I have a crossplatform application (linux, macos and ms windows) that generates bitmaps dynamically from images via a custom artprovider.
The concrete problem I am having is that the way I used to handle bitmaps that would display correctly in high dpi displays in MacOS was by setting a size for the wx.Bitmap that was different from that of the underlying image. However after the recent update of wxpython to track the master branch of wxwidgets, the size of a bitmap can no longer be set once it has been created from an image. (This is a change in wxWidgets)
The following code exemplifies my former approach:
import wx
class MainFrame(wx.Frame):
def __init__(self):
wx.Frame.__init__(self, None, wx.ID_ANY, 'test')
sizer = wx.BoxSizer(wx.HORIZONTAL)
img = wx.Image('mytestimage.png').ConvertToBitmap()
scale = wx.GetApp().GetTopWindow().GetContentScaleFactor()
print(f"scale={scale}, originalSize={img.GetSize()}")
img.SetSize((img.GetWidth() // int(scale), img.GetHeight() // int(scale)))
print(f"newSize={img.GetSize()}")
bmp = wx.StaticBitmap(self, wx.ID_ANY, img)
sizer.Add(bmp, 0, wx.ALL, 0)
self.SetSizer(sizer)
self.Show()
app = wx.App(False)
mf = MainFrame()
app.MainLoop()
But after the update, the line img.SetSize ... is illegal and the program doesn’t run. The concrete error is Bitmap scaling failed: wxAssertionError, C++ assertion "GetHeight() == h" failed at /Users/robind/projects/bb2/dist-osx-py38/build/ext/wxWidgets/src/osx/core/bitmap.cpp(1380) in SetHeight(): Changing the bitmap height is not supported
To illustrate the effect of the SetSize line in a display with ContentScaleFactor=2.0, see the following image:
img.SetSize ..., which is that the macos toolkit scales it up by ContentScaleFactor.
So my question is, what is the correct way of telling the macos toolkit that my application (or at least this bitmap) is dpi aware and need not be rescaled? I am aware of ctypes.windll.shcore.SetProcessDpiAwareness in ms windows to inform the underlying toolkit that my application is dpi aware and the bitmaps it produces need not be rescaled. Is there something similar for macos?
I remark that using @x2 filenames is not an option for me, because as I mentioned above, in my real application (not the minimal sample above) I create the bitmaps from a custom artprovider and the images are not read from files.
Thank you.