The invisible scrollbar release

A mixed bag of fixes and API improvements.

Notable breaking change is that the tree-sitter code has been split out. If you need syntax highlighting in the TextArea, you can install it with this:

pip install "textual[syntax]"

[0.39.0] - 2023-10-10

Fixed

• Pilot.click/Pilot.hover can't use Screen as a selector #3395
• App exception when a Tree is initialized/mounted with disabled=True #3407
• Fixed print locations not being correctly reported in textual console #3237
• Fix location of IME and emoji popups #3408
• Fixed application freeze when pasting an emoji into an application on Windows #3178
• Fixed duplicate option ID handling in the OptionList #3455
• Fix crash when removing and updating DataTable cell at same time #3487
• Fixed fractional styles to allow integer values #3414
• Stop eating stdout/stderr in headless mode - print works again in tests #3486

Added

• OutOfBounds exception to be raised by Pilot #3360
• TextArea.cursor_screen_offset property for getting the screen-relative position of the cursor #3408
• Input.cursor_screen_offset property for getting the screen-relative position of the cursor #3408
• Reactive cell_padding (and respective parameter) to define horizontal cell padding in data table columns #3435
• Added Input.clear method #3430
• Added TextArea.SelectionChanged and TextArea.Changed messages #3442
• Added wait_for_dismiss parameter to App.push_screen #3477
• Allow scrollbar-size to be set to 0 to achieve scrollable containers with no visible scrollbars #3488

Changed

• Breaking change: tree-sitter and tree-sitter-languages dependencies moved to syntax extra #3398
• Pilot.click/Pilot.hover now raises OutOfBounds when clicking outside visible screen #3360
• Pilot.click/Pilot.hover now return a Boolean indicating whether the click/hover landed on the widget that matches the selector #3360
• Added a delay to when the No Matches message appears in the command palette, thus removing a flicker #3399