1 /* 2 * Copyright (C) 2006 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.view.animation; 18 19 import android.annotation.FloatRange; 20 import android.graphics.Matrix; 21 import android.graphics.Rect; 22 23 import java.io.PrintWriter; 24 25 /** 26 * Defines the transformation to be applied at 27 * one point in time of an Animation. 28 * 29 */ 30 public class Transformation { 31 /** 32 * Indicates a transformation that has no effect (alpha = 1 and identity matrix.) 33 */ 34 public static final int TYPE_IDENTITY = 0x0; 35 /** 36 * Indicates a transformation that applies an alpha only (uses an identity matrix.) 37 */ 38 public static final int TYPE_ALPHA = 0x1; 39 /** 40 * Indicates a transformation that applies a matrix only (alpha = 1.) 41 */ 42 public static final int TYPE_MATRIX = 0x2; 43 /** 44 * Indicates a transformation that applies an alpha and a matrix. 45 */ 46 public static final int TYPE_BOTH = TYPE_ALPHA | TYPE_MATRIX; 47 48 protected Matrix mMatrix; 49 protected float mAlpha; 50 protected int mTransformationType; 51 52 private boolean mHasClipRect; 53 private Rect mClipRect = new Rect(); 54 55 /** 56 * Creates a new transformation with alpha = 1 and the identity matrix. 57 */ Transformation()58 public Transformation() { 59 clear(); 60 } 61 62 /** 63 * Reset the transformation to a state that leaves the object 64 * being animated in an unmodified state. The transformation type is 65 * {@link #TYPE_BOTH} by default. 66 */ clear()67 public void clear() { 68 if (mMatrix == null) { 69 mMatrix = new Matrix(); 70 } else { 71 mMatrix.reset(); 72 } 73 mClipRect.setEmpty(); 74 mHasClipRect = false; 75 mAlpha = 1.0f; 76 mTransformationType = TYPE_BOTH; 77 } 78 79 /** 80 * Indicates the nature of this transformation. 81 * 82 * @return {@link #TYPE_ALPHA}, {@link #TYPE_MATRIX}, 83 * {@link #TYPE_BOTH} or {@link #TYPE_IDENTITY}. 84 */ getTransformationType()85 public int getTransformationType() { 86 return mTransformationType; 87 } 88 89 /** 90 * Sets the transformation type. 91 * 92 * @param transformationType One of {@link #TYPE_ALPHA}, 93 * {@link #TYPE_MATRIX}, {@link #TYPE_BOTH} or 94 * {@link #TYPE_IDENTITY}. 95 */ setTransformationType(int transformationType)96 public void setTransformationType(int transformationType) { 97 mTransformationType = transformationType; 98 } 99 100 /** 101 * Clones the specified transformation. 102 * 103 * @param t The transformation to clone. 104 */ set(Transformation t)105 public void set(Transformation t) { 106 mAlpha = t.getAlpha(); 107 mMatrix.set(t.getMatrix()); 108 if (t.mHasClipRect) { 109 setClipRect(t.getClipRect()); 110 } else { 111 mHasClipRect = false; 112 mClipRect.setEmpty(); 113 } 114 mTransformationType = t.getTransformationType(); 115 } 116 117 /** 118 * Apply this Transformation to an existing Transformation, e.g. apply 119 * a scale effect to something that has already been rotated. 120 * @param t 121 */ compose(Transformation t)122 public void compose(Transformation t) { 123 mAlpha *= t.getAlpha(); 124 mMatrix.preConcat(t.getMatrix()); 125 if (t.mHasClipRect) { 126 Rect bounds = t.getClipRect(); 127 if (mHasClipRect) { 128 setClipRect(mClipRect.left + bounds.left, mClipRect.top + bounds.top, 129 mClipRect.right + bounds.right, mClipRect.bottom + bounds.bottom); 130 } else { 131 setClipRect(bounds); 132 } 133 } 134 } 135 136 /** 137 * Like {@link #compose(Transformation)} but does this.postConcat(t) of 138 * the transformation matrix. 139 * @hide 140 */ postCompose(Transformation t)141 public void postCompose(Transformation t) { 142 mAlpha *= t.getAlpha(); 143 mMatrix.postConcat(t.getMatrix()); 144 if (t.mHasClipRect) { 145 Rect bounds = t.getClipRect(); 146 if (mHasClipRect) { 147 setClipRect(mClipRect.left + bounds.left, mClipRect.top + bounds.top, 148 mClipRect.right + bounds.right, mClipRect.bottom + bounds.bottom); 149 } else { 150 setClipRect(bounds); 151 } 152 } 153 } 154 155 /** 156 * @return The 3x3 Matrix representing the trnasformation to apply to the 157 * coordinates of the object being animated 158 */ getMatrix()159 public Matrix getMatrix() { 160 return mMatrix; 161 } 162 163 /** 164 * Sets the degree of transparency 165 * @param alpha 1.0 means fully opaqe and 0.0 means fully transparent 166 */ setAlpha(@loatRangefrom=0.0, to=1.0) float alpha)167 public void setAlpha(@FloatRange(from=0.0, to=1.0) float alpha) { 168 mAlpha = alpha; 169 } 170 171 /** 172 * Sets the current Transform's clip rect 173 * @hide 174 */ setClipRect(Rect r)175 public void setClipRect(Rect r) { 176 setClipRect(r.left, r.top, r.right, r.bottom); 177 } 178 179 /** 180 * Sets the current Transform's clip rect 181 * @hide 182 */ setClipRect(int l, int t, int r, int b)183 public void setClipRect(int l, int t, int r, int b) { 184 mClipRect.set(l, t, r, b); 185 mHasClipRect = true; 186 } 187 188 /** 189 * Returns the current Transform's clip rect 190 * @hide 191 */ getClipRect()192 public Rect getClipRect() { 193 return mClipRect; 194 } 195 196 /** 197 * Returns whether the current Transform's clip rect is set 198 * @hide 199 */ hasClipRect()200 public boolean hasClipRect() { 201 return mHasClipRect; 202 } 203 204 /** 205 * @return The degree of transparency 206 */ getAlpha()207 public float getAlpha() { 208 return mAlpha; 209 } 210 211 @Override toString()212 public String toString() { 213 StringBuilder sb = new StringBuilder(64); 214 sb.append("Transformation"); 215 toShortString(sb); 216 return sb.toString(); 217 } 218 219 /** 220 * Return a string representation of the transformation in a compact form. 221 */ toShortString()222 public String toShortString() { 223 StringBuilder sb = new StringBuilder(64); 224 toShortString(sb); 225 return sb.toString(); 226 } 227 228 /** 229 * @hide 230 */ toShortString(StringBuilder sb)231 public void toShortString(StringBuilder sb) { 232 sb.append("{alpha="); sb.append(mAlpha); 233 sb.append(" matrix="); mMatrix.toShortString(sb); 234 sb.append('}'); 235 } 236 237 /** 238 * Print short string, to optimize dumping. 239 * @hide 240 */ printShortString(PrintWriter pw)241 public void printShortString(PrintWriter pw) { 242 pw.print("{alpha="); pw.print(mAlpha); 243 pw.print(" matrix="); 244 mMatrix.printShortString(pw); 245 pw.print('}'); 246 } 247 } 248