import numpy as np
import win32gui
import win32ui, win32con
from threading import Thread, Lock
import time
#DEBUG
from skimage.io import imread
#Asyncronously captures screens of a window. Provides functions for accessing
#the captured screen.
class ScreenViewer:
def __init__(self):
self.mut = Lock()
self.hwnd = None
self.its = None #Time stamp of last image
self.i0 = None #i0 is the latest image;
self.i1 = None #i1 is used as a temporary variable
self.cl = False #Continue looping flag
#Left, Top, Right, and bottom of the screen window
self.l, self.t, self.r, self.b = 0, 0, 0, 0
#Border on left and top to remove
self.bl, self.bt, self.br, self.bb = 12, 31, 12, 20
def GetHWND(self, wname = None):
'''
Gets handle of window to view
wname: Title of window to find
Return: True on success; False on failure
'''
if wname is None:
self.hwnd = win32gui.GetDesktopWindow()
else:
self.hwnd = win32gui.FindWindow(None, wname)
if self.hwnd == 0:
self.hwnd = None
return False
self.l, self.t, self.r, self.b = win32gui.GetWindowRect(self.hwnd)
return True
def GetScreen(self):
'''
Get's the latest image of the window
'''
while self.i0 is None: #Screen hasn't been captured yet
pass
self.mut.acquire()
s = self.i0
self.mut.release()
return s
def GetScreenWithTime(self):
'''
Get's the latest image of the window along with timestamp
'''
while self.i0 is None: #Screen hasn't been captured yet
pass
self.mut.acquire()
s = self.i0
t = self.its
self.mut.release()
return s, t
def GetScreenSize(self):
return (self.b - self.t, self.r - self.l)
def GetScreenTime(self):
'''
Get the timestamp of the last image of screen
'''
while self.i0 is None: #Screen hasn't been captured yet
pass
self.mut.acquire()
s = self.its
self.mut.release()
return s
def GetScreenImg1(self): #DEBUG ONLY
#return imread('Train/Images/20170411195037_1.jpg')[0:-14, 1:-1, :]
#For 800x600 images:
#Remove 12 pixels from bottom 4 from right and left
return imread('TS/Train/Images/20170507141446_1.jpg')[0:-12, 4:-4, :]
def GetScreenImg(self):
'''
Gets the screen of the window referenced by self.hwnd
'''
if self.hwnd is None:
raise Exception("HWND is none. HWND not called or invalid window name provided.")
self.l, self.t, self.r, self.b = win32gui.GetWindowRect(self.hwnd)
#Remove border around window (8 pixels on each side)
#Remove 4 extra pixels from left and right 16 + 8 = 24
w = self.r - self.l - self.br - self.bl
#Remove border on top and bottom (31 on top 8 on bottom)
#Remove 12 extra pixels from bottom 39 + 12 = 51
h = self.b - self.t - self.bt - self.bb
wDC = win32gui.GetWindowDC(self.hwnd)
dcObj = win32ui.CreateDCFromHandle(wDC)
cDC = dcObj.CreateCompatibleDC()
dataBitMap = win32ui.CreateBitmap()
dataBitMap.CreateCompatibleBitmap(dcObj, w, h)
cDC.SelectObject(dataBitMap)
#First 2 tuples are top-left and bottom-right of destination
#Third tuple is the start position in source
cDC.BitBlt((0,0), (w, h), dcObj, (self.bl, self.bt), win32con.SRCCOPY)
bmInfo = dataBitMap.GetInfo()
im = np.frombuffer(dataBitMap.GetBitmapBits(True), dtype = np.uint8)
dcObj.DeleteDC()
cDC.DeleteDC()
win32gui.ReleaseDC(self.hwnd, wDC)
win32gui.DeleteObject(dataBitMap.GetHandle())
#Bitmap has 4 channels like: BGRA. Discard Alpha and flip order to RGB
#31 pixels from border on top, 8 on bottom
#8 pixels from border on the left and 8 on right
#Remove 1 additional pixel from left and right so size is 1278 | 9
#Remove 14 additional pixels from bottom so size is 786 | 6
#return im.reshape(bmInfo['bmHeight'], bmInfo['bmWidth'], 4)[31:-22, 9:-9, -2::-1]
#For 800x600 images:
#Remove 12 pixels from bottom + border
#Remove 4 pixels from left and right + border
return im.reshape(bmInfo['bmHeight'], bmInfo['bmWidth'], 4)[:, :, -2::-1]
def GetWindowPos(self):
'''
Gets the left, top, right, and bottom coordinates of the window
'''
return self.l + self.bl, self.t + self.bt, self.r - self.br, self.b - self.bb
def Start(self):
'''
#Begins recording images of the screen
#wf: Write flag; write screen captures to file
'''
#if self.hwnd is None:
# return False
self.cl = True
thrd = Thread(target = self.ScreenUpdateT)
thrd.start()
return True
def Stop(self):
'''
Stop the async thread that is capturing images
'''
self.cl = False
def ScreenUpdateT(self):
'''
Thread used to capture images of screen
'''
while self.cl: #Keep updating screen until terminating
self.i1 = self.GetScreenImg()
self.mut.acquire()
self.i0 = self.i1 #Update the latest image in a thread safe way
self.its = time.time()
self.mut.release()
def WindowDraw(self, rect):
'''
Draws a rectangle to the window
'''
if self.hwnd is None:
return
#raise Exception("HWND is none. HWND not called or invalid window name provided.")
wDC = win32gui.GetWindowDC(self.hwnd)
dcObj = win32ui.CreateDCFromHandle(wDC)
#Set background mode to transparent
#dcObj.SetBkColor(0x12345)
#dcObj.SetBkMode(0)
dcObj.Rectangle(rect)
# Free Resources
dcObj.DeleteDC()
win32gui.ReleaseDC(self.hwnd, wDC)
