Added operate() methods and tests for TimePicker widget

#383 in iced-rs/iced_aw — merged 2025-12-28

Changes

TimePicker Integration Testing Support:

• Implemented operate() method in src/widget/time_picker.rs to delegate to underlay widget
• Implemented operate() method in src/widget/overlay/time_picker.rs to expose:
  • Digital clock elements (hour, minute, second, period indicators)
  • Cancel and submit buttons
  • Full widget tree structure for test interaction

TimePicker Integration Tests (tests/time_picker_integration_tests.rs - 19 tests):

• Underlay button functionality and picker visibility
• Hour/minute/second increment/decrement via UI interactions
• Time boundary wrapping (23:59→00:00, etc.)
• 12h/24h format display and AM/PM indicators
• Cancel and submit button workflows
• Keyboard navigation
• Complete user workflows (adjust time, submit, etc.)

TimePicker Unit Tests (41 new tests):

• src/widget/time_picker.rs (22 tests):

• State creation and management

• TimePicker widget construction and builder methods

• Time type conversions (12h/24h, noon/midnight edge cases)

• Widget trait implementations

• src/widget/overlay/time_picker.rs (19 tests):

• Overlay state initialization

• Focus navigation with/without seconds display

• ClockDragged and Focus enum behavior

• Overlay button structure

# Widget unit tests
cargo test widget::time_picker

# Overlay unit tests
cargo test widget::overlay::time_picker

# Integration tests (using iced_test simulator)
cargo test --test time_picker_integration_tests