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      1 /*
      2  * Copyright (C) 2010 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 android.graphics.Canvas;
     21 import android.graphics.Color;
     22 import android.graphics.PixelFormat;
     23 import android.graphics.Rect;
     24 import android.graphics.Region;
     25 import android.util.DisplayMetrics;
     26 import android.util.Slog;
     27 import android.view.Display;
     28 import android.view.Surface;
     29 import android.view.SurfaceSession;
     30 
     31 class StrictModeFlash {
     32     private static final String TAG = "StrictModeFlash";
     33 
     34     Surface mSurface;
     35     int mLastDW;
     36     int mLastDH;
     37     boolean mDrawNeeded;
     38     final int mThickness = 20;
     39 
     40     public StrictModeFlash(Display display, SurfaceSession session) {
     41         try {
     42             mSurface = new Surface(session, 0, "StrictModeFlash", -1, 1, 1, PixelFormat.TRANSLUCENT, 0);
     43         } catch (Surface.OutOfResourcesException e) {
     44             return;
     45         }
     46 
     47         mSurface.setLayer(WindowManagerService.TYPE_LAYER_MULTIPLIER * 101);  // one more than Watermark? arbitrary.
     48         mSurface.setPosition(0, 0);
     49         mDrawNeeded = true;
     50     }
     51 
     52     private void drawIfNeeded() {
     53         if (!mDrawNeeded) {
     54             return;
     55         }
     56         mDrawNeeded = false;
     57         final int dw = mLastDW;
     58         final int dh = mLastDH;
     59 
     60         Rect dirty = new Rect(0, 0, dw, dh);
     61         Canvas c = null;
     62         try {
     63             c = mSurface.lockCanvas(dirty);
     64         } catch (IllegalArgumentException e) {
     65         } catch (Surface.OutOfResourcesException e) {
     66         }
     67         if (c == null) {
     68             return;
     69         }
     70 
     71         // Top
     72         c.clipRect(new Rect(0, 0, dw, mThickness), Region.Op.REPLACE);
     73         c.drawColor(Color.RED);
     74         // Left
     75         c.clipRect(new Rect(0, 0, mThickness, dh), Region.Op.REPLACE);
     76         c.drawColor(Color.RED);
     77         // Right
     78         c.clipRect(new Rect(dw - mThickness, 0, dw, dh), Region.Op.REPLACE);
     79         c.drawColor(Color.RED);
     80         // Bottom
     81         c.clipRect(new Rect(0, dh - mThickness, dw, dh), Region.Op.REPLACE);
     82         c.drawColor(Color.RED);
     83 
     84         mSurface.unlockCanvasAndPost(c);
     85     }
     86 
     87     // Note: caller responsible for being inside
     88     // Surface.openTransaction() / closeTransaction()
     89     public void setVisibility(boolean on) {
     90         if (mSurface == null) {
     91             return;
     92         }
     93         drawIfNeeded();
     94         if (on) {
     95             mSurface.show();
     96         } else {
     97             mSurface.hide();
     98         }
     99     }
    100 
    101     void positionSurface(int dw, int dh) {
    102         if (mLastDW == dw && mLastDH == dh) {
    103             return;
    104         }
    105         mLastDW = dw;
    106         mLastDH = dh;
    107         mSurface.setSize(dw, dh);
    108         mDrawNeeded = true;
    109     }
    110 
    111 }
    112