111 public ShaderFactory getShaderFactory() { 112 return mShapeState.mShaderFactory; 113 } 114 115 /** 116 * Returns the Paint used to draw the shape. 117 */ 118 public Paint getPaint() { 119 return mShapeState.mPaint; 120 } 121 122 /** 123 * Sets padding for the shape. 124 * 125 * @param left padding for the left side (in pixels) 126 * @param top padding for the top (in pixels) 127 * @param right padding for the right side (in pixels) 128 * @param bottom padding for the bottom (in pixels) 129 */ 130 public void setPadding(int left, int top, int right, int bottom) { 131 if ((left | top | right | bottom) == 0) { 132 mShapeState.mPadding = null; 133 } else { 134 if (mShapeState.mPadding == null) { 135 mShapeState.mPadding = new Rect(); 136 } 137 mShapeState.mPadding.set(left, top, right, bottom); 138 } 139 invalidateSelf(); 140 } 141 142 /** 143 * Sets padding for this shape, defined by a Rect object. 144 * Define the padding in the Rect object as: left, top, right, bottom. 145 */ 146 public void setPadding(Rect padding) { 147 if (padding == null) { 148 mShapeState.mPadding = null; 149 } else { 150 if (mShapeState.mPadding == null) { 151 mShapeState.mPadding = new Rect(); 152 } 153 mShapeState.mPadding.set(padding); 154 } 155 invalidateSelf(); 156 } 157 158 /** 159 * Sets the intrinsic (default) width for this shape. 160 * 161 * @param width the intrinsic width (in pixels) 162 */ 163 public void setIntrinsicWidth(int width) { 164 mShapeState.mIntrinsicWidth = width; 165 invalidateSelf(); 166 } 167 168 /** 169 * Sets the intrinsic (default) height for this shape. 170 * 171 * @param height the intrinsic height (in pixels) 172 */ 173 public void setIntrinsicHeight(int height) { 174 mShapeState.mIntrinsicHeight = height; 175 invalidateSelf(); 176 } 177 178 @Override 179 public int getIntrinsicWidth() { 180 return mShapeState.mIntrinsicWidth; 181 } 182 183 @Override 184 public int getIntrinsicHeight() { 185 return mShapeState.mIntrinsicHeight; 186 } 187 188 @Override 189 public boolean getPadding(Rect padding) { 190 if (mShapeState.mPadding != null) { 191 padding.set(mShapeState.mPadding); 192 return true; 193 } else { 194 return super.getPadding(padding); 195 } 196 } 197 198 private static int modulateAlpha(int paintAlpha, int alpha) { 199 int scale = alpha + (alpha >>> 7); // convert to 0..256 200 return paintAlpha * scale >>> 8; 201 } 202 203 /** 204 * Called from the drawable's draw() method after the canvas has been set 205 * to draw the shape at (0,0). Subclasses can override for special effects 206 * such as multiple layers, stroking, etc. 207 */ 208 protected void onDraw(Shape shape, Canvas canvas, Paint paint) { 209 shape.draw(canvas, paint); 210 } 211 212 @Override 213 public void draw(Canvas canvas) { 214 Rect r = getBounds(); 215 Paint paint = mShapeState.mPaint; 216 217 int prevAlpha = paint.getAlpha(); 218 paint.setAlpha(modulateAlpha(prevAlpha, mShapeState.mAlpha)); 219 220 // only draw shape if it may affect output 221 if (paint.getAlpha() != 0 || paint.getXfermode() != null || paint.hasShadow) { 222 if (mShapeState.mShape != null) { 223 // need the save both for the translate, and for the (unknown) Shape 224 int count = canvas.save(); 225 canvas.translate(r.left, r.top); 226 onDraw(mShapeState.mShape, canvas, paint); 227 canvas.restoreToCount(count); 228 } else { 229 canvas.drawRect(r, paint); 230 } 231 } 232 233 // restore 234 paint.setAlpha(prevAlpha); 235 } 236 237 @Override 238 public int getChangingConfigurations() { 239 return super.getChangingConfigurations() 240 | mShapeState.mChangingConfigurations; 241 } 242 243 /** 244 * Set the alpha level for this drawable [0..255]. Note that this drawable 245 * also has a color in its paint, which has an alpha as well. These two 246 * values are automatically combined during drawing. Thus if the color's 247 * alpha is 75% (i.e. 192) and the drawable's alpha is 50% (i.e. 128), then 248 * the combined alpha that will be used during drawing will be 37.5% 249 * (i.e. 96). 250 */ 251 @Override public void setAlpha(int alpha) { 252 mShapeState.mAlpha = alpha; 253 invalidateSelf(); 254 } 255 256 @Override 257 public void setColorFilter(ColorFilter cf) { 258 mShapeState.mPaint.setColorFilter(cf); 259 invalidateSelf(); 260 } 261 262 @Override 263 public int getOpacity() { 264 if (mShapeState.mShape == null) { 265 final Paint p = mShapeState.mPaint; 266 if (p.getXfermode() == null) { 267 final int alpha = p.getAlpha(); 268 if (alpha == 0) { 269 return PixelFormat.TRANSPARENT; 270 } 271 if (alpha == 255) { 272 return PixelFormat.OPAQUE; 273 } 274 } 275 } 276 // not sure, so be safe 277 return PixelFormat.TRANSLUCENT; 278 } 279 280 @Override 281 public void setDither(boolean dither) { 282 mShapeState.mPaint.setDither(dither); 283 invalidateSelf(); 284 } 285 286 @Override 287 protected void onBoundsChange(Rect bounds) { 288 super.onBoundsChange(bounds); 289 updateShape(); 290 } 291 292 /** 293 * Subclasses override this to parse custom subelements. 294 * If you handle it, return true, else return <em>super.inflateTag(...)</em>. 295 */ 296 protected boolean inflateTag(String name, Resources r, XmlPullParser parser, 297 AttributeSet attrs) { 298 299 if ("padding".equals(name)) { 300 TypedArray a = r.obtainAttributes(attrs, 301 com.android.internal.R.styleable.ShapeDrawablePadding); 302 setPadding( 303 a.getDimensionPixelOffset( 304 com.android.internal.R.styleable.ShapeDrawablePadding_left, 0), 305 a.getDimensionPixelOffset( 306 com.android.internal.R.styleable.ShapeDrawablePadding_top, 0), 307 a.getDimensionPixelOffset( 308 com.android.internal.R.styleable.ShapeDrawablePadding_right, 0), 309 a.getDimensionPixelOffset( 310 com.android.internal.R.styleable.ShapeDrawablePadding_bottom, 0)); 311 a.recycle(); 312 return true; 313 } 314 315 return false; 316 } 317 318 @Override 319 public void inflate(Resources r, XmlPullParser parser, AttributeSet attrs) 320 throws XmlPullParserException, IOException { 321 super.inflate(r, parser, attrs); 322 323 TypedArray a = r.obtainAttributes(attrs, com.android.internal.R.styleable.ShapeDrawable); 324 325 int color = mShapeState.mPaint.getColor(); 326 color = a.getColor(com.android.internal.R.styleable.ShapeDrawable_color, color); 327 mShapeState.mPaint.setColor(color); 328 329 boolean dither = a.getBoolean(com.android.internal.R.styleable.ShapeDrawable_dither, false); 330 mShapeState.mPaint.setDither(dither); 331 332 setIntrinsicWidth((int) 333 a.getDimension(com.android.internal.R.styleable.ShapeDrawable_width, 0f)); 334 setIntrinsicHeight((int) 335 a.getDimension(com.android.internal.R.styleable.ShapeDrawable_height, 0f)); 336 337 a.recycle(); 338 339 int type; 340 final int outerDepth = parser.getDepth(); 341 while ((type=parser.next()) != XmlPullParser.END_DOCUMENT 342 && (type != XmlPullParser.END_TAG || parser.getDepth() > outerDepth)) { 343 if (type != XmlPullParser.START_TAG) { 344 continue; 345 } 346 347 final String name = parser.getName(); 348 // call our subclass 349 if (!inflateTag(name, r, parser, attrs)) { 350 android.util.Log.w("drawable", "Unknown element: " + name + 351 " for ShapeDrawable " + this); 352 } 353 } 354 } 355 356 private void updateShape() { 357 if (mShapeState.mShape != null) { 358 final Rect r = getBounds(); 359 final int w = r.width(); 360 final int h = r.height(); 361 362 mShapeState.mShape.resize(w, h); 363 if (mShapeState.mShaderFactory != null) { 364 mShapeState.mPaint.setShader(mShapeState.mShaderFactory.resize(w, h)); 365 } 366 } 367 invalidateSelf(); 368 } 369 370 @Override 371 public ConstantState getConstantState() { 372 mShapeState.mChangingConfigurations = getChangingConfigurations(); 373 return mShapeState; 374 } 375 376 @Override 377 public Drawable mutate() { 378 if (!mMutated && super.mutate() == this) { 379 if (mShapeState.mPaint != null) { 380 mShapeState.mPaint = new Paint(mShapeState.mPaint); 381 } else { 382 mShapeState.mPaint = new Paint(Paint.ANTI_ALIAS_FLAG); 383 } 384 if (mShapeState.mPadding != null) { 385 mShapeState.mPadding = new Rect(mShapeState.mPadding); 386 } else { 387 mShapeState.mPadding = new Rect(); 388 } 389 try { 390 mShapeState.mShape = mShapeState.mShape.clone(); 391 } catch (CloneNotSupportedException e) { 392 return null; 393 } 394 mMutated = true; 395 } 396 return this; 397 } 398 399 /** 400 * Defines the intrinsic properties of this ShapeDrawable's Shape. 401 */ 402 final static class ShapeState extends ConstantState { 403 int mChangingConfigurations; 404 Paint mPaint; 405 Shape mShape; 406 Rect mPadding; 407 int mIntrinsicWidth; 408 int mIntrinsicHeight; 409 int mAlpha = 255; 410 ShaderFactory mShaderFactory; 411 412 ShapeState(ShapeState orig) { 413 if (orig != null) { 414 mPaint = orig.mPaint; 415 mShape = orig.mShape; 416 mPadding = orig.mPadding; 417 mIntrinsicWidth = orig.mIntrinsicWidth; 418 mIntrinsicHeight = orig.mIntrinsicHeight; 419 mAlpha = orig.mAlpha; 420 mShaderFactory = orig.mShaderFactory; 421 } else { 422 mPaint = new Paint(Paint.ANTI_ALIAS_FLAG); 423 } 424 } 425 426 @Override 427 public Drawable newDrawable() { 428 return new ShapeDrawable(this); 429 } 430 431 @Override 432 public Drawable newDrawable(Resources res) { 433 return new ShapeDrawable(this); 434 } 435 436 @Override 437 public int getChangingConfigurations() { 438 return mChangingConfigurations; 439 } 440 } 441 442 /** 443 * Base class defines a factory object that is called each time the drawable 444 * is resized (has a new width or height). Its resize() method returns a 445 * corresponding shader, or null. 446 * Implement this class if you'd like your ShapeDrawable to use a special 447 * {@link android.graphics.Shader}, such as a 448 * {@link android.graphics.LinearGradient}. 449 * 450 */ 451 public static abstract class ShaderFactory { 452 /** 453 * Returns the Shader to be drawn when a Drawable is drawn. 454 * The dimensions of the Drawable are passed because they may be needed 455 * to adjust how the Shader is configured for drawing. 456 * This is called by ShapeDrawable.setShape(). 457 * 458 * @param width the width of the Drawable being drawn 459 * @param height the heigh of the Drawable being drawn 460 * @return the Shader to be drawn 461 */ 462 public abstract Shader resize(int width, int height); 463 } 464 465 // other subclass could wack the Shader's localmatrix based on the 466 // resize params (e.g. scaletofit, etc.). This could be used to scale 467 // a bitmap to fill the bounds without needing any other special casing. 468} 469 470