#!/usr/bin/env python
# -*- coding: utf-8 -*-

"""
Created on 2018年3月24日
@author: Irony
@site: https://pyqt5.com, https://github.com/892768447
@email: 892768447@qq.com
@file: SimpleImageView
@description: 图片视图
"""
import struct
from time import time

from PIL import Image
from PIL.Image import fromarray
from PIL.ImageQt import fromqpixmap
from PyQt5.QtCore import QStandardPaths, Qt
from PyQt5.QtGui import QColor, QPainter, QPixmap, QImage, qRgb, qRed, qGreen,\
    qBlue, QCursor
from PyQt5.QtWidgets import QGraphicsView, QGraphicsScene, QFileDialog, \
    QGraphicsItem
import numpy


try:
    from PyQt5.QtOpenGL import QGLFormat  # , QGL, QGLWidget
    hasOpenGL = True
except Exception as e:
    print(e)
    hasOpenGL = False

__Author__ = """By: Irony
QQ: 892768447
Email: 892768447@qq.com"""
__Copyright__ = 'Copyright (c) 2018 Irony'
__Version__ = 1.0


class SimpleImageView(QGraphicsView):

    # 背景区域颜色
    backgroundColor = QColor(28, 31, 34)

    def __init__(self, *args, **kwargs):
        super(SimpleImageView, self).__init__(*args, **kwargs)
        # 设置背景颜色
        self.setBackgroundBrush(self.backgroundColor)
        # 缓存背景
        self.setCacheMode(self.CacheBackground)
        # 设置拖拽样式
        # self.setDragMode(self.ScrollHandDrag)
        self.setRenderHints(
            QPainter.Antialiasing | QPainter.TextAntialiasing | QPainter.SmoothPixmapTransform)
        # opengl
        if hasOpenGL and QGLFormat.hasOpenGL():
            #             self.setViewport(QGLWidget(QGLFormat(QGL.SampleBuffers), self))
            self.setRenderHint(QPainter.HighQualityAntialiasing)
            self.setViewportUpdateMode(self.FullViewportUpdate)
        else:
            # 尝试通过分析需要重绘的区域来找到最佳的更新模式
            self.setViewportUpdateMode(self.SmartViewportUpdate)
        self._scene = QGraphicsScene(self)
        self.setScene(self._scene)

        # 图片item
        self._itemImage = None
        self._itemImageNew = None

    def keyReleaseEvent(self, event):
        """按键处理事件"""
        self._scaleImage(event)
        super(SimpleImageView, self).keyReleaseEvent(event)

    def closeEvent(self, event):
        """窗口关闭时清空场景中的所有item"""
        self._scene.clear()
        self._itemImage = None
        self._itemImageNew = None
        super(SimpleImageView, self).closeEvent(event)

    def _scaleImage(self, event):
        """缩放图片操作"""
        item = self._scene.focusItem()
        if not item:
            item = self._scene.items()
            if not item:
                return
            item = item[0]
        # 获取item的缩放度
        scale = item.scale()
        if event.key() == Qt.Key_Plus:
            # 放大
            if scale >= 0.91:
                return
            item.setScale(scale + 0.1)
        elif event.key() == Qt.Key_Minus:
            # 缩小
            if scale <= 0.11:
                return
            item.setScale(scale - 0.1)

    def loadImage(self):
        path, _ = QFileDialog.getOpenFileName(
            self, '请选择图片', QStandardPaths.writableLocation(QStandardPaths.DesktopLocation), '图片文件(*.jpg *.png)')
        if not path:
            return
        if self._itemImageNew:
            self._scene.removeItem(self._itemImageNew)
            del self._itemImageNew
            self._itemImageNew = None
        if self._itemImage:
            # 删除以前的item
            self._scene.removeItem(self._itemImage)
            del self._itemImage
            self._itemImage = None
        self._itemImage = self._scene.addPixmap(QPixmap(path))
        self._itemImage.setFlag(QGraphicsItem.ItemIsMovable)
        self._itemImage.setFlag(QGraphicsItem.ItemIsFocusable)
        self._itemImage.setScale(0.1)  # 默认加载比例
        self._scene.setFocusItem(self._itemImage)
        print(self._itemImage.zValue())

        size = self._itemImage.pixmap().size()
        # 调整图片在中间
        self._itemImage.setPos(
            -size.width() * self._itemImage.scale() / 2,
            -size.height() * self._itemImage.scale() / 2
        )

    def _greyScale(self):
        if not self._itemImage:
            return
        if self._itemImageNew:
            self._scene.removeItem(self._itemImageNew)
            del self._itemImageNew
            self._itemImageNew = None
        t = time()
        # QPixmap 转 PIL Image 转 numpy array
        image = numpy.array(fromqpixmap(self._itemImage.pixmap()).convert('L'))
        image = fromarray(image).toqpixmap()
        self._itemImageNew = self._scene.addPixmap(image)
        self._itemImageNew.setFlag(QGraphicsItem.ItemIsFocusable)
        self._itemImageNew.setFlag(QGraphicsItem.ItemIsMovable)
        self._itemImageNew.setScale(self._itemImage.scale())  # 默认加载比例
        self._scene.setFocusItem(self._itemImageNew)
        print(self._itemImageNew.zValue())
        print(time() - t)


if __name__ == '__main__':
    import sys
    from PyQt5.QtWidgets import QApplication
    app = QApplication(sys.argv)
    w = SimpleImageView()
    w.resize(800, 600)
    w.show()
    sys.exit(app.exec_())