Mastering TAdvSpinEdit: Tips & Best PracticesTAdvSpinEdit is a powerful and flexible spin edit control commonly used in Delphi (and C++Builder) applications to provide a compact, user-friendly way for users to select numeric values. Unlike the standard TSpinEdit, TAdvSpinEdit (part of TMS components or similar third‑party suites) offers extended customization, more events, and better visual styling options. This article covers practical tips, best practices, and real-world examples to help you get the most out of TAdvSpinEdit in your projects.
What makes TAdvSpinEdit different?
TAdvSpinEdit provides enhanced styling, input validation, and event handling compared to standard spin controls. Key advantages include:
- Greater control over appearance (borders, colors, glyphs, flat style).
- Support for floating-point values, thousands separators, prefixes/suffixes.
- More granular events for input and focus handling.
- Built‑in properties for formatting and incremental stepping.
Basic setup and configuration
Begin by placing a TAdvSpinEdit on your form (or create it at runtime). Important properties to configure:
- Min and Max: set sensible bounds to prevent invalid user input.
- Increment: define how much the value changes per click or arrow key.
- DecimalPlaces: when dealing with non-integer values, set decimals precisely.
- ThousandSeparator / UseThousandSeparator: improve readability for large numbers.
- DisplayFormat / EditFormat: use consistent formatting for display vs. editing.
Example (conceptual):
AdvSpinEdit1.Min := 0; AdvSpinEdit1.Max := 1000; AdvSpinEdit1.Increment := 5; AdvSpinEdit1.DecimalPlaces := 2; AdvSpinEdit1.UseThousandSeparator := True; AdvSpinEdit1.Prefix := '$'; Input validation and error handling
Although TAdvSpinEdit prevents many invalid inputs by design, combine its properties with code checks for robust validation:
- OnExit / OnChange: validate final value and provide user feedback.
- OnUserInput or OnValidate (if available): intercept edits as they occur.
- Clamp programmatically: ensure values fall within Min/Max after paste or programmatic set.
Example:
procedure TForm1.AdvSpinEdit1Exit(Sender: TObject); begin if AdvSpinEdit1.Value < AdvSpinEdit1.Min then AdvSpinEdit1.Value := AdvSpinEdit1.Min; if AdvSpinEdit1.Value > AdvSpinEdit1.Max then AdvSpinEdit1.Value := AdvSpinEdit1.Max; end; Keyboard and accessibility considerations
Make controls keyboard-friendly and accessible:
- Ensure TabOrder allows logical navigation.
- Support arrow keys and PageUp/PageDown for larger increments.
- Provide accessible names and tooltips for screen readers.
- Consider larger hit areas or alternative input for touch devices.
Performance tips for forms with many controls
If your form contains many TAdvSpinEdit controls or frequent updates:
- Batch updates using BeginUpdate/EndUpdate if available.
- Temporarily disable Align or Layout updates while adding controls.
- Use OnChange handlers sparingly; avoid heavy processing on every change.
- Virtualize lists or use fewer controls where possible.
Styling and theming
TAdvSpinEdit often supports visual styles and theme integration:
- Use FlatStyle or custom border settings to match app design.
- Adjust button glyphs, colors, and hover effects for clarity.
- Consider dark/light theme variants—ensure contrast for readability.
Example properties:
AdvSpinEdit1.Flat := True; AdvSpinEdit1.ButtonColor := clSilver; AdvSpinEdit1.HotTrack := True; Advanced features and tricks
- Prefixes/suffixes: show units (e.g., “px”, “kg”) without affecting numeric parsing.
- Linked controls: synchronize with sliders or trackbars for continuous input.
- Custom validation: use event hooks to enforce domain-specific rules (e.g., only even numbers).
- Tooltips and inline help: show context when hovering to improve UX.
Example of linking with a trackbar:
procedure TForm1.TrackBar1Change(Sender: TObject); begin AdvSpinEdit1.Value := TrackBar1.Position * 0.1; end; procedure TForm1.AdvSpinEdit1Change(Sender: TObject); begin TrackBar1.Position := Round(AdvSpinEdit1.Value * 10); end; Localization and formatting
When building international apps:
- Respect locale settings for decimal and thousand separators.
- Avoid hardcoding formats; use system locale or allow user preference.
- Translate prefixes/suffixes and tooltips.
Testing and edge cases
Test these scenarios:
- Paste non-numeric text into the control.
- Rapidly increment/decrement (keyboard or mouse) to detect performance or overflow issues.
- Programmatic value changes versus user edits—ensure events behave consistently.
- Different DPI and font sizes to validate layout and button hit areas.
Example: Implementing a temperature input control
- Min = -273.15, Max = 1000, DecimalPlaces = 2, Suffix = ‘ °C’
- Validate to prevent values below absolute zero.
- Sync with a graphing component to update charts on change.
Troubleshooting common problems
- Values not updating visually: ensure Repaint or Refresh is called after bulk changes.
- Formatting not applied: verify DisplayFormat vs. EditFormat usage.
- Event firing order confusion: document and centralize validation logic to avoid duplication.
When to use TAdvSpinEdit vs alternatives
Use TAdvSpinEdit when you need:
- Rich formatting and styling.
- Floating point support and prefixes/suffixes.
- Extended events and customization.
Consider alternatives (TSpinEdit, TStringGrid editors, custom composite controls) when you need extremely lightweight controls or tight integration with grid components.
Summary
TAdvSpinEdit is a feature-rich control that, when used thoughtfully, improves numeric input UX and consistency. Pay attention to validation, localization, accessibility, and performance. Combine built-in properties with event hooks to tailor behavior to your application’s domain.
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