I am using ‘appdesigner’, I would like to programmatically scroll to the bottom of a TextArea, is this possible?

I am using ‘appdesigner’.

I would like to programmatically scroll to the bottom of a TextArea, is this possible?

My text area is being used a "console log".

Thanks, Gregg

[Eric Sargent]

As of R2020b uitextarea now supports scroll.

In this case you could use:

scroll(textArea, 'bottom')

https://www.mathworks.com/help/matlab/ref/matlab.ui.container.tree.scroll.html?searchHighlight=scroll%20uitextarea&s_tid=srchtitle

Answer 1

[Michael Corbett]

To accomplish a scrolling text area, I did the following:

- Create the Text Area with 3 lines high (or as many as you'd like).

- Create a public consoleObj object using

properties (Access = public)
    consoleObj
end

- On startup, write lines one and two (change to whatever appropriate):

app.consoleObj.line1 = 'Console Started';
app.consoleObj.line2 = 'System ready';
app.consoleObj.line3 = '';
app.ConsoleTextArea.Value = {app.consoleObj.line1;app.consoleObj.line2;app.consoleObj.line3};

- Wrote a function that would replace line1 with line2, line2 with line3, then add the new line3 and display:

methods (Access = public)

          function writeConsoleLine(app,lineIn)
              app.consoleObj.line1 = app.consoleObj.line2;
              app.consoleObj.line2 = app.consoleObj.line3;
              app.consoleObj.line3 = lineIn;
              app.ConsoleTextArea.Value = {app.consoleObj.line1;app.consoleObj.line2;app.consoleObj.line3};
          end

- Call the function to display the new text.

writeConsoleLine(app,'Pushbutton pressed');

[Marko Antila]

Thanks Michael! This seems to be currently the best solution to create some kind of a console window.

[Jan]

@Marko: Please use flags only to inform admins and editors about content, which might conflict with the terms of use, like spam or rudeness. Thanks.

If this answer solves your problem, "accept" it instead of setting a flag.

[Samuel Salinas]

I tried the same approach but the "app.ConsoleTextArea.Value" field demands a string scalar or charcater vector, not a cell.

How do I go around this?

Answer 2

[Joshua Welsh]

Put your text into a ListBox instead of text area and then use the scroll function:

     scroll(app.ListBox, 'bottom')

[Marko Antila]

Unfortunately this does not work, at least in App Designer in Matlab 2018b. Scroll function at callbacks does nothing, and in startupFcn it hides the List Box permanently. Hope this bug will be ironed out in near future. Or even better, a console component will be added to the component library.

[Rayan Alkashgari]

This works in Matlab 2018b. Make sure to pause after adding an item then execute:

app.ListBox.scroll('bottom')

[Cool_CZ]

Thanks Rayan! That works for me(R2018b), just add "drawnow" before above command.

Answer 3

[Han Geerligs]

Hi Gregg,

I have the same question. Do you have any solution already?

regards, Han

Answer 4

[Eric Sargent]

As of R2020b uitextarea now supports scroll.

In this case you could use:

scroll(textArea, 'bottom')

https://www.mathworks.com/help/matlab/ref/matlab.ui.container.tree.scroll.html?searchHighlight=scroll%20uitextarea&s_tid=srchtitle