“““?QtImageViewer.py:?PyQt?image?viewer?widget?for?a?QPixmap?in?a?QGraphicsView?scene?with?mouse?zooming?and?panning.

“““

import?os.path
try:
????from?PyQt5.QtCore?import?Qt?QRectF?pyqtSignal?QT_VERSION_STR
????from?PyQt5.QtGui?import?QImage?QPixmap?QPainterPath
????from?PyQt5.QtWidgets?import?QGraphicsView?QGraphicsScene?QFileDialog
except?ImportError:
????try:
????????from?PyQt4.QtCore?import?Qt?QRectF?pyqtSignal?QT_VERSION_STR
????????from?PyQt4.QtGui?import?QGraphicsView?QGraphicsScene?QImage?QPixmap?QPainterPath?QFileDialog
????except?ImportError:
????????raise?ImportError（“ImageViewerQt:?Requires?PyQt5?or?PyQt4.“）


__author__?=?“Marcel?Goldschen-Ohm?“
__version__?=?‘0.9.0‘


class?QtImageViewer（QGraphicsView）:
????“““?PyQt?image?viewer?widget?for?a?QPixmap?in?a?QGraphicsView?scene?with?mouse?zooming?and?panning.

????Displays?a?QImage?or?QPixmap?（QImage?is?internally?converted?to?a?QPixmap）.
????To?display?any?other?image?format?you?must?first?convert?it?to?a?QImage?or?QPixmap.

????Some?useful?image?format?conversion?utilities:
????????qimage2ndarray:?NumPy?ndarray?<==>?QImage????（https://github.com/hmeine/qimage2ndarray）
????????ImageQt:?PIL?Image?<==>?QImage??（https://github.com/python-pillow/Pillow/blob/master/PIL/ImageQt.py）

????Mouse?interaction:
????????Left?mouse?button?drag:?Pan?image.
????????Right?mouse?button?drag:?Zoom?box.
????????Right?mouse?button?doubleclick:?Zoom?to?show?entire?image.
????“““

????#?Mouse?button?signals?emit?image?scene?（x?y）?coordinates.
????#?!!!?For?image?（row?column）?matrix?indexing?row?=?y?and?column?=?x.
????leftMouseButtonPressed?=?pyqtSignal（float?float）
????rightMouseButtonPressed?=?pyqtSignal（float?float）
????leftMouseButtonReleased?=?pyqtSignal（float?float）
????rightMouseButtonReleased?=?pyqtSignal（float?float）
????leftMouseButtonDoubleClicked?=?pyqtSignal（float?float）
????rightMouseButtonDoubleClicked?=?pyqtSignal（float?float）

????def?__init__（self）:
????????QGraphicsView.__init__（self）

????????#?Image?is?displayed?as?a?QPixmap?in?a?QGraphicsScene?attached?to?this?QGraphicsView.
????????self.scene?=?QGraphicsScene（）
????????self.setScene（self.scene）

????????#?Store?a?local?handle?to?the?scene‘s?current?image?pixmap.
????????self._pixmapHandle?=?None

????????#?Image?aspect?ratio?mode.
????????#?!!!?ONLY?applies?to?full?image.?Aspect?ratio?is?always?ignored?when?zooming.
????????#???Qt.IgnoreAspectRatio:?Scale?image?to?fit?viewport.
????????#???Qt.KeepAspectRatio:?Scale?image?to?fit?inside?viewport?preserving?aspect?ratio.
????????#???Qt.KeepAspectRatioByExpanding:?Scale?image?to?fill?the?viewport?preserving?aspect?ratio.
????????self.aspectRatioMode?=?Qt.KeepAspectRatio

????????#?Scroll?bar?behaviour.
????????#???Qt.ScrollBarAlwaysOff:?Never?shows?a?scroll?bar.
????????#???Qt.ScrollBarAlwaysOn:?Always?shows?a?scroll?bar.
????????#???Qt.ScrollBarAsNeeded:?Shows?a?scroll?bar?only?when?zoomed.
????????self.setHorizontalScrollBarPolicy（

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????目錄???????????0??2017-12-02?17:26??PyQtImageViewer-master\
?????文件?????????471??2017-12-02?17:26??PyQtImageViewer-master\.gitignore
?????文件????????1088??2017-12-02?17:26??PyQtImageViewer-master\LICENSE
?????文件????????9541??2017-12-02?17:26??PyQtImageViewer-master\QtImageViewer.py
?????文件????????3700??2017-12-02?17:26??PyQtImageViewer-master\README.md