caprure_region.py

from PySide.QtCore import *
from PySide.QtGui import *
import sys


regionColor = QColor(200,200,200)
textColor = QColor(0,0,0)
bgColor = QColor(200,200,200)

class captureRegionClass(QWidget):
    endSelectionSignal = Signal(QPixmap)
    def __init__(self):
        super(captureRegionClass, self).__init__()
        self.setWindowFlags( Qt.WindowStaysOnTopHint | Qt.FramelessWindowHint)
        scr = QApplication.desktop()
        w = scr.winId()
        rec = QRect(0,0,scr.width(), scr.height())
        self.pix = QPixmap.grabWindow(w,0,0,scr.width(), scr.height())
        self.setGeometry(rec)
        self.startPos = None
        self.endPos= None

    def showEvent(self, event):
        QApplication.setOverrideCursor(QCursor(Qt.CrossCursor))
        super(captureRegionClass, self).showEvent(event)

    def paintEvent(self, event):
        super(captureRegionClass, self).paintEvent(event)
        painter = QPainter()
        painter.begin(self)
        painter.drawPixmap(0, 0, self.pix)
        if self.startPos and self.endPos:
            # draw frame
            painter.setCompositionMode(QPainter.RasterOp_SourceXorDestination)
            painter.setPen(QPen( QBrush(regionColor), 1 ))
            rec = QRect(self.startPos, self.endPos).normalized ()
            painter.drawRect(rec)
            # text bg
            bgPos1 = rec.topLeft() + QPoint(0, -5)
            bgPos2 = bgPos1 + QPoint(60, -18)
            painter.setCompositionMode(QPainter.CompositionMode_SourceOver)
            bgRec = QRect(bgPos1, bgPos2)
            brush = QBrush(bgColor)
            painter.fillRect(bgRec, brush)
            # text
            textPos = rec.topLeft() - QPoint(-4, 10)
            painter.setPen(QPen( QBrush(textColor), 1 ))
            painter.drawText(textPos, '%s x %s' % (rec.width(), rec.height()))
        painter.end()

    def mousePressEvent(self, event):
        if event.button() == Qt.LeftButton:
            self.startPos = event.pos()
            self.endPos = event.pos()
        super(captureRegionClass, self).mousePressEvent(event)

    def mouseReleaseEvent(self, event):
        if event.button() == Qt.LeftButton:
            QApplication.restoreOverrideCursor()
            self.sendImage()
        super(captureRegionClass, self).mouseReleaseEvent(event)

    def mouseMoveEvent(self, event):
        self.endPos = event.pos()
        self.repaint()
        super(captureRegionClass, self).mouseMoveEvent(event)

    def keyPressEvent(self, event):
        if event.key() == Qt.Key_Escape:
            QApplication.restoreOverrideCursor()
            self.hide()

    def cutRegion(self, region):
        path = QFileDialog.getSaveFileName(self,'Save file to...', '', ("Images JPG (*.jpg)"))
        if path[0]:
            cut = self.pix.copy(region)
            cut.save(path[0], 'JPG', 90)
        self.hide()

    def getRegion(self):
        if self.region:
            cut = self.pix.copy(self.region)
            return cut


    def saveRegion(self):
        self.region = QRect(self.startPos, self.endPos).normalized()

    def sendImage(self):
        self.hide()
        region = QRect(self.startPos, self.endPos).normalized()
        cut = self.pix.copy(region)
        self.endSelectionSignal.emit(cut)
        self.pix = None

if __name__ == '__main__':
    app = QApplication([])
    grabber = captureRegionClass()
    grabber.show()
    app.exec_()