Designing Seamless User Interfaces with TAdvTouchKeyboard in C++Builder

TAdvTouchKeyboard is a highly configurable VCL on-screen keyboard component developed by TMS Software for touchscreen applications built in Delphi and C++Builder. It is a core part of the TMS VCL UI Pack, designed to facilitate text input in environments where physical keyboards are absent, such as medical kiosks, POS terminals, and industrial control machines. 🔑 Core Mechanics: How It Sends Input

The component provides two distinct workflows for processing text entry:

Automatic Routing (AutoPostKey = True)When enabled, dropping the component onto a form allows it to automatically post key values directly to whichever standard control currently holds the OS input focus (e.g., a TEdit or TMemo). No extra code is required.

Manual Event Handling (AutoPostKey = False)If you want to intercept or sanitize keystrokes before they hit a control, you can turn off automatic routing and use these two primary events:

OnKeyDown: Intercepts the key code and active shift state (Shift, Alt, Ctrl).

OnKeyClick: Returns the exact index of the button pressed from the component’s internal Keys collection. 🎨 Visual & Behavioral Customization

Unlike default OS keyboards, TAdvTouchKeyboard allows deep design-time and runtime adjustments to perfectly match your user interface:

Built-in & Custom Layouts: Select layouts like QWERTY, AZERTY, DVORAK, Numeric, or Cellphone layouts out of the box using the KeyboardType property. You can also build entirely unique button mappings using the TAdvTouchKeyItem collection.

Sticky Keys Feature: Special modifier keys (Shift, Alt, Ctrl, Alt Gr) behave as “sticky” toggles. A single tap locks the key down, and a second tap releases it, allowing touchscreen users to execute multi-key combinations comfortably without multi-finger multi-touch acrobatics.

Visual States: The keyboard automatically updates key captions depending on the shift state (e.g., changing letters to uppercase when Shift is active). Keys can be customized with discrete colors, text fonts, background states, or graphical images.

Dynamic Highlight Colors: Use HighlightCaps or HighlightAltGr to change the specific color of alternative character symbols (like the Euro currency symbol €) when a modifier is pressed, guiding the user’s eye to secondary layouts. 🗂️ Component Variations

Developers typically choose between two specific classes in the TMS palette depending on deployment context: TAdvTouchKeyBoard – TMS Software