jroimartin / gocui

Minimalist Go package aimed at creating Console User Interfaces.
BSD 3-Clause "New" or "Revised" License
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Updating the UI with a writer correctly #199

Open amlwwalker opened 5 years ago

amlwwalker commented 5 years ago

How can I update the UI (I am outputting logs to the UI) properly so that it updates automatically, rather than updating when I manually press the up/down arrows?

I am using the io.Writer interface:

func (cGui *clientGui) Write(p []byte) (n int, err error) {
    cGui.gui.Update(func(g *gocui.Gui) error {
        logCounter = logCounter + 1
        fmt.Fprintf(cGui.views["logging"], strconv.Itoa(logCounter)+" - "+string(p))
        return nil
    })
    return len(p), nil
}

The above works however if multiple things write to it at once, then the logs get jumbled on the console. The image below is the output, as you can see, lines 11,12,13 have been jumbled with the lines 10 and 14 (the number on the left is the logCounter variable from above, and should be consecutive. image

If I do

func (cGui *clientGui) Write(p []byte) (n int, err error) {
    fmt.Fprintf(cGui.views["logging"], strconv.Itoa(logCounter)+" - "+string(p))
    return len(p), nil
}

It works, but I have to manually "do something" like press a key to get the log output to appear.

Thanks

cheeseprocedure commented 4 years ago

I'm late to the game here, but hopefully this'll help someone: when I ran into this, the solution was to wrap the write to the view in *Gui.Update.

From the Godocs:

IMPORTANT: Views can only be created, destroyed or updated in three ways: from the Layout function within managers, from keybinding callbacks or via Gui.Update(). The reason for this is that it allows gocui to be concurrent-safe. So, if you want to update your GUI from a goroutine, you must use Gui.Update().

Moving my fmt.Fprintln calls into g.Update resulted in realtime updates.