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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.view.Display;
     26 import android.view.Surface;
     27 import android.view.SurfaceSession;
     28 
     29 class StrictModeFlash {
     30     private static final String TAG = "StrictModeFlash";
     31 
     32     Surface mSurface;
     33     int mLastDW;
     34     int mLastDH;
     35     boolean mDrawNeeded;
     36     final int mThickness = 20;
     37 
     38     public StrictModeFlash(Display display, SurfaceSession session) {
     39         try {
     40             mSurface = new Surface(session, "StrictModeFlash",
     41                 1, 1, PixelFormat.TRANSLUCENT, Surface.HIDDEN);
     42         } catch (Surface.OutOfResourcesException e) {
     43             return;
     44         }
     45 
     46         mSurface.setLayerStack(display.getLayerStack());
     47         mSurface.setLayer(WindowManagerService.TYPE_LAYER_MULTIPLIER * 101);  // one more than Watermark? arbitrary.
     48         mSurface.setPosition(0, 0);
     49         mSurface.show();
     50         mDrawNeeded = true;
     51     }
     52 
     53     private void drawIfNeeded() {
     54         if (!mDrawNeeded) {
     55             return;
     56         }
     57         mDrawNeeded = false;
     58         final int dw = mLastDW;
     59         final int dh = mLastDH;
     60 
     61         Rect dirty = new Rect(0, 0, dw, dh);
     62         Canvas c = null;
     63         try {
     64             c = mSurface.lockCanvas(dirty);
     65         } catch (IllegalArgumentException e) {
     66         } catch (Surface.OutOfResourcesException e) {
     67         }
     68         if (c == null) {
     69             return;
     70         }
     71 
     72         // Top
     73         c.clipRect(new Rect(0, 0, dw, mThickness), Region.Op.REPLACE);
     74         c.drawColor(Color.RED);
     75         // Left
     76         c.clipRect(new Rect(0, 0, mThickness, dh), Region.Op.REPLACE);
     77         c.drawColor(Color.RED);
     78         // Right
     79         c.clipRect(new Rect(dw - mThickness, 0, dw, dh), Region.Op.REPLACE);
     80         c.drawColor(Color.RED);
     81         // Bottom
     82         c.clipRect(new Rect(0, dh - mThickness, dw, dh), Region.Op.REPLACE);
     83         c.drawColor(Color.RED);
     84 
     85         mSurface.unlockCanvasAndPost(c);
     86     }
     87 
     88     // Note: caller responsible for being inside
     89     // Surface.openTransaction() / closeTransaction()
     90     public void setVisibility(boolean on) {
     91         if (mSurface == null) {
     92             return;
     93         }
     94         drawIfNeeded();
     95         if (on) {
     96             mSurface.show();
     97         } else {
     98             mSurface.hide();
     99         }
    100     }
    101 
    102     void positionSurface(int dw, int dh) {
    103         if (mLastDW == dw && mLastDH == dh) {
    104             return;
    105         }
    106         mLastDW = dw;
    107         mLastDH = dh;
    108         mSurface.setSize(dw, dh);
    109         mDrawNeeded = true;
    110     }
    111 
    112 }
    113