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