swt2c
commented
2 years ago The issue is that SetAttr() on the C++ side takes control of the wxCalendarDateAttr that you pass in. If you pass in the same instance of wxCalendarDateAttr, then there is going to be an issue because the C++ side is going to try to delete it twice. As a workaround, do as you are doing and always pass a unique wxCalendarDateAttr into SetAttr(). We might be able to make this better on the Python side - internally create a copy of the wxCalendarDateAttr when you call SetAttr?
reticulatus
fullwehrer
RobinD42
Operating system: Linux Mint 20.3 wxPython version & source: wxPython 4.1.1 gtk3 (phoenix) wxWidgets 3.1.5 (built from https://extras.wxpython.org/wxPython4/extras/linux/gtk3/ubuntu-20.04 using pip). Python version & source: Python 3.8.10 from Linux Mint distribution.
Description of the problem: I have been experimenting with highlighting certain days in a GenericCalendarCtrl.
My code creates a CalendarDateAttr with a bold font and applies it to the required days in calendar control.
If I create the CalendarDateAttr as an instance attribute, the program crashes with "double free or corruption (fasttop)" when you change the month or year in the calendar control or just exit the program (see example generic_calendar_exp_2.py below).
I have modified that program so that a new CalendarDateAttr is created just before being applied to the required days. This version of the program (see generic_calendar_exp_3.py) doesn't crash.
Is the CalendarDateAttr being deleted prematurely?
Code Example (click to expand)
```python # generic_calendar_exp_2.py # This program crashes when you change month or year, or just exit. import wx import wx.adv import calendar special_dates = { (2022, 1) : (2,5,7,11,30), (2022, 2) : (6,12,13,20,27), (2022, 3) : (1,27) } class MyFrame(wx.Frame): def __init__(self, *args, **kwds): kwds["style"] = kwds.get("style", 0) | wx.DEFAULT_FRAME_STYLE wx.Frame.__init__(self, *args, **kwds) self.SetSize((400, 300)) self.SetTitle("Calendar Test") self.panel_1 = wx.Panel(self, wx.ID_ANY) sizer_1 = wx.BoxSizer(wx.VERTICAL) cal_style = wx.adv.CAL_MONDAY_FIRST | wx.adv.CAL_SHOW_SURROUNDING_WEEKS self.calendar_ctrl = wx.adv.GenericCalendarCtrl(self.panel_1, wx.ID_ANY, style=cal_style) self.calendar_ctrl.SetMinSize((216, 166)) sizer_1.Add(self.calendar_ctrl, 0, wx.ALL, 8) self.panel_1.SetSizer(sizer_1) self.Layout() self.Bind(wx.adv.EVT_CALENDAR_SEL_CHANGED, self.OnCalChanged, self.calendar_ctrl) attr = self.calendar_ctrl.GetClassDefaultAttributes() bold_font = attr.font.Bold() self.highlight_attr = wx.adv.CalendarDateAttr(font=bold_font) self.highlightDates() def highlightDates(self): date = self.calendar_ctrl.GetDate() year = date.year month = date.month + 1 last_day = calendar.monthrange(year, month)[1] bold_days = special_dates.get((year, month), ()) print("Bold days : ", bold_days) for d in range(1, last_day+1): attr = self.calendar_ctrl.GetAttr(d) if d in bold_days: if attr != self.highlight_attr: self.calendar_ctrl.SetAttr(d, self.highlight_attr) else: if attr is not None: self.calendar_ctrl.ResetAttr(d) self.calendar_ctrl.Refresh() def OnCalChanged(self, event): date = event.GetDate() print("Date changed :", date.Format("%d/%m/%Y")) self.highlightDates() class MyApp(wx.App): def OnInit(self): self.frame = MyFrame(None, wx.ID_ANY, "") self.SetTopWindow(self.frame) self.frame.Show() return True if __name__ == "__main__": app = MyApp(0) app.MainLoop() ``` ```python # generic_calendar_exp_3.py # This program doesn't crash when you change month or year, or exit import wx import wx.adv import calendar special_dates = { (2022, 1) : (2,5,7,11,30), (2022, 2) : (6,12,13,20,27), (2022, 3) : (1,27) } class MyFrame(wx.Frame): def __init__(self, *args, **kwds): kwds["style"] = kwds.get("style", 0) | wx.DEFAULT_FRAME_STYLE wx.Frame.__init__(self, *args, **kwds) self.SetSize((400, 300)) self.SetTitle("Calendar Test") self.panel_1 = wx.Panel(self, wx.ID_ANY) sizer_1 = wx.BoxSizer(wx.VERTICAL) cal_style = wx.adv.CAL_MONDAY_FIRST | wx.adv.CAL_SHOW_SURROUNDING_WEEKS self.calendar_ctrl = wx.adv.GenericCalendarCtrl(self.panel_1, wx.ID_ANY, style=cal_style) self.calendar_ctrl.SetMinSize((216, 166)) sizer_1.Add(self.calendar_ctrl, 0, wx.ALL, 8) self.panel_1.SetSizer(sizer_1) self.Layout() self.Bind(wx.adv.EVT_CALENDAR_SEL_CHANGED, self.OnCalChanged, self.calendar_ctrl) attr = self.calendar_ctrl.GetClassDefaultAttributes() self.bold_font = attr.font.Bold() self.highlightDates() def highlightDates(self): date = self.calendar_ctrl.GetDate() year = date.year month = date.month + 1 last_day = calendar.monthrange(year, month)[1] bold_days = special_dates.get((year, month), ()) print("Bold days : ", bold_days) for d in range(1, last_day+1): attr = self.calendar_ctrl.GetAttr(d) if d in bold_days: highlight_attr = wx.adv.CalendarDateAttr(font=self.bold_font) if attr != highlight_attr: self.calendar_ctrl.SetAttr(d, highlight_attr) else: if attr is not None: self.calendar_ctrl.ResetAttr(d) self.calendar_ctrl.Refresh() def OnCalChanged(self, event): date = event.GetDate() print("Date changed :", date.Format("%d/%m/%Y")) self.highlightDates() class MyApp(wx.App): def OnInit(self): self.frame = MyFrame(None, wx.ID_ANY, "") self.SetTopWindow(self.frame) self.frame.Show() return True if __name__ == "__main__": app = MyApp(0) app.MainLoop() ```