仅在面板调整大小事件结束时重新绘制图形

时间:2017-03-02 12:43:27

标签: python performance matplotlib wxpython

我目前正在尝试改进绘制软件的一部分。

我们正在使用WXPython和Matplotlib来向用户显示许多包含各种控件的图。

总结一下,这是上下文:

Context

Matplotlib性能适用于我们的绘图需求,但是,调整我们的wxpython主框架的大小是调整包含matplotlib画布的wx面板。

(在每一步或调整大小,而不仅仅是在结束时)

如果速度很快调整面板大小,但matplotlib也会在调整大小的每个步骤重绘画布和数字,从而产生视觉冻结和一些延迟。

总结一下,问题是:

enter image description here

我想知道是否有办法在我们的WX Frame resize事件期间禁用(临时)matplotlib事件/自动重绘事件,然后在其末尾应用重绘。

有什么想法吗?

1 个答案:

答案 0 :(得分:0)

这只是答案的一半,因为(1)我在这里使用PyQt而不是WX,(2)它只显示如何防止调整大小的发生,以便以后可以手动完成。

我们的想法是继承FigureCanvas并接管resizeEvent方法。在这种方法中只存储resize事件,但不要让它发生 稍后手动触发事件。

import sys
from PyQt4 import QtGui, QtCore
from matplotlib.backends.backend_qt4agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.figure import Figure
import numpy as np

class MyFigureCanvas(FigureCanvas):
    """ Subclass canvas to catch the resize event """
    def __init__(self, figure):
        self.lastEvent = False # store the last resize event's size here
        FigureCanvas.__init__(self, figure)

    def resizeEvent(self, event):
        if not self.lastEvent:
            # at the start of the app, allow resizing to happen.
            super(MyFigureCanvas, self).resizeEvent(event)
        # store the event size for later use
        self.lastEvent = (event.size().width(),event.size().height())
        print "try to resize, I don't let you."

    def do_resize_now(self):
        # recall last resize event's size
        newsize = QtCore.QSize(self.lastEvent[0],self.lastEvent[1] )
        # create new event from the stored size
        event = QtGui.QResizeEvent(newsize, QtCore.QSize(1, 1))
        print "Now I let you resize."
        # and propagate the event to let the canvas resize.
        super(MyFigureCanvas, self).resizeEvent(event)


class ApplicationWindow(QtGui.QMainWindow):
    def __init__(self):
        QtGui.QMainWindow.__init__(self)
        self.main_widget = QtGui.QWidget(self)
        l = QtGui.QVBoxLayout(self.main_widget)
        self.fig = Figure()
        # use subclassed FigureCanvas
        self.canvas = MyFigureCanvas(self.fig)
        self.button = QtGui.QPushButton("Manually Resize")        
        l.addWidget(self.button)
        l.addWidget(self.canvas)
        self.setCentralWidget(self.main_widget)
        self.button.clicked.connect(self.action)     
        self.plot()

    def action(self):
        # when button is clicked, resize the canvas.
        self.canvas.do_resize_now()

    def plot(self):
        # just some random plots
        self.axes = []
        for i in range(4):
            ax = self.fig.add_subplot(2,2,i+1)
            a = np.random.rand(100,100)
            ax.imshow(a)
            self.axes.append(ax)
        self.fig.tight_layout()


qApp = QtGui.QApplication(sys.argv)
aw = ApplicationWindow()
aw.show()
sys.exit(qApp.exec_())

可能在WX中这样做并没有太大的不同。