Question

目标

我想同时：

1）通过window-select在matplotlib画布上选择多个艺术家。

我的意思是，如果我按住鼠标按钮，拖动鼠标，并释放，由x，y位置定义的矩形中的所有艺术家按下按钮和按钮释放。

2）拖动多个选定的艺术家，然后向下按鼠标选定的艺术家之一，移动鼠标，并释放。

这与普通文件浏览器中的预期完全相同。

以前的尝试和遗留的问题

为此，我已经开始编写两个类<script> var xhr = new XMLHttpRequest(); var url = "http://example.api.com/path/etc/etc/"; xhr.open("POST", url, true); xhr.setRequestHeader("Accept", "application/json"); xhr.setRequestHeader("Content-type", "application/json"); xhr.setRequestHeader("custom-header-1", "foo"); xhr.setRequestHeader("custom-header-2", "bla"); xhr.send(requ); //... </script>和。{ WindowSelect，如下所示。

除了I之外，

Draggable实现了（1）的逻辑不知道如何手动触发选择器功能 matplotlib documentation中提到的。相反，我称一个占位符函数WindowSelect。

除了a之外，

func实现了（2）的逻辑一次挑选一位艺术家（无耻地从中拣选出来另一个表示SO回答）。 matplotlib documentation {{3}} 表示同时挑选多位艺术家是可能的（网页上的最后一个例子）。但是，如果我，为例如，将选取器的公差设置得非常高，只有一个艺术家似乎被选中/然后可以被拖动画布，所以我不确定代码需要如何改变以适应多位艺术家。

代码

Draggable

Answer 1

很难保持选择和拖动分开。这是因为根据您当前是选择还是拖动，各个事件需要执行不同的任务。因此，在每个时间点，您需要知道当前正在执行哪个操作，并且最好在单个类中完成，您可能在其中有两个不同的标志self.currently_selecting和self.currently_dragging。然后，您还需要一个选定的艺术家列表self.selected_artists，可以在需要时拖动它们。

我会摆脱pick_event，因为很难区分button_press_event（它们会被同时触发，而不是先确定性的）。相反，单个button_press_event可以处理所有逻辑;即找出艺术家是否发生了点击，如果是，则开始拖动，否则开始选择。

import numpy as np
import matplotlib.pyplot as plt
import matplotlib.patches as patches


class WindowSelect(object):

    def __init__(self, artists):
        self.artists = artists
        self.colors = [a.get_facecolor() for a in self.artists]
        # assume all artists are in the same figure, otherwise selection is meaningless
        self.fig = self.artists[0].figure
        self.ax = self.artists[0].axes

        self.fig.canvas.mpl_connect('button_press_event', self.on_press)
        self.fig.canvas.mpl_connect('button_release_event', self.on_release)
        self.fig.canvas.mpl_connect('motion_notify_event', self.on_motion)

        self.currently_selecting = False
        self.currently_dragging = False
        self.selected_artists = []
        self.offset = np.zeros((1,2))
        self.rect = plt.Rectangle((0,0),1,1, linestyle="--",
                                  edgecolor="crimson", fill=False)
        self.ax.add_patch(self.rect)
        self.rect.set_visible(False)

    def on_press(self, event):
        # is the press over some artist
        isonartist = False
        for artist in self.artists:
            if artist.contains(event)[0]:
                isonartist = artist
        self.x0 = event.xdata
        self.y0 = event.ydata
        if isonartist:
            # add clicked artist to selection
            self.select_artist(isonartist)
            # start dragging
            self.currently_dragging = True
            ac = np.array([a.center for a in self.selected_artists])
            ec = np.array([event.xdata, event.ydata])
            self.offset = ac - ec
        else:
            #start selecting
            self.currently_selecting = True
            self.deseclect_artists()

    def on_release(self, event):
        if self.currently_selecting:

            for artist in self.artists:
                if self.is_inside_rect(*artist.center):
                    self.select_artist(artist)
            self.fig.canvas.draw_idle()
            self.currently_selecting = False
            self.rect.set_visible(False)

        elif self.currently_dragging:
            self.currently_dragging = False


    def on_motion(self, event):
        if self.currently_dragging:
            newcenters = np.array([event.xdata, event.ydata])+self.offset
            for i, artist in enumerate(self.selected_artists):
                artist.center = newcenters[i]
            self.fig.canvas.draw_idle()
        elif self.currently_selecting:
            self.x1 = event.xdata
            self.y1 = event.ydata
            #add rectangle for selection here
            self.selector_on()
            self.fig.canvas.draw_idle()

    def is_inside_rect(self, x, y):
        xlim = np.sort([self.x0, self.x1])
        ylim = np.sort([self.y0, self.y1])
        if (xlim[0]<=x) and (x<xlim[1]) and (ylim[0]<=y) and (y<ylim[1]):
            return True
        else:
            return False

    def select_artist(self, artist):
        artist.set_color('k')
        if artist not in self.selected_artists:
            self.selected_artists.append(artist)

    def deseclect_artists(self):
        for artist,color in zip(self.artists, self.colors):
            artist.set_color(color)
        self.selected_artists = []

    def selector_on(self):
        self.rect.set_visible(True)
        xlim = np.sort([self.x0, self.x1])
        ylim = np.sort([self.y0, self.y1])
        self.rect.set_xy((xlim[0],ylim[0] ) )
        self.rect.set_width(np.diff(xlim))
        self.rect.set_height(np.diff(ylim))


def demo():

    fig, ax = plt.subplots(1,1)
    xlim = [-5, 5]
    ylim = [-5, 5]
    ax.set(xlim=xlim, ylim=ylim)

    circles = [patches.Circle((3.0, 3.0), 0.5, fc='r', alpha=1.0),
               patches.Circle((0.0, 0.0), 0.5, fc='b', alpha=1.0),
               patches.Circle((0.0, 3.0), 0.5, fc='g', alpha=1.0)]

    for circle in circles:
        ax.add_patch(circle)

    w = WindowSelect(circles)
    plt.show()

if __name__ == '__main__':
    demo()

Answer 2

您的第二课程需要的唯一修改是一次跟踪和移动多个artists。修改以下功能将允许这样做。

def on_pick(self, event):
    if self.current_artist is None:
        self.current_artist = event.artist
        ecoord = array([event.mouseevent.xdata, event.mouseevent.ydata])
        self.offsets = [a.center for a in self.artists] - ecoord

def on_motion(self, event):
    if not self.currently_dragging:
        return
    if self.current_artist is None:
        return

    center = event.xdata, event.ydata
    for artist, delta in zip(self.artists, self.offsets):
        artist.center = center + delta
    self.artists[0].figure.canvas.draw()

窗口选择多个艺术家并将其拖动到画布上

目标

以前的尝试和遗留的问题

代码

2 个答案: