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      1 /*
      2  * Copyright (C) 2014 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.server.wm;
     18 
     19 
     20 import static com.android.server.wm.WindowManagerDebugConfig.DEBUG_SURFACE_TRACE;
     21 import static com.android.server.wm.WindowManagerDebugConfig.TAG_WITH_CLASS_NAME;
     22 import static com.android.server.wm.WindowManagerDebugConfig.TAG_WM;
     23 
     24 import android.graphics.Canvas;
     25 import android.graphics.Color;
     26 import android.graphics.Paint;
     27 import android.graphics.PixelFormat;
     28 import android.graphics.Point;
     29 import android.graphics.PorterDuff;
     30 import android.graphics.PorterDuffXfermode;
     31 import android.graphics.Rect;
     32 import android.util.Slog;
     33 import android.view.Display;
     34 import android.view.Surface;
     35 import android.view.Surface.OutOfResourcesException;
     36 import android.view.SurfaceControl;
     37 import android.view.SurfaceSession;
     38 
     39 class CircularDisplayMask {
     40     private static final String TAG = TAG_WITH_CLASS_NAME ? "CircularDisplayMask" : TAG_WM;
     41 
     42     // size of the chin
     43     private int mScreenOffset = 0;
     44     // Display dimensions
     45     private Point mScreenSize;
     46 
     47     private final SurfaceControl mSurfaceControl;
     48     private final Surface mSurface = new Surface();
     49     private int mLastDW;
     50     private int mLastDH;
     51     private boolean mDrawNeeded;
     52     private Paint mPaint;
     53     private int mRotation;
     54     private boolean mVisible;
     55     private boolean mDimensionsUnequal = false;
     56     private int mMaskThickness;
     57 
     58     public CircularDisplayMask(Display display, SurfaceSession session, int zOrder,
     59             int screenOffset, int maskThickness) {
     60         mScreenSize = new Point();
     61         display.getSize(mScreenSize);
     62         if (mScreenSize.x != mScreenSize.y + screenOffset) {
     63             Slog.w(TAG, "Screen dimensions of displayId = " + display.getDisplayId() +
     64                     "are not equal, circularMask will not be drawn.");
     65             mDimensionsUnequal = true;
     66         }
     67 
     68         SurfaceControl ctrl = null;
     69         try {
     70             if (DEBUG_SURFACE_TRACE) {
     71                 ctrl = new WindowSurfaceController.SurfaceTrace(session, "CircularDisplayMask",
     72                         mScreenSize.x, mScreenSize.y, PixelFormat.TRANSLUCENT,
     73                         SurfaceControl.HIDDEN);
     74             } else {
     75                 ctrl = new SurfaceControl(session, "CircularDisplayMask", mScreenSize.x,
     76                         mScreenSize.y, PixelFormat.TRANSLUCENT, SurfaceControl.HIDDEN);
     77             }
     78             ctrl.setLayerStack(display.getLayerStack());
     79             ctrl.setLayer(zOrder);
     80             ctrl.setPosition(0, 0);
     81             ctrl.show();
     82             mSurface.copyFrom(ctrl);
     83         } catch (OutOfResourcesException e) {
     84         }
     85         mSurfaceControl = ctrl;
     86         mDrawNeeded = true;
     87         mPaint = new Paint();
     88         mPaint.setAntiAlias(true);
     89         mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));
     90         mScreenOffset = screenOffset;
     91         mMaskThickness = maskThickness;
     92     }
     93 
     94     private void drawIfNeeded() {
     95         if (!mDrawNeeded || !mVisible || mDimensionsUnequal) {
     96             return;
     97         }
     98         mDrawNeeded = false;
     99 
    100         Rect dirty = new Rect(0, 0, mScreenSize.x, mScreenSize.y);
    101         Canvas c = null;
    102         try {
    103             c = mSurface.lockCanvas(dirty);
    104         } catch (IllegalArgumentException e) {
    105         } catch (Surface.OutOfResourcesException e) {
    106         }
    107         if (c == null) {
    108             return;
    109         }
    110         switch (mRotation) {
    111         case Surface.ROTATION_0:
    112         case Surface.ROTATION_90:
    113             // chin bottom or right
    114             mSurfaceControl.setPosition(0, 0);
    115             break;
    116         case Surface.ROTATION_180:
    117             // chin top
    118             mSurfaceControl.setPosition(0, -mScreenOffset);
    119             break;
    120         case Surface.ROTATION_270:
    121             // chin left
    122             mSurfaceControl.setPosition(-mScreenOffset, 0);
    123             break;
    124         }
    125 
    126         int circleRadius = mScreenSize.x / 2;
    127         c.drawColor(Color.BLACK);
    128 
    129         // The radius is reduced by mMaskThickness to provide an anti aliasing effect on the display edges.
    130         c.drawCircle(circleRadius, circleRadius, circleRadius - mMaskThickness, mPaint);
    131         mSurface.unlockCanvasAndPost(c);
    132     }
    133 
    134     // Note: caller responsible for being inside
    135     // Surface.openTransaction() / closeTransaction()
    136     public void setVisibility(boolean on) {
    137         if (mSurfaceControl == null) {
    138             return;
    139         }
    140         mVisible = on;
    141         drawIfNeeded();
    142         if (on) {
    143             mSurfaceControl.show();
    144         } else {
    145             mSurfaceControl.hide();
    146         }
    147     }
    148 
    149     void positionSurface(int dw, int dh, int rotation) {
    150         if (mLastDW == dw && mLastDH == dh && mRotation == rotation) {
    151             return;
    152         }
    153         mLastDW = dw;
    154         mLastDH = dh;
    155         mDrawNeeded = true;
    156         mRotation = rotation;
    157         drawIfNeeded();
    158     }
    159 
    160 }
    161