1 /* 2 * Copyright (C) 2016 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 com.android.launcher3.keyboard; 18 19 import android.animation.Animator; 20 import android.animation.AnimatorListenerAdapter; 21 import android.animation.ObjectAnimator; 22 import android.animation.PropertyValuesHolder; 23 import android.animation.RectEvaluator; 24 import android.animation.ValueAnimator; 25 import android.animation.ValueAnimator.AnimatorUpdateListener; 26 import android.annotation.TargetApi; 27 import android.graphics.Canvas; 28 import android.graphics.Color; 29 import android.graphics.Paint; 30 import android.graphics.Rect; 31 import android.os.Build.VERSION_CODES; 32 import android.util.Property; 33 import android.view.View; 34 import android.view.View.OnFocusChangeListener; 35 36 import com.android.launcher3.R; 37 38 /** 39 * A helper class to draw background of a focused view. 40 */ 41 @TargetApi(VERSION_CODES.LOLLIPOP) 42 public abstract class FocusIndicatorHelper implements 43 OnFocusChangeListener, AnimatorUpdateListener { 44 45 private static final float MIN_VISIBLE_ALPHA = 0.2f; 46 private static final long ANIM_DURATION = 150; 47 48 public static final Property<FocusIndicatorHelper, Float> ALPHA = 49 new Property<FocusIndicatorHelper, Float>(Float.TYPE, "alpha") { 50 @Override 51 public void set(FocusIndicatorHelper object, Float value) { 52 object.setAlpha(value); 53 } 54 55 @Override 56 public Float get(FocusIndicatorHelper object) { 57 return object.mAlpha; 58 } 59 }; 60 61 public static final Property<FocusIndicatorHelper, Float> SHIFT = 62 new Property<FocusIndicatorHelper, Float>( 63 Float.TYPE, "shift") { 64 65 @Override 66 public void set(FocusIndicatorHelper object, Float value) { 67 object.mShift = value; 68 } 69 70 @Override 71 public Float get(FocusIndicatorHelper object) { 72 return object.mShift; 73 } 74 }; 75 76 private static final RectEvaluator RECT_EVALUATOR = new RectEvaluator(new Rect()); 77 private static final Rect sTempRect1 = new Rect(); 78 private static final Rect sTempRect2 = new Rect(); 79 80 private final View mContainer; 81 private final Paint mPaint; 82 private final int mMaxAlpha; 83 84 private final Rect mDirtyRect = new Rect(); 85 private boolean mIsDirty = false; 86 87 private View mLastFocusedView; 88 89 private View mCurrentView; 90 private View mTargetView; 91 /** 92 * The fraction indicating the position of the focusRect between {@link #mCurrentView} 93 * & {@link #mTargetView} 94 */ 95 private float mShift; 96 97 private ObjectAnimator mCurrentAnimation; 98 private float mAlpha; 99 100 public FocusIndicatorHelper(View container) { 101 mContainer = container; 102 103 mPaint = new Paint(Paint.ANTI_ALIAS_FLAG); 104 int color = container.getResources().getColor(R.color.focused_background); 105 mMaxAlpha = Color.alpha(color); 106 mPaint.setColor(0xFF000000 | color); 107 108 setAlpha(0); 109 mShift = 0; 110 } 111 112 protected void setAlpha(float alpha) { 113 mAlpha = alpha; 114 mPaint.setAlpha((int) (mAlpha * mMaxAlpha)); 115 } 116 117 @Override 118 public void onAnimationUpdate(ValueAnimator animation) { 119 invalidateDirty(); 120 } 121 122 protected void invalidateDirty() { 123 if (mIsDirty) { 124 mContainer.invalidate(mDirtyRect); 125 mIsDirty = false; 126 } 127 128 Rect newRect = getDrawRect(); 129 if (newRect != null) { 130 mContainer.invalidate(newRect); 131 } 132 } 133 134 public void draw(Canvas c) { 135 if (mAlpha > 0) { 136 Rect newRect = getDrawRect(); 137 if (newRect != null) { 138 mDirtyRect.set(newRect); 139 c.drawRect(mDirtyRect, mPaint); 140 mIsDirty = true; 141 } 142 } 143 } 144 145 private Rect getDrawRect() { 146 if (mCurrentView != null) { 147 viewToRect(mCurrentView, sTempRect1); 148 149 if (mShift > 0 && mTargetView != null) { 150 viewToRect(mTargetView, sTempRect2); 151 return RECT_EVALUATOR.evaluate(mShift, sTempRect1, sTempRect2); 152 } else { 153 return sTempRect1; 154 } 155 } 156 return null; 157 } 158 159 @Override 160 public void onFocusChange(View v, boolean hasFocus) { 161 if (hasFocus) { 162 endCurrentAnimation(); 163 164 if (mAlpha > MIN_VISIBLE_ALPHA) { 165 mTargetView = v; 166 167 mCurrentAnimation = ObjectAnimator.ofPropertyValuesHolder(this, 168 PropertyValuesHolder.ofFloat(ALPHA, 1), 169 PropertyValuesHolder.ofFloat(SHIFT, 1)); 170 mCurrentAnimation.addListener(new ViewSetListener(v, true)); 171 } else { 172 setCurrentView(v); 173 174 mCurrentAnimation = ObjectAnimator.ofPropertyValuesHolder(this, 175 PropertyValuesHolder.ofFloat(ALPHA, 1)); 176 } 177 178 mLastFocusedView = v; 179 } else { 180 if (mLastFocusedView == v) { 181 mLastFocusedView = null; 182 endCurrentAnimation(); 183 mCurrentAnimation = ObjectAnimator.ofPropertyValuesHolder(this, 184 PropertyValuesHolder.ofFloat(ALPHA, 0)); 185 mCurrentAnimation.addListener(new ViewSetListener(null, false)); 186 } 187 } 188 189 // invalidate once 190 invalidateDirty(); 191 192 mLastFocusedView = hasFocus ? v : null; 193 if (mCurrentAnimation != null) { 194 mCurrentAnimation.addUpdateListener(this); 195 mCurrentAnimation.setDuration(ANIM_DURATION).start(); 196 } 197 } 198 199 protected void endCurrentAnimation() { 200 if (mCurrentAnimation != null) { 201 mCurrentAnimation.cancel(); 202 mCurrentAnimation = null; 203 } 204 } 205 206 protected void setCurrentView(View v) { 207 mCurrentView = v; 208 mShift = 0; 209 mTargetView = null; 210 } 211 212 /** 213 * Gets the position of {@param v} relative to {@link #mContainer}. 214 */ 215 public abstract void viewToRect(View v, Rect outRect); 216 217 private class ViewSetListener extends AnimatorListenerAdapter { 218 private final View mViewToSet; 219 private final boolean mCallOnCancel; 220 private boolean mCalled = false; 221 222 public ViewSetListener(View v, boolean callOnCancel) { 223 mViewToSet = v; 224 mCallOnCancel = callOnCancel; 225 } 226 227 @Override 228 public void onAnimationCancel(Animator animation) { 229 if (!mCallOnCancel) { 230 mCalled = true; 231 } 232 } 233 234 @Override 235 public void onAnimationEnd(Animator animation) { 236 if (!mCalled) { 237 setCurrentView(mViewToSet); 238 mCalled = true; 239 } 240 } 241 } 242 } 243