Tip: Fix flickering pointer in MacOS TextArea

General
1

A quick tip:

In my app, the mouse cursor starting flickering between standard cursor and the I-beam when moved over a textarea on Mojave. On Sierra, the cursor refused to show the I-beam over the textarea.

The culprit was another, unrelated, custom control calling this on mouseexit:

  app.MouseCursor=System.cursors.standardpointer

Changing that code to

app.MouseCursor=nil

Fixes the flicker in the unrelated TextArea

Thanks to Norman Palardy for figuring this out!

2

What‘s the rationale behind it?

3

the custom control would, when the mouse exited, set the mouse pointer back to the std pointer (it would actually oresevre the state on entry and restore that but it didnt seem to matter)

then when the mouse cursor was moved over the text area you would get what appeared to be the framework fighting with itself as the text area wanted the i-beam but the rest of the framework was trying to set the cursor back to std pointer

you’d get rapid flickering between the two

but setting it back to NIL instead of the std pointer the framework could decide what to do and the flicker went away

could this be a bug report ? … possibly

4

Thanks for the explanation.