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/packages/SystemUI/src/com/android/systemui/recent/FadedEdgeDrawHelper.java

https://github.com/aizuzi/platform_frameworks_base
Java | 189 lines | 140 code | 26 blank | 23 comment | 26 complexity | 13313fb1061da69c3838054650653b6a MD5 | raw file
  1/*
  2 * Copyright (C) 2011 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 com.android.systemui.recent;
 18
 19import android.content.Context;
 20import android.content.res.TypedArray;
 21import android.graphics.Canvas;
 22import android.graphics.LinearGradient;
 23import android.graphics.Matrix;
 24import android.graphics.Paint;
 25import android.graphics.Shader;
 26import android.util.AttributeSet;
 27import android.view.View;
 28import android.view.ViewConfiguration;
 29import android.widget.LinearLayout;
 30
 31import com.android.systemui.R;
 32
 33public class FadedEdgeDrawHelper {
 34    public static final boolean OPTIMIZE_SW_RENDERED_RECENTS = true;
 35    public static final boolean USE_DARK_FADE_IN_HW_ACCELERATED_MODE = true;
 36    private View mScrollView;
 37
 38    private int mFadingEdgeLength;
 39    private boolean mIsVertical;
 40    private boolean mSoftwareRendered = false;
 41    private Paint mBlackPaint;
 42    private Paint mFadePaint;
 43    private Matrix mFadeMatrix;
 44    private LinearGradient mFade;
 45
 46    public static FadedEdgeDrawHelper create(Context context,
 47            AttributeSet attrs, View scrollView, boolean isVertical) {
 48        boolean isTablet = context.getResources().
 49                getBoolean(R.bool.config_recents_interface_for_tablets);
 50        if (!isTablet && (OPTIMIZE_SW_RENDERED_RECENTS || USE_DARK_FADE_IN_HW_ACCELERATED_MODE)) {
 51            return new FadedEdgeDrawHelper(context, attrs, scrollView, isVertical);
 52        } else {
 53            return null;
 54        }
 55    }
 56
 57    public FadedEdgeDrawHelper(Context context,
 58            AttributeSet attrs, View scrollView, boolean isVertical) {
 59        mScrollView = scrollView;
 60        TypedArray a = context.obtainStyledAttributes(attrs, com.android.internal.R.styleable.View);
 61        mFadingEdgeLength = a.getDimensionPixelSize(android.R.styleable.View_fadingEdgeLength,
 62                ViewConfiguration.get(context).getScaledFadingEdgeLength());
 63        mIsVertical = isVertical;
 64    }
 65
 66    public void onAttachedToWindowCallback(
 67            LinearLayout layout, boolean hardwareAccelerated) {
 68        mSoftwareRendered = !hardwareAccelerated;
 69        if ((mSoftwareRendered && OPTIMIZE_SW_RENDERED_RECENTS)
 70                || USE_DARK_FADE_IN_HW_ACCELERATED_MODE) {
 71            mScrollView.setVerticalFadingEdgeEnabled(false);
 72            mScrollView.setHorizontalFadingEdgeEnabled(false);
 73        }
 74    }
 75
 76    public void addViewCallback(View newLinearLayoutChild) {
 77        if (mSoftwareRendered && OPTIMIZE_SW_RENDERED_RECENTS) {
 78            final RecentsPanelView.ViewHolder holder =
 79                    (RecentsPanelView.ViewHolder) newLinearLayoutChild.getTag();
 80            holder.labelView.setDrawingCacheEnabled(true);
 81            holder.labelView.buildDrawingCache();
 82        }
 83    }
 84
 85    public void drawCallback(Canvas canvas,
 86            int left, int right, int top, int bottom, int scrollX, int scrollY,
 87            float topFadingEdgeStrength, float bottomFadingEdgeStrength,
 88            float leftFadingEdgeStrength, float rightFadingEdgeStrength, int mPaddingTop) {
 89
 90        if ((mSoftwareRendered && OPTIMIZE_SW_RENDERED_RECENTS)
 91                || USE_DARK_FADE_IN_HW_ACCELERATED_MODE) {
 92            if (mFadePaint == null) {
 93                mFadePaint = new Paint();
 94                mFadeMatrix = new Matrix();
 95                // use use a height of 1, and then wack the matrix each time we
 96                // actually use it.
 97                mFade = new LinearGradient(0, 0, 0, 1, 0xCC000000, 0, Shader.TileMode.CLAMP);
 98                // PULL OUT THIS CONSTANT
 99                mFadePaint.setShader(mFade);
100            }
101
102            // draw the fade effect
103            boolean drawTop = false;
104            boolean drawBottom = false;
105            boolean drawLeft = false;
106            boolean drawRight = false;
107
108            float topFadeStrength = 0.0f;
109            float bottomFadeStrength = 0.0f;
110            float leftFadeStrength = 0.0f;
111            float rightFadeStrength = 0.0f;
112
113            final float fadeHeight = mFadingEdgeLength;
114            int length = (int) fadeHeight;
115
116            // clip the fade length if top and bottom fades overlap
117            // overlapping fades produce odd-looking artifacts
118            if (mIsVertical && (top + length > bottom - length)) {
119                length = (bottom - top) / 2;
120            }
121
122            // also clip horizontal fades if necessary
123            if (!mIsVertical && (left + length > right - length)) {
124                length = (right - left) / 2;
125            }
126
127            if (mIsVertical) {
128                topFadeStrength = Math.max(0.0f, Math.min(1.0f, topFadingEdgeStrength));
129                drawTop = topFadeStrength * fadeHeight > 1.0f;
130                bottomFadeStrength = Math.max(0.0f, Math.min(1.0f, bottomFadingEdgeStrength));
131                drawBottom = bottomFadeStrength * fadeHeight > 1.0f;
132            }
133
134            if (!mIsVertical) {
135                leftFadeStrength = Math.max(0.0f, Math.min(1.0f, leftFadingEdgeStrength));
136                drawLeft = leftFadeStrength * fadeHeight > 1.0f;
137                rightFadeStrength = Math.max(0.0f, Math.min(1.0f, rightFadingEdgeStrength));
138                drawRight = rightFadeStrength * fadeHeight > 1.0f;
139            }
140
141            if (drawTop) {
142                mFadeMatrix.setScale(1, fadeHeight * topFadeStrength);
143                mFadeMatrix.postTranslate(left, top);
144                mFade.setLocalMatrix(mFadeMatrix);
145                canvas.drawRect(left, top, right, top + length, mFadePaint);
146
147                if (mBlackPaint == null) {
148                    // Draw under the status bar at the top
149                    mBlackPaint = new Paint();
150                    mBlackPaint.setColor(0xFF000000);
151                }
152                canvas.drawRect(left, top - mPaddingTop, right, top, mBlackPaint);
153            }
154
155            if (drawBottom) {
156                mFadeMatrix.setScale(1, fadeHeight * bottomFadeStrength);
157                mFadeMatrix.postRotate(180);
158                mFadeMatrix.postTranslate(left, bottom);
159                mFade.setLocalMatrix(mFadeMatrix);
160                canvas.drawRect(left, bottom - length, right, bottom, mFadePaint);
161            }
162
163            if (drawLeft) {
164                mFadeMatrix.setScale(1, fadeHeight * leftFadeStrength);
165                mFadeMatrix.postRotate(-90);
166                mFadeMatrix.postTranslate(left, top);
167                mFade.setLocalMatrix(mFadeMatrix);
168                canvas.drawRect(left, top, left + length, bottom, mFadePaint);
169            }
170
171            if (drawRight) {
172                mFadeMatrix.setScale(1, fadeHeight * rightFadeStrength);
173                mFadeMatrix.postRotate(90);
174                mFadeMatrix.postTranslate(right, top);
175                mFade.setLocalMatrix(mFadeMatrix);
176                canvas.drawRect(right - length, top, right, bottom, mFadePaint);
177            }
178        }
179    }
180
181    public int getVerticalFadingEdgeLength() {
182        return mFadingEdgeLength;
183    }
184
185    public int getHorizontalFadingEdgeLength() {
186        return mFadingEdgeLength;
187    }
188
189}