Fix business card display

[nnja]

I noticed strange behavior when using the business card function in this library.

The text would display, then hide, then display again. Additionally, the image elements wouldn't appear at the same time.

It looked like this:

I made some updates to make the text appear smoothly with the background. It now looks like this:

Notes:

• I removed the call to wait_for_frame(), since the release notes for CircuitPython 5.0.0 Alpha 2 say it's no longer necessary.
• Removed the target_frames_per_second argument to refresh, since that's the default value.

As a side effect, the text displayed no longer has a black background. That might have been a bug in the original code, since I couldn't find a background color property on adafruit_display_text.label.

Tested on a PyBadge LC.

[makermelissa]

Can you test on the latest stable release (4.1.2)? I don't believe display.refresh() is a function on there, which is why we have the try block.

[nnja]

@makermelissa That function is in fact missing in 4.1.2.

I didn't release that the latest version of the libraries supports both CircuitPython 4 and 5. Added back the try/except, and added some comments for clarity. I can remove the comments if you think they're unnecessary.

[makermelissa]

Thanks. The comments are good. Once we're at 5.0.0 stable, we can change it so it only uses the CP5 method. :)

[makermelissa]

Hi, tested on a PyGamer with CP 5.0 Beta 5 and it appears to draw it twice still. Black background is gone still, which is good.

[caternuson]

As maybe another way to do this, but 5.x only, try setting display.auto_refresh = False before doing all the group appends, and then setting back to True at the end to show them. This is how I dealt with a similar issue here:
https://github.com/adafruit/Adafruit_Learning_System_Guides/blob/master/TFT_Gizmo_Candy_Hearts/candy_hearts.py#L59

[makermelissa]

The label redrawing issue is fixed on CP 4.0 with this PR. However, while holding down the button on CP 5, it will continue to draw the label over and over. Maybe @caternuson's suggestion would fix it.

[nnja]

My goal with this PR was to fix the double redraw / blinking when initially navigating to this screen with one button press. I think redrawing while the button is held down is OK, since I don't think holding down the button is expected user behavior.

That said, I did try @caternuson's approach and it does work fine when the button is held down.

Unfortunately, it made the code overly complex. I don't think it's worth complicating things if the code is temporary until CP5 is out of beta but I'm happy to put in the patch if that's what would work best for the library.

Additionally, using CP5 I still had to call self.display.refresh() after setting self.display.auto_refresh = True, otherwise the background image wouldn't appear. I'm not sure if that's expected behavior or a potential bug.

For reference, here's the code I tried:

        business_card_splash = displayio.Group(max_size=4)
        self.display.show(business_card_splash)
        with open(image_name, "rb") as file_name:
            on_disk_bitmap = displayio.OnDiskBitmap(file_name)
            face_image = displayio.TileGrid(on_disk_bitmap, pixel_shader=displayio.ColorConverter())

            is_cp_version_5 = hasattr(self.display, "auto_refresh")
            if is_cp_version_5:
                # Temporary turn off auto refresh while we change some things
                self.display.auto_refresh = False

            # Add the background and the text to the splash
            business_card_splash.append(face_image)
            for group in business_card_label_groups:
                business_card_splash.append(group)

            if is_cp_version_5:  # Refresh display in CircuitPython 5
                self.display.auto_refresh = True
                self.display.refresh()
            else:  # Refresh display in CircuitPython 4
                self.display.wait_for_frame()

Commenting out self.display.refresh() will prevent the background from appearing in CP5.

[makermelissa]

Ok, thanks for trying. It's still an improvement on the existing code.

[makermelissa]

Thanks for making these changes.