Struct DataFormat 

pub struct DataFormat {
    pub alignments: HashMap<DataType, Align>,
    pub auto_col_width: bool,
    pub decimal: usize,
    pub header_padding: f32,
    pub use_enhanced_header: bool,
}

Holds user-configurable settings for data presentation in the table.

State Management & Interaction:

• UI State: An instance is held in PolarsViewApp (layout.rs) as applied_format, representing the current UI configuration. render_format modifies this instance directly.
• Data State: An Arc<DataFormat> is stored within each DataFrameContainer (container.rs), capturing the format settings active when that data state was created (e.g., after load or sort).
• Update Flow: Changes in render_format are detected, triggering an async DataFrameContainer::update_format call in layout.rs. This creates a new DataFrameContainer with the updated Arc<DataFormat>, ensuring the table re-renders with the new settings.

Fields

alignments: HashMap<DataType, Align>

Stores the current alignment setting for each DataType, overriding DEFAULT_ALIGNMENTS.

• Modified by UI widgets rendered by render_alignment_panel.
• Read by get_decimal_and_layout to determine egui::Layout for table cells.

auto_col_width: bool

Controls the table column sizing strategy (container.rs::build_table).

• true: Column::auto() (content-based, potentially slower).
• false (Default): Column::initial() (uniform fixed widths, faster).
• Important: Toggling this changes the TableBuilder ID salt in container.rs::build_table, forcing egui to discard cached column widths and apply the new strategy.

decimal: usize

Number of decimal places for displaying floats (Float32, Float64).

• Modified by the DragValue in render_decimal_input.
• Used by get_decimal_and_layout / data_container.rs::format_cell_value. (Note: decimal_and_layout_v2 might override for specific columns).

header_padding: f32

User-configurable additional vertical padding for the table header row.

• Applied in container.rs::build_table when calculating header height.
• Modified by DragValue in render_header_padding_input (if use_enhanced_header).

use_enhanced_header: bool

Toggles the table header’s visual style and click behavior.

• Modified by checkbox in render_header.
• Read by container.rs::render_table_header to choose between:
  • true (Default): Enhanced (styled text, wrapping, icon-only sort click).
  • false: Simple (plain button, non-wrapping, full button sort click).

Implementations

impl DataFormat

pub fn get_default_padding(&self) -> f32

Gets the default header padding value defined in DataFormat::default(). Used internally, e.g., by container.rs when use_enhanced_header is false.

pub fn render_format(&mut self, ui: &mut Ui) -> Option<DataFormat>

Renders UI controls for modifying format settings in the side panel (“Format” section).

Change Detection & Update Flow:

1. Capture Initial State: Clones self before rendering widgets (format_former).
2. Render Widgets: Widgets (checkbox, radio_value, DragValue) bind to &mut self and modify its fields directly based on user interaction within this frame.
3. Compare States: After rendering all widgets, compares the potentially modified self with format_former.
4. Signal Change: If self != format_former, returns Some(self.clone()). layout.rs uses this signal to trigger an asynchronous DataFrameContainer::update_format task, applying the changes efficiently without reloading data. If no change, returns None.

Arguments

• ui: Mutable reference to the egui::Ui context for drawing.

Returns

• Option<DataFormat>: Some(updated_format) if a setting was changed, otherwise None.

Trait Implementations

impl Clone for DataFormat

fn clone(&self) -> DataFormat

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for DataFormat

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for DataFormat

fn default() -> Self

Creates a DataFormat with default settings. Initializes alignments by cloning the DEFAULT_ALIGNMENTS map.

impl PartialEq for DataFormat

fn eq(&self, other: &DataFormat) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for DataFormat