[GH-ISSUE #312] Clear previously-drawn text on screen. #236

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opened 2026-03-04 01:03:13 +03:00 by kerem · 3 comments

kerem commented

2026-03-04 01:03:13 +03:00

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Originally created by @iwasaki-kenta on GitHub (Jun 17, 2019).
Original GitHub issue: https://github.com/rivo/tview/issues/312

I noticed using a scrollable TextView that scrolled-over text is not cleared off of the screen once text I have written to the TextView exceeds the scrollable area.

Is there any way to forcefully clear the screen before drawing new text?

The view in particular is set to have a default color background.

view := tview.NewTextView()
view.SetBackgroundColor(tcell.ColorDefault)

Originally created by @iwasaki-kenta on GitHub (Jun 17, 2019). Original GitHub issue: https://github.com/rivo/tview/issues/312 I noticed using a scrollable TextView that scrolled-over text is not cleared off of the screen once text I have written to the TextView exceeds the scrollable area. ![image](https://user-images.githubusercontent.com/8392982/59606238-30dae900-9143-11e9-968e-fa0949430d03.png) Is there any way to forcefully clear the screen before drawing new text? The view in particular is set to have a default color background. ```go view := tview.NewTextView() view.SetBackgroundColor(tcell.ColorDefault) ```

kerem closed this issue

2026-03-04 01:03:13 +03:00

kerem commented

2026-03-04 01:03:14 +03:00

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@eu81273 commented on GitHub (Jun 18, 2019):

@iwasaki-kenta
This seems related with #270
I think tview has problem when BackgroundColor to set tcell.ColorDefault.

@eu81273 commented on GitHub (Jun 18, 2019): @iwasaki-kenta This seems related with #270 I think tview has problem when BackgroundColor to set tcell.ColorDefault.

kerem commented

2026-03-04 01:03:14 +03:00

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@iwasaki-kenta commented on GitHub (Jun 18, 2019):

@iwasaki-kenta
This seems related with #270
I think tview has problem when BackgroundColor to set tcell.ColorDefault.

That worked well, thanks 😄. Clearing the entire screen buffer is pretty expensive though; would be good for tview to perhaps manually clear tcell views where the background is tcell.ColorDefault?

@iwasaki-kenta commented on GitHub (Jun 18, 2019): > @iwasaki-kenta > This seems related with #270 > I think tview has problem when BackgroundColor to set tcell.ColorDefault. That worked well, thanks :smile:. Clearing the entire screen buffer is pretty expensive though; would be good for tview to perhaps manually clear tcell views where the background is `tcell.ColorDefault`?

kerem commented

2026-03-04 01:03:14 +03:00

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@rivo commented on GitHub (Jul 10, 2019):

@eu81273 is right. This is `tcell.ColorDefault´'s description:

ColorDefault is used to leave the Color unchanged from whatever system or teminal default may exist.

I don't see why clearing the screen buffer should be very expensive. It's just a virtual buffer and the real bottleneck is more likely in sending the characters to the terminal. But my understanding is that tcell optimizes for that, thus we have a lot of freedom to do with the buffer what we want.

@rivo commented on GitHub (Jul 10, 2019): @eu81273 is right. This is `tcell.ColorDefault´'s description: > ColorDefault is used to leave the Color unchanged from whatever system or teminal default may exist. I don't see why clearing the screen buffer should be very expensive. It's just a virtual buffer and the real bottleneck is more likely in sending the characters to the terminal. But my understanding is that `tcell` optimizes for that, thus we have a lot of freedom to do with the buffer what we want.