wxpython: How do I move the caret in a TextCtrl to the mouse position when opening a context menu

Question

In wxpython the default behavior of a TextCtrl context menu is that the caret moves to the position in the TextCtrl that was right-clicked. When I overwrite the EVT_CONTEXT_MENU event and create my own menu, this behavior is missing. Is there an easy way to change this?

My objective is to allow tagging the right-clicked sentence or paragraph, but the current behavior requires the user to first left click the relevant sentence/paragraph to move the caret, then right click to select how much to tag.

Relevant code:

self.textbox.Bind(wx.EVT_CONTEXT_MENU, self.textbox_context_menu)

def textbox_context_menu(self, event):
    """ show context menu when right-clicking on text """
    menu = wx.Menu()

    menu.Append(self.mark_sentence_id, "mark sentence")
    menu.Append(self.mark_paragraph_id, "mark paragraph")

    self.PopupMenu(menu)

EDIT: Here a minimalistic example that can be executed:

import wx
import wx.richtext as rt


class MCVE(wx.App):
    """ App """
    def OnInit(self):
        frame = Frame()
        frame.Show()
        return True


class Frame(wx.Frame):
    """ Frame """
    def __init__(self):
        style = wx.SYSTEM_MENU | wx.CAPTION | wx.MINIMIZE_BOX | wx.MAXIMIZE_BOX | wx.CLOSE_BOX | wx.CLIP_CHILDREN | wx.RESIZE_BORDER
        super(Frame, self).__init__(parent=None, title="LabelingTool", style=style, size=(800, 600))
        self.panel = Panel(parent=self)


class Panel(wx.Panel):
    """ Panel """
    def __init__(self, parent):
        super(Panel, self).__init__(parent)
        # textbox
        hboxsizer = wx.BoxSizer(wx.HORIZONTAL)
        text = "Lorem Ipsum\n\nLorem ipsum dolor sit amet, consectetur adipiscing elit. Aenean eget enim vitae elit convallis ultrices. Sed vestibulum in metus id tempus. Phasellus tincidunt risus elit, id sagittis erat placerat quis. Donec ac porta tortor, non varius purus. Suspendisse euismod auctor maximus. Suspendisse nec orci vel dui posuere ultrices. Vivamus dictum vel enim nec interdum. Nunc tincidunt nulla sed facilisis suscipit. Nunc eget nisi ut turpis venenatis faucibus.\n\nInteger mauris nulla, malesuada quis lacus vitae, condimentum tincidunt dui. Aliquam non nisi aliquam, vulputate dolor ut, fringilla ligula. Nulla vitae tellus sit amet nulla ultrices pellentesque eu vitae lectus. Aliquam fringilla mauris tortor, et maximus lorem bibendum quis. Nam in magna gravida, accumsan libero accumsan, feugiat nisl. Donec tincidunt, tortor ut aliquam convallis, urna odio imperdiet ligula, dignissim vulputate ligula diam sit amet tortor. Ut a eros risus.\n\nCras et erat sodales, tempus nulla a, vulputate metus. Maecenas lacinia, nulla ac congue pharetra, lorem nibh pharetra metus, eu porttitor turpis leo ut lectus. Proin luctus rutrum mi id pharetra. Suspendisse aliquet id est nec efficitur. Maecenas dolor dui, vulputate et pulvinar at, venenatis id lorem. Praesent vel nisi ultrices massa rhoncus vestibulum. Nunc imperdiet consectetur pharetra. In cursus nec massa nec finibus. Aliquam et ligula bibendum, sodales mauris a, efficitur sapien. Ut mattis et ipsum eget sodales. Vestibulum maximus libero id ipsum placerat interdum at luctus risus. In finibus accumsan nunc, vitae posuere est interdum quis. Vivamus sed neque metus. Etiam fringilla efficitur lacus, vel aliquam purus lobortis vitae. Donec ut placerat orci. Etiam efficitur efficitur eleifend.\n\nAenean in imperdiet nisl. Donec dapibus neque tincidunt, fringilla velit vel, vestibulum velit. Sed at lorem id tortor accumsan interdum eu ut orci. Aenean convallis aliquet libero eu congue. In dapibus posuere massa, quis finibus neque volutpat et. Integer non massa tristique, gravida justo id, accumsan nibh. Ut ac nisl purus. Integer vestibulum sem in ante pellentesque, ac interdum augue faucibus.\n\nInteger bibendum eros vitae aliquam venenatis. Integer feugiat orci eu metus placerat, ut dictum leo posuere. Vivamus eget ligula vitae ante porttitor cursus. Nulla consectetur enim eu nisi aliquam mollis. Aliquam elementum consequat mauris, dignissim tempus libero sodales eu. In ultrices ullamcorper nulla, vel aliquet est vestibulum non. Nullam nec est ante. Phasellus eleifend lacinia nulla nec ultricies."
        self.textbox = rt.RichTextCtrl(parent=self, value=text, style=wx.TE_MULTILINE | wx.TE_READONLY)
        self.textbox.Bind(wx.EVT_CONTEXT_MENU, self.textbox_context_menu)
        hboxsizer.Add(self.textbox, proportion=1, flag=wx.EXPAND)
        self.SetSizerAndFit(hboxsizer)
        # event handling
        self.tag_sentence_id = 100
        self.tag_paragraph_id = 200
        self.Bind(wx.EVT_MENU, self.menu_event)

    def textbox_context_menu(self, event):
        """ show context menu when right-clicking on text """
        menu = wx.Menu()
        menu.Append(self.tag_sentence_id, "tag sentence")
        menu.Append(self.tag_paragraph_id, "tag paragraph")
        self.PopupMenu(menu)

    def menu_event(self, event):
        """ handle context menu events """
        event_id = event.GetId()
        self.tag(event_id)

    def tag(self, event_id):
        # get caret position
        caret_position = self.textbox.GetCaretPosition()+1
        # tag by event
        if event_id == self.tag_paragraph_id:
            paragraph = self.find_paragraph(caret_position)
            start = self.textbox.GetValue().find(paragraph)
            end = start + len(paragraph)
            self.apply_tag((start, end))
        elif event_id == self.tag_sentence_id:
            sentence = self.find_sentence(caret_position)
            start = self.textbox.GetValue().find(sentence.strip())
            end = start + len(sentence.strip())
            self.apply_tag((start, end))

    def apply_tag(self, position):
        self.textbox.SetStyle(position[0], position[1], wx.TextAttr(colText=wx.WHITE, colBack=wx.BLACK))

    def find_paragraph(self, caret_position):
        paragraphs = self.textbox.GetValue().split("\n\n")
        for paragraph in paragraphs:
            paragraph = paragraph.strip()
            start = self.textbox.GetValue().find(paragraph)
            end = start + len(paragraph)
            if start < caret_position < end:
                return paragraph

    def find_sentence(self, caret_position):
        sentences = self.find_paragraph(caret_position).split(".")
        for sentence in sentences:
            sentence = sentence.strip()
            start = self.textbox.GetValue().find(sentence)
            end = start + len(sentence)
            # append dot if applicable
            if self.textbox.GetValue()[end] == ".":
                sentence += "."
            if start < caret_position < end:
                return sentence


if __name__ == "__main__":
    app = MCVE()
    app.MainLoop()

If you comment out the line self.textbox.Bind(wx.EVT_CONTEXT_MENU, self.textbox_context_menu) you get the default context menu with the desired behavior of moving the caret to the right-clicked position in the text before opening the context menu, which allows for "tagging" the right-clicked sentence/paragraph without left-clicking first.

Answer 1

Use SetContextMenu and create menu before hand

import wx
import wx.richtext as rt


class MCVE(wx.App):
    """ App """
    def OnInit(self):
        frame = Frame()
        frame.Show()
        return True


class Frame(wx.Frame):
    """ Frame """
    def __init__(self):
        style = wx.SYSTEM_MENU | wx.CAPTION | wx.MINIMIZE_BOX | wx.MAXIMIZE_BOX | wx.CLOSE_BOX | wx.CLIP_CHILDREN | wx.RESIZE_BORDER
        super(Frame, self).__init__(parent=None, title="LabelingTool", style=style, size=(800, 600))
        self.panel = Panel(parent=self)


class Panel(wx.Panel):
    """ Panel """
    def __init__(self, parent):
        super(Panel, self).__init__(parent)
        # textbox
        hboxsizer = wx.BoxSizer(wx.HORIZONTAL)
        text = "Lorem Ipsum\n\nLorem ipsum dolor sit amet, consectetur adipiscing elit. Aenean eget enim vitae elit convallis ultrices. Sed vestibulum in metus id tempus. Phasellus tincidunt risus elit, id sagittis erat placerat quis. Donec ac porta tortor, non varius purus. Suspendisse euismod auctor maximus. Suspendisse nec orci vel dui posuere ultrices. Vivamus dictum vel enim nec interdum. Nunc tincidunt nulla sed facilisis suscipit. Nunc eget nisi ut turpis venenatis faucibus.\n\nInteger mauris nulla, malesuada quis lacus vitae, condimentum tincidunt dui. Aliquam non nisi aliquam, vulputate dolor ut, fringilla ligula. Nulla vitae tellus sit amet nulla ultrices pellentesque eu vitae lectus. Aliquam fringilla mauris tortor, et maximus lorem bibendum quis. Nam in magna gravida, accumsan libero accumsan, feugiat nisl. Donec tincidunt, tortor ut aliquam convallis, urna odio imperdiet ligula, dignissim vulputate ligula diam sit amet tortor. Ut a eros risus.\n\nCras et erat sodales, tempus nulla a, vulputate metus. Maecenas lacinia, nulla ac congue pharetra, lorem nibh pharetra metus, eu porttitor turpis leo ut lectus. Proin luctus rutrum mi id pharetra. Suspendisse aliquet id est nec efficitur. Maecenas dolor dui, vulputate et pulvinar at, venenatis id lorem. Praesent vel nisi ultrices massa rhoncus vestibulum. Nunc imperdiet consectetur pharetra. In cursus nec massa nec finibus. Aliquam et ligula bibendum, sodales mauris a, efficitur sapien. Ut mattis et ipsum eget sodales. Vestibulum maximus libero id ipsum placerat interdum at luctus risus. In finibus accumsan nunc, vitae posuere est interdum quis. Vivamus sed neque metus. Etiam fringilla efficitur lacus, vel aliquam purus lobortis vitae. Donec ut placerat orci. Etiam efficitur efficitur eleifend.\n\nAenean in imperdiet nisl. Donec dapibus neque tincidunt, fringilla velit vel, vestibulum velit. Sed at lorem id tortor accumsan interdum eu ut orci. Aenean convallis aliquet libero eu congue. In dapibus posuere massa, quis finibus neque volutpat et. Integer non massa tristique, gravida justo id, accumsan nibh. Ut ac nisl purus. Integer vestibulum sem in ante pellentesque, ac interdum augue faucibus.\n\nInteger bibendum eros vitae aliquam venenatis. Integer feugiat orci eu metus placerat, ut dictum leo posuere. Vivamus eget ligula vitae ante porttitor cursus. Nulla consectetur enim eu nisi aliquam mollis. Aliquam elementum consequat mauris, dignissim tempus libero sodales eu. In ultrices ullamcorper nulla, vel aliquet est vestibulum non. Nullam nec est ante. Phasellus eleifend lacinia nulla nec ultricies."
        self.textbox = rt.RichTextCtrl(parent=self, value=text, style=wx.TE_MULTILINE | wx.TE_READONLY)
        
        # event handling
        self.tag_sentence_id = 100
        self.tag_paragraph_id = 200

        self.menu = wx.Menu()
        self.menu.Append(self.tag_sentence_id, "tag sentence")
        self.menu.Append(self.tag_paragraph_id, "tag paragraph")
        
        self.textbox.SetContextMenu(self.menu)
        
        hboxsizer.Add(self.textbox, proportion=1, flag=wx.EXPAND)
        self.SetSizerAndFit(hboxsizer)

        self.Bind(wx.EVT_MENU, self.menu_event)


    def menu_event(self, event):
        """ handle context menu events """
        event_id = event.GetId()
        self.tag(event_id)

    def tag(self, event_id):
        # get caret position
        caret_position = self.textbox.GetCaretPosition()+1
        # tag by event
        if event_id == self.tag_paragraph_id:
            paragraph = self.find_paragraph(caret_position)
            start = self.textbox.GetValue().find(paragraph)
            end = start + len(paragraph)
            self.apply_tag((start, end))
        elif event_id == self.tag_sentence_id:
            sentence = self.find_sentence(caret_position)
            start = self.textbox.GetValue().find(sentence.strip())
            end = start + len(sentence.strip())
            self.apply_tag((start, end))

    def apply_tag(self, position):
        self.textbox.SetStyle(position[0], position[1], wx.TextAttr(colText=wx.WHITE, colBack=wx.BLACK))

    def find_paragraph(self, caret_position):
        paragraphs = self.textbox.GetValue().split("\n\n")
        for paragraph in paragraphs:
            paragraph = paragraph.strip()
            start = self.textbox.GetValue().find(paragraph)
            end = start + len(paragraph)
            if start < caret_position < end:
                return paragraph

    def find_sentence(self, caret_position):
        sentences = self.find_paragraph(caret_position).split(".")
        for sentence in sentences:
            sentence = sentence.strip()
            start = self.textbox.GetValue().find(sentence)
            end = start + len(sentence)
            # append dot if applicable
            if self.textbox.GetValue()[end] == ".":
                sentence += "."
            if start < caret_position < end:
                return sentence


if __name__ == "__main__":
    app = MCVE()
    app.MainLoop()