Android Question Displaying a large text (log) file

Indy · Mar 27, 2021

Hi All,

I'd like to build a function to display the application's logfile. However, I don't know what is the best "view" to use. The logfile could be quite large so guess using a Label or Edit view will not work. I built a test function using a label inside a scrollview but that obviously the label has a height limit as the bottom half of the text is missing. Does anyone have any pointers on how best to achieve this?

Thanks

JohnC · Mar 27, 2021

You could just display the log file in a webview control, which will automatically provide scrolling ability.

Quandalle · Mar 27, 2021

You can also use a customListview

B4X:

private clv As CustomListView  ' declare by the designer

 
 Sub displayLog
    Dim List1 As List
    List1 = File.ReadList(PathLog, "log.txt")
    clv.Clear
    For i = List1.Size-1 To 0 Step -1 ' populate the list : last log events, at the top of list 
        clv.AddTextItem(List1.Get(i),Null)   
    Next
End Sub

Indy · Mar 27, 2021

Quandalle said:

You can also use a customListview

B4X:

private clv As CustomListView  ' declare by the designer


Sub displayLog
    Dim List1 As List
    List1 = File.ReadList(PathLog, "log.txt")
    clv.Clear
    For i = List1.Size-1 To 0 Step -1 ' populate the list : last log events, at the top of list
        clv.AddTextItem(List1.Get(i),Null)  
    Next
End Sub

Hi

This is not a bad idea. Seems to do what I need. However, noticed that the text wraps on physically smaller screens. Couldn't see anywhere in the settings of un-wrapping text. Not really a show-stopper. Thanks for helping.

Indy · Mar 27, 2021

JohnC said:
You could just display the log file in a webview control, which will automatically provide scrolling ability.

I did think of that first but, wanted to avoid using the WebView because then you have to format the text in html to get it to look good. Thanks for the tip though.

Sandman · Mar 27, 2021

I'd probably use bbcodeview.

[B4X] BCTextEngine / BBCodeView - Text engine + BBCode parser + Rich Text View

Be open minded. This is a cross platform library with several features: - Text drawing engine. - Text layout engine. - BBCode parser. - Two custom views that connect everything: BBCodeView - multiline, scrollable with support for embedded views. BBLabel - lightweight label. - NEW...

www.b4x.com

klaus · Mar 27, 2021

Indy said:
I built a test function using a label inside a scrollview but that obviously the label has a height limit as the bottom half of the text is missing.

How did you set the height of the Label and the internal ScrollView.Panel?
I would have used this.
Maybe, you could have a look at THIS post.

Anyway, xCustomListview is based on a ScrollView.

aeric · Mar 27, 2021

klaus said:
have a look at THIS post.

Wow, you still can remember a post from more than 11 years ago! ?

klaus · Mar 27, 2021

Sure, look at my age.
Elder people loose recent events in memory, but remember the older ones !
You are lucky that I remembered your post after reading it.

JohnC · Mar 27, 2021

Indy said:
I did think of that first but, wanted to avoid using the WebView because then you have to format the text in html to get it to look good. Thanks for the tip though.

Even if you use clv, you would still need to set the style/format of it.

Formatting text in webview is simple and allows for a nice feature to hilight errors:

B4X:

<!DOCTYPE html>
<html>
<body>

<p style="font-family:'Courier New'; font-size:11px">

[text from your log]

</p>

</body>
</html>

Your log file probably contains both events and errors in it. Using a webview can help highlight error lines.

For example, in your code, when you add an error line to the log file, you could make it noticeable by displaying it in red in the webview control using the font tag:

B4X:

<font color="red">This line is an error</font>

This way as you scroll through the log file, error's can be easily seen.

Android Question Displaying a large text (log) file

Indy

Active Member

JohnC

Expert

Quandalle

Member

Indy

Active Member

Indy

Active Member

Sandman

Expert

[B4X] BCTextEngine / BBCodeView - Text engine + BBCode parser + Rich Text View

klaus

Expert

aeric

Expert

klaus

Expert

JohnC

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